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Quantitative Electroencephalography (QEEG) Research

Abstracts posted by "A Matter of Mind"

Last updated: April 2011.

Eur J Neurosci. 2011 Apr;33(7):1281-90. doi: 10.1111/j.1460-9568.2010.07588.x. Epub 2011 Feb 16.

A computational model of thalamocortical dysrhythmia.

Henning Proske J, Jeanmonod D, Verschure PF.

Institute for Neuroinformatics, Uni/ETH Zurich, Winterthurerstr. 190, 8057 Zurich, Switzerland Laboratory for Functional Neurosurgery, University Hospital Zurich, Zurich, Switzerland Catalan Institute of Advanced Studies (ICREA), Barcelona, Spain Institute of Audio-Visual Studies, Universitat Pompeu Fabra, Barcelona, Spain.

Functional stereotactic lesions in the central lateral nucleus of the medial thalamus have proved to be an effective treatment of neurogenic pain and other neurological disorders associated with thalamocortical dysrhythmia. The mechanisms underlying patient recovery after surgery are currently being explored using quantitative electroencephalography. Here we test the hypothesis that the particular role played by the non-specific medial thalamic nuclei in thalamocortical dysrhythmia is based on the divergent connectivity between these  non-specific and reticular nuclei. We built a spiking computer model of the human thalamocortical system consisting of specific, non-specific and reticular thalamic nuclei. In our simulations of the thalamocortical system, deafferentation of peripheral thalamic afferents leads to hyperpolarization and subsequent bursting in the reticular nucleus. This provides strong inhibitory feedback to both the specific and the non-specific thalamic nuclei and initiates  a feedback cycle of thalamic bursts in the theta frequency range. The divergent connections between the reticular and non-specific thalamic nuclei provide synchronization of the oscillating circuits. Functional silencing of the non-specific model nucleus limits reverberation and rescues the system from these oscillations. The same effect could be achieved by increasing the input to the non-specific nucleus from cortical areas. The model predicts that the invasiveness of functional neurosurgery can be reduced by targeting only deafferented areas in the medial nuclei as these are the key areas for generation and maintenance of pathological rhythms.

http://www.ncbi.nlm.nih.gov/pubmed/21323765

Res Vet Sci. 2011 Apr;90(2):306-11. Epub 2010 Jun 29.

Electroencephalographic recordings in dogs: Prevention of muscle artifacts and evaluation of two activation techniques in healthy individuals.

Brauer C, Kästner SB, Schenk HC, Tünsmeyer J, Tipold A.

Department of Small Animal Medicine and Surgery, University of Veterinary Medicine Hannover, Germany. christina.brauer@tiho-hannover.de

This study was performed to improve a standard anesthetic protocol for electroencephalography (EEG) in dogs and to evaluate the effect of photic stimulation and hyperventilation on the EEG of healthy dogs. Ten clinically and neurologically normal beagle dogs were anesthetized with propofol given intravenously with average doses of 7.5mg/kg for induction and 0.37mg/kg/min constant rate infusion for maintenance. Rocuronium bromide (0.4mg/kg IV) was used as a peripheral muscle relaxant in order to prevent muscle artifacts. EEGs were recorded digitally using five subdermal needle electrodes. Photic stimulation and hyperventilation were performed to evaluate two activation techniques commonly used in human EEG recording methods. Monopolar and bipolar montages were analyzed visually and quantitatively. The use of rocuronium produced muscle artifact-free  EEG recordings during the given recording procedure which indicates that rocuronium is a valuable adjunct to anesthesia during EEG recording. Photic stimulation and hyperventilation did not provoke paroxysmal discharges in the EEG of healthy dogs. Analysis of quantitative EEG data showed that background activity did not differ significantly between periods with and without stimulation. This data are important basic values and will further help to compare the effects of photic stimulation and hyperventilation of healthy dogs and those suffering from epilepsy.

http://www.ncbi.nlm.nih.gov/pubmed/20591453

Expert Rev Mol Med. 2011 Mar 23;13:e9.

Electrophysiological markers of genetic risk for attention deficit hyperactivity  disorder.

Tye C, McLoughlin G, Kuntsi J, Asherson P.

MRC Social Genetic Developmental Psychiatry Centre (SGDP), Institute of Psychiatry, London, UK.

Attention deficit hyperactivity disorder (ADHD) is a highly heritable neurodevelopmental disorder with complex genetic aetiology. The identification of candidate intermediate phenotypes may facilitate the detection of susceptibility  genes and neurobiological mechanisms underlying the disorder. Electroencephalography (EEG) is an ideal neuroscientific approach, providing a direct measurement of neural activity that demonstrates reliability, developmental stability and high heritability. This systematic review evaluates the utility of a subset of electrophysiological measures as potential intermediate phenotypes for ADHD: quantitative EEG indices of arousal and intraindividual variability, and functional investigations of attention, inhibition and performance monitoring using the event-related potential (ERP) technique. Each measure demonstrates consistent and meaningful associations with  ADHD, a degree of genetic overlap with ADHD and potential links to specific genetic variants. Investigations of the genetic and environmental contributions to EEG/ERP and shared genetic overlap with ADHD might enhance molecular genetic studies and provide novel insights into aetiology. Such research will aid in the  precise characterisation of the clinical deficits seen in ADHD and guide the development of novel intervention and prevention strategies for those at risk.

http://www.ncbi.nlm.nih.gov/pubmed/21426626

Int J Psychophysiol. 2011 Mar 16. [Epub ahead of print]

Clinical electrophysiologic assessments and mild traumatic brain injury: State-of-the-science and implications for clinical practice.

Arciniegas DB.

Conventional and quantitative electroencephalography (EEG and QEEG, respectively) may enhance clinical diagnosis and treatment planning provided to persons with mild traumatic brain injury (mTBI) and postconcussive symptoms. Effective and appropriate use of EEG and QEEG in this context requires expert-level knowledge of these technologies, mTBI, and the differential diagnosis for postconcussive symptoms. A practical and brief review from the perspective of a clinician-scientist engaged principally in the care and study of persons with mTBI therefore may be of use and value to other clinicians and scientists interested in these matters. Toward that end, this article offers an overview of  the current applications of conventional EEG and QEEG to the study and clinical evaluation of persons with mTBI. The clinical case definition of TBI, the differential diagnosis of post-injury neuropsychiatric disturbances, and the typical course of recovery following mTBI are reviewed. With this background and  context, the strengths and limitations of the literature describing EEG and QEEG  studies in this population are considered. The implications of this review on the applications of these electrophysiologic assessments to the clinical evaluation of persons with mTBI and postconcussive symptoms are then considered. Finally, suggestions are offered regarding the design of future studies using these technologies in this population. Although this review may be of interest and value to professionals engaged in clinical or research electrophysiology in their daily work, it is intended to serve more immediately the needs of clinicians less familiar with these types of clinical electrophysiologic assessments.

http://www.ncbi.nlm.nih.gov/pubmed/21419178

Arch Dis Child Fetal Neonatal Ed. 2011 Mar;96(2):F108-13. Epub 2010 Sep 24.

Cot-side electroencephalography for outcome prediction in preterm infants: observational study.

West CR, Harding JE, Williams CE, Nolan M, Battin MR.

Neonatal Intensive Care Unit, Middlemore Hospital, Otahuhu, Manukau 1640, Auckland, New Zealand. westc@middlemore.co.nz

OBJECTIVE: To assess the use of two-channel electroencephalographical (EEG) recordings for predicting adverse neurodevelopmental outcome (death or Bayley II  mental developmental index/psychomotor developmental index < 70) in extremely preterm infants and to determine the relationship between quantitative continuity measures and a specialist neurophysiologist assessment of the same EEG segment for predicting outcome. DESIGN: Observational study. SETTING: The study was conducted in a neonatal intensive care unit. PATIENTS: Preterm infants born <29 weeks' gestation. INTERVENTIONS: Two-channel EEGs using the reBRM2 monitor (BrainZ Instruments, Auckland, New Zealand) within 48 h of delivery. One-hour segments were analysed,  blinded to the clinical outcome, by off-line quantitative analysis of continuity  and a review of the raw EEG by a neurophysiologist. MAIN OUTCOME MEASURES: Developmental assessment at a median of 15 months' corrected age. RESULTS: 76 infants had an EEG within 48 h of delivery and a developmental assessment. The analysed segment of the EEG was obtained at 24 (3-48) h of age (median (range)). The neurophysiologist's assessment was a better predictor of adverse outcome than the continuity measures (positive predictive value 95% CI 75 (54% to 96%) vs 41 (22% to 60) at 25-µV threshold, negative predictive value 88 (80% to 96%) vs 84 (74% to 94%) and positive likelihood ratio 9.0 (3.2 to 24.6) vs 2.0 (1.2 to 3.6)). All the infants with definite seizures identified by the neurophysiologist had poor outcomes. CONCLUSIONS: Modified cot-side EEG has potential to assist with identification of extremely preterm infants at risk for adverse neurodevelopmental outcomes. However, analysis by a neurophysiologist performed better than the currently available continuity analyses.

http://www.ncbi.nlm.nih.gov/pubmed/20870908

Early Hum Dev. 2011 Mar;87(3):217-21. Epub 2011 Jan 14.

Amplitude-integrated electroencephalography in preterm infants with cystic periventricular leukomalacia.

Kato T, Okumura A, Hayakawa F, Tsuji T, Natsume J, Hayakawa M.

Department of Pediatrics, Okazaki City Hospital, Okazaki, Aichi, Japan. kato-jes@umin.ac.jp

AIM: This study aimed to assess amplitude-integrated electroencephalography (aEEG) findings in preterm infants with cystic periventricular leukomalacia (cPVL) in the early neonatal period. METHODS: We analyzed five infants with cPVL, whose gestational age was between 27 and 30 weeks, and 15 matched control infants. Two-channel (C3-O1 and C4-O2) aEEG  was obtained by digital conversion from a conventional electroencephalogram, which was recorded at days 0-5, 6-13, and 21-34 in each infant. We evaluated the  averaged two-channel values of several measurements using visual and quantitative analyses. RESULTS: Infants with cPVL had a significant higher maximal upper-margin amplitude value, with a median of 47.5 μV (range of 42.5-60) compared with the control infants (median, 33.8; range, 23.8-50) in the second visual-analysis record. Infants with cPVL also had a significantly higher mean upper-margin amplitude value, with a median of 18.8 μV (range, 17.7-23.2) compared with the control infants (median, 16.3; range, 10.3-19.0) in the second quantitative-analysis record. CONCLUSIONS: We demonstrated that the upper-margin amplitude of aEEG in infants with cPVL was significantly higher than that in the control infants at 6-13 days  after birth.

http://www.ncbi.nlm.nih.gov/pubmed/21237587

Int Arch Med. 2011 Feb 4;4(1):6.

Effects of Methylphenidate on performance of a practical pistol shooting task: a  quantitative electroencephalography (QEEG) study.

Paes F, Machado S, Arias-Carrión O, Domingues CA, Teixeira S, Velasques B, Cunha  M, Minc D, Basile LF, Budde H, Cagy M, Piedade R, Kerick S, Menéndez-González M,  Skaper SD, Norwood BA, Ribeiro P, Nardi AE.

Panic and Respiration Laboratory, Institute of Psychiatry, Federal University of  Rio de Janeiro, Rio de Janeiro, RJ, Brazil. secm80@yahoo.com.br.

ABSTRACT:BACKGROUND: The present study examined absolute alpha power using quantitative electroencephalogram (QEEG) in bilateral temporal and parietal cortices in novice soldiers under the influence of methylphenidate (MPH) during the preparatory aiming period in a practical pistol-shooting task. We anticipated higher bi-hemispheric cortical activation in the preparatory period relative to pre-shot baseline in the methylphenidate group when compared with the control group because methylphenidate has been shown to enhance task-related cognitive functions. METHODS: Twenty healthy, novice soldiers were equally distributed in control (CG; n = 10) and MPH groups 10 mg (MG; n = 10) using a randomized, double blind design. Subjects performed a pistol-shooting task while electroencephalographic activity was acquired. RESULTS: We found main effects for group and practice blocks on behavioral measures, and interactions between group and phases on electroencephalographic measures for the electrodes T3, T4, P3 and P4. Regarding the behavioral measures, the MPH group demonstrated significantly poorer in shooting performance when compared with the control and, in addition, significant increases in the scores over practice blocks were found on both groups. In addition, regarding the electroencephalographic data, we observed a significant increase in alpha power over practice blocks, but alpha power was significantly lower for the MPH group when compared with the placebo group. Moreover, we observed a significant decrease in alpha power in electrodes T4 and P4 during PTM. CONCLUSION: Although we found no correlation between behavioral and EEG data, our findings show that MPH did not prevent the learning of the task in healthy subjects. However, during the practice blocks (PBs) it also did not favor the performance when compared with control group performance. It seems that the CNS effects of MPH demanded an initial readjustment period of integrated operations relative to the sensorimotor system. In other words, MPH seems to provoke a period of initial instability due to a possible modulation in neural activity, which can be explained by lower levels of alpha power (i.e., higher cortical activity). However, after the end of the PB1 a new stabilization was established  in neural circuits, due to repetition of the task, resulting higher cortical activity during the task. In conclusion, MPH group performance was not initially  superior to that of the control group, but eventually exceeded it, albeit without achieving statistical significance.

http://www.ncbi.nlm.nih.gov/pubmed/21294887

Ann Clin Psychiatry. 2011 Feb;23(1):48-62.

The emerging use of technology for the treatment of depression and other neuropsychiatric disorders.

Howland RH, Shutt LS, Berman SR, Spotts CR, Denko T.

Department of Psychiatry, Western Psychiatric Institute and Clinic, University of Pittsburgh School of Medicine, Pittsburgh, PA 15213, USA. HowlandRH@upmc.edu

BACKGROUND: Our objective is to review emerging technologies intended for the treatment of depression and other neuropsychiatric disorders. METHODS: These technologies include repetitive transcranial magnetic stimulation  (rTMS), magnetic seizure therapy (MST), vagus nerve stimulation (VNS), deep brain stimulation (DBS), cortical brain stimulation (CBS), and quantitative electroencephalography (QEEG). RESULTS: The rationale for these technologies, their mechanisms of action, and how they are used in clinical practice are described. rTMS and VNS are effective  for treatment-resistant depression. DBS is effective for resistant obsessive-compulsive disorder. QEEG can help predict a patient's response to an antidepressant. All of these technologies continue to be investigated in treatment studies. CONCLUSIONS: As these and other emerging technologies for depression and other neuropsychiatric disorders are development and applied, psychiatrists should understand the rationale for these modalities, how they work, and how they can be used in clinical practice.

http://www.ncbi.nlm.nih.gov/pubmed/21318196

Brain. 2011 Feb;134(Pt 2):345-58. Epub 2010 Dec 22.

Gamma oscillations in the hippocampus require high complex I gene expression and  strong functional performance of mitochondria.

Kann O, Huchzermeyer C, Kovács R, Wirtz S, Schuelke M.

Institute for Neurophysiology, Charité-Universitätsmedizin Berlin, Berlin, Germany. oliver.kann@gmail.com

Comment in     Brain. 2011 Feb;134(Pt 2):330-2.

Fast neuronal network oscillations in the gamma range (~30-90 Hz) have been implicated in complex brain functions such as sensory processing, memory formation and, perhaps, consciousness, and appear to be exceptionally vulnerable  to various pathologies. However, both energy demand and mitochondrial performance underlying gamma oscillations are unknown. We investigated the fundamental relationship between acetylcholine-induced gamma oscillations, mitochondrial gene expression and oxidative metabolism in hippocampal slice preparations of mouse and rat by applying electrophysiology, in situ hybridization, quantitative polymerase chain reaction, oxygen sensor microelectrode (interstitial partial oxygen pressure) and imaging of mitochondrial redox state [nicotinamide adenine dinucleotide (phosphate) and flavin adenine dinucleotide fluorescence]. We show that (i) gamma oscillation power, oxygen consumption and expression of complex I  (nicotinamide adenine dinucleotide:ubiquinone oxidoreductase) subunits are higher in hippocampal subfield CA3 than in CA1 and dentate gyrus; (ii) the amount of oxygen consumption of gamma oscillations reaches that of seizure-like events; (iii) gamma oscillations are exquisitely sensitive to pharmacological complex I inhibition; and (iv) gamma oscillations utilize mitochondrial oxidative capacity  near limit. These data suggest that gamma oscillations are especially energy demanding and require both high complex I expression and strong functional performance of mitochondria. Our study helps to explain the exceptional vulnerability of complex brain functions in ischaemia as well as in neurodegenerative and psychiatric disorders that are associated with mitochondrial dysfunction.

http://www.ncbi.nlm.nih.gov/pubmed/21183487

Neuroimage. 2011 Feb 1;54(3):1951-65. Epub 2010 Oct 30.

A mini-cap for simultaneous EEG and fMRI recording in rodents.

Sumiyoshi A, Riera JJ, Ogawa T, Kawashima R.

Institute of Development, Aging and Cancer, Tohoku University, Aoba-ku, Sendai, Japan.

Simultaneous recording of electroencephalography (EEG) and functional magnetic resonance imaging (fMRI) is now widely accepted as a prevailing tool to study brain functions. For over a decade, EEG caps with high-dense arrays of electrodes for EEG-fMRI studies in humans have been commercially available. However, simultaneous EEG and fMRI recording in rodents has been limited to only a few electrodes due mainly to two technical reasons, i.e. a small available scalp area and the proximity of the electrodes to the brain tissue. In this paper, we introduce both a new EEG mini-cap and a protocol to obtain whole scalp EEG recordings simultaneously with 7 T fMRI signals in rodents. We provide methodological protocol to evaluate a number of problems emerging from the particulars of using rodents in simultaneous EEG and fMRI recording. The quality  and reproducibility of both EEG and fMRI signals were demonstrated using a conventional forepaw stimulation paradigm in Wistar rats. Based on this quantitative analysis, we conclude that simultaneous EEG-fMRI recordings are achievable in rodents without significant signal loss. In light of the contemporary transgenic models and advanced drug administration protocols in rodents, the proposed methodology could be remarkable as a futurist experimental  platform.

http://www.ncbi.nlm.nih.gov/pubmed/20920590

Ideggyogy Sz. 2011 Jan 30;64(1-2):14-23.

[EEG investigations in cognitive impairments].

[Article in Hungarian]

Szirmai I, Kamondi A.

Semmelweis Egyetem, Neurológiai Klinika, Budapest. szirmaiimre@gmail.com

The EEG is an indicator of all physiological and neuropsychological activity. The alpha rhythm was considered as a key phenomenon in research of human mentation from the discovery of EEG. Two methods are known for the estimation of cognitive  deficit by the use of quantitative EEG (QEEG). The first is based on the hypothesis, that the mean values of the normal EEG from healthy volunteers can be used as reference, and deviation from the normal values of EEG parameters may suggest disease. This kind of "neurometry" was elaborated by R. E. John. The second method assesses event related (ER) transients evoked by somatosensory and  mental stimuli. Quantity and localization of signals may refer to the functional  state of the cortex. These reactions depend strongly on the test-paradigms. Recognition of the attention-intention cycle disclosed the physiological mechanism of ERD (event related desynchronisation) and ERS (event related synchronisation). In contrast with the classical "stimulus-reaction" model, both  perception and voluntary movement are initiated by the brain itself, and not by the environment. Human behavior and conscious actions depend on the intention. QEEG analysis proved that the attention and intention localize in segregate areas of the brain. Both "static" and "dynamic" neurometric methods are able to differentiate the EEG records of demented patients from healthy controls, furthermore some dementias from each other. We conclude that with the help of sophisticated methods of QEEG analysis minimal functional deficit of the electrogenesis can be recognized, which could be helpful in the differential diagnosis Notwithstanding the EEG can not explain the evolution neither the normal or the diseased mental processes. The only "instrument" which is able to approach the human mind is the human cogitation itself with the aids of appropriate tests. The QEEG can be conclusive in the analysis of particular processes of mental activity, such as timing, state of activation, hierarchical organisation of cortical territories and mechanism of electrogenesis.

http://www.ncbi.nlm.nih.gov/pubmed/21428034

J Affect Disord. 2011 Jan 20. [Epub ahead of print]

Cortical mechanisms of the symptomatology in major depressive disorder: A resting EEG study.

Lee TW, Yu YW, Chen MC, Chen TJ.

Department of Psychiatry, Chang Gung Memorial Hospital, Taoyuan County, Taiwan; College of Medicine, Chang Gung University, Taoyuan County, Taiwan.

BACKGROUND: Diagnosis and treatment rely on symptom criteria in modern psychiatry. However, the cortical mechanisms of symptomatology in major depressive disorder (MDD) are still not clear. This study examined neural correlates of symptom clusters of MDD by electroencephalography (EEG). METHODS: Resting state eye-closed EEG signals were recorded in 196 depressive patients. quantitative EEG (QEEG) of regional power, coherence and power series correlation across delta, theta, alpha and beta frequencies were used to correlate with overall depression severity evaluated by the Hamilton Depression Rating Scale (HDRS). Further, statistical comparisons between patients with high vs. low QEEG  indices (median-split) were undertaken regarding symptom severity of core depression, sleep, activity, psychic anxiety, somatic anxiety, and delusion. RESULTS: None of the QEEG indices significantly correlated with overall depression severity or differentiated symptom severity of core depression, sleep, activity and psychic anxiety. A higher symptom severity of somatic anxiety was associated with higher regional power over widespread cortical regions and lower  strengths at bi-temporal, temporo-parietal and fronto-parietal connections. A higher symptom severity of delusion was associated with higher regional power in  the frontal and temporal regions, and lower strengths at inter-hemispheric (frontal, temporal and parietal) and fronto-temporo-parietal connections. LIMITATIONS: Our EEG recording with sampling rate of 128Hz and 20 electrodes may  provide restricted spatial and temporal precision. CONCLUSIONS: Our results suggest that cortical mechanisms play important roles in the symptom manifestation of cognitive distortion (sub-score of delusion) and somatic anxiety in MDD. Our findings further imply that psychic anxiety and somatic anxiety are distinct entities.

http://www.ncbi.nlm.nih.gov/pubmed/21256600

Brain Res. 2011 Jan 7;1367:114-21. Epub 2010 Oct 23.

The non-coding RNA BC1 is down-regulated in the hippocampus of Wistar Audiogenic  Rat (WAR) strain after audiogenic kindling.

Gitaí DL, Fachin AL, Mello SS, Elias CF, Bittencourt JC, Leite JP, Passos GA, Garcia-Cairasco N, Paçó-Larson ML.

Department of Cellular and Molecular Biology, Ribeirão Preto School of Medicine,  University of São Paulo, Brazil.

The aim of this study was to identify molecular pathways involved in audiogenic seizures in the epilepsy-prone Wistar Audiogenic Rat (WAR). For this, we used a suppression-subtractive hybridization (SSH) library from the hippocampus of WARs  coupled to microarray comparative gene expression analysis, followed by Northern  blot validation of individual genes. We discovered that the levels of the non-protein coding (npc) RNA BC1 were significantly reduced in the hippocampus of WARs submitted to repeated audiogenic seizures (audiogenic kindling) when compared to Wistar resistant rats and to both naive WARs and Wistars. By quantitative in situ hybridization, we verified lower levels of BC1 RNA in the GD-hilus and significant signal ratio reduction in the stratum radiatum and stratum pyramidale of hippocampal CA3 subfield of audiogenic kindled animals. Functional results recently obtained in a BC1⁻/⁻ mouse model and our current data are supportive of a potential disruption in signaling pathways, upstream of BC1,  associated with the seizure susceptibility of WARs.

http://www.ncbi.nlm.nih.gov/pubmed/20974111

Clin EEG Neurosci. 2011 Jan;42(1):59-61.

QEEG-guided neurofeedback for recurrent migraine headaches.

Walker JE.

Neurotherapy Center of Dallas, 12870 Hillcrest, Suite 201, Dallas, Texas 75230, USA. admin@neurotherapydallas.com

Seventy-one patients with recurrent migraine headaches, aged 17-62, from one neurological practice, completed a quantitative electroencephalogram (QEEG) procedure. All QEEG results indicated an excess of high-frequency beta activity (21-30 Hz) in 1-4 cortical areas. Forty-six of the 71 patients selected neurofeedback training while the remaining 25 chose to continue on drug therapy.  Neurofeedback protocols consisted of reducing 21-30 Hz activity and increasing 10 Hz activity (5 sessions for each affected site). All the patients were classified as migraine without aura. For the neurofeedback group the majority (54%) experienced complete cessation of their migraines, and many others (39%) experienced a reduction in migraine frequency of greater than 50%. Four percent experienced a decrease in headache frequency of < 50%. Only one patient did not experience a reduction in headache frequency. The control group of subjects who chose to continue drug therapy as opposed to neurofeedback experienced no change  in headache frequency (68%), a reduction of less than 50% (20%), or a reduction greater than 50% (8%). QEEG-guided neurofeedback appears to be dramatically effective in abolishing or significantly reducing headache frequency in patients  with recurrent migraine.

http://www.ncbi.nlm.nih.gov/pubmed/21309444

Clin EEG Neurosci. 2011 Jan;42(1):53-8.

Decreased delta event-related synchronization in patients with early vascular dementia.

Xu J, Zhao S, Zhang H, Zheng C.

The Key Laboratory of Biomedical Information of Ministry of Education, Institute  of Biomedical Engineering, Xi'an Jiaotong University, Xi'an, ShaanXi Province 710049, PR China. jinxu10@gmail.com

Electroencephalogram (EEG) activity, recorded while performing an "odd ball" detection task, was compared between patients with early vascular dementia (VD),  healthy young controls and healthy elderly controls performing the same task. The data were analyzed using the event-related synchronization/desynchronization (ERS/ERD) method. VD patients, compared with controls, showed decreased ERS effects in the delta frequency band (0.5-3.5Hz) of EEG after the target stimulus  appeared in frontal, central and parietal regions. Similarly, elderly controls also showed a decreased ERS compared with young controls only in central and parietal regions. As part of this analysis, we introduce a novel quantitative index, the Event-related Energy Change Progression (EECP), which provides a reliable measure that distinguishes these groups and thereby provides a promising marker for early diagnosis of VD.

http://www.ncbi.nlm.nih.gov/pubmed/21309443

Clin Neurophysiol. 2011 Jan;122(1):134-47. Epub 2010 Jul 1.

Model-based analysis and quantification of age trends in auditory evoked potentials.

Kerr CC, Rennie CJ, Robinson PA.

School of Physics, University of Sydney, New South Wales 2006, Australia. ckerr@physics.usyd.edu.au

OBJECTIVE: The physiological basis for the changes in auditory evoked potentials  (AEPs) during development and aging is currently unknown. This study investigates age- and task-related changes via a mathematical model of neuronal activity, which allows a number of physiological changes to be inferred. METHODS: A quantitative, physiology-based model of activity in cortical and thalamic neurons was used to analyze oddball AEPs recorded from 1498 healthy subjects aged 6-86 years. RESULTS: Differences between standard and target responses can be largely explained by differences in connection strengths between thalamic and cortical neurons. The time it takes signals to travel between the thalamus and cortex decreases during development and increases during aging. Strong age trends are also seen in intracortical and thalamocortical neuronal connection strengths. CONCLUSIONS: Changes in AEP latency can be attributed to changes in the thalamocortical signal propagation time. Large changes in the connection strengths between neuronal populations occur during development, resulting in increased thalamocortical inhibition and decreased thalamocortical excitation. Standard and target parameters are similar in children but diverge during adolescence, due to changes in thalamocortical loop activity. SIGNIFICANCE: Model-based AEP analysis links age-related changes in brain electrophysiology to underlying changes in brain anatomy and physiology, and yields quantitative predictions of several currently unknown physiological and anatomical properties of the brain.

http://www.ncbi.nlm.nih.gov/pubmed/20594907

Georgian Med News. 2011 Jan;(190):42-8.

Quantitative electroencephalography coherence and dipole source index during various cognitive tasks in children with attention deficit hyperactivity disorder.

Bakhtadze S, Janelidze M, Khachapuridze N.

S. Khechinashvili University Clinic, Tbilisi, Georgia.

Attention deficit hyperactivity disorder (ADHD) is one of the most important disorder of childhood and adolescence. Debates about diagnostic approaches requiring for the precise assessment of ADHD remains actual till nowadays. The role of neurophysiological methods for this purpose is controversial. Thus the aim of our study was to observe QEEG changes by means of the most modern software analysis systems- coherence and brainwave activity dipole source localization. We have assessed 39 children- 18 of them from control group (Age range 9-12 years).  QEEG was registered during Raven test and adding of one digit numbers. The results were analyzed by means of coherence measures and brainwave bilateral synchronous activity dipole source generator localization detection system (BrainLoc. 6). As a result we observed high coherence measures for ADHD compared  to controls. As for dipole source generator we have detected higher dipole equivalent index in control group compared with ADHD children. Thus according to  our results it is obvious that QEEG can serve as a valid neurometric tool in the  diagnosis of Attention deficit hyperactivity disorder.

http://www.ncbi.nlm.nih.gov/pubmed/21346267

Neuropsychologia. 2011 Jan;49(2):254-63. Epub 2010 Nov 24.

A big-world network in ASD: dynamical connectivity analysis reflects a deficit in long-range connections and an excess of short-range connections.

Barttfeld P, Wicker B, Cukier S, Navarta S, Lew S, Sigman M.

Integrative Neuroscience Laboratory, Physics Department, University of Buenos Aires, Buenos Aires, Argentina. pbarttfeld@fi.uba.ar

Over the last years, increasing evidence has fuelled the hypothesis that Autism Spectrum Disorder (ASD) is a condition of altered brain functional connectivity.  The great majority of these empirical studies relies on functional magnetic resonance imaging (fMRI) which has a relatively poor temporal resolution. Only a  handful of studies has examined networks emerging from dynamic coherence at the millisecond resolution and there are no investigations of coherence at the lowest frequencies in the power spectrum-which has recently been shown to reflect long-range cortico-cortical connections. Here we used electroencephalography (EEG) to assess dynamic brain connectivity in ASD focusing in the low-frequency (delta) range. We found that connectivity patterns were distinct in ASD and control populations and reflected a double dissociation: ASD subjects lacked long-range connections, with a most prominent deficit in fronto-occipital connections. Conversely, individuals with ASD showed increased short-range connections in lateral-frontal electrodes. This effect between categories showed  a consistent parametric dependency: as ASD severity increased, short-range coherence was more pronounced and long-range coherence decreased. Theoretical arguments have been proposed arguing that distinct patterns of connectivity may result in networks with different efficiency in transmission of information. We show that the networks in ASD subjects have less Clustering coefficient, greater  Characteristic Path Length than controls - indicating that the topology of the network departs from small-world behaviour - and greater modularity. Together these results show that delta-band coherence reveal qualitative and quantitative  aspects associated with ASD pathology.

http://www.ncbi.nlm.nih.gov/pubmed/21110988

Acta Psychiatr Scand. 2010 Dec;122(6):461-9. doi: 10.1111/j.1600-0447.2010.01560.x.

Brain functional changes (QEEG cordance) and worsening suicidal ideation and mood symptoms during antidepressant treatment.

Hunter AM, Leuchter AF, Cook IA, Abrams M.

Semel Institute for Neuroscience and Human Behavior at UCLA, Los Angeles, CA 90024-1759, USA. amhunter@ucla.edu

Comment in     Acta Psychiatr Scand. 2010 Dec;122(6):442-3.

OBJECTIVE: Antidepressant medications are efficacious overall; however, some individuals experience worsening mood symptoms and increased suicidal ideation (SI) during treatment. We examined the quantitative electroencephalographic (QEEG) cordance biomarker of brain function biomarker in relation to treatment-emergent symptom worsening. METHOD: Seventy-two major depressive disorder (MDD) subjects were treated with fluoxetine 20 mg (n = 13), venlafaxine 150 mg (n = 24), or placebo (n = 35) under double-blind conditions. Behavioral ratings determined whether each subject demonstrated worsening of depressed mood, anxiety, or SI during treatment. QEEG cordance data were analyzed to determine whether symptom worsening was associated with neurophysiological changes. RESULTS: Antidepressant treatment-emergent SI (13.5%) was associated with a large transient decrease in midline-and-right-frontal (MRF) cordance 48 h after start of medication. CONCLUSION: Hypothesis-generating results suggest a pattern of functional changes in midline and right frontal brain regions associated with antidepressant treatment-emergent SI in MDD.

http://www.ncbi.nlm.nih.gov/pubmed/20384600

Addict Behav. 2010 Dec;35(12):1120-30. Epub 2010 Aug 10.

A quantitative analysis of subjective, cognitive, and physiological manifestations of the acute tobacco abstinence syndrome.

Leventhal AM, Waters AJ, Moolchan ET, Heishman SJ, Pickworth WB.

Department of Preventive Medicine, University of Southern California Keck School  of Medicine, Los Angeles, CA 90033, USA. adam.leventhal@usc.edu

RATIONALE: Previous studies have documented the existence of signs and symptoms of the acute tobacco abstinence syndrome; however, less attention has been paid to quantifying the magnitude of these effects. OBJECTIVE: The present study quantified the relative magnitude of subjective, cognitive, and physiological manifestations of acute tobacco abstinence. METHOD: Smokers (N=203, ≥ 15 cig/day) attended two counterbalanced laboratory sessions, one following 12-h of abstinence and the other following ad-lib smoking. At both sessions, they completed an extensive battery of self-report measures (withdrawal, affect, hunger, craving, subjective attentional bias towards smoking cues), physiological assessments (heart rate, blood pressure, brain EEG), and cognitive performance tasks (psychomotor processing, sustained attention, objective attentional bias). RESULTS: Abstinence effects were largest for craving, subjective attentional bias, negative affect, overall withdrawal severity, concentration difficulty, hunger, and heart rate. Effects were moderate for positive affect and EEG power.  Effects were small, but reliable, for psychomotor speed, sustained attention, and somatic symptoms. Effects on performance-based indices of attentional bias towards smoking-related cues were small and reliable for some indices but not others. Effects were small and inconsistent for blood pressure and EEG frequency. Variation in internal consistency accounted for 33% of the variation in abstinence effect sizes across measures. CONCLUSIONS: There was a wide range of effect sizes both across and within domains, indicating that the acute tobacco abstinence syndrome is not a monotonic phenomenon. These findings may be indicative of the relative magnitudes of signs  and symptoms that the average smoker may exhibit during acute abstinence.

http://www.ncbi.nlm.nih.gov/pubmed/20807673

Epilepsia. 2010 Dec;51(12):2406-11. doi: 10.1111/j.1528-1167.2010.02747.x. Epub 2010 Sep 30.

The EEG response to pyridoxine-IV neither identifies nor excludes pyridoxine-dependent epilepsy.

Bok LA, Maurits NM, Willemsen MA, Jakobs C, Teune LK, Poll-The BT, de Coo IF, Toet MC, Hagebeuk EE, Brouwer OF, van der Hoeven JH, Sival DA.

Department of Pediatrics, Máxima Medical Center, Veldhoven, The Netherlands.

PURPOSE: Pyridoxine-dependent epilepsy (PDE) is characterized by therapy-resistant seizures (TRS) responding to intravenous (IV) pyridoxine. PDE can be identified by increased urinary alpha-aminoadipic semialdehyde (α-AASA) concentrations and mutations in the ALDH7A1 (antiquitin) gene. Prompt recognition of PDE is important for treatment and prognosis of seizures. We aimed to determine whether immediate electroencephalography (EEG) alterations by pyridoxine-IV can identify PDE in neonates with TRS. METHODS: In 10 neonates with TRS, we compared online EEG alterations by pyridoxine-IV between PDE (n = 6) and non-PDE (n = 4). EEG segments were visually and digitally analyzed for average background amplitude and total power and relative power (background activity magnitude per frequency band and contribution of the frequency band to the spectrum). RESULTS: In 3 of 10 neonates with TRS (2 of 6 PDE and 1 of 4 non-PDE neonates), pyridoxine-IV caused flattening of the EEG amplitude and attenuation of epileptic activity. quantitative EEG alterations by pyridoxine-IV consisted of (1) decreased central amplitude, p < 0.05 [PDE: median -30% (range -78% to -3%); non-PDE: -20% (range -45% to -12%)]; (2) unaltered relative power; (3) decreased  total power, p < 0.05 [PDE: -31% (-77% to -1%); -27% (-73% to -13%); -35% (-56% to -8%) and non-PDE: -16% (-43% to -5%); -28% (-29% to -17%); -26% (-54% to -8%), in delta-, theta- and beta-frequency bands, respectively]; and (4) similar EEG responses in PDE and non-PDE. DISCUSSION: In neonates with TRS, pyridoxine-IV induces nonspecific EEG responses that neither identify nor exclude PDE. These data suggest that neonates with TRS  should receive pyridoxine until PDE is fully excluded by metabolic and/or DNA analysis.

http://www.ncbi.nlm.nih.gov/pubmed/20887371

J Med Syst. 2010 Dec;34(6):1073-81. Epub 2009 Jun 18.

Application of paraconsistent artificial neural networks as a method of aid in the diagnosis of Alzheimer disease.

da Silva Lopes HF, Abe JM, Anghinah R.

University of São Paulo, São Paulo, Brazil. helder@autobyte.com.br

The visual analysis of EEG has shown useful in helping the diagnosis of Alzheimer disease (AD) when the diagnosis remains uncertain, being used in some clinical protocols. However, such analysis is subject to the inherent equipment imprecision, patient movement, electrical records, and physician interpretation of the visual analysis variation. The Artificial Neural Network (ANN) could be a  helpful tool, appropriate to address problems such as prediction and pattern recognition. In this work, it has use a new class of ANN, the Paraconsistent Artificial Neural Network (PANN), which is capable of handling uncertain, inconsistent, and paracomplete information, for recognizing predetermined patterns of EEG and to assess its value as a possible auxiliary method for AD diagnosis. Thirty three patients with Alzheimer's disease and 34 controls patients of EEG records were obtained during relaxed wakefulness. It was considered as normal patient pattern, the background EEG activity between 8.0 and 12.0 Hz (with an average frequency of 10 Hz), allowing a range of 0.5 Hz. The PANN was able to recognize waves that belonging to their respective bands of clinical use (theta, delta, alpha, and beta), leading to an agreement with the clinical diagnosis at 82% of sensitivity and at 61% of specificity. Supported with these results, the PANN could be a promising tool to manipulate EEG analysis, bearing in mind the following considerations: the growing interest of specialists in EEG analysis visual and the ability of the PANN to deal directly imprecise, inconsistent and paracomplete data, providing an interesting quantitative and qualitative analysis.

http://www.ncbi.nlm.nih.gov/pubmed/20703601

J Med Syst. 2010 Dec;34(6):1059-71. Epub 2009 Jun 9.

A survey on application of quantitative methods on analysis of brain parameters changing with temperature.

Demirhan A, Kaymaz M, Ahıska R, Güler I.

Department of Electronics and Computer Technology, Gazi University, Teknikokullar, Ankara, Turkey.

Brain temperature fluctuations occur in consequence of physiological and pathophysiological conditions and indicate changes in brain metabolism, cerebral  blood flow (CBF), brain functions and neural damage. Lowering the brain temperature of patients with traumatic brain injuries achieves considerable improvements. When the human brain is cooled down to 30°C, it switches to a sub functional regime where it can live longer with less oxygen, glucose and other supplies. Fluctuations in brain temperature cause changes in brain parameters which can be measured by electroencephalogram (EEG) and transcranial Doppler (TCD). It is very important to understand the temperature dependencies of brain's electrical activity and blood flow and their interrelations considering the good  clinical results achieved by lowering the brain temperature of neurologically injured patients. Since protecting the patient's brain is of primary importance in many fields including cardiology, neurology, traumatology and anesthesia it can be clearly seen that this subject is very important. In this study, we survey the "state-of-the-art" in analysis of EEG and TCD brain parameters changing with  temperature and present further research opportunities.

http://www.ncbi.nlm.nih.gov/pubmed/20703602

Neurocrit Care. 2010 Dec;13(3):355-8.

Intracortical EEG for the detection of vasospasm in patients with poor-grade subarachnoid hemorrhage.

Stuart RM, Waziri A, Weintraub D, Schmidt MJ, Fernandez L, Helbok R, Kurtz P, Lee K, Badjatia N, Emerson R, Mayer SA, Connolly ES, Hirsch LJ, Claassen J.

Department of Neurological Surgery, Columbia University College of Physicians and Surgeons, New York, NY 10032, USA.

BACKGROUND: To study the feasibility of utilizing intracortical electroencephalography (ICE) including quantitative EEG (QEEG) analysis for the detection of vasospasm in five consecutive poor-grade SAH patients. METHODS: Intracortical electroencephalography (ICE) was obtained via a single miniature parenchymal 8-contact depth electrode placed at the bedside. quantitative EEG parameters, calculated on surface EEG and ICE, included alpha/delta ratio (ADR), mean amplitude, suppression percent, and total power. Percent changes between averaged values over 4-6 h of baseline EEG and EEG prior  to angiography were calculated. The entire continuous QEEG recording for each patient was then reviewed to determine optimal automated alarm criteria. RESULTS: ICE ADR was the most accurate for predicting angiographic vasospasm (5/5). ICE ADR decreased between baseline and follow-up by 42% (from 0.56 ± 0.07  to 0.32 ± 0.03) for those with vasospasm (N = 3) compared to 17% (0.62 ± 0.06 to  0.51 ± 0.03) for those without (N = 2). A sustained decrease in the ICE ADR from  baseline (>25% for ≥ 4 h) occurred in all three patients with angiographically confirmed vasospasm and not in the two without; this decline occurred 1-3 days prior to angiographic confirmation. CONCLUSIONS: Intracortical EEG is promising for detecting ischemia from vasospasm in poor-grade SAH patients, may be superior to scalp EEG, and allow automated detection, particularly using the ADR. Larger studies are needed to better define the effectiveness of this approach.

http://www.ncbi.nlm.nih.gov/pubmed/20652443

J Neurosci Methods. 2010 Nov 30;193(2):321-33. Epub 2010 Sep 15.

Characterization of the bout durations of sleep and wakefulness.

McShane BB, Galante RJ, Jensen ST, Naidoo N, Pack AI, Wyner A.

Kellogg School of Management, Northwestern University, Evanston, IL, USA.

STUDY OBJECTIVES: (a) Develop a new statistical approach to describe the microarchitecture of wakefulness and sleep in mice; (b) evaluate differences among inbred strains in this microarchitecture; (c) compare results when data are scored in 4-s versus 10-s epochs. DESIGN: Studies in male mice of four inbred strains: AJ, C57BL/6, DBA and PWD. EEG/EMG were recorded for 24h and scored independently in 4-s and 10-s epochs. MEASUREMENTS AND RESULTS: Distribution of bout durations of wakefulness, NREM and REM sleep in mice has two distinct components, i.e., short and longer bouts. This is described as a spike (short bouts) and slab (longer bouts) distribution, a particular type of mixture model. The distribution in any state depends on the state the mouse is transitioning from and can be characterized by three parameters: the number of such bouts conditional on the previous state, the size  of the spike, and the average length of the slab. While conventional statistics such as time spent in state, average bout duration, and number of bouts show some differences between inbred strains, this new statistical approach reveals more major differences. The major difference between strains is their ability to sustain long bouts of NREM sleep or wakefulness. Scoring mouse sleep/wake in 4-s  epochs offered little new information when using conventional metrics but did when evaluating the microarchitecture based on this new approach. CONCLUSIONS: Standard statistical approaches do not adequately characterize the microarchitecture of mouse behavioral state. Approaches based on a spike-and-slab provide a quantitative description.

http://www.ncbi.nlm.nih.gov/pubmed/20817037

Respir Physiol Neurobiol. 2010 Nov 30;174(1-2):128-34. Epub 2010 May 15.

Cardioventilatory coupling in preterm and term infants: effect of position and sleep state.

Elder DE, Larsen PD, Galletly DC, Campbell AJ.

Department of Paediatrics, University of Otago Wellington, Wellington, New Zealand. dawn.elder@otago.ac.nz

This study documented the effect of position on cardioventilatory coupling (CVC), the triggering of inspiratory onset by a preceding heartbeat, in infants. Cardiorespiratory signals and corresponding oxygen saturation (SpO(2)) were downloaded from Quiet Sleep (QS) and Active Sleep (AS) in prone and supine from preterm (PT) and term (T) infants. Inspiratory onsets (I) and timing of the corresponding ECG R wave were determined and R-R and R-I intervals calculated. The RI(-1) interval (time between inspiration and the preceding R wave) dispersion was measured using proportional Shannon Entropy of the RI(-1) interval (SH(α)), to provide a quantitative measure of CVC. CVC was more frequently seen in QS in PT (p=0.002) and T (p=0.02) infants but not influenced by position (p=0.71, p=0.46). CVC correlated with SpO(2) in PT (r=-0.230, p=0.03) but not T infants (r=0.085, p=0.34). These data imply an augmentation of cardiac influence  on ventilatory rhythm in infants in QS. In preterm infants CVC may have a role in supporting oxygenation.

http://www.ncbi.nlm.nih.gov/pubmed/20478413

Clin Neurophysiol. 2010 Nov;121(11):1844-54.

Reduced fronto-cortical brain connectivity during NREM sleep in Asperger syndrome: an EEG spectral and phase coherence study.

Lázár AS, Lázár ZI, Bíró A, Gyori M, Tárnok Z, Prekop C, Keszei A, Stefanik K, Gádoros J, Halász P, Bódizs R.

Institute of Behavioural Sciences, Semmelweis University, Budapest, Hungary. a.lazar@surrey.ac.uk

OBJECTIVE: To investigate whether sleep macrostructure and EEG power spectral density and coherence during NREM sleep are different in Asperger syndrome (AS) compared to typically developing children and adolescents. METHODS: Standard all night EEG sleep parameters were obtained from 18 un-medicated subjects with AS and 14 controls (age range: 7.5-21.5years) after one adaptation night. Spectral, and phase coherence measures were computed for multiple frequency bands during NREM sleep. RESULTS: Sleep latency and wake after sleep onset were increased in AS. Absolute  power spectrum density (PSD) was significantly reduced in AS in the alpha, sigma, beta and gamma bands and in all 10 EEG derivations. Relative PSD showed a significant increase in delta and a decrease in the sigma band for frontal, and in beta for centro-temporal derivations. Intrahemispheric coherence measures were markedly lower in AS in the frontal areas, and the right hemisphere over all EEG  channels. The most prominent reduction in intrahemispheric coherence was observed over the fronto-central areas in delta, theta, alpha and sigma EEG frequency bands. CONCLUSION: EEG power spectra and coherence during NREM sleep, in particular in fronto-cortical derivations are different in AS compared to typically developing  children and adolescents. SIGNIFICANCE: Quantitative analysis of the EEG during NREM sleep supports the hypothesis of frontal dysfunction in AS.

http://www.ncbi.nlm.nih.gov/pubmed/20434395

Epilepsy Behav. 2010 Nov;19(3):522-5.

Ictal consciousness in epilepsy and nonepileptic attack disorder.

Ali F, Rickards H, Bagary M, Greenhill L, McCorry D, Cavanna AE.

Department of Neuropsychiatry, Birmingham and Solihull Mental Health NHS Foundation Trust and University of Birmingham, Birmingham, UK.

Exploration of subjective experiences during seizures may enhance knowledge of the differing natures of epilepsy and nonepileptic attack disorder (NEAD). We performed a quantitative evaluation of both the general level of awareness and the specific contents of consciousness during seizures using the Ictal Consciousness Inventory (ICI). Ninety-five adult outpatients attending general neuropsychiatry and epilepsy clinics with established diagnoses of either epilepsy (n = 66) or NEAD (n = 29) completed one ICI for each witnessed seizure recalled. Patients with a dubious/dual diagnosis were excluded. ICI Level (ICI-L) and ICI Content (ICI-L) scores were calculated for the 167 questionnaires generated by patients with epilepsy (n = 119, of which 58 from patients with temporal lobe epilepsy, 14 frontal lobe epilepsy, and 47 idiopathic 30 generalized epilepsy) and patients with NEAD (n = 48). Mann-Whitney U tests revealed statistically significant higher ICI-L and ICI-C scores for patients with NEAD (both P = 0.01). Subjective reports of consciousness experiences varied between epilepsy and NEAD, with patients with NEAD reporting significantly greater levels of general awareness/responsiveness and more vivid subjective experiences during attacks. The ICI is proposed as a potentially useful self-report instrument to supplement clinical and instrumental tests for the differential diagnosis of epilepsy and NEAD.

http://www.ncbi.nlm.nih.gov/pubmed/20920893

Genes Brain Behav. 2010 Nov;9(8):1004-12. doi: 10.1111/j.1601-183X.2010.00648.x.  Epub 2010 Oct 18.

Pleiotropic effects of the 11p13 locus on developmental verbal dyspraxia and EEG  centrotemporal sharp waves.

Pal DK, Li W, Clarke T, Lieberman P, Strug LJ.

King's College London, Institute of Psychiatry, Department of Clinical Neuroscience, London, UK. deb.pal@kcl.ac.uk

We recently showed genomewide linkage of centrotemporal sharp waves (CTS) in classic Rolandic epilepsy (RE) families to chromosome 11p13, and fine-mapped this locus to variants in the ELP4 gene. Speech sound disorder (SSD) is a common comorbidity in RE subjects, of unknown etiology, which co-aggregates in family members in a manner that could hypothetically be explained by shared underlying genetic risk with CTS. Furthermore, the neural mechanism of SSD is unknown, although individuals with rare, Mendelian forms of RE are described with severe verbal and oromotor apraxia. We therefore first performed genomewide linkage analysis for SSD, operationally defined as clinical history consistent with ICD-10 speech articulation disorder, in 38 families singly ascertained through a  proband with RE. We tested the hypothesis of shared genetic risk with CTS at the  11p13 locus. In the second part of the study we used computerized acoustic analysis of recorded speech to test the hypothesis of dyspraxia as a mechanism for SSD in a smaller subset of RE probands and relatives. In two-point and multipoint LOD score analysis, we found that evidence for linkage to the 11p13 locus increased substantially when the phenotype was broadened from CTS to CTS/SSD. In multipoint analysis, the LOD score rose by 3.2 to HLOD 7.54 at D11S914 for CTS/SSD, the same marker at which multipoint linkage maximized for CTS alone. Non-parametric, affected-only methods in a sub-set of the data provide further confirmatory evidence for pleiotropy. In acoustic analysis there were voice-onset time abnormalities in 10/18 RE probands, 8/16 siblings and 5/15 parents, providing evidence of breakdown in the spatial/temporal properties of speech articulation consistent with a dyspraxic mechanism. The results from genetic and physiological studies suggest a pleiotropic role for the 11p13 locus  in the development of both SSD and CTS, and also indicate a dyspraxic mechanism for the SSD linked to 11p13. Taken together, these data strongly support a neurodevelopmental origin for classic RE.

http://www.ncbi.nlm.nih.gov/pubmed/20825490

Hum Brain Mapp. 2010 Nov;31(11):1627-42.

Cortical gamma-oscillations modulated by auditory-motor tasks-intracranial recording in patients with epilepsy.

Nagasawa T, Rothermel R, Juhász C, Fukuda M, Nishida M, Akiyama T, Sood S, Asano  E.

Department of Pediatrics, Children's Hospital of Michigan, Wayne State University, Detroit Medical Center, Detroit, Michigan 48201, USA.

Human activities often involve hand-motor responses following external auditory-verbal commands. It has been believed that hand movements are predominantly driven by the contralateral primary sensorimotor cortex, whereas auditory-verbal information is processed in both superior temporal gyri. It remains unknown whether cortical activation in the superior temporal gyrus during an auditory-motor task is affected by laterality of hand-motor responses. Here, event-related γ-oscillations were intracranially recorded as quantitative measures of cortical activation; we determined how cortical structures were activated by auditory-cued movement using each hand in 15 patients with focal epilepsy. Auditory-verbal stimuli elicited augmentation of γ-oscillations in a posterior portion of the superior temporal gyrus, whereas hand-motor responses elicited γ-augmentation in the pre- and postcentral gyri. The magnitudes of such  γ-augmentation in the superior temporal, precentral, and postcentral gyri were significantly larger when the hand contralateral to the recorded hemisphere was required to be used for motor responses, compared with when the ipsilateral hand  was. The superior temporal gyrus in each hemisphere might play a greater pivotal  role when the contralateral hand needs to be used for motor responses, compared with when the ipsilateral hand does.

http://www.ncbi.nlm.nih.gov/pubmed/20143383

J Neural Transm. 2010 Nov;117(11):1307-18. Epub 2010 Oct 8.

Comparative EEG mapping studies in Huntington's disease patients and controls.

Painold A, Anderer P, Holl AK, Letmaier M, Saletu-Zyhlarz GM, Saletu B, Bonelli RM.

Department of Psychiatry, Medical University of Graz, Graz, Austria.

Huntington's disease (HD) is a devastating neurodegenerative disorder with prominent motor and cognitive decline. Previous studies with small sample sizes and methodological limitations have described abnormal electroencephalograms (EEG) in this cohort. The aim of the present study was to investigate objectively and quantitatively the neurophysiological basis of the disease in HD patients as  compared to normal controls, utilizing EEG mapping. In 55 HD patients and 55 healthy controls, a 3-min vigilance-controlled EEG (V-EEG) was recorded during midmorning hours. Evaluation of 36 EEG variables was carried out by spectral analysis and visualized by EEG mapping techniques. To elucidate drug interference, the analysis was performed for the total group, unmedicated patients only and between treated and untreated patients. Statistical overall analysis by the omnibus significance test demonstrated significant (p < 0.01 and  p < 0.05) EEG differences between HD patients and controls. Subsequent univariate analysis revealed a general decrease in total power and absolute alpha and beta power, an increase in delta/theta power, and a slowing of the centroids of delta/theta, beta and total power. The slowing of the EEG in HD reflects a disturbed brain function in the sense of a vigilance decrement, electrophysiologically characterized by inhibited cortical areas (increased delta/theta power) and a lack of normal routine and excitatory activity (decreased alpha and beta power). The results are similar to those found in other dementing disorders. Medication did not affect the overall interpretation of the  quantitative EEG analysis, but certain differences might be due to drug interaction, predominantly with antipsychotics. Spearman rank correlations revealed significant correlations between EEG mapping and cognitive and motor impairment in HD patients.

http://www.ncbi.nlm.nih.gov/pubmed/20931245

Neuroimage. 2010 Nov 1;53(2):399-411. Epub 2010 Jul 12.

Regional differences in neurovascular coupling in rat brain as determined by fMRI and electrophysiology.

Sloan HL, Austin VC, Blamire AM, Schnupp JW, Lowe AS, Allers KA, Matthews PM, Sibson NR.

Department of Physiology, Anatomy and Genetics, University of Oxford, UK.

Increases in neuronal activity induce local increases in cerebral perfusion. However, our understanding of the processes underlying this neurovascular coupling remains incomplete and, particularly, how these vary across the brain. Recent work supports an important role for astrocytes in neurovascular coupling,  in large part via activation of their metabotropic glutamate receptors (mGluR). Here, using a combination of functional magnetic resonance imaging (fMRI) and electrophysiology we demonstrate regional heterogeneity in the mechanisms underlying neurovascular coupling. Direct electrical stimulation of the rat hindpaw sensorimotor cortex induces blood oxygenation level dependent (BOLD) and  cerebral blood volume (CBV) fMRI responses in several anatomically distinct cortical and subcortical structures. Following intraperitoneal administration of  the type 5 mGluR antagonist, MPEP, both BOLD and CBV responses to cortical stimulation were significantly reduced, whilst the local field potential (LFP) responses remained largely constant. Spatially, the degree of reduction in fMRI responses varied between cortical and subcortical regions (primary cortex approximately 18% vs. striatum approximately 66%), and also between primary and secondary cortical areas ( approximately 18% vs. approximately 55%). Similarly, greater decreases in response amplitude were seen in the contralateral secondary  cortex ( approximately 91%) and ipsilateral striatum (approximately 70%), compared to the primary cortex (approximately 44%). Following MPEP, a negative component of the BOLD and CBV responses became more apparent, suggesting that different mechanisms mediate vasodilatory and vasoconstrictory responses. Interestingly, under baseline conditions the quantitative relationship between fMRI and LFP responses in cortical and subcortical regions was markedly different. Our data indicate that coupling between neuronal and fMRI responses is neither empirically nor mechanistically consistent across the brain.

http://www.ncbi.nlm.nih.gov/pubmed/20633665

Postgrad Med. 2010 Nov;122(6):214-26.

Overcoming QEEG abnormalities and reward gene deficits during protracted abstinence in male psychostimulant and polydrug abusers utilizing putative dopamine D₂ agonist therapy: part 2.

Blum K, Chen TJ, Morse S, Giordano J, Chen AL, Thompson J, Allen C, Smolen A, Lubar J, Stice E, Downs BW, Waite RL, Madigan MA, Kerner M, Fornari F, Braverman  ER.

Department of Psychiatry and McKnight Brain Institute, University of Florida College of Medicine, Gainesville, FL, USA. drd2gene@aol.com

BACKGROUND: It is well established that in both food- and drug-addicted individuals there is "dopamine resistance" associated with the DRD2 gene A1 allele. Based on earlier studies, evidence is emerging wherein the potential of utilizing a natural, nonaddicting, safe, putative D2 agonist may play a significant role in the recovery of individuals with reward deficiency syndrome,  including those addicted to psychoactive chemicals. FINDINGS: Positive outcomes demonstrated by quantitative electroencephalographic  (QEEG) imaging in a randomized, triple-blind, placebo-controlled, crossover study involving oral Synaptose Complex KB220Z™ showed an increase of alpha waves and low beta wave activity in the parietal brain region. Using t statistics, significant differences observed between placebo and Synaptose Complex KB220Z™ consistently occurred in the frontal regions after week 1 and then again after week 2 of analyses (P = 0.03). This is the first report to demonstrate involvement of the prefrontal cortex in the QEEG response to a natural putative D2 agonist (Synaptose Complex KB220Z™), especially evident in dopamine D2 A1 allele subjects. Independently, we have further supported this finding with an additional study of 3 serious polydrug abusers undergoing protracted abstinence who carried the DRD2 A1 allele. Significant QEEG differences were found between those who received 1 dose of placebo compared with those who were administered Synaptose Complex KB220Z™. Synaptose Complex KB220Z™ induced positive regulation  of the dysregulated electrical activity of the brain in these addicts. The results are indicative of a phase change from low amplitude or low power in the brain to a more regulated state by increasing an average of 6.169 mV(2) across the prefrontal cortical region. In the first experiment we found that while 50% of the subjects carried the DRD2 A1 allele, 100% carried ≥ 1 risk allele. Specifically, based on the proposed addiction risk score for these 14 subjects, 72% had moderate-to-severe addiction risk. Similar findings were obtained by repeating the experiment in 3 additional currently abstinent polydrug abusers carrying the DRD2 A1 allele. CONCLUSION: This seminal work will provide important information that may ultimately lead to significant improvement in the recovery of individuals with psychostimulant and polydrug abuse problems, specifically those with genetically  induced dopamine deficiency. Based on this small sample size, we are proposing that with necessary large populations supporting these initial results, and possibly even additional candidate genes and single nucleotide polymorphisms, we  may eventually have the clinical ability to classify severity according to genotype and possession of risk alleles, along with offering a safe, nonaddicting, natural dopaminergic receptor agonist that potentially upregulates  instead of downregulates dopaminergic receptors, preferably the D2 subtype.

http://www.ncbi.nlm.nih.gov/pubmed/21084796

Postgrad Med. 2010 Nov;122(6):188-213.

Acute intravenous synaptamine complex variant KB220™ "normalizes" neurological dysregulation in patients during protracted abstinence from alcohol and opiates as observed using quantitative electroencephalographic and genetic analysis for reward polymorphisms: part 1, pilot study with 2 case reports.

Miller DK, Bowirrat A, Manka M, Miller M, Stokes S, Manka D, Allen C, Gant C, Downs BW, Smolen A, Stevens E, Yeldandi S, Blum K.

LifeStream Solutions, Inc., Prescott, AZ, USA.

It is well established that in both food- and drug-addicted individuals, there is dopamine resistance due to an association with the DRD2 gene A1 allele. Evidence  is emerging whereby the potential of utilizing a natural, nonaddicting, safe, putative D2 agonist may find its place in recovery from reward deficiency syndrome (RDS) in patients addicted to psychoactive chemicals. Utilizing quantitative electroencephalography (QEEG) as an imaging tool, we show the impact of Synaptamine Complex Variant KB220™ as a putative activator of the mesolimbic system. We demonstrate for the first time that its intravenous administration reduces or "normalizes" aberrant electrophysiological parameters of the reward circuitry site. For this pilot study, we report that the QEEGs of an alcoholic and a heroin abuser with existing abnormalities (ie, widespread theta and widespread alpha activity, respectively) during protracted abstinence are significantly normalized by the administration of 1 intravenous dose of Synaptamine Complex Variant KB220™. Both patients were genotyped for a number of  neurotransmitter reward genes to determine to what extent they carry putative dopaminergic risk alleles that may predispose them for alcohol or heroin dependence, respectively. The genes tested included the dopamine transporter (DAT1, locus symbol SLC6A3), dopamine D4 receptor exon 3 VNTR (DRD4), DRD2 TaqIA  (rs1800497), COMT val158 met SNP (rs4680), monoamine oxidase A upstream VNTR (MAOA-uVNTR), and serotonin transporter-linked polymorphic region (5HTTLPR, locus symbol SLC6A4). We emphasize that these are case studies, and it would be unlikely for all individuals to carry all putative risk alleles. Based on previous research and our QEEG studies (parts 1 and 2 of this study), we cautiously suggest that long-term activation of dopaminergic receptors (ie, DRD2  receptors) will result in their proliferation and lead to enhanced "dopamine sensitivity" and an increased sense of happiness, particularly in carriers of the DRD2 A1 allele. This is supported by a clinical trial on Synaptamine Complex Variant KB220™ using intravenous administration in > 600 alcoholic patients, resulting in significant reductions in RDS behaviors. It is also confirmed by the expanded oral study on Synaptose Complex KB220Z™, published as part 2 of this study. Future studies must await both functional magnetic resonance imaging and positron emission tomography scanning to determine the acute and chronic effects  of oral KB220™ on numbers of D2 receptors and direct interaction at the nucleus accumbens. Confirmation of these results in large, population-based, case-controlled experiments is necessary. These studies would provide important information that could ultimately lead to significant improvement in recovery for those with RDS and dopamine deficiency as a result of a multiple neurotransmitter signal transduction breakdown in the brain reward cascade.

http://www.ncbi.nlm.nih.gov/pubmed/21084795

Sleep. 2010 Nov 1;33(11):1511-6.

Analysis of slow-wave activity and slow-wave oscillations prior to somnambulism.

Jaar O, Pilon M, Carrier J, Montplaisir J, Zadra A.

Centre D'étude de Sommeil Hôpital de Sacré-Coeur, Montréal, Québec, Canada.

STUDY OBJECTIVIES: several studies have investigated slow wave sleep EEG parameters, including slow-wave activity (SWA) in relation to somnambulism, but results have been both inconsistent and contradictory. The first goal of the present study was to conduct a quantitative analysis of sleepwalkers' sleep EEG by studying fluctuations in spectral power for delta (1-4 Hz) and slow delta (0.5-1 Hz) before the onset of somnambulistic episodes. A secondary aim was to detect slow-wave oscillations to examine changes in their amplitude and density prior to behavioral episodes.PARTICIPANTS: twenty-two adult sleepwalkers were investigated polysomnographically following 25 h of sleep deprivation. RESULTS: analysis of patients' sleep EEG over the 200 sec prior to the episodes'  onset revealed that the episodes were not preceded by a gradual increase in spectral power for either delta or slow delta over frontal, central, or parietal  leads. However, time course comparisons revealed significant changes in the density of slow-wave oscillations as well as in very slow oscillations with significant increases occurring during the final 20 sec immediately preceding episode onset. CONCLUSIONS: the specificity of these sleep EEG parameters for the occurrence and diagnosis of NREM parasomnias remains to be determined.

http://www.ncbi.nlm.nih.gov/pubmed/21102993

Neurology. 2010 Oct 26;75(17):1501-8. Epub 2010 Sep 22.

Seizure identification in the ICU using quantitative EEG displays.

Stewart CP, Otsubo H, Ochi A, Sharma R, Hutchison JS, Hahn CD.

Division of Neurology, The Hospital for Sick Children, Toronto, Canada.

OBJECTIVE: To evaluate the diagnostic accuracy of 2 quantitative EEG display tools, color density spectral array (CDSA) and amplitude-integrated EEG (aEEG), for seizure identification in the intensive care unit (ICU). METHODS: A set of 27 continuous EEG recordings performed in pediatric ICU patients was transformed into 8-channel CDSA and aEEG displays. Three neurophysiologists underwent 2 hours of training to identify seizures using these techniques. They were then individually presented with a series of CDSA and aEEG  displays, blinded to the raw EEG, and asked to mark any events suspected to be seizures. Their performance was compared to seizures identified on the underlying conventional EEG. RESULTS: The 27 EEG recordings contained 553 discrete seizures over 487 hours. The median sensitivity for seizure identification across all recordings was 83.3% using CDSA and 81.5% using aEEG. However, among individual recordings, the sensitivity ranged from 0% to 100%. Factors reducing the sensitivity included low-amplitude, short, and focal seizures. False-positive rates were generally very low, with misidentified seizures occurring once every 17-20 hours. CONCLUSIONS: Both CDSA and aEEG demonstrate acceptable sensitivity and false-positive rates for seizure identification among critically ill children. Accuracy of these tools would likely improve during clinical use, when findings can be correlated in real-time with the underlying raw EEG. In the hands of neurophysiologists, CDSA and aEEG displays represent useful screening tools for seizures during continuous EEG monitoring in the ICU. The suitability of these tools for bedside use by ICU nurses and physicians requires further study.

http://www.ncbi.nlm.nih.gov/pubmed/20861452

PLoS Curr. 2010 Oct 25;2:RRN1192.

QEEG Measures in Huntington's Disease: A Pilot Study.

Hunter A, Bordelon Y, Cook I, Leuchter A.

UCLA School of Medicine; Department of Neurology UCLA; UCLA Semel Institute and UCLA.

Structural brain changes as measured with Magnetic Resonance Imaging (MRI) are associated with progression of Huntington's Disease (HD), a trinucleotide repeat  neurodegenerative disorder. Neurophysiological measures may offer additional biomarkers of the onset and progression of brain disease. We used quantitative electroencephalography (QEEG) power measures to assess resting state brain function in 27 HD subjects and 15 healthy controls. Those QEEG features that distinguished between HD subjects and healthy controls were examined in relation  to illness severity, using Unified Huntington Disease Rating Scale (UHDRS) subscales, as well as to the number of CAG repeats in the HD cohort. HD subjects  showed a global increase in delta power as compared to controls, even when examining unmedicated HD subjects only (n = 13), or premanifest HD subjects only  (n = 3). HD subjects also showed loss of the normal anterior-posterior (AP) gradient of relative alpha and delta power. Relative alpha AP gradient loss was associated with lower Total Functional Capacity (TFC) and greater cognitive dysfunction. Relative delta AP gradient loss was associated with lower TFC, more  severe motor symptoms, and greater number of CAG repeats. Overall, results suggest that QEEG power measures may capture perturbations of brain function that are related to functional status as well as to underlying genetic repeat expansion in HD. Pilot data in the three premanifest HD subjects are consistent with the hypothesis that brain functional abnormalities may be detectable even in premanifest gene carriers. Cross-sectional findings suggest that QEEG measures may be biomarkers of HD progression; prospective studies in larger samples are needed to confirm these findings and test hypotheses regarding underlying mechanisms.

http://www.ncbi.nlm.nih.gov/pubmed/21037796

Biochem Pharmacol. 2010 Oct 19. [Epub ahead of print]

Aligning strategies for using EEG as a surrogate biomarker: A review of preclinical and clinical research.

Leiser SC, Dunlop J, Bowlby MR, Devilbiss DM.

Synaptic Transmission, Lundbeck Research USA, Inc., 215 College Road, Paramus, NJ 07652, United States.

Electroencephalography (EEG) and related methodologies offer the promise of predicting the likelihood that novel therapies and compounds will exhibit clinical efficacy early in preclinical development. These analyses, including quantitative EEG (e.g. brain mapping) and evoked/event-related potentials (EP/ERP), can provide a physiological endpoint that may be used to facilitate drug discovery, optimize lead or candidate compound selection, as well as afford  patient stratification and Go/No-Go decisions in clinical trials. Currently, the  degree to which these different methodologies hold promise for translatability between preclinical models and the clinic have not been well summarized. To address this need, we review well-established and emerging EEG analytic approaches that are currently being integrated into drug discovery programs throughout preclinical development and clinical research. Furthermore, we present the use of EEG in the drug development process in the context of a number of major central nervous system disorders including Alzheimer's disease, schizophrenia, depression, attention deficit hyperactivity disorder, and pain. Lastly, we discuss the requirements necessary to consider EEG technologies as a biomarker. Many of these analyses show considerable translatability between species and are used to predict clinical efficacy from preclinical data. Nonetheless, the next challenge faced is the selection and validation of EEG endpoints that provide a set of robust and translatable biomarkers bridging preclinical and clinical programs.

http://www.ncbi.nlm.nih.gov/pubmed/20937262

Neuroimage. 2010 Oct 15;53(1):221-32. Epub 2010 May 25.

Temporal dynamics of prediction error processing during reward-based decision making.

Philiastides MG, Biele G, Vavatzanidis N, Kazzer P, Heekeren HR.

Max Planck Institute for Human Development, Berlin, 14195, Germany; Max Planck Institute for Human Cognitive & Brain Sciences, Leipzig, 04303, Germany. marios.philiastides@gmail.com

Adaptive decision making depends on the accurate representation of rewards associated with potential choices. These representations can be acquired with reinforcement learning (RL) mechanisms, which use the prediction error (PE, the difference between expected and received rewards) as a learning signal to update  reward expectations. While EEG experiments have highlighted the role of feedback-related potentials during performance monitoring, important questions about the temporal sequence of feedback processing and the specific function of feedback-related potentials during reward-based decision making remain. Here, we  hypothesized that feedback processing starts with a qualitative evaluation of outcome-valence, which is subsequently complemented by a quantitative representation of PE magnitude. Results of a model-based single-trial analysis of EEG data collected during a reversal learning task showed that around 220ms after feedback outcomes are initially evaluated categorically with respect to their valence (positive vs. negative). Around 300ms, and parallel to the maintained valence-evaluation, the brain also represents quantitative information about PE magnitude, thus providing the complete information needed to update reward expectations and to guide adaptive decision making. Importantly, our single-trial EEG analysis based on PEs from an RL model showed that the feedback-related potentials do not merely reflect error awareness, but rather quantitative information crucial for learning reward contingencies.

http://www.ncbi.nlm.nih.gov/pubmed/20510376

Acta Paediatr. 2010 Oct;99(10):1493-7. doi: 10.1111/j.1651-2227.2010.01857.x.

Does indomethacin for closure of patent ductus arteriosus affect cerebral function?

Flisberg A, Kjellmer I, Löfhede J, Löfgren N, Rosa-Zurera M, Lindecrantz K, Thordstein M.

Department of Pediatrics, The Queen Silvia Children's Hospital Sahlgrenska University Hospital-Östra, Göteborg, Sweden. anders.flisberg@vgregion.se

OBJECTIVE: To study whether indomethacin used in conventional dose for closure of patent ductus arteriosus affects cerebral function measured by electroencephalograms (EEG) evaluated by quantitative measures. STUDY DESIGN: Seven premature neonates with haemodynamically significant persistent ductus arteriosus were recruited. EEG were recorded before, during and after an intravenous infusion of 0.2 mg/kg indomethacin over 10 min. The EEG was  analysed by two methods with different degrees of complexity for the amount of low-activity periods (LAP, "suppressions") as an indicator of affection of cerebral function. RESULTS: Neither of the two methods identified any change in the amount of LAPs in the EEG as compared to before the indomethacin infusion. CONCLUSION: Indomethacin in conventional dose for closure of patent ductus arteriosus does not affect cerebral function as evaluated by quantitative EEG.

http://www.ncbi.nlm.nih.gov/pubmed/20456268

Alcohol Clin Exp Res. 2010 Oct;34(10):1751-8. doi: 10.1111/j.1530-0277.2010.01262.x. Epub 2010 Jul 9.

quantitative EEG in patients with alcohol-related seizures.

Sand T, Bjørk M, Bråthen G, Michler RP, Brodtkorb E, Bovim G.

Dept. of Neurology and Clinical Neurophysiology, St. Olavs Hospital, Trondheim, Norway. trond.sand@ntnu.no

BACKGROUND: To investigate whether quantitative electroencephalography (QEEG) recorded within a few days after a generalized seizure can improve the discrimination between alcohol-related seizures (ARSs), seizures in epilepsy and  other seizures. In addition, we wanted to evaluate the influence of various external factors on QEEG, e.g., drug use, time from seizure occurrence, and alcohol intake. METHODS: An ARS was defined by (i) scores ≥8 in the Alcohol Use Disorders Identification Test (AUDIT) and (ii) no history of epilepsy. Twenty-two ARS patients, 21 epileptic patients with seizures (ES), 30 AUDIT-negative patients with seizures (OS), and 37 well-controlled epileptic outpatients (EPO) were included. EEG from 79 sciatica patients (SC) served as an additional control group. EEG was recorded in relaxed wakefulness with eyes closed. Spectral analysis of ongoing resting EEG activity was performed. For the main analysis, spectral band amplitudes were averaged across 14 electrodes. RESULTS: Major quantitative EEG abnormalities were mainly seen in the ES group. AUDIT score correlated negatively with QEEG band amplitudes in patients with seizures unrelated to alcohol, but not in the ARS group. Recent alcohol intake correlated negatively with delta and theta amplitude. We could not confirm that beta activity is increased in ARS subjects. CONCLUSIONS: A QEEG with slightly reduced alpha amplitude supports a clinical diagnosis of ARS. An abnormally slow QEEG profile and asymmetry in the temporal regions indicates ES. QEEG predicted the clinical diagnosis better than standard  EEG.

http://www.ncbi.nlm.nih.gov/pubmed/20626731

Clin EEG Neurosci. 2010 Oct;41(4):219-22.

EEG analysis of male to female transsexuals: discriminant function and source analysis.

Flor-Henry P.

Department of Psychiatry, University of Alberta, Edmonton, Canada. Pierre.FlorHenry@albertahealthservices.ca

A small series of consecutive, unmedicated male to female transsexuals were studied before hormonal treatment and prior to reassignment surgery. quantitative EEG and LORETA source localization in the Eyes Open and Eyes Closed conditions were carried out, and they were compared to sinistral/ambilateral male and female controls, as the transsexual group was overwhelmingly sinistral. Discriminant function analysis and source localization showed that the transsexual group was similar to female heterosexual controls, with increased sources in the right hemisphere in the fast frequencies.

http://www.ncbi.nlm.nih.gov/pubmed/21077575

Clin Neurophysiol. 2010 Oct;121(10):1707-8. Epub 2010 Jul 24.

quantitative EEG and cerebral ischemia.

Friedman D, Claassen J.

Comment on     Clin Neurophysiol. 2010 Oct;121(10):1719-25.

http://www.ncbi.nlm.nih.gov/pubmed/20656550

Clin Neurophysiol. 2010 Oct;121(10):1719-25. Epub 2010 Feb 23.

Additional value of quantitative EEG in acute anterior circulation syndrome of presumed ischemic origin.

Sheorajpanday RV, Nagels G, Weeren AJ, De Surgeloose D, De Deyn PP.

Department of Neurology and Stroke Unit, ZNA Middelheim Hospital, Antwerp, Belgium.

Comment in     Clin Neurophysiol. 2010 Oct;121(10):1707-8.

OBJECTIVE: The clinical course of acute stroke can be highly variable and for effective management outcome prediction needs to be refined. We investigated whether EEG parameters are of additional diagnostic and prognostic value in the early phase of acute ischemic anterior circulation stroke. METHODS: Ninety-four patients presenting with acute anterior circulation syndrome (ACS) of presumed ischemic origin were incrementally included. Clinical characteristics were correlated with volume of ischemia and EEG parameters. Predictive values for definite stroke, early neurological deterioration, spontaneous early neurological improvement and death within 1 week after ACS were calculated using ROC curves and logistic regression modelling. RESULTS: In patients with normal or near normal NIHSS score of 0 or 1, the pairwise derived brain symmetry index (pdBSI) was an independent predictor for definite stroke displaying an overall accuracy of 80%. Early neurological deterioration was independently predicted by pdBSI with a correct classification  rate of 95%. In ROC analysis, death was predicted by pdBSI with overall accuracy  of 97%. Spontaneous neurological improvement was independently predicted by the delta+theta/alpha+beta - ratio with overall accuracy of 75%. Small-vessel stroke  was independently predicted by pdBSI with a correct classification rate of 92%. CONCLUSIONS: EEG may be of prognostic value for spontaneous neurological improvement, early neurological deterioration and death in the acute setting of acute anterior circulation syndrome of presumed ischemic origin. SIGNIFICANCE: These findings may have an impact on stroke care.

http://www.ncbi.nlm.nih.gov/pubmed/20181521

Epilepsia. 2010 Oct;51(10):2140-6. doi: 10.1111/j.1528-1167.2010.02599.x.

Significance of lateralization of upper limb automatisms in temporal lobe epilepsy: a quantitative movement analysis.

Mirzadjanova Z, Peters AS, Rémi J, Bilgin C, Silva Cunha JP, Noachtar S.

Epilepsy Center, Department of Neurology, University of Munich, Munich, Germany.

PURPOSE: To evaluate the significance of lateralization of ictal upper limb automatisms in patients with temporal lobe epilepsy (TLE). METHODS: Ictal upper limb automatisms of 28 patients with temporal lobe epilepsy  were quantified. Duration of automatisms in relation to total seizure duration, movement speed, extent, length, and predominant frequencies of the movements were analyzed for both upper extremities separately and compared to the lateralization of the epileptogenic temporal lobe. RESULTS: Predominantly ipsilateral upper limb automatisms were more common (n = 19) than predominantly contralateral automatisms (n = 9). The duration of ictal ipsilateral upper limb automatisms was significantly longer than the duration of  contralateral automatisms (ipsilateral automatisms: 29 of 86 s total seizure duration; contralateral automatisms: 19 of 110 s total seizure duration; p = 0.048). Patients with ipsilateral upper limb automatisms had more often exclusively unitemporal interictal epileptiform discharges (IEDs) (84.2%) than patients with contralateral automatisms (11.1%; p < 0.001). The positive predictive value (PPV) of the combination of these parameters is 84.2%. Excellent surgical seizure outcome was better in patients with ipsilateral upper limb automatisms (77.8%) compared to those with contralateral automatisms (20%) (p = 0.09). The quantitative analysis of movement extent, average speed, maximum speed, and repetition rate of ipsilateral and contralateral upper limb automatisms did not show any statistically significant difference in this patient sample. CONCLUSION: The lateralization of upper limb automatisms in TLE has a good lateralizing value if the lateralization of IEDs were also taken into consideration.

http://www.ncbi.nlm.nih.gov/pubmed/20491870

Epilepsy Behav. 2010 Oct;19(2):140-5. Epub 2010 Aug 8.

Postictal language function.

Privitera M, Kim KK.

Department of Neurology, University of Cincinnati, Cincinnati, OH, USA. michael.privitera@uc.edu

Language function in the postictal state can be successfully assessed and provides valuable information on seizure localization and spread. Several studies have shown that postictal paraphasic errors and ictal speech have value for seizure localization. The Cincinnati method is a simple, repeatable test that involves presenting a single test sentence on a card and asking the patient to read the sentence repeatedly until it is read correctly. It increases the yield of detecting paraphasic errors and ictal speech, and provides a quantitative measure of language recovery known as the postictal language delay, defined as the time from the end of the EEG ictal discharge until the test sentence is read  correctly. This language testing method has been used for all patients admitted to the epilepsy monitoring unit at the Cincinnati Epilepsy Center for more than 20 years and has been shown to: (1) lateralize temporal lobe complex partial seizures; (2) identify when temporal lobe complex partial seizures spread to the  dominant hemisphere; (3) identify patients with atypical language lateralization; (4) distinguish between temporal and frontal complex partial seizures; and (5) provide some insight into speech prosody changes in nondominant temporal lobe complex partial seizures. The method has some limitations because it requires vigilance of the patient and direct interaction by the technologist, and may be incomplete as a result of patient agitation, but has been successfully completed  in more than 80% of patients admitted to the epilepsy monitoring unit. This highly cost-effective test provides important information on seizure localization and spread; is easily taught to technologists, nurses, and family members; and should be added to testing procedures in all epilepsy monitoring units.

http://www.ncbi.nlm.nih.gov/pubmed/20696620

Neurosurgery. 2010 Oct;67(4):901-5; discussion 905.

Fractional anisotropy levels derived from diffusion tensor imaging in cervical syringomyelia.

Roser F, Ebner FH, Maier G, Tatagiba M, Nägele T, Klose U.

Department of Neurosurgery, University of Tübingen, Tübingen, Germany. f.roser@gmx.de

Erratum in     Neurosurgery. 2010 Dec;67(6):E1867. Ebner, Florian [corrected to Ebner, Florian H].

BACKGROUND: Syringomyelia can result in major functional disability. Conventional imaging techniques frequently fail to detect the underlying cause of syringomyelia. The prediction as to whether syringomyelia might lead to neurological deficits is still challenging. OBJECTIVE: We hypothesized that fractional anisotropy (FA) derived from diffusion tensor imaging (DTI) is a parameter to detect dynamic forms of syringomyelia. METHODS: Six patients with cervical syringomyelia, all comparable in size, shape, and location, were examined, along with 2 volunteers. Patients underwent electrophysiological recordings (somatosensory evoked potentials, motor evoked potentials, silent periods). Magnetic resonance imaging (1.5 T) was performed with a 6-element spine coil. Anatomic images were acquired with a 3-dimensional,  constructive interference in steady-state sequence, and DTI with an echo-planar imaging sequence (5-mm thickness, b value 800 s/mm) using the generalized autocalibrating partially parallel acquisitions technique. The positions were centered on the syrinx in the volunteers between the C2 and Th1. DTI data were interpolated to a spatial resolution of 0.5 mm. After calculation of a diffusion  tensor in each pixel, an FA map was calculated and profiles of the FA values across the spinal cord were calculated in all slices. RESULTS: FA values were lower at the level of all examined syrinxes and reached normal values beyond them. Electrophysiological results correlated with the decrease in FA value. There were no presyrinx changes in the white matter tracts  in terms of signs of FA changes beneath the syrinx. CONCLUSION: DTI of syringomyelia can demonstrate white matter fiber tracts around and beyond the syrinx consistent with electrophysiological values. DTI of the cervical spine can provide quantitative information about the pathological characteristics beyond the abnormalities visible on magnetic resonance imaging.

http://www.ncbi.nlm.nih.gov/pubmed/20881553

Pediatr Neonatol. 2010 Oct;51(5):279-84.

Infant with in utero ketamine exposure: quantitative measurement of residual dosage in hair.

Su PH, Chang YZ, Chen JY.

Division of Genetics, Department of Pediatrics, Chung Shan Medical University Hospital, School of Medicine, Chung Shan Medical University, Taichung, Taiwan.

BACKGROUND: The drug ketamine is frequently abused for recreational use in Asia,  but few studies in humans have focused on the effects of ketamine exposure during pregnancy on the health of neonates. Here, we report a neonate whose mother was suspected of ketamine abuse during pregnancy. The case was confirmed by testing hair samples of the neonate. METHODS: Hair samples of the neonate were taken on the first day of referral. Levels of common drugs of abuse in Asia were measured in the hair sample by gas chromatography-mass spectrometry using our previously reported method with modifications. This method was developed and validated to simultaneously quantify levels of amphetamine, ketamine and opiate in human hair. RESULTS: The neonate was a female baby, born full term, with a low birth weight of 2250 g. Very high levels of ketamine were detected in the neonate's hair, even though the mother stated that she had stopped abusing ketamine during the early stage of pregnancy. The neonate suffered from general hypotonia; moderate cerebral dysfunction was found by electroencephalography. Fortunately, her hypotonia improved gradually within 21 days. CONCLUSION: This is the first report of ketamine exposure during late pregnancy detected by hair testing. We noted several clinical features in this case, including the infant being small for gestational age, intrauterine growth retardation, remarkable hypotonia, and poor reflex responses. Although the mother denied the use of ketamine during the late stage of her pregnancy, significant amount of ketamine and norketamine was still found in hair samples (only 2 cm long and 25 mg) from the infant.

http://www.ncbi.nlm.nih.gov/pubmed/20951358

Appl Psychophysiol Biofeedback. 2010 Sep;35(3):219-28.

Respiratory sinus arrhythmia feedback in a stressed population exposed to a brief stressor demonstrated by quantitative EEG and sLORETA.

Sherlin L, Muench F, Wyckoff S.

Nova Tech EEG, Inc., 8503 E. Keats Ave, Mesa, AZ 85209, USA. lesliesherlin@mac.com

Previous investigations of electroencephalograms during relaxation have identified increases in slow wave band power, correlations between increased levels of alpha activity with lower levels of anxiety, and autonomic changes characterized by otherwise documented decreased sympathetic activity. This study  was carried out to determine the overall changes in quantitative electroencephalographic activity and the current source as a result of an acute session of respiratory sinus arrhythmia (RSA) biofeedback in a population of subjects experiencing stress. This study's findings provide physiological evidence of RSA feedback effect and suggest that RSA training may decrease arousal by promoting an increase of alpha band frequencies and decrease in beta frequencies overall and in areas critical to the regulation of stress. It was of  interest that novices could achieve these objective alterations in EEG activity after minimal training and intervention periods considering that the previous literature on EEG and meditative states involve experienced meditators or participants who had been given extensive training. Additionally, these effects were present immediately following the training suggesting that the intervention  may have effects beyond the actual practice.

http://www.ncbi.nlm.nih.gov/pubmed/20414803

Brain. 2010 Sep;133(9):2528-39. Epub 2010 Aug 18.

Operculo-insular pain (parasylvian pain): a distinct central pain syndrome.

Garcia-Larrea L, Perchet C, Creac'h C, Convers P, Peyron R, Laurent B, Mauguière  F, Magnin M.

Central Integration of Pain Unit, U879 INSERM & University Claude Bernard, Lyon 1, Neurological Hospital, Lyon, France. larrea@univ-lyon1.fr

Central pain with dissociated thermoalgesic sensory loss is common in spinal and  brainstem syndromes but not in cortical lesions. Out of a series of 270 patients  investigated because of somatosensory abnormalities, we identified five subjects  presenting with central pain and pure thermoalgesic sensory loss contralateral to cortical stroke. All of the patients had involvement of the posterior insula and  inner parietal operculum. Lemniscal sensory modalities (position sense, graphaestesia, stereognosis) and somatosensory evoked potentials to non-noxious inputs were always preserved, while thermal and pain sensations were profoundly altered, and laser-evoked potentials to thermo-nocoiceptive stimuli were always abnormal. Central pain resulting from posterior parasylvian lesions appears to be a distinct entity that can be identified unambiguously on the basis of clinical,  radiological and electrophysiological data. It presents with predominant or isolated deficits for pain and temperature sensations, and is paradoxically closer to pain syndromes from brainstem lesions affecting selectively the spinothalamic pathways than to those caused by focal lesions of the posterior thalamus. The term 'pseudo-thalamic' is therefore inappropriate to describe it, and we propose parasylvian or operculo-insular pain as appropriate labels. Parasylvian pain may be extremely difficult to treat; the magnitude of pain-temperature sensory disturbances may be prognostic for its development, hence the importance of early sensory assessment with quantitative methods.

http://www.ncbi.nlm.nih.gov/pubmed/20724291

Brain. 2010 Sep;133(9):2763-77. Epub 2010 Jun 24.

Loss and reorganization of calretinin-containing interneurons in the epileptic human hippocampus.

Tóth K, Eross L, Vajda J, Halász P, Freund TF, Maglóczky Z.

Institute of Experimental Medicine, Hungarian Academy of Sciences, Szigony utca 43, Budapest, Hungary.

Calretinin is expressed mainly in interneurons that specialize to innervate either principal cell dendrites or other interneurons in the human hippocampus. Calretinin-containing cells were shown to be vulnerable in animal models of ischaemia and epilepsy. In the human hippocampus, controversial data were published regarding their sensitivity in epilepsy. Therefore we aimed to reveal the fate of this cell type in human epileptic hippocampi. Surgically removed hippocampi of patients with drug-resistant temporal lobe epileptic (n = 44) were  examined and compared to control (n = 8) samples with different post-mortem delays. The samples were immunostained for calretinin and the changes in the distribution, density and synaptic target selectivity of calretinin-positive cells were analysed. Control samples with post-mortem delays longer than 8 h resulted in a reduced number of immunolabelled cells compared to controls with short post-mortem delay. The number of calretinin-positive cells in the epileptic tissue was considerably decreased in correlation with the severity of principal cell loss. Preserved cells had segmented and shortened dendrites. Electron microscopic examination revealed that in controls, 23% of the calretinin-positive interneuronal terminals targeted calretinin-positive dendrites, whereas in the epileptic samples it was reduced to 3-5%. The number of contacts between calretinin-positive dendrites also dropped. The present quantitative data suggest that calretinin-containing cells in the human hippocampus are highly vulnerable,  thus inhibition mediated by dendritic inhibitory cells and their synchronization  by interneuron-specific interneurons may be impaired in epilepsy. We hypothesize  that reorganization of the interneuron-selective cells may be implicated in the occurrence of seizures in non-sclerotic patients, where the majority of principal and non-principal cells are preserved.

http://www.ncbi.nlm.nih.gov/pubmed/20576695

Epilepsy Res. 2010 Sep;91(1):94-100. Epub 2010 Jul 31.

quantitative EEG abnormalities in persons with "pure" epileptic predisposition without epilepsy: a low resolution electromagnetic tomography (LORETA) study.

Puskás S, Bessenyei M, Fekete I, Hollódy K, Clemens B.

University of Debrecen, Medical and Health Science Center, Department of Neurology, Móricz Zsigmond krt. 22, 4032 Debrecen, Hungary.

OBJECTIVE: Epileptic predisposition means genetically determined, increased seizure susceptibility. Neurophysiological evaluation of this condition is still  lacking. In order to investigate "pure epileptic predisposition" (without epilepsy) in this pilot study the authors prospectively recruited ten persons who displayed generalized tonic-clonic seizures precipitated by 24 or more hours of sleep deprivation but were healthy in any other respects. METHODS: 21-channel EEGs were recorded in the morning, in the waking state, after a night of sufficient sleep in the interictal period. For each person, a total of 120s artifact-free EEG was processed to low resolution electromagnetic tomography (LORETA) analysis. LORETA activity (Ampers/meters squared) was computed for 2394  voxels, 19 active electrodes and 1Hz very narrow bands from 1 to 25Hz. The data were compressed into four frequency bands (delta: 0.5-4.0Hz, theta: 4.5-8.0Hz, alpha: 8.5-12.0Hz, beta: 12.5-25.0Hz) and projected onto the MRI figures of a digitized standard brain atlas. The band-related LORETA results were compared to  those of ten, age- and sex-matched healthy persons using independent t-tests. p<0.01 differences were accepted as statistically significant. RESULTS: Statistically significant decrease of alpha activity was found in widespread, medial and lateral parts of the cortex above the level of the basal ganglia. Maximum alpha decrease and statistically significant beta decrease were  found in the left precuneus. Statistically not significant differences were delta increase in the medial-basal frontal area and theta increase in the same area and in the basal temporal area. DISCUSSION: The significance of alpha decrease in the patient group remains enigmatic. beta decrease presumably reflects non-specific dysfunction of the cortex. Prefrontal delta and theta increase might have biological meaning despite the lack of statistical significance: these findings are topographically similar  to those reported in idiopathic generalized epilepsy in previous investigations. SIGNIFICANCE: quantitative EEG characteristics of the genetically determined epilepsy predisposition were given in terms of frequency bands and anatomical distribution.

http://www.ncbi.nlm.nih.gov/pubmed/20674273

Hum Brain Mapp. 2010 Sep;31(9):1327-38.

Correlation between quantitative EEG and MRI in idiopathic generalized epilepsy.

Betting LE, Li LM, Lopes-Cendes I, Guerreiro MM, Guerreiro CA, Cendes F.

Department of Neurology, Faculty of Medical Sciences, University of Campinas--UNICAMP, Campinas, SP, Brazil.

The objective of this study was to investigate the relationship between the focal discharges sometimes observed in the electroencephalogram of patients with idiopathic generalized epilepsies and subtle structural magnetic resonance imaging abnormalities. The main hypothesis to be assessed is that focal discharges may arise from areas of structural abnormality which can be detected by quantitative neuroimaging. Focal discharges were used for quantitative electroencephalogram source detection. Neuroimaging investigations consisted of voxel-based morphometry and region of interest volumetry. For voxel-based morphometry, volumetric MRI were acquired and processed. The images of each patient were individually compared with a control group. Statistical analysis was used to detect differences in gray matter volumes. Region of interest-based morphometry was automatically performed and used essentially to confirm voxel-based morphometry findings. The localization of the focal discharges on the electroencephalogram was compared to the neuroimaging results. Twenty-two patients with idiopathic generalized epilepsies were evaluated. Gray matter abnormalities were detected by voxel-based morphometry analysis in 77% of the patients. There was a good concordance between EEG source detection and voxel-based morphometry. On average, the nearest voxels detected by these methods were 19 mm (mm) apart and the most statistically significant voxels were 34 mm apart. This study suggests that in some cases subtle gray matter abnormalities are associated with focal epileptiform discharges observed in the electroencephalograms of patients with idiopathic generalized epilepsies.

http://www.ncbi.nlm.nih.gov/pubmed/20082332

Neuroimage. 2010 Sep;52(3):1041-58. Epub 2010 Jan 4.

Bifurcation analysis of neural mass models: Impact of extrinsic inputs and dendritic time constants.

Spiegler A, Kiebel SJ, Atay FM, Knösche TR.

Max Planck Institute for Human Cognitive and Brain Sciences, Leipzig, Germany. spiegler@cbs.mpg.de

Neural mass models (NMMs) explain dynamics of neuronal populations and were designed to strike a balance between mathematical simplicity and biological plausibility. They are currently widely used as generative models for noninvasive electrophysiological brain measurements; that is, magneto- and electroencephalography (M/EEG). Here, we systematically describe the oscillatory  regimes which a NMM of a single cortical source with extrinsic input from other cortical and subcortical areas to each subpopulation can explain. For this purpose, we used bifurcation analysis to describe qualitative changes in system behavior in response to quantitative input changes. This approach allowed us to describe sequences of oscillatory regimes, given some specific input trajectory.  We systematically classified these sequential phenomena and mapped them into parameter space. Our analysis suggests a principled scheme of how complex M/EEG phenomena can be modeled parsimoniously on two time scales: While the system displays fast oscillations, it slowly traverses phase space to another qualitatively different oscillatory regime, depending on the input dynamics. The  resulting scheme is useful for applications where one needs to model an ordered sequence of switching between qualitatively different oscillatory regimes, for example, in pharmacological interventions, epilepsy, sleep, or context-induced state changes.

http://www.ncbi.nlm.nih.gov/pubmed/20045068

Psychol Med. 2010 Sep;40(9):1443-51. Epub 2009 Dec 9.

Subanesthetic dose of ketamine decreases prefrontal theta cordance in healthy volunteers: implications for antidepressant effect.

Horacek J, Brunovsky M, Novak T, Tislerova B, Palenicek T, Bubenikova-Valesova V, Spaniel F, Koprivova J, Mohr P, Balikova M, Hoschl C.

Prague Psychiatric Centre, Prague, Czech Republic. horacek@pcp.lf3.cuni.cz

BACKGROUND: Theta cordance is a novel quantitative electroencephalography (QEEG)  measure that correlates with cerebral perfusion. A series of clinical studies has demonstrated that the prefrontal theta cordance value decreases after 1 week of treatment in responders to antidepressants and that this effect precedes clinical improvement. Ketamine, a non-competitive antagonist of N-methyl-D-aspartate (NMDA) receptors, has a unique rapid antidepressant effect but its influence on theta cordance is unknown. METHOD: In a double-blind, cross-over, placebo-controlled experiment we studied the acute effect of ketamine (0.54 mg/kg within 30 min) on theta cordance in a group of 20 healthy volunteers. RESULTS: Ketamine infusion induced a decrease in prefrontal theta cordance and an increase in the central region theta cordance after 10 and 30 min. The change in  prefrontal theta cordance correlated with ketamine and norketamine blood levels after 10 min of ketamine infusion. CONCLUSIONS: Our data indicate that ketamine infusion immediately induces changes similar to those that monoamineric-based antidepressants induce gradually. The reduction in theta cordance could be a marker and a predictor of the fast-acting  antidepressant effect of ketamine, a hypothesis that could be tested in depressive patients treated with ketamine.

http://www.ncbi.nlm.nih.gov/pubmed/19995475

Seizure. 2010 Sep;19(7):414-20. Epub 2010 Jul 14.

Status epilepticus alters hippocampal PKAbeta and PKAgamma expression in mice.

Liu JX, Tang YC, Liu Y, Tang FR.

Institute of Neurobiology, School of Medicine, Xi'an Jiaotong University, Xi'an,  PR China.

OBJECTIVES: To investigate the localization and progressive changes of cyclic-AMP dependent protein kinase (cPKA) in the mouse hippocampus at acute stages during and after pilocarpine induced status epilepticus. METHODS: Pilocarpine induced status epilepticus mice were sacrificed 30 min, 2 h  or 1 day after the start of a approximately 7 h lasting status as assessed by video-electroencephalography. Brains were processed for quantitative immunohistochemistry of hippocampal cPKAbeta and cPKAgamma, and immunohistochemical co-localization of cPKAbeta and cPKAgamma with calbindin (CB), calretinin (CR), and parvalbumin (PV). RESULTS: Based on anatomical and morphological assessment, cPKAbeta was primarily expressed by principal cells and cPKAgamma by interneurons. In CA1, cPKAbeta co-localized with 76% of CB, 41% of CR, and 95% of PV-immunopositive cells, while cPKAgamma co-localized with 50% of CB, 29% of CR, and 80% of PV-immunopositive cells. Upon induction of status epilepticus, cPKAbeta expression was transiently  reduced in CA1, whereas cPKAgamma expression was sustainably reduced. CONCLUSION: cPKA may play an important role in neuronal hyperexcitability, death  and epileptogenesis during and after pilocarpine induced status epilepticus.

http://www.ncbi.nlm.nih.gov/pubmed/20630779

Hum Mov Sci. 2010 Aug 26. [Epub ahead of print]

EEG correlates of postural audio-biofeedback.

Pirini M, Mancini M, Farella E, Chiari L.

DEIS - Department of Electronics, Computer Science, and Systems, Università di Bologna, Italy.

The control of postural sway depends on the dynamic integration of multi-sensory  information in the central nervous system. Augmentation of sensory information, such as during auditory biofeedback (ABF) of the trunk acceleration, has been shown to improve postural control. By means of quantitative electroencephalography (EEG), we examined the basic processes in the brain that are involved in the perception and cognition of auditory signals used for ABF. ABF and Fake ABF (FAKE) auditory stimulations were delivered to 10 healthy naive  participants during quiet standing postural tasks, with eyes-open and closed. Trunk acceleration and 19-channels EEG were recorded at the same time. Advanced,  state-of-the-art EEG analysis and modeling methods were employed to assess the possibly differential, functional activation, and localization of EEG spectral features (power in alpha, beta, and gamma bands) between the FAKE and the ABF conditions, for both the eyes-open and the eyes-closed tasks. Participants gained advantage by ABF in reducing their postural sway, as measured by a reduction of the root mean square of trunk acceleration during the ABF compared to the FAKE condition. Population-wise localization analysis performed on the comparison FAKE - ABF revealed: (i) a significant decrease of alpha power in the right inferior parietal cortex for the eyes-open task; (ii) a significant increase of gamma power in left temporo-parietal areas for the eyes-closed task; (iii) a significant increase of gamma power in the left temporo-occipital areas in the eyes-open task. EEG outcomes supported the idea that ABF for postural control heavily modulates (increases) the cortical activation in healthy participants. The sites showing the higher ABF-related modulation are among the known cortical  areas associated with multi-sensory, perceptual integration, and sensorimotor integration, showing a differential activation between the eyes-open and eyes-closed conditions.

http://www.ncbi.nlm.nih.gov/pubmed/20800912

J Med Syst. 2010 Aug 14. [Epub ahead of print]

Detection of Abnormalities for Diagnosing of Children with Autism Disorders Using of Quantitative Electroencephalography Analysis.

Sheikhani A, Behnam H, Mohammadi MR, Noroozian M, Mohammadi M.

Biomedical Engineering, Science and Research Branch, Islamic Azad University, Tehran, Iran, sheikhani_al_81@srbiau.ac.ir.

Quantitative electroencephalography (QEEG) has been used as a tool for neurophysiologic diagnostic. We used spectrogram and coherence values for evaluating QEEG in 17 children (13 boys and 4 girls aged between 6 and 11) with autism disorders (ASD) and 11 control children (7 boys and 4 girls with the same  age range). Evaluation of QEEG with statistical analysis demonstrated that alpha  frequency band (8-13 Hz) had the best distinction level of 96.4% in relaxed eye-opened condition using spectrogram criteria. The ASD group had significant lower spectrogram criteria values in left brain hemisphere, (p < 0.01) at F3 and  T3 electrodes and (p < 0.05) at FP1, F7, C3, Cz and T5 electrodes. Coherence values at 171 pairs of EEG electrodes indicated that there are more abnormalities with higher values in the connectivity of temporal lobes with other lobes in gamma frequency band (36-44 Hz).

http://www.ncbi.nlm.nih.gov/pubmed/20711644

Clin Neurophysiol. 2010 Aug;121(8):1213-9. Epub 2010 Apr 2.

Uncommon EEG burst-suppression in severe postanoxic encephalopathy.

van Putten MJ, van Putten MH.

Department of Neurology and Clinical Neurophysiology, Medisch Spectrum Twente and MIRA-Institute for Biomedical Technology and Technical Medicine, University of Twente, Enschede, The Netherlands. m.j.a.m.vanputten@tnw.utwente.nl

OBJECTIVE: In patients suffering from severe hypoxia, the EEG may show a burst-suppression pattern, characterized by low-voltage activity and the occurrence of high amplitude burst-like events. We describe the two-timescale burst phenomenology of this postanoxic condition. METHODS: We present EEG recordings showing remarkable burst phenomenology in two  postanoxic patients and consider potential mechanisms responsible for the generation of the burst-suppression patterns. We quantify the postanoxic condition in terms of the dimension (number of degrees of freedom) of its dynamics by comparing our data with a system of three ordinary differential equations with two timescales subject to varying degrees of noise. RESULTS: EEGs displayed extreme similarity of the bursts, separated by interburst intervals up to more than 300s. This pattern reflects a significant reduction in  the number of functional brain states. This post-anoxic condition is found to have dimension 3, consisting of fast dynamics responsible for the bifurcation to  bursting behavior, and a long time-scale responsible for burst termination and the interburst intervals. CONCLUSIONS: Low-dimensional postanoxic brain states, as manifested by burst-similarity, appears to indicate an irreversible loss of brain function and  consciousness. SIGNIFICANCE: Evidence of brain functionality in a persistent low dimensional state due to severe hypoxia is indicative of permanent loss of consciousness with essentially no chance for recovery. Quantitative evidence for such degenerate states is important for clinical decision making.

http://www.ncbi.nlm.nih.gov/pubmed/20363179

Epilepsia. 2010 Aug;51(8):1365-73. doi: 10.1111/j.1528-1167.2010.02552.x. Epub 2010 Apr 2.

The topography and significance of extratemporal hypometabolism in refractory mesial temporal lobe epilepsy examined by FDG-PET.

Wong CH, Bleasel A, Wen L, Eberl S, Byth K, Fulham M, Somerville E, Mohamed A.

Department of Neurology, Westmead Hospital, Westmead, NSW, Australia.

PURPOSE: This study aims to map the temporal and extratemporal 18-fluorodeoxyglucose positron emission tomography (FDG-PET)-defined hypometabolism in mesial temporal lobe epilepsy (MTLE). We hypothesize that quantitative analysis will reveal extensive extratemporal glucose hypometabolism  (EH), that the EH is related to seizure propagation beyond the temporal lobe, hypometabolism restricted to one temporal lobe predicts a good outcome following  surgery, and EH predicts a poor outcome. METHODS: Sixty-four patients were studied who had undergone temporal lobectomy for intractable MTLE and had at least 2 years of postoperative follow-up. Spatial preprocessing and statistical analysis on preoperative interictal FDG-PET using statistical parametric mapping (SPM 2) identified significant regions of hypometabolism compared to normal controls. The predictors of outcome were determined by univariable and multiple logistic regression analyses. RESULTS: EH was common and widespread, occurring most frequently in the ipsilateral insula and frontal lobe. The extent of EH was not significantly associated with age of onset or the duration of epilepsy. Presence of secondarily generalized tonic--clonic seizures (SGTCS) was associated with a larger extent of remote hypometabolism (RH, p < 0.005). Multiple logistic regression analysis identified the extent of RH and the age at surgery as independent predictors of seizure outcome. DISCUSSION: Our results indicate that RH in MTLE is associated with a poorer surgical outcome, especially if seen in the contralateral hemisphere. The extent  of RH relates to SGTCS but not to duration of epilepsy.

http://www.ncbi.nlm.nih.gov/pubmed/20384730

Epilepsy Behav. 2010 Aug;18(4):335-43. Epub 2010 Jun 11.

Toward a quantitative multivariate analysis of the efficacy of antiseizure therapies.

Osorio I, Manly B, Sunderam S.

University of Kansas Medical Center, Kansas City, KS, USA. iosorio@kumc.edu

Seizure frequency is the only variable used for assessing therapeutic efficacy. Advances in quantitative analyses allow measurement of intensity, duration, spread, and time between seizures (TBS). These variables are used here to investigate the efficacy of brain electrical stimulation in humans with pharmacoresistant seizures. The results of a trial of contingent high-frequency electrical stimulation (HFES) for abatement of clinical and subclinical seizures  are examined using principal component analysis (PCA) and regression models. HFES significantly: (1) Decreased seizure severity in two of eight and increased TBS in one of eight subjects; (2) decreased seizure severity in the primary epileptogenic zone of one subject but increased it in the secondary zones; (3) had both a beneficial and detrimental effect on severity and/or TBS (increase). These effects were immediate and also outlasted the duration of stimulation ("carryover"). Contingent HFES has multifarious and complex effects, intra- and interindividually, on seizure severity and TBS. Two inferences, at once promising and sobering may be drawn from these results: one, that contingent electrical stimulation deserves a place in the armamentarium of therapies for pharmacoresistant seizures, and the other, that its apparently narrow therapeutic ratio calls for careful implementation and multivariate quantification of its effects.

http://www.ncbi.nlm.nih.gov/pubmed/20541980

J Neurosci. 2010 Jul 28;30(30):10076-85.

Coalescence and fragmentation of cortical networks during focal seizures.

Kramer MA, Eden UT, Kolaczyk ED, Zepeda R, Eskandar EN, Cash SS.

Department of Mathematics and Statistics, Boston University, 111 Cummington Street, Boston, MA 02215, USA. mak@bu.edu

Epileptic seizures reflect a pathological brain state characterized by specific clinical and electrical manifestations. The proposed mechanisms are heterogeneous but united by the supposition that epileptic activity is hypersynchronous across  multiple scales, yet principled and quantitative analyses of seizure dynamics across space and throughout the entire ictal period are rare. To more completely  explore spatiotemporal interactions during seizures, we examined electrocorticogram data from a population of male and female human patients with  epilepsy and from these data constructed dynamic network representations using statistically robust measures. We found that these networks evolved through a distinct topological progression during the seizure. Surprisingly, the overall synchronization changed only weakly, whereas the topology changed dramatically in organization. A large subnetwork dominated the network architecture at seizure onset and preceding termination but, between, fractured into smaller groups. Common network characteristics appeared consistently for a population of subjects, and, for each subject, similar networks appeared from seizure to seizure. These results suggest that, at the macroscopic spatial scale, epilepsy is not so much a manifestation of hypersynchrony but instead of network reorganization.

http://www.ncbi.nlm.nih.gov/pubmed/20668192

Clin EEG Neurosci. 2010 Jul;41(3):170-7.

Effectiveness of neurofeedback training as a treatment for opioid-dependent patients.

Arani FD, Rostami R, Nostratabadi M.

Department of Psychology, University of Tehran, Iran. f.dehghani.a@ut.ac.ir

Neurofeedback (NF) training has been employed as a therapeutic method in substance-dependence disorder over the last three decades. The purpose of the present study was to examine the effectiveness of this method on improvement of comorbid neuro-psychological syndromes in opioid-dependence disorder. Psychopathological and craving dimensions and brain activity signals of 20 opioid dependent patients were measured using Symptom Checklist-90-Revised (SCL-90-R), Heroin Craving Questionnaire (HCQ), and quantitative electroencephalography (QEEG). All the patients were undergoing pharmacotherapy. They were assigned to two groups that were matched based on SCL-90-R scores, education and age. The experimental group received 30 sessions of NF training in addition to their medicine. The control group received only the usual pharmacotherapy. The probable changes were monitored by reappraisal of all the patients after the treatment. We hypothesized that patients in the experimental group would show more reduction in their comorbid syndromes. The Multivariate Analysis of Covariance (MANCOVA) showed that the experimental group, in comparison with control group, showed significantly more improvement in all three outcome measures. In the SCL-90-R, improvement was noted with the hypochondriacs, obsession, interpersonal sensitivity, aggression, psychosis, and general symptomatic indexes. In the HCQ,  improvement was found in the anticipation of positive outcome, desire to use substance, and total average score. Finally, the QEEG showed positive changes in  frontal, central and parietal delta, frontal and central theta, parietal alpha and frontal and central Sensory Motor Rhythm (SMR) amplitudes. This study suggests that NF can be used as a therapeutic method to ameliorate abnormalities  related to opioid-dependence disorders. The results emphasize the importance of neuropsychological interventions in treatment of substance-dependence disorders.

http://www.ncbi.nlm.nih.gov/pubmed/20722354

Clin EEG Neurosci. 2010 Jul;41(3):132-9.

Quantitative electroencephalographic abnormalities in fibromyalgia patients.

Hargrove JB, Bennett RM, Simons DG, Smith SJ, Nagpal S, Deering DE.

Department of Medicine, Michigan State University College of Human Medicine, Kettering University, Flint, Michigan 48504, USA. jhargrov@kettering.edu

There is increasing acceptance that pain in fibromyalgia (FM) is a result of dysfunctional sensory processing in the spinal cord and brain, and a number of recent imaging studies have demonstrated abnormal central mechanisms. The objective of this report is to statistically compare quantitative electroencephalogram (QEEG) measures in 85 FM patients with age and gender matched controls in a normative database. A statistically significant sample (minimum 60 seconds from each subject) of artifact-free EEG data exhibiting a minimum split-half reliability ratio of 0.95 and test-retest reliability ratio of 0.90 was used as the threshold for acceptable data inclusion. FM subject EEG data was compared to EEGs of age and gender matched healthy subjects in the Lifespan Normative Database and analyzed using NeuroGuide 2.0 software. Analyses were based on spectral absolute power, relative power and coherence. Clinical evaluations included the Fibromyalgia Impact Questionnaire (FIQ), Beck Depression Inventory and Fischer dolorimetry for pain pressure thresholds. Based on Z-statistic findings, the EEGs from FM subjects differed from matched controls in the normative database in three features: (1) reduced EEG spectral absolute power in the frontal International 10-20 EEG measurement sites, particularly in the low- to mid-frequency EEG spectral segments; (2) elevated spectral relative power of high frequency components in frontal/central EEG measurement sites; and (3) widespread hypocoherence, particularly in low- to mid-frequency EEG spectral segments, in the frontal EEG measurement sites. A consistent and significant negative correlation was found between pain severity and the magnitude of the EEG abnormalities. No relationship between EEG findings and medicine use was found. It is concluded that QEEG analysis reveals significant differences between FM patients compared to age and gender matched healthy controls in a normative database, and has the potential to be a clinically useful tool for assessing brain function in FM patients.

http://www.ncbi.nlm.nih.gov/pubmed/20722346

Eur Neuropsychopharmacol. 2010 Jul;20(7):459-66. Epub 2010 Apr 24.

The change of prefrontal QEEG theta cordance as a predictor of response to bupropion treatment in patients who had failed to respond to previous antidepressant treatments.

Bares M, Brunovsky M, Novak T, Kopecek M, Stopkova P, Sos P, Krajca V, Höschl C.

Prague Psychiatric Center, Ustavni 91, Prague 8-Bohnice, 181 03, Czech Republic.  bares@pcp.lf3.cuni.cz

The aim of the study was to examine whether the reduction of theta prefrontal quantitative EEG (QEEG) cordance after one week of bupropion administration is a  predictor of response to a 4-week treatment in patients that had failed to respond to previous antidepressant treatments. Method: EEG data of 18 inpatients  were monitored at baseline and after one week. QEEG cordance was computed at 3 frontal electrodes (Fp1, Fp2, Fz). Response to treatment was defined as a >/=50%  reduction of MADRS score. Results: Nine of the eleven responders and one of the seven non-responders showed decreased prefrontal cordance value after the first week of treatment (p=0.01). Positive and negative predictive values of cordance reduction for the prediction of response to the treatment were 0.9 and 0.75, respectively. Conclusion: Similar to other antidepressants, the reduction of prefrontal QEEG cordance might be helpful in the prediction of the acute outcome  of bupropion treatment.

http://www.ncbi.nlm.nih.gov/pubmed/20421161

J Head Trauma Rehabil. 2010 Jul-Aug;25(4):283-92.

Acute effects and recovery after sport-related concussion: a neurocognitive and quantitative brain electrical activity study.

McCrea M, Prichep L, Powell MR, Chabot R, Barr WB.

Neuroscience Center, Waukesha Memorial Hospital, Waukesha, Wisconsin 53118, USA.  michael.mccrea@phci.org

OBJECTIVE: To investigate the clinical utility and sensitivity of a portable, automatic, frontal quantitative electroencephalographic (QEEG) acquisition device currently in development in detecting abnormal brain electrical activity after sport-related concussion. DESIGN: This was a prospective, non-randomized study of 396 high school and college football players, including cohorts of 28 athletes with concussion and 28 matched controls. All subjects underwent preseason baseline testing on measures of postconcussive symptoms, postural stability, and cognitive functioning, as well as QEEG. Clinical testing and QEEG were repeated on day of injury and days 8 and 45 postinjury for the concussion and control groups. MAIN OUTCOMES AND RESULTS: The injured group reported more significant postconcussive symptoms during the first 3 days postinjury, which resolved by days 5 and 8. Injured subjects also performed poorer than controls on neurocognitive testing on the day of injury, but no differences were evident on day 8 or day 45. QEEG studies revealed significant abnormalities in electrical brain activity in the injured group on day of injury and day 8 postinjury, but not on day 45. CONCLUSIONS: Results from the current study on clinical recovery after sport-related concussion are consistent with early reports indicating a typical course of full recovery in symptoms and cognitive dysfunction within the first week of injury. QEEG results, however, suggest that the duration of physiological recovery after concussion may extend longer than observed clinical recovery. Further study is required to replicate and extend these findings in a larger clinical sample, and further demonstrate the utility of QEEG as a marker of recovery after sport-related concussion.

http://www.ncbi.nlm.nih.gov/pubmed/20611046

J Neurosci Methods. 2010 Jun 15;189(2):281-94. Epub 2010 Apr 2.

Visualization and modelling of STLmax topographic brain activity maps.

Mammone N, Principe JC, Morabito FC, Shiau DS, Sackellares JC.

DIMET, University of Reggio Calabria, Reggio Calabria, Italy. nadia.mammone@unirc.it

This paper evaluates the descriptive power of brain topography based on a dynamical parameter, the Short-Term Maximum Lyapunov Exponent (STLmax), estimated from EEG, for finding out a relationship of STLmax spatial distribution with the  onset zone and with the mechanisms leading to epileptic seizures. Our preliminary work showed that visual assessment of STLmax topography exhibited a link with the location of seizure onset zone. The objective of the present work is to model the spatial distribution of STLmax in order to automatically extract these features from the maps. One-hour preictal segments from four long-term continuous EEG recordings (two scalp and two intracranial) were processed and the corresponding  STLmax profiles were estimated. The spatial STLmax maps were modelled by a combination of two Gaussians functions. The parameters of the fitted model allow  automatic extraction of quantitative information about the spatial distribution of STLmax: the EEG signal recorded from the brain region where seizures originate exhibited low-STLmax levels, long before the seizure onset, in 3 out of 4 patients (1 out of 2 of scalp patients and 2 out of 2 in intracranial patients).  Topographic maps extracted directly from the EEG power did not provide useful information about the location, therefore we conclude that the analysis so far carried out suggests the possibility of using a model of STLmax topography as a tool for monitoring the evolution of epileptic brain dynamics. In the future, a more elaborate approach will be investigated in order to improve the specificity  of the method.

http://www.ncbi.nlm.nih.gov/pubmed/20363254

Biomed Tech (Berl). 2010 Jun;55(3):133-46.

Comparison between realistic and spherical approaches in EEG forward modelling.

Meneghini F, Vatta F, Esposito F, Mininel S, Di Salle F.

DEEI, University of Trieste, Trieste, Italy.

Abstract In electroencephalography (EEG) a valid conductor model of the head (forward model) is necessary for predicting measurable scalp voltages from intra-cranial current distributions. All inverse models, capable of inferring the spatial distribution of the neural sources generating measurable electrical and magnetic signals outside the brain are normally formulated in terms of a pre-estimated forward model, which implies considering one (or more) current dipole(s) inside the head and computing the electrical potentials generated at the electrode sites on the scalp surface. Therefore, the accuracy of the forward  model strongly affects the reliability of the source reconstruction process independently of the specific inverse model. So far, it is as yet unclear which brain regions are more sensitive to the choice of different model geometry, from  both quantitative and qualitative points of view. In this paper, we compare the finite difference method-based realistic model with the four-layers sensor-fitted spherical model using simulated cortical sources in the MNI152 standard space. We focused on the investigation of the spatial variation of the lead fields produced by simulated cortical sources which were placed on the reconstructed mesh of the  neocortex along the surface electrodes of a 62-channel configuration. This comparison is carried out by evaluating a point spread function all over the brain cortex, with the aim of finding the lead fields mismatch between realistic  and spherical geometry. Realistic geometry turns out to be a relevant factor of improvement which is particularly important when considering sources placed in the temporal or in the occipital cortex. In these situations, using a realistic head model will allow a better spatial discrimination of neural sources when compared to the spherical model.

http://www.ncbi.nlm.nih.gov/pubmed/20178450

Brain. 2010 Jun;133(Pt 6):1612-21. Epub 2010 Mar 30.

Resting state networks change in clinically isolated syndrome.

Roosendaal SD, Schoonheim MM, Hulst HE, Sanz-Arigita EJ, Smith SM, Geurts JJ, Barkhof F.

VU University Medical Centre, Department of Radiology, PO Box 7057, 1007 MB Amsterdam, the Netherlands. s.roosendaal@vumc.nl

Task-functional magnetic resonance imaging studies have shown that early cortical recruitment exists in multiple sclerosis, which can partly explain the discrepancy between conventional magnetic resonance imaging and clinical disability. The study of the brain 'at rest' may provide additional information,  because task-induced metabolic changes are relatively small compared to the energy use of the resting brain. We therefore questioned whether functional changes exist at rest in the early phase of multiple sclerosis, and addressed this question by a network analysis of no-task functional magnetic resonance imaging data. Fourteen patients with symptoms suggestive of multiple sclerosis (clinically isolated syndrome), 31 patients with relapsing remitting multiple sclerosis and 41 healthy controls were included. Resting state functional magnetic resonance imaging data were brought to standard space using non-linear registration, and further analysed using multi-subject independent component analysis and individual time-course regression. Eight meaningful resting state networks were identified in our subjects and compared between the three groups with non-parametric permutation testing, using threshold-free cluster enhancement to correct for multiple comparisons. Additionally, quantitative measures of structural damage were obtained. Grey and white matter volumes, normalized for head size, were measured for each subject. White matter integrity was investigated with diffusion tensor measures that were compared between groups voxel-wise using tract-based spatial statistics. Patients with clinically isolated syndrome showed increased synchronization in six of the eight resting state networks, including the default mode network and sensorimotor network, compared to controls or relapsing remitting patients. No significant decreases were found in patients with clinically isolated syndrome. No significant resting  state synchronization differences were found between relapsing remitting patients and controls. Normalized grey matter volume was decreased and white matter diffusivity measures were abnormal in relapsing remitting patients compared to controls, whereas no atrophy or diffusivity changes were found for the clinically isolated syndrome group. Thus, early synchronization changes are found in patients with clinically isolated syndrome that are suggestive of cortical reorganization of resting state networks. These changes are lost in patients with relapsing remitting multiple sclerosis with increasing brain damage, indicating that cortical reorganization of resting state networks is an early and finite phenomenon in multiple sclerosis.

http://www.ncbi.nlm.nih.gov/pubmed/20356855

Brain Topogr. 2010 Jun;23(2):199-204. Epub 2009 Nov 27.

Gender differences in brain functional organization during verbal and spatial cognitive challenges.

Koles ZJ, Lind JC, Flor-Henry P.

Department of Electrical and Computer Engineering, University of Alberta, W2-040  ECERF, Edmonton, T6G 2V4, Canada. z.koles@ualberta.ca

This is a quantitative EEG study of gender-related differences in brain function. It is novel in that to elicit gender differences, it was necessary to apply a spatial filter to the EEGs that was effective for suppressing components common to different cognitive states. The study involved estimates of both the source-current power density in the brain and the complex coherence between different regions in the brain, the latter probably unique in EEG source analysis. Gender effects are shown in terms of differences in both lateralized source power and complex coherence in response to verbal and spatial cognitive challenges. The results provide evidence that verbal and spatial challenges are more lateralized in males than in females, that females are more verbal than males, that males are more spatial than females, that females verbalize more interpretively than males and that males verbalize more consequentially than females.

http://www.ncbi.nlm.nih.gov/pubmed/19943102

J Affect Disord. 2010 Jun;123(1-3):270-5. Epub 2009 Sep 15.

Distinct neuronal oscillatory responses between patients with bipolar and unipolar disorders: a magnetoencephalographic study.

Lee PS, Chen YS, Hsieh JC, Su TP, Chen LF.

Institute of Brain Science, National Yang-Ming University, Taipei, Taiwan.

BACKGROUND: Bipolar disorder (BD) and major depressive disorder (MDD) have distinct pathophysiologies but similar depressive appearances. The present study  aimed at the differentiation of the brain responses between BD and MDD patients.  We hypothesized that different affective disorder patients may have distinct patterns of oscillatory cortical activities in response to negative emotional stimuli. METHODS: Twenty BD patients, twenty MDD patients, and twenty age- and gender-matched healthy normal subjects were recruited. We adopted an implicit emotional task with facial image stimuli. The acquired event-related magnetoencephalographic signals were processed by the time-frequency analysis and beamformer-based source imaging techniques followed by statistical inference. RESULTS: We found that there were gamma oscillation decreases in the frontal regions of both BD and MDD patients, gamma oscillation increases in the bilateral temporal regions of MDD, and alpha-beta rhythm increases in BD patients. Relative to the cortical activation in the control group, the BD patients displayed more widely increased oscillatory activities over the fronto-parieto-occipital regions than MDD patients. CONCLUSIONS: Our results demonstrate the distinct neuropathological patterns of emotional responses in BD and MDD patients. The findings suggest that the dysfunction of emotion regulation in BD may result from the increased sensitivity to emotionally salient information, implicating the potential cause of the emotion lability. The present study also suggests that the implicit emotional task is an effective approach to differentiate bipolar from unipolar disorders and their distinct neuropathological patterns to emotional stimuli may provide objective and quantitative measures for potential diagnostic significance.

http://www.ncbi.nlm.nih.gov/pubmed/19755202

J Clin Neurophysiol. 2010 Jun;27(3):193-7.

quantitative EEG analysis of executive dysfunction in Parkinson disease.

Kamei S, Morita A, Serizawa K, Mizutani T, Hirayanagi K.

Division of Neurology, Department of Medicine, Nihon University School of Medicine, Tokyo, Japan. skamei@med.nihon-u.ac.jp

quantitative EEG evaluation in Parkinson disease (PD) reveals diffuse slowing. This is the first quantitative EEG evaluation of the differences between PD with  and without executive dysfunction (ExD). The subjects were 32 PD patients without remarkable dementia. The lack of ischemic lesions was confirmed by magnetic resonance imaging. ExD was defined as <70 points on the age-controlled standardized score of the Behavioral Assessment of the Dysexecutive Syndrome. Absolute power was measured for four frequency bands from delta to beta. Electrodes were placed at frontal pole, frontal, central, parietal, occipital, and temporal locations. Spectral ratio was calculated as the sum of power values  for alpha and beta waves divided by the sum of values for the slow waves. In multiple logistic regression analysis of each electrode location, the dependent variable was ExD or not, and the independent variables were spectral ratio, age,  and Unified Parkinson Disease Rating Scale. The only significant predictor of ExD was spectral ratio at the frontal pole (P = 0.031) and frontal (P = 0.048) locations. PD with ExD exhibited an increase in slow wave activity and a decrease in alpha and fast wave activities in these locations. These findings indicated that the ExD in PD was caused by frontal dysfunction.

http://www.ncbi.nlm.nih.gov/pubmed/20461018

J Clin Neurophysiol. 2010 Jun;27(3):179-90.

Patterns of spontaneous magnetoencephalographic activity in patients with schizophrenia.

Siekmeier PJ, Stufflebeam SM.

Harvard Medical School and McLean Hospital, Belmont, Massachusetts 02478, USA. psiekmeier@mclean.harvard.edu

Magnetoencephalography noninvasively measures the magnetic fields produced by the brain. Pertinent research articles from 1993 to 2009 that measured spontaneous, whole-head magnetoencephalography activity in patients with schizophrenia were reviewed. Data on localization of oscillatory activity and correlation of these findings with psychotic symptoms are summarized. Although the variety of measures used by different research groups makes a quantitative meta-analysis difficult, it appears that magnetoencephalography activity in patients may exhibit identifiable patterns, defined by topographic organization and frequency band. Specifically, 11 of the 12 studies showed increased theta (4-8 Hz) and delta (1-4 Hz) band oscillations in the temporal lobes of patients; of the 10 studies that examined the relationship between oscillatory activity and symptomatology, 8 found a positive correlation between temporal lobe theta activity and positive schizophrenic symptoms. Abnormally high frontal delta activity was not seen. These findings are analyzed in comparison with the electroencephalogram literature on schizophrenics, and possible confounds (e.g., medication effects) are discussed. In the future, magnetoencephalography might be used to assist in diagnosis or might be fruitfully used in conjunction with new neuroscience research approaches such as computational modeling, which may be able to link oscillatory activity and cellular-level pathology.

http://www.ncbi.nlm.nih.gov/pubmed/20461010

J Korean Med Sci. 2010 Jun;25(6):905-11. Epub 2010 May 25.

Increased seizure susceptibility and up-regulation of nNOS expression in hippocampus following recurrent early-life seizures in rats.

Kim DK.

Department of Pediatrics, Dongguk University College of Medicine, Gyeongju, Korea. pedepi@hotmail.com

This study aimed to determine the long-term change of seizure susceptibility and  the role of nNOS on brain development following recurrent early-life seizures in  rats. Video-EEG recordings were conducted between postnatal days 50 and 60. Alterations in seizure susceptibility were assayed on day 22 or 50 using the flurothyl method. Changes in nNOS expression were determined by quantitative immunoblotting on day 50. On average, rats had 8.4+/-2.7 seizures during 10 daily 1 hr behavioral monitoring sessions. As adults (days 50-60), all rats displayed interictal spikes in the hippocampus and/or overlying cortex. Brief electrographic seizures were recorded in only one of five animals. Rats appeared  to progress from a period of marked seizure susceptibility (day 22) to one of lessened seizure susceptibility (day 50). Up-regulation of nNOS expression following early-life recurrent seizures was observed on day 50. In conclusion, these data suggested that recurrent early-life seizures had the long-term effects on seizure susceptibility late in life and up-regulatory nNOS expression on the hippocampus during brain development, and nNOS appeared to contribute to the persistent changes in seizure susceptibility, and epileptogenesis.

http://www.ncbi.nlm.nih.gov/pubmed/20514313

J Neurophysiol. 2010 Jun;103(6):3139-52. Epub 2010 Mar 24.

Investigation of linear coupling between single-event blood flow responses and interictal discharges in a model of experimental epilepsy.

Vanzetta I, Flynn C, Ivanov AI, Bernard C, Bénar CG.

Centre National de la Recherche Scientifique, Unité Mixte de Rechereche 6193, 13402 Marseille Cedex 20, France. ivo.vanzetta@incm.cnrs-mrs.fr

A successful outcome of epilepsy neurosurgery relies on an accurate delineation of the epileptogenic region to be resected. Functional magnetic resonance imaging (fMRI) would allow doing this noninvasively at high spatial resolution. However,  a clear, quantitative description of the relationship between hemodynamic changes and the underlying epileptiform neuronal activity is still missing, thereby preventing the systematic use of fMRI for routine epilepsy surgery planning. To this aim, we used a local epilepsy model to record simultaneously cerebral blood  flow (CBF) with laser Doppler (LD) and local field potentials (LFP) in rat frontal cortex. CBF responses to individual interictal-like spikes were large and robust. Their amplitude correlated linearly with spike amplitude. Moreover, the CBF response added linearly in time over a large range of spiking rates. CBF responses could thus be predicted by a linear model of the kind currently used for the interpretation of fMRI data, but including also the spikes' amplitudes as additional information. Predicted and measured CBF responses matched accurately.  For high spiking frequencies (above approximately 0.2 Hz), the responses saturated but could eventually recover, indicating the presence of multiple neurovascular coupling mechanisms, which might act at different spatiotemporal scales. Spatially, CBF responses peaked at the center of epileptic activity and displayed a spatial specificity at least as good as the millimeter. These results suggest that simultaneous electroencephalographic and blood flow-based fMRI recordings should be suitable for the noninvasive precise localization of hyperexcitable regions in epileptic patients candidate for neurosurgery.

http://www.ncbi.nlm.nih.gov/pubmed/20457851

Neurosci Behav Physiol. 2010 May;40(4):411-9. Epub 2010 Mar 26.

Auditory evoked potentials and impairments to psychomotor activity evoked by falling asleep.

Dorokhov VB, Verbitskaya YS, Lavrova TP.

Institute of Higher Nervous Activity and Neurophysiology, Russian Academy of Sciences, Moscow, Russia. vbdorokhov@mail.ru

Sounds provide the most suitable stimuli for studies of information processes occurring in the brain during falling asleep and at different stages of sleep. The widely used analysis of evoked potentials averaged for groups of subjects has a number of disadvantages associated with their individual variability. Thus, in  the present study, measures of the individual components of auditory evoked potentials were determined and selectively summed for individual subjects, with subsequent analysis by group. The aim of the present work was to identify measures of auditory evoked potentials providing quantitative assessment of the dynamics of the brain's functional state during the appearance of errors in activity associated with decreases in the level of waking and falling asleep. A monotonous psychomotor test was performed in the lying position with the eyes closed; this consisted of two alternating parts: the first was counting auditory  stimuli from 1 to 10 with simultaneous pressing of a button, and the second was counting stimuli from 1 to 5 silently without pressing the button, and so on. Computer-generated sound stimuli (duration 50 msec, envelope filling frequency 1000 Hz, intensity 60 dB) were presented binaurally with interstimulus intervals  of 2.4-2.7 sec. A total of 41 subjects took part (both genders, mean age 25 years), of which only 23 fell asleep; data for 14 subjects with sufficient episodes of falling asleep were analyzed. Comparison of measures of auditory evoked potentials (the latencies and amplitudes of the N1, P2, N2, and P3 components) during correct and erroneous psychomotor test trials showed that decreases in the level of consciousness elicited significant increases in the amplitudes of the components of the vertex N1-P2-N2 complex in series without button pressing. The greatest changes in auditory evoked potentials in both series were seen in the N2 component, with latency 330-360 msec, which has a common origin with the EEG theta rhythm and is characteristic of the first stage  of sleep.

http://www.ncbi.nlm.nih.gov/pubmed/20339938

Pediatr Res. 2010 May;67(5):538-44.

Decreased aEEG continuity and baseline variability in the first 48 hours of life  associated with poor short-term outcome in neonates born before 29 weeks gestation.

Bowen JR, Paradisis M, Shah D.

Department of Neonatology, Royal North Shore Hospital, St Leonards, New South Wales 2065, Australia.

Amplitude-integrated electroencephalography (aEEG) provides us with a method of assessing brain activity in critically ill neonates. In extremely premature neonates, the aEEG trace is predominantly discontinuous, making it difficult to distinguish between a "normal" and "abnormal" trace. We measured aEEG activity in the first 48 h of life in neonates born before 29-wk gestation and used both visual and quantitative analysis of the aEEG data to assess differences in neonates with poor short-term outcome [death or peri/intraventricular hemorrhage  (P/IVH)] compared with those who survived without P/IVH to identify features of an abnormal aEEG. On quantitative analysis, EEG continuity <80% at 10-microV level was a sensitive and specific marker of poor short-term outcome. By using this marker, we identified 83% of neonates who died or developed grade 3 or 4 IVH and 60% of neonates who developed grades 1 or 2 IVH, with a positive predictive value for death or any IVH of 73% and a negative predictive value of 86%. Absence of sleep-wake cycling with baseline variability <2 microV was the strongest predictor of outcome using visual analysis alone.

http://www.ncbi.nlm.nih.gov/pubmed/20098343

Clin Neurophysiol. 2010 Apr;121(4):577-87. Epub 2010 Jan 27.

Functional characterisation of sensory ERPs using probabilistic ICA: effect of stimulus modality and stimulus location.

Liang M, Mouraux A, Chan V, Blakemore C, Iannetti GD.

Department of Physiology, Anatomy and Genetics, University of Oxford, UK.

OBJECTIVE: To decompose sensory event-related brain potentials (ERPs) into a set  of independent components according to the modality and the spatial location of the eliciting sensory stimulus, and thus provide a quantitative analysis of their underlying components. METHODS: Auditory, somatosensory and visual ERPs were recorded from 124 electrodes in thirteen healthy participants. Probabilistic Independent Component  Analysis (P-ICA) was used to decompose these sensory ERPs into a set of independent components according to the modality (auditory, somatosensory, visual or multimodal) and the spatial location (left or right side) of the eliciting stimulus. RESULTS: Middle-latency sensory ERPs were explained by a large contribution of multimodal neural activities, and a smaller contribution of unimodal neural activities. While a significant fraction of unimodal neural activities were dependent on the location of the eliciting stimulus, virtually all multimodal neural activities were not (i.e. their scalp distributions and time courses were  not different when stimuli were presented on the left and right sides). CONCLUSION: These findings show that P-ICA can be used to dissect effectively sensory ERPs into physiologically meaningful components, and indicate a new approach for exploring the effect of various experimental modulations of sensory  ERPs. SIGNIFICANCE: This approach offers a better understanding of the functional significance of sensory ERPs.

http://www.ncbi.nlm.nih.gov/pubmed/20110192

Early Hum Dev. 2010 Apr;86(4):219-24. Epub 2010 Apr 10.

Quantitative analysis of maturational changes in EEG background activity in very  preterm infants with a normal neurodevelopment at 1 year of age.

Niemarkt HJ, Andriessen P, Peters CH, Pasman JW, Zimmermann LJ, Bambang Oetomo S.

Máxima Medical Centre, Veldhoven, The Netherlands.

BACKGROUND: The electroencephalographic (EEG) background pattern of preterm infants changes with postmenstrual age (PMA) from discontinuous activity to continuous activity. However, changes in discontinuity have been investigated by  visual analysis only. AIM: To investigate the maturational changes in EEG discontinuity in healthy preterm infants using an automated EEG detection algorithm. STUDY DESIGN: Weekly 4h EEG recordings were performed in preterm infants with a gestational age (GA)<32weeks and normal neurological follow-up at 1year. The channel C3-C4 was analyzed using an algorithm which automatically detects periods of EEG inactivity (interburst intervals). The interburst-burst ratio (IBR, percentage of EEG inactivity during a moving time window of 600s) and mean length of the interburst intervals were calculated. Using the IBR, discontinuous background activity (periods with high IBR) and continuous background activity (periods with low IBR) were automatically detected and their mean length during each recording was calculated. Data were analyzed with regression and multivariate analysis. RESULTS: 79 recordings were performed in 18 infants. All recordings showed a cyclical pattern in EEG discontinuity. With advancing PMA, IBR (R(2)=0.64; p<0.001), interburst interval length (R(2)=0.43; p<0.001) and length of discontinuous activity (R(2)=0.38; p<0.001) decreased, while continuous activity  increased (R(2)=0.50; p<0.001). Multivariate analysis showed that all EEG discontinuity parameters were equally influenced by GA and postnatal age. CONCLUSION: Analyzing EEG background activity in preterm infants is feasible with an automated algorithm and shows maturational changes of several EEG derived parameters. The cyclical pattern in IBR suggests brain organisation in preterm infant.

http://www.ncbi.nlm.nih.gov/pubmed/20382486

J Child Neurol. 2010 Apr;25(4):469-74. Epub 2009 Sep 17.

Cognitive function and event-related potentials in children with type 1 diabetes  mellitus.

Shehata G, Eltayeb A.

Department of Neurology and Psychiatry, Assiut University, Assiut, Egypt. ghaydaa83@yahoo.com

Type 1 diabetes mellitus is associated with cognitive changes, but the extent of  cognition decline depends on age at onset, duration of diabetes, and occurrence of attacks of hypoglycemia or ketoacidosis. This study was designed to assess cognitive function in a group of children with type 1 diabetes mellitus. A total  of 40 diabetic children were recruited from the pediatric department of Assiut University Hospital, Egypt. Forty healthy children matched for age, sex, and socioeconomic status were chosen as controls for comparison. Cognition was assessed using Stanford-Binet and event-related potentials tests. Compared to the control group, patients reported a significant reduction in intelligent quotient, comprehension, abstract visual reasoning, quantitative reasoning, bead memory, and total short memory testing for cognitive functions. Prolonged N1, P200, N2, and P300 latencies and reduced P300-N2 amplitude were reported. Significant negative correlations were identified in most studied cognitive functions and ketoacidosis or family history of diabetes mellitus.

http://www.ncbi.nlm.nih.gov/pubmed/19762507

J Neurosci. 2010 Mar 24;30(12):4496-502.

Oscillatory correlates of vibrotactile frequency processing in human working memory.

Spitzer B, Wacker E, Blankenburg F.

Department of Neurology and Bernstein Center for Computational Neuroscience, Charité, Philippstrasse 13, House 6, 10115 Berlin, Germany. bernhard.spitzer@bccn-berlin.de

Previous animal research has revealed neuronal activity underlying short-term retention of vibrotactile stimuli, providing evidence for a parametric representation of stimulus frequency in primate tactile working memory (Romo et al., 1999). Here, we investigated the neural correlates of vibrotactile frequency processing in human working memory, using noninvasive electroencephalography (EEG). Participants judged the frequencies of vibrotactile stimuli delivered to the fingertip in a delayed match-to-sample frequency discrimination task. As expected, vibrotactile stimulation elicited pronounced steady-state evoked potentials, which were source-localized in primary somatosensory cortex. Furthermore, parametric analysis of induced EEG responses revealed that the frequency of stimulation was reflected by systematic modulations of synchronized  oscillatory activity in nonprimary cortical areas. Stimulus processing was accompanied by frequency-dependent alpha-band responses (8-12 Hz) over dorsal occipital cortex. The critical new finding was that, throughout the retention interval, the stimulus frequency held in working memory was systematically represented by a modulation in prefrontal beta activity (20-25 Hz), which was source-localized to the inferior frontal gyrus. This modulation in oscillatory activity during stimulus retention was related to successful frequency discrimination, thus reflecting behaviorally relevant information. Together, the  results complement previous findings of parametric working memory correlates in nonhuman primates and suggest that the quantitative representation of vibrotactile frequency in sensory memory entails systematic modulations of synchronized neural activity in human prefrontal cortex.

http://www.ncbi.nlm.nih.gov/pubmed/20335486

Acta Neurol Scand. 2010 Mar;121(3):209-16. Epub 2009 Nov 25.

Arterial spin labeling demonstrates that focal amygdalar glutamatergic agonist infusion leads to rapid diffuse cerebral activation.

Munasinghe JP, Banerjee M, Acosta MT, Banks M, Heffer A, Silva AC, Koretsky A, Theodore WH.

MRI Research Facility, National Institute of Neurological Disorders and Stroke, National Institutes of Health, Bethesda, MD, USA.

OBJECTIVES: To investigate acute effects of intra-amygdalar excitatory amino acid administration on blood flow, relaxation time and apparent diffusion coefficient  in rat brain. MATERIALS AND METHODS: Several days after MR-compatible cannula placement in right basolateral amygdala, anesthetized rats were imaged at 7 T. Relative cerebral blood flow (CBF) was measured before and 60 min after infusion of 10 nmol KA, cAMPA, ATPA, or normal saline using arterial spin labeling. Quantitative T(2) and diffusion-weighted images were acquired. rCBF, T(2) and ADC values were  evaluated in bilateral basolateral amygdala, hippocampus, basal ganglia, frontal  and parietal regions. RESULTS: KA led to the highest, and ATPA lowest bilateral rCBF increases. Time courses varied among drugs. T(2) for KA and AMPA was higher while ADC was lower for KA. CONCLUSIONS: Intra-amygdalar injection of GluR agonists evoked bilateral seizure  activity and increased rCBF, greater for KA and AMPA than selective ATPA GluR5 activation.

http://www.ncbi.nlm.nih.gov/pubmed/19951270

Appl Psychophysiol Biofeedback. 2010 Mar;35(1):25-7. Epub 2009 Oct 15.

Recent advances in quantitative EEG as an aid to diagnosis and as a guide to neurofeedback training for cortical hypofunctions, hyperfunctions, disconnections, and hyperconnections: improving efficacy in complicated neurological and psychological disorders.

Walker JE.

Neurotherapy Center of Dallas, Dallas, TX 75230, USA. admin@neurotherapydallas.com

Recent advances in QEEG-databases have enabled improvements in interpretation, which in turn have led to more effective neurofeedback interventions. These improvements relate mostly to evaluations conducted in the high frequency beta range (21-30 Hz) evaluation and in single Hz bins, which more specifically address which frequencies need to be trained to most quickly and effectively normalize their dysfunctions and remediate their difficulties. Use of the modular activation/coherence model (Walker et al. in J Neurother 11: 25-44, 2007) provides a framework for correcting the slow or fast modular dysfunctions, as well as normalizing connectivity using coherence training.

http://www.ncbi.nlm.nih.gov/pubmed/19830549

Appl Psychophysiol Biofeedback. 2010 Mar;35(1):31-6. Epub 2009 Sep 4.

The need for individualization in neurofeedback: heterogeneity in QEEG patterns associated with diagnoses and symptoms.

Hammond DC.

University of Utah School of Medicine, Salt Lake City, UT 84132-2119, USA. D.C.Hammond@utah.edu

Very diverse assessment procedures are utilized by neurofeedback practitioners, many of which are not based on careful examination of raw EEG data followed by scientifically objective quantitative EEG (QEEG) database comparisons. Research is reviewed demonstrating the great heterogeneity in the EEG patterns associated  with various diagnoses and symptoms. The fact that most patients qualify for dual diagnoses, with co-morbid psychiatric and medical conditions present, complicates the ability of clinicians to estimate what electrophysiological patterns may be associated with symptoms. In such cases treatment planning is characterized by a  great deal of guesswork and experimentation. Peer reviewed publications have documented that neurofeedback treatment can sometimes be associated with both transient side effects as well as more serious negative effects. It is believed that the lack of comprehensive and objective assessment of brain functioning may  increase the risk of neurofeedback either being ineffective or causing iatrogenic harm. QEEG provides reliable, non-invasive, objective, culture-free and relatively low cost evaluation of brain functioning, permitting individualization of treatment and added liability protection.

http://www.ncbi.nlm.nih.gov/pubmed/19760143

Appl Psychophysiol Biofeedback. 2010 Mar;35(1):13-23. Epub 2009 Aug 1.

The relative efficacy of connectivity guided and symptom based EEG biofeedback for autistic disorders.

Coben R, Myers TE.

Neurorehabilitation & Neuropsychological Services, Massapequa Park, NY 11762, USA. robcoben@optonline.net

Autism is a neurodevelopmental disorder characterized by deficits in communication, social interaction, and a limited range of interests with repetitive stereotypical behavior. Various abnormalities have been documented in  the brains of individuals with autism, both anatomically and functionally. The connectivity theory of autism is a recently developed theory of the neurobiological cause of autisic symptoms. Different patterns of hyper- and hypo-connectivity have been identified with the use of quantitative electroencephalogray (QEEG), which may be amenable to neurofeedback. In this study, we compared the results of two published controlled studies examining the  efficacy of neurofeedback in the treatment of autism. Specifically, we examined whether a symptom based approach or an assessment/connectivity guided based approach was more effective. Although both methods demonstrated significant improvement in symptoms of autism, connectivity guided neurofeedback demonstrated greater reduction on various subscales of the Autism Treatment Evaluation Checklist (ATEC). Furthermore, when individuals were matched for severity of symptoms, the amount of change per session was significantly higher in the Coben  and Padolsky (J Neurother 11:5-23, 2007) study for all five measures of the ATEC. Our findings suggest that an approach guided by QEEG based connectivity assessment may be more efficacious in the treatment of autism. This permits the targeting and amelioration of abnormal connectivity patterns in the brains of people who are autistic.

http://www.ncbi.nlm.nih.gov/pubmed/19649702

Biol Psychol. 2010 Mar;83(3):239-49. Epub 2010 Jan 20.

Neural correlates of task and source switching: similar or different?

Dumontheil I, Gilbert SJ, Burgess PW, Otten LJ.

Institute of Cognitive Neuroscience, University College London (UCL), 17 Queen Square, London, WC1N 3AR, UK. i.dumontheil@ucl.ac.uk

Controlling everyday behaviour relies on the ability to configure appropriate task sets and guide attention towards information relevant to the current context and goals. Here, we ask whether these two aspects of cognitive control have different neural bases. Electrical brain activity was recorded while sixteen adults performed two discrimination tasks. The tasks were performed on either a visual input (letter on the screen) or self-generated information (letter generated internally by continuing the alphabetical sequence). In different blocks, volunteers either switched between (i) the two tasks, (ii) the two sources of information, or (iii) tasks and source of information. Event-related potentials differed significantly between switch and no-switch trials from an early point in time, encompassing at least three distinct effects. Crucially, although these effects showed quantitative differences across switch types, no qualitative differences were observed. Thus, at least under the current circumstances, switching between different tasks and between perceptually derived or self-generated sources of information rely on similar neural correlates until  at least 900 ms after the onset of a switch event.

http://www.ncbi.nlm.nih.gov/pubmed/20093165

Clin Neurophysiol. 2010 Mar;121(3):380-5. Epub 2010 Jan 13.

Impact of regional retinal responses on cortical visually evoked responses: multifocal ERGs and VEPs in the retinitis pigmentosa model.

Parisi V, Ziccardi L, Stifano G, Montrone L, Gallinaro G, Falsini B.

Fondazione G.B. Bietti, Istituto di Ricovero e Cura a Carattere Scientifico (IRCCS), Rome, Italy.

Comment in     Clin Neurophysiol. 2010 Mar;121(3):270-1.

OBJECTIVE: To determine the impact of the regional retinal responses on cortical  visually evoked responses, by evaluating the relationship between multifocal ERG  (mfERG) and multifocal VEP (mfVEP), in the retinitis pigmentosa (RP) model. METHODS: MfERGs and mfVEPs were recorded from 20 typical RP patients. Response amplitude density (RAD, nV/deg(2)) and implicit time (ms) of the mfERG 1st order  binary kernel (N1-P1) and mfVEP 2nd order binary kernel (P1) components were measured. Ring analysis, matched for mfERG and mfVEP stimuli, was performed between fovea and mid-periphery (0-2.5, 2.5-5, 5-10, 10-15 and 15-20deg). RESULTS: At central and pericentral retinal regions (four eccentricities between  0 and 15deg), mfERG N1 RADs were positively correlated (r0.68, p<0.01) with corresponding mfVEP P1 RADs. Similarly, mfERG P1 implicit times were positively correlated (r>or=0.65, p<0.01) with corresponding mfVEP N1 implicit times. CONCLUSIONS: There are quantitative correlations between mfERG and mfVEP components in RP. SIGNIFICANCE: The data suggest that regional responses of the photoreceptors and  off-bipolar cells, the main generators of mfERG N1, have a major impact on the corresponding cortical activity.

http://www.ncbi.nlm.nih.gov/pubmed/20071230

Clin Neurophysiol. 2010 Mar;121(3):281-9. Epub 2009 Dec 16.

Independent component approach to the analysis of EEG recordings at early stages  of depressive disorders.

Grin-Yatsenko VA, Baas I, Ponomarev VA, Kropotov JD.

Laboratory of Neurobiology of Action Programming, Institute of the Human Brain of Russian Academy of Sciences, St. Petersburg, ul. Acad. Pavlova, Russian Federation. veragrin@yahoo.com

OBJECTIVE: A modern approach for blind source separation of electrical activity represented by Independent Components Analysis (ICA) was used for QEEG analysis in depression. METHODS: The spectral characteristics of the resting EEG in 111 adults in the early stages of depression and 526 non-depressed subjects were compared between groups of patients and healthy controls using a combination of ICA and sLORETA methods. RESULTS: Comparison of the power of independent components in depressed patients  and healthy controls have revealed significant differences between groups for three frequency bands: theta (4-7.5Hz), alpha (7.5-14Hz), and beta (14-20Hz) both in Eyes closed and Eyes open conditions. An increase in slow (theta and alpha) activity in depressed patients at parietal and occipital sites may reflect a decreased cortical activation in these brain regions, and a diffuse enhancement of beta power may correlate with anxiety symptoms playing an important role on the onset of depressive disorder. CONCLUSIONS: ICA approach used in the present study allowed us to localize the EEG spectra differences between the two groups. SIGNIFICANCE: A relatively rare approach which uses the ICA spectra for comparison of the quantitative parameters of EEG in different groups of patients/subjects allows to improve an accuracy of measurement.

http://www.ncbi.nlm.nih.gov/pubmed/20006545

Clin Physiol Funct Imaging. 2010 Mar;30(2):135-40. Epub 2010 Jan 20.

Brain electrical activity during food presentation in obese binge-eating women.

Tammela LI, Pääkkönen A, Karhunen LJ, Karhu J, Uusitupa MI, Kuikka JT.

Department of Clinical Nutrition, School of Public Health and Clinical Nutrition, University of Kuopio, and Kuopio University Hospital, Kuopio, Finland.

Binge-eating (BE) subjects have shown altered brain activity at frontal regions during food presentation. The aim of this study was to examine the frontal brain  electrical activity in obese BE women (n = 12) and in obese women without BE (non-BE, n = 13). Brain electrical activity was measured using a quantitative electroencephalography during a resting state (eyes-closed) and when the subjects focused (eyes-open) their attention on a picture of a landscape (control experiment) or on a meal (food experiment). The BE showed greater frontal beta activity (14-20 Hz) than the non-BE in both the eyes-closed (on average 52%) and  the eyes-open situations and independently of the stimulus (control experiment: 57% and food experiment: 71%). No significant differences between the groups were found in alpha, delta or theta amplitudes. Increased beta activity correlated positively with the disinhibition factor of the Three-Factor Eating Questionnaire. Thus, our results suggest that elevated frontal beta activity may  be a marker of dysfunctional disinhibition-inhibition mechanism, which could make the obese BE women more vulnerable or sensitive to food and the environmental cues.

http://www.ncbi.nlm.nih.gov/pubmed/20095978

Hum Brain Mapp. 2010 Mar;31(3):487-97.

Drug effect on EEG connectivity assessed by linear and nonlinear couplings.

Alonso JF, Mañanas MA, Romero S, Hoyer D, Riba J, Barbanoj MJ.

Biomedical Engineering Research Center, Department of Automatic Control, Universitat Politècnica de Catalunya, Barcelona, Spain. joan.francesc.alonso@upc.edu

Quantitative analysis of human electroencephalogram (EEG) is a valuable method for evaluating psychopharmacological agents. Although the effects of different drug classes on EEG spectra are already known, interactions between brain locations remain unclear. In this work, cross mutual information function and appropriate surrogate data were applied to assess linear and nonlinear couplings  between EEG signals. The main goal was to evaluate the pharmacological effects of alprazolam on brain connectivity during wakefulness in healthy volunteers using a cross-over, placebo-controlled design. Eighty-five pairs of EEG leads were selected for the analysis, and connectivity was evaluated inside anterior, central, and posterior zones of the scalp. Connectivity between these zones and interhemispheric connectivity were also measured. Results showed that alprazolam  induced significant changes in EEG connectivity in terms of information transfer  in comparison with placebo. Trends were opposite depending on the statistical characteristics: decreases in linear connectivity and increases in nonlinear couplings. These effects were generally spread over the entire scalp. Linear changes were negatively correlated, and nonlinear changes were positively correlated with drug plasma concentrations; the latter showed higher correlation  coefficients. The use of both linear and nonlinear approaches revealed the importance of assessing changes in EEG connectivity as this can provide interesting information about psychopharmacological effects.

http://www.ncbi.nlm.nih.gov/pubmed/19894215

J Neural Transm. 2010 Mar;117(3):285-92. Epub 2010 Jan 6.

Activation of 5-HT3 receptors leads to altered responses 6 months after MDMA treatment.

Gyongyosi N, Balogh B, Katai Z, Molnar E, Laufer R, Tekes K, Bagdy G.

Department of Pharmacodynamics, Semmelweis University, Budapest, Hungary. norbert.gyongyosi@eok.sote.hu

The recreational drug "Ecstasy" [3,4-methylenedioxymethamphetamine (MDMA)] has a  well-characterised neurotoxic effect on the 5-hydroxytryptamine (5-HT) neurons in animals. Despite intensive studies, the long-term functional consequencies of the 5-HT neurodegeneration remains elusive. The aim of this study was to investigate  whether any alteration of 5-hydroxytryptamine-3 (5-HT(3)) receptor functions on the sleep-wake cycle, motor activity, and quantitative EEG could be detected 6 months after a single dose of 15 mg/kg of MDMA. The selective 5-HT(3) receptor agonist m-chlorophenylbiguanide (mCPBG; 1 mg/kg, i.p.) or vehicle was administered to freely moving rats pre-treated with MDMA (15 mg/kg, i.p.) or vehicle 6 months earlier. Polysomnographic and motor activity recordings were performed. Active wake (AW), passive wake (PW), light slow wave sleep (SWS-1), deep slow wave sleep (SWS-2), and paradoxical sleep were classified. In addition, EEG power spectra were calculated for the second hour after mCPBG treatment for each stage. AW increased and SWS-1 decreased in the second hour after mCPBG treatment in control animals. mCPBG caused significant changes in the EEG power in states with cortical activation (AW, PW, paradoxical sleep). In addition, mCPBG had a biphasic effect on hippocampal theta power in AW with a decrease in 7 Hz and a stage-selective increase in the upper range (8-9 Hz). Effects of mCPBG on the time spent in AW and SWS-1 were eliminated or reduced in MDMA-treated animals. In addition, mCPBG did not increase the upper theta power of AW in rats  pre-treated with MDMA. These data suggest long-term changes in 5-HT(3) receptor function after MDMA.

http://www.ncbi.nlm.nih.gov/pubmed/20052506

J Psychiatr Res. 2010 Mar;44(4):242-52. Epub 2009 Sep 16.

Wake and sleep EEG provide biomarkers in depression.

Steiger A, Kimura M.

Max Planck Institute of Psychiatry, Department of Psychiatry, Kraepelinstrasse 10, 80804 Munich, Germany. steiger@mpipsykl.mpg.de

Both wake and sleep electroencephalogram (EEG) provide biomarkers of depression and antidepressive therapy, respectively. For a long time it is known that EEG activity is altered by drugs. quantitative EEG analysis helps to delineate effects of antidepressants on brain activity. Cordance is an EEG measure with a superior correlation with regional brain perfusion. Prefrontal quantitative EEG cordance appears to be a predictor of the response to antidepressants. Sleep EEG  shows characteristic changes in depression as impaired sleep continuity, desinhibition of REM sleep and changes of nonREM sleep. Elevated REM density (a measure for frequency of rapid eye movements) characterizes an endophenotype in family studies of depression. REM-sleep changes including a more distinct REM rebound after sleep deprivation are found in animal models of depression. Most antidepressants suppress REM sleep in depressed patients, normal controls and laboratory animals. REM suppression appears to be a distinct, but not an absolute requirement for antidepressive effects of a compound. Sleep-EEG variables like REM latency or certain clusters of variables were shown to predict the response to the treatment with a certain antidepressant or even the course of the disorder for several years. Some of these predictive sleep-EEG markers of the longterm course of depression appear to be closely related to hypothalamo-pituitary-adrenocortical system activity.

http://www.ncbi.nlm.nih.gov/pubmed/19762038

J Sleep Res. 2010 Mar;19(1 Pt 2):214-27. Epub 2009 Oct 14.

Daytime sleepiness, psychomotor performance, waking EEG spectra and evoked potentials in women with severe premenstrual syndrome.

Baker FC, Colrain IM.

Human Sleep Research Program, SRI International, 333 Ravenswood Avenue, Menlo Park, CA 94043, USA. fiona.baker@sri.com

We assessed daytime sleepiness using objective and subjective measures in women with severe premenstrual syndrome (PMS) compared with women without significant premenstrual symptoms. Nine women with severe PMS and eight controls (aged 18-40  years) completed a laboratory-based daytime protocol including the maintenance of wakefulness test (MWT), psychomotor vigilance task (PVT), quantitative waking electroencephalogram (EEG), auditory and visual event-related potentials (ERPs),  and sleepiness and mood scales during the mid-follicular and late-luteal (premenstrual) phases of the menstrual cycle. In association with increased perceived sleepiness, fatigue and other premenstrual symptoms in the late-luteal  phase, women with PMS performed more poorly on the PVT, with increased lapses and slower reaction times (P < 0.05), compared with the follicular phase and controls. However, there were no significant group or menstrual phase differences in latency to sleep on the MWT. Waking spectral EEG power and ERP measures also did not differentiate PMS women when symptomatic. Both groups of women displayed  increased spectral power in the delta/theta frequencies (2-6 Hz) and fast alpha frequency (11-12 Hz) in the late-luteal phase relative to the follicular phase. Trait-like differences were apparent in that women with PMS had increased beta1 (12-16 Hz) power and smaller P300 amplitude than controls in both menstrual cycle phases. Our findings indicate that women with severe PMS are subjectively sleepy  and fatigued, and show psychomotor slowing when symptomatic compared with when they are symptom-free and compared with controls. However, the ability to maintain wakefulness under soporific conditions, spectral properties of waking EEG and cognitive processing do not vary in synchrony with premenstrual symptoms.

http://www.ncbi.nlm.nih.gov/pubmed/19840240

Neuroimage. 2010 Mar;50(1):99-111. Epub 2009 Dec 11.

A novel approach for enhancing the signal-to-noise ratio and detecting automatically event-related potentials (ERPs) in single trials.

Hu L, Mouraux A, Hu Y, Iannetti GD.

Department of Neuroscience, University College London, UK.

Brief radiant laser pulses can be used to activate cutaneous Adelta and C nociceptors selectively and elicit a number of transient brain responses in the ongoing EEG (N1, N2 and P2 waves of laser-evoked brain potentials, LEPs). Despite its physiological and clinical relevance, the early-latency N1 wave of LEPs is often difficult to measure reliably, because of its small signal-to-noise ratio (SNR), thus producing unavoidable biases in the interpretation of the results. Here, we aimed to develop a method to enhance the SNR of the N1 wave and measure  its peak latency and amplitude in both average and single-trial waveforms. We obtained four main findings. First, we suggest that the N1 wave can be better detected using a central-frontal montage (Cc-Fz), as compared to the recommended  temporal-frontal montage (Tc-Fz). Second, we show that the N1 wave is optimally detected when the neural activities underlying the N2 wave, which interfere with  the scalp expression of the N1 wave, are preliminary isolated and removed using independent component analysis (ICA). Third, we show that after these N2-related  activities are removed, the SNR of the N1 wave can be further enhanced using a novel approach based on wavelet filtering. Fourth, we provide quantitative evidence that a multiple linear regression approach can be applied to these filtered waveforms to obtain an automatic, reliable and unbiased estimate of the  peak latency and amplitude of the N1 wave, both in average and single-trial waveforms.

http://www.ncbi.nlm.nih.gov/pubmed/20004255

Sleep. 2010 Mar 1;33(3):297-306.

Abnormal sleep/wake dynamics in orexin knockout mice.

Diniz Behn CG, Klerman EB, Mochizuki T, Lin SC, Scammell TE.

Department of Neurology, Beth Israel Deaconess Medical Center Boston, MA, USA. cdbehn@umich.edu

STUDY OBJECTIVES: Narcolepsy with cataplexy is caused by a loss of orexin (hypocretin) signaling, but the physiologic mechanisms that result in poor maintenance of wakefulness and fragmented sleep remain unknown. Conventional scoring of sleep cannot reveal much about the process of transitioning between states or the variations within states. We developed an EEG spectral analysis technique to determine whether the state instability in a mouse model of narcolepsy reflects abnormal sleep or wake states, faster movements between states, or abnormal transitions between states. DESIGN: We analyzed sleep recordings in orexin knockout (OXKO) mice and wild type (WT) littermates using a state space analysis technique. This non-categorical approach allows quantitative and unbiased examination of sleep/wake states and state transitions. MEASUREMENTS AND RESULTS: OXKO mice spent less time in deep, delta-rich NREM sleep and in active, theta-rich wake and instead spent more time near the transition zones between states. In addition, while in the midst of what should be stable wake, OXKO mice initiated rapid changes into NREM sleep with high velocities normally seen only in transition regions. Consequently, state transitions were much more frequent and rapid even though the EEG progressions during state transitions were normal. CONCLUSIONS: State space analysis enables visualization of the boundaries between sleep and wake and shows that narcoleptic mice have less distinct and more labile states of sleep and wakefulness. These observations provide new perspectives on the abnormal state dynamics resulting from disrupted orexin signaling and highlight the usefulness of state space analysis in understanding narcolepsy and  other sleep disorders.

http://www.ncbi.nlm.nih.gov/pubmed/20337187

World J Biol Psychiatry. 2010 Mar;11(2 Pt 2):357-63.

Carbon dioxide-induced panic attacks and quantitative electroencephalogram in panic disorder patients.

Lopes FL, Oliveira MM, Freire RC, Caldirola D, Perna G, Bellodi L, Valença AM, Nascimento I, Piedade RA, Ribeiro P, Zin WA, Nardi AE.

Panic and Respiration Laboratory, Institute of Psychiatry, Federal University of  Rio de Janeiro, INCT Translational Medicine (CNPq), Rio de Janeiro, RJ, Brazil.

The objective of the study was to investigate and compare the brain cortical activity, as indexed by quantitative electroencephalographic (QEEG) power, coherence and asymmetry measures, in panic disorder (PD) patients during an induced panic attack with a 35% CO(2) challenge test and also in a resting condition. Fifteen subjects with PD were randomly assigned to both 35% CO(2) mixture and atmospheric compressed air, in a double-blind study design, with EEG  being recorded for a 20-min period. During induced panic attacks we found a reduced right-sided frontal orbital asymmetry in the beta band, a decreased occipital frontal intra-hemispheric coherence in the delta band at both right and left sides, a left-sided occipital delta inter-hemispheric asymmetry and an increased relative power in the beta wave at T4. Our data showed a disturbed frontal cortical processing, pointing to an imbalance of the frontal and occipital sites, common to both hemispheres, and an increased right posterior activity related to the high arousing panic attack condition. Those findings corroborate the Neuroanatomical hypothesis of PD.

http://www.ncbi.nlm.nih.gov/pubmed/19958206

Psychiatry Res. 2010 Feb 28;181(2):155-64. Epub 2009 Dec 16.

EEG source analysis of chronic fatigue syndrome.

Flor-Henry P, Lind JC, Koles ZJ.

Alberta Hospital Edmonton, Box 307, Edmonton, Edmonton, Alberta, Canada T5J 2J7.  Pierre.Flor-Henry@capitalhealth.ca

Sixty-one dextral, unmedicated women with chronic fatigue syndrome (CFS) diagnosed according to the Fukuda criteria (1994) and referred for investigation  by rheumatologists and internists were studied with quantitative EEG (43 channels) at rest with eyes open and during verbal and spatial cognitive activation. The EEGs from the patients were compared with recordings from 80 dextral healthy female controls. Only those subjects who could provide 20 1-s artefact-free segments of EEG were admitted into the study. The analysis consisted of the identification of the spatial patterns in the EEGs that maximally differentiated the two groups and the estimation of the cortical source distributions underlying these patterns. Spatial patterns were analyzed in the alpha (8-13Hz) and beta (14-20Hz) bands and the source distributions were estimated using the Borgiotti-Kaplan BEAMFORMER algorithm. The results indicate that the spatial patterns identified were effective in separating the two groups, providing a minimum correct retrospective classification rate of 72% in both frequency bands while the subjects were at rest to a maximum of 83% in the alpha  band during the verbal cognitive condition. Underlying cortical source distributions showed significant differences between the two groups in both frequency bands and in all cognitive conditions. Lateralized cortical differences were evident between the two groups in the both frequency bands during both the verbal and spatial cognitive conditions. During these active cognitive conditions, the CFS group showed significantly greater source-current activity than the controls in the left frontal-temporal-parietal regions of the cortex.

http://www.ncbi.nlm.nih.gov/pubmed/20006474

Epilepsia. 2010 Feb;51(2):243-50. Epub 2009 Sep 3.

Real-time differentiation of nonconvulsive status epilepticus from other encephalopathies using quantitative EEG analysis: a pilot study.

Zhang J, Xanthopoulos P, Liu CC, Bearden S, Uthman BM, Pardalos PM.

Department of Industrial and Systems Engineering, University of Florida, Gainesville, Florida, USA.

PURPOSE: Distinguishing nonconvulsive status epilepticus (NCSE) from some nonepileptic encephalopathies is a challenging problem. In many situations, NCSE  and nonepileptic encephalopathies are indistinguishable by clinical symptoms and  can produce very similar electroencephalography (EEG) patterns. Misdiagnosis or delay to diagnosis of NCSE may increase the rate of morbidity and mortality. METHODS: We developed a fast-differentiating algorithm using quantitative EEG analysis to distinguish NCSE patients from patients with toxic/metabolic encephalopathy (TME). EEG recordings were collected from 11 patients, including 6 with NCSE and 5 with TME. Three nonlinear dynamic measures were used in the proposed algorithm: the maximum short-term Lyapunov exponent (STLmax), phase of attractor (phase/angular frequency), and approximate entropy (ApEn). A further refined metric derived from STLmax and phase of attractor (the mean distance to EEG epoch samples from their centroid in the feature space) was also utilized as  a criterion. Paired t tests were carried out to further clarify the separation between the EEG patterns of NCSE and TME. RESULTS: Computational results showed that the performance of the proposed algorithm was sufficient to distinguish NCSE from TME. The results were consistent in all subjects in our study. CONCLUSIONS: The study presents evidence that the maximum short-term Lyapunov exponents (STLmax) and phase of attractors (phase/angular frequency) can be useful in assisting clinical diagnosis of NCSE. Findings presented in this article provide a promising indication that the proposed algorithm may correctly  distinguish NCSE from TME. Although the exact mechanism of this association remains unknown, the authors suggest that epileptic activity is highly associated with and can be modeled by dynamic systems.

http://www.ncbi.nlm.nih.gov/pubmed/19732132

Epilepsy Res. 2010 Feb;88(2-3):208-14. Epub 2009 Dec 30.

Children with new-onset epilepsy exhibit diffusion abnormalities in cerebral white matter in the absence of volumetric differences.

Hutchinson E, Pulsipher D, Dabbs K, Myers y Gutierrez A, Sheth R, Jones J, Seidenberg M, Meyerand E, Hermann B.

Neuroscience Training Program, University of Wisconsin, 7225 Medical Sciences Center, Madison, WI 53706, USA. ehutchinson@wisc.edu

The purpose of this investigation was to examine the diffusion properties of cerebral white matter in children with recent onset epilepsy (n=19) compared to healthy controls (n=11). Subjects underwent DTI with quantification of mean diffusion (MD), fractional anisotropy (FA), axial diffusivity (D(ax)) and radial  diffusivity (D(rad)) for regions of interest including anterior and posterior corpus callosum, fornix, cingulum, and internal and external capsules. Quantitative volumetrics were also performed for the corpus callosum and its subregions (anterior, midbody and posterior) and total lobar white and gray matter for the frontal, parietal, temporal and occipital lobes. The results demonstrated no group differences in total lobar gray or white matter volumes or  volume of the corpus callosum and its subregions, but did show reduced FA and increased D(rad) in the posterior corpus callosum and cingulum. These results provide the earliest indication of microstructural abnormality in cerebral white  matter among children with idiopathic epilepsies. This abnormality occurs in the  context of normal volumetrics and suggests disruption in myelination processes.

http://www.ncbi.nlm.nih.gov/pubmed/20044239

IEEE Trans Biomed Eng. 2010 Feb;57(2):469-78. Epub 2009 Sep 29.

Nonstationary brain source separation for multiclass motor imagery.

Gouy-Pailler C, Congedo M, Brunner C, Jutten C, Pfurtscheller G.

Department Images-Signal, Grenoble Images, Speech, Signal and Control Laboratory, Grenoble 38031, France. cedric.gouypailler@gmail.com

This paper describes a method to recover task-related brain sources in the context of multiclass brain--computer interfaces (BCIs) based on noninvasive EEG. We extend the method joint approximate diagonalization (JAD) for spatial filtering using a maximum likelihood framework. This generic formulation: 1) bridges the gap between the common spatial patterns (CSPs) and blind source separation of nonstationary sources; and 2) leads to a neurophysiologically adapted version of JAD, accounting for the successive activations/deactivations of brain sources during motor imagery (MI) trials. Using dataset 2a of BCI Competition IV (2008) in which nine subjects were involved in a four-class two-session MI-based BCI experiment, a quantitative evaluation of our extension is provided by comparing its performance against JAD and CSP in the case of cross-validation, as well as session-to-session transfer. While JAD, as already proposed in other works, does not prove to be significantly better than classical one-versus-rest CSP, our extension is shown to perform significantly better than  CSP for cross-validated and session-to-session performance. The extension of JAD  introduced in this paper yields among the best session-to-session transfer results presented so far for this particular dataset; thus, it appears to be of great interest for real-life BCIs.

http://www.ncbi.nlm.nih.gov/pubmed/19789106

J Clin Exp Neuropsychol. 2010 Feb;32(2):174-89. Epub 2009 May 29.

Neuropsychological effects of hostility and pain on emotion perception.

Mitchell GA, Harrison DW.

Adams State College, Alamosa, CO 81101, USA. gmollet@adams.edu

In order to examine the neuropsychological effects of hostility on emotional and  pain processing, auditory emotion perception before and after cold pressor pain in high and low hostile men was examined. Additionally, quantitative electroencephalography (QEEG) was recorded between each experimental manipulation. Results indicated that identification of emotion post cold pressor  differed as a function of hostility level and ear. Primary QEEG findings indicated increased left temporal activation after cold pressor exposure and increased reactivity to cold pressor pain in the high hostile group. Low hostile  men had a bilateral increase in high beta magnitude at the temporal lobes and a bilateral increase in delta magnitude at the frontal lobes after the cold pressor. Taken together, results from the dichotic listening task and the QEEG suggest decreased cerebral laterality and left hemisphere activation for emotional and pain processing in high hostile men.

http://www.ncbi.nlm.nih.gov/pubmed/19484642

J Inherit Metab Dis. 2010 Feb;33(1):85-90. Epub 2010 Jan 6.

A new case of GABA transaminase deficiency facilitated by proton MR spectroscopy.

Tsuji M, Aida N, Obata T, Tomiyasu M, Furuya N, Kurosawa K, Errami A, Gibson KM,  Salomons GS, Jakobs C, Osaka H.

Clinical Research Institute, Kanagawa Children's Medical Center, Minami-ku, Yokohama, Japan.

BACKGROUND: Deficiency of 4-aminobutyrate aminotransferase (GABA-T) is a rare disorder of GABA catabolism, with only a single sibship reported. We report on a  third case, a Japanese female infant with severe psychomotor retardation and recurrent episodic lethargy with intractable seizures, with the diagnosis facilitated by proton magnetic resonance (MR) spectroscopy ((1)H-MRS). METHODS: Neuroimaging was performed at the first episode of lethargy. For (1)H-MRS, locations were placed in the semioval center and the basal ganglia. Quantification of metabolite concentrations were derived using the LCModel. We confirmed the diagnosis subsequently by enzyme and molecular studies, which involved direct DNA sequence analysis and the development of a novel multiplex ligation-dependent probe amplification test. RESULTS: (1)H-MRS analysis revealed an elevated GABA concentration in the basal ganglia (2.9 mmol/l). Based on the results of quantitative (1)H-MRS and clinical  findings, GABA-T deficiency was suspected and confirmed in cultured lymphoblasts. Molecular studies of the GABA-T gene revealed compound heterozygosity for a deletion of one exon and a missense mutation, 275G>A, which was not detected in 210 control chromosomes. CONCLUSIONS: Our results suggest that excessive prenatal GABA exposure in the central nervous system (CNS) was responsible for the clinical manifestations of GABA transaminase deficiency. Our findings suggest the dual nature of GABA as an  excitatory molecule early in life, followed by a functional switch to an inhibitory species later in development. Furthermore, quantitative (1)H-MRS appears to be a useful, noninvasive tool for detecting inborn errors of GABA metabolism in the CNS.

http://www.ncbi.nlm.nih.gov/pubmed/20052547

J Perinatol. 2010 Feb;30(2):122-6. Epub 2009 Sep 10.

quantitative EEG in babies at risk for hypoxic ischemic encephalopathy after perinatal asphyxia.

Hathi M, Sherman DL, Inder T, Rothman NS, Natarajan M, Niesen C, Korst LM, Pantano T, Natarajan A.

Infinite Biomedical Technologies, Baltimore, MD 21211, USA. manan@i-biomed.com

OBJECTIVE: To evaluate an electroencephalography (EEG)-based index, the Cerebral  Health Index in babies (CHI/b), for identification of neonates with high Sarnat scores and abnormal EEG as markers of hypoxic ischemic encephalopathy (HIE) after perinatal asphyxia. STUDY DESIGN: This is a retrospective study using 30 min of EEG data collected from 20 term neonates with HIE and 20 neurologically normal neonates. The HIE diagnosis was made on clinical grounds based on history and examination findings. The maximum-modified clinical Sarnat score was used to grade HIE severity within  72 h of life. All neonates underwent 2-channel bedside EEG monitoring. A trained  electroencephalographer blinded to clinical data visually classified each EEG as  normal, mild or severely abnormal. The CHI/b was trained using data from Channel  1 and tested on Channel 2. RESULT: The CHI/b distinguished among HIE and controls (P<0.02) and among the three visually interpreted EEG categories (P<0.0002). It showed a sensitivity of  82.4% and specificity of 100% in detecting high grades of neonatal encephalopathy (Sarnat 2 and 3), with an area under the receiver operator characteristic (ROC) curve of 0.912. CHI/b also identified differences between normal vs mildly abnormal (P<0.005), mild vs severely abnormal (P<0.01) and normal vs severe (P<0.002) EEG groups. An ROC curve analysis showed that the optimal ability of CHI/b to discriminate poor outcome was 89.7% (sensitivity: 87.5%; specificity: 82.4%). CONCLUSION: The CHI/b identified neonates with high Sarnat scores and abnormal EEG. These results support its potential as an objective indicator of neurological injury in infants with HIE.

http://www.ncbi.nlm.nih.gov/pubmed/19741652

Neurobiol Aging. 2010 Feb;31(2):215-23.

Slowing of EEG correlates with CSF biomarkers and reduced cognitive speed in elderly with normal cognition over 4 years.

Stomrud E, Hansson O, Minthon L, Blennow K, Rosén I, Londos E.

Clinical Memory Research Unit, Department of Clinical Sciences Malmö, Lund University, S-205 02 Malmö, Sweden. erik.stomrud@med.lu.se

BACKGROUND: Cerebrospinal fluid (CSF) biomarkers and quantitative EEG show particular patterns of change in Alzheimer's disease (AD) and reflect neuropathologic processes and cerebral function, respectively. The changes precede cognitive decline and should be visible already in preclinical stages. We therefore aimed to investigate their relationship in cognitively healthy individuals. METHOD: Thirty-three (33) elderly individuals with repeated normal scores on cognitive tests over 4.5 years underwent EEG recording with quantitative frequency analysis and analysis of CSF total tau (T-tau), phosphorylated tau (P-tau) and beta-amyloid(1-42) (Abeta42). RESULTS: CSF T-tau and P-tau correlated with relative EEG theta power (r(s)>0.545; p<0.01), but not with relative alpha, beta or delta power. The combined P-tau/Abeta42 ratio exhibited an even stronger correlation with relative theta power (r(s)=0.622; p<0.001), especially in the right posterior quadrant of  the head (r(s)=0.643; p<10(-4)). Slowing of cognitive speed correlated with increased relative theta power, foremost in the posterior quadrants (r(s)>0.503;  p<0.01), and high P-tau/Abeta42 ratio (r(s)>0.462; p<0.01). CONCLUSIONS: Our results suggest that already in cognitively healthy elderly subjects, biochemical changes in CSF, and the possible underlying neuropathologic processes it reflects, have an effect on cerebral function as visualized by the EEG rhythm and cognitive speed. It hereby suggests that CSF biomarkers and EEG theta activity might indicate early abnormal degenerative changes in the brain.

http://www.ncbi.nlm.nih.gov/pubmed/18462837

Neuroimage. 2010 Feb 1;49(3):2735-45. Epub 2009 Oct 27.

Cortical gamma-oscillations modulated by listening and overt repetition of phonemes.

Fukuda M, Rothermel R, Juhász C, Nishida M, Sood S, Asano E.

Department of Pediatrics, Children's Hospital of Michigan, Wayne State University, Detroit, MI 48201, USA.

Both superior temporal gyrus and inferior Rolandic area have been reported to be  involved in perception and production of speech in humans. Here, we determined how these cortical structures were activated by listening and subsequent overt articulation of syllables, by measuring event-related gamma-oscillations as quantitative measures of cortical activation. Fifteen subjects were presented an  auditory syllable consisting of either "fee [fi:]," "faa [falpha:]," "hee [hi:]," or "haa [halpha:]," and were instructed to overtly repeat each given syllable. Gamma-oscillations in the superior temporal gyrus were highly augmented during syllable-presentation, least augmented at the onset of syllable-articulation, and again highly augmented following syllable-articulation. Gamma-oscillations were augmented in the inferior Rolandic area prior to and during syllable-articulation with the onset and peak occurring earlier in the left side. Subsets of the inferior Rolandic sites, more frequently on the left side, showed differential gamma-augmentation elicited by articulation of phoneme [f] more than [h] or phoneme [i:] more than [alpha:]. Our observations suggest that the superior temporal gyrus may be active when externally presented or articulated auditory stimuli are present, and may be minimally active when articulation is about to be initiated. Our novel observation of phoneme-specific differential gamma-augmentation in the inferior Rolandic area may be partially attributed to the mouth position during phoneme-articulation. Our observations support the hypothesis that positioning of the mouth to articulate phonemes is predominantly  driven and/or monitored by the primary sensorimotor area on the left side.

http://www.ncbi.nlm.nih.gov/pubmed/19874898

Mol Pain. 2010 Jan 21;6:3.

Effects of Parecoxib and Fentanyl on nociception-induced cortical activity.

Peng YZ, Li XX, Wang YW.

Department of Anesthesiology, Xinhua Hospital, Shanghai Jiaotong University School of Medicine, Shanghai 200092, China.

BACKGROUND: Analgesics, including opioids and non-steroid anti-inflammatory drugs reduce postoperative pain. However, little is known about the quantitative effects of these drugs on cortical activity induced by nociceptive stimulation. The aim of the present study was to determine the neural activity in response to  a nociceptive stimulus and to investigate the effects of fentanyl (an opioid agonist) and parecoxib (a selective cyclooxygenase-2 inhibitor) on this nociception-induced cortical activity evoked by tail pinch. Extracellular recordings (electroencephalogram and multi-unit signals) were performed in the area of the anterior cingulate cortex while intracellular recordings were made in the primary somatosensory cortex. The effects of parecoxib and fentanyl on induced cortical activity were compared. RESULTS: Peripheral nociceptive stimulation in anesthetized rats produced an immediate electroencephalogram (EEG) desynchronization resembling the cortical arousal (low-amplitude, fast-wave activity), while the membrane potential switched into a persistent depolarization state. The induced cortical activity was abolished by fentanyl, and the fentanyl's effect was reversed by the opioid receptor antagonist, naloxone. Parecoxib, on the other hand, did not significantly affect the neural activity. CONCLUSION: Cortical activity was modulated by nociceptive stimulation in anesthetized rats. Fentanyl showed a strong inhibitory effect on the nociceptive-stimulus induced cortical activity while parecoxib had no significant effect.

http://www.ncbi.nlm.nih.gov/pubmed/20089200

Neurosci Lett. 2010 Jan 18;469(1):145-9. Epub 2009 Nov 27.

Gamma band oscillations under influence of bromazepam during a sensorimotor integration task: an EEG coherence study.

Minc D, Machado S, Bastos VH, Machado D, Cunha M, Cagy M, Budde H, Basile L, Piedade R, Ribeiro P.

Brain Mapping and Sensory Motor Integration, Institute of Psychiatry of Federal University of Rio de Janeiro (IPUB/UFRJ), Rio de Janeiro, RJ, Brazil.

The goal of the present study was to explore the dynamics of the gamma band using the coherence of the quantitative electroencephalography (QEEG) in a sensorimotor integration task and the influence of the neuromodulator bromazepam on the band behavior. Our hypothesis is that the needs of the typewriting task will demand the coupling of different brain areas, and that the gamma band will promote the binding of information. It is also expected that the neuromodulator will modify this coupling. The sample was composed of 39 healthy subjects. We used a randomized double-blind design and divided subjects into three groups: placebo (n=13), bromazepam 3mg (n=13) and bromazepam 6 mg (n=13). The two-way ANOVA analysis demonstrated a main effect for the factors condition (i.e., C4-CZ electrode pair) and moment (i.e., C3-CZ, C3-C4 and C4-CZ pairs of electrodes). We propose that the gamma band plays an important role in the binding among several  brain areas in complex motor tasks and that each hemisphere is influenced in a different manner by the neuromodulator.

http://www.ncbi.nlm.nih.gov/pubmed/19945509

Arch Dis Child Fetal Neonatal Ed. 2010 Jan;95(1):F53-8. Epub 2009 Aug 13.

Effect of the "InSurE" procedure on cerebral oxygenation and electrical brain activity of the preterm infant.

van den Berg E, Lemmers PM, Toet MC, Klaessens JH, van Bel F.

Department of Neonatology, Room KE.04.123.1, Wilhelmina Children's Hospital, University Medical Center Utrecht, PO Box 85090, 3508 AB Utrecht, The Netherlands.

BACKGROUND: In preterm infants with respiratory distress syndrome (RDS) nasal continuous positive airway pressure (nCPAP) with the "InSurE" procedure (intubation, surfactant, extubation) is increasingly used. However, its effect on cerebral oxygenation and brain function is not known. OBJECTIVE: To evaluate the effects of the "InSurE" procedure in infants with RDS  on regional cerebral oxygen saturation (rScO(2)) and relative cerebral fractional tissue oxygen extraction (cFTOE) using near infrared spectroscopy and on electrical brain activity using amplitude-integrated electroencephalography (aEEG). METHODS: Sixteen infants with RDS, treated with the "InSurE" procedure, and 16 matched controls with nCPAP, were monitored for mean arterial blood pressure (MABP), arterial oxygen saturation (SaO(2)), rScO(2), cFTOE and aEEG. Ten-minute  periods were selected and averaged at 120 and 20 minutes before, during the procedure and at 30 minutes, 1, 2, 6, 12 and 24 h after the start of the "InSurE" procedure. aEEG was analysed by quantitative and qualitative (Burdjalov score) methods. RESULTS: MABP was not different between groups on all time points. rScO(2) and cFTOE were comparable between groups, but there was a trend towards lower rScO(2) and higher cFTOE 30 minutes after opioid administration in the "InSurE" infants compared with controls (62% (SD 11) vs 68% (SD 10) and 0.30 (SD 0.10 ) vs 0.28 (SD 0.11), respectively). aEEG amplitudes and Burdjalov scores were significantly lower in "InSurE" infants from 30 minutes after opioid administration up to 24 h  after the start of the procedure (p<0.05). CONCLUSION: In the present study, the "InSurE" procedure did not induce perturbation of cerebral oxygen delivery and extraction, whereas electrical brain activity decreased for a prolonged period of time.

http://www.ncbi.nlm.nih.gov/pubmed/19679893

Clin EEG Neurosci. 2010 Jan;41(1):32-41.

Post WISC-R and TOVA improvement with QEEG guided neurofeedback training in mentally retarded: a clinical case series of behavioral problems.

Surmeli T, Ertem A.

Living Mental Healthy Center for Research and Education, Istanbul, Turkey. neuropsychiatry@yahoo.com

According to the DSM-IV, Mental Retardation is significantly sub-average general  intellectual functioning accompanied by significant limitations in adaptive functioning in at least two of the following skill areas: communication, self-care, home living, social/interpersonal skills, use of community resources,  self-direction, functional academic skills, work, leisure, health and safety. In  pilot work, we have seen positive clinical effects of Neurofeedback (NF) applied  to children with Trisomy 21 (Down Syndrome) and other forms of mental retardation. Given that many clinicians use NF in Attention Deficit Hyperactivity Disorder and Generalized Learning Disability cases, we studied the outcomes of a  clinical case series using quantitative EEG (QEEG) guided NF in the treatment of  mental retardation. All 23 subjects received NF training. The QEEG data for most  subjects had increased theta, alpha, and coherence abnormalities. A few showed increased delta over the cortex. Some of the subjects were very poor in reading and some had illegible handwriting, and most subjects had academic failures, impulsive behavior, and very poor attention, concentration, memory problems, and  social skills. This case series shows the impact of QEEG-guided NF training on these clients' clinical outcomes. Fourteen out of 23 subjects formerly took medications without any improvement. Twenty-three subjects ranging from 7-16 years old attending private learning centers were previously diagnosed with mental retardation (severity of degree: from moderate to mild) at various university hospitals. Evaluation measures included QEEG analysis, WISC-R (Wechsler Intelligence Scale for Children-Revised) IQ test, TOVA (Test of Variables of Attention) test, and DPC-P (Developmental Behaviour Checklist) were  filled out by the parents. NF trainings were performed by Lexicor Biolex software. NX-Link was the commercial software reference database used to target the treatment protocols, along with the clinical judgment of the first author. QEEG signals were sampled at 128 samples per second per channel and electrodes were placed according to the International 10-20 system. Between 80 and 160 NF training sessions were completed, depending on the case. None of the subjects received any special education during NF treatment. Two subjects with the etiology of epilepsy were taking medication, and the other 21 subjects were medication-free at the baseline. Twenty-two out of 23 patients who received NF training showed clinical improvement according to the DPC-P with QEEG reports. Nineteen out of 23 patients showed significant improvement on the WISC-R, and the TOVA. For the WISC-R test, 2 showed decline on total IQ due to the decline on some of the subtests, 2 showed no improvement on total IQ although improvement was seen on some of the subtests, however even these cases showed improvement on  QEEG and DPC-P. This study provides the first evidence for positive effects of NF treatment in mental retardation. The results of this study encourage further research.

http://www.ncbi.nlm.nih.gov/pubmed/20307014

Clin Neurophysiol. 2010 Jan;121(1):7-13. Epub 2009 Nov 11.

Partial seizures are associated with early increases in signal complexity.

Jouny CC, Bergey GK, Franaszczuk PJ.

Johns Hopkins University School of Medicine, Department of Neurology - Epilepsy Research Laboratory, Meyer 2-147, 600 N Wolfe Street, Baltimore, MD 21287, USA. cjouny@jhmi.edu

OBJECTIVES: Partial seizures are often believed to be associated with EEG signals of low complexity because seizures are associated with increased neural network synchrony. The investigations reported here provide an assessment of the signal complexity of epileptic seizure onsets using newly developed quantitative measures. METHODS: Using the Gabor atom density (GAD) measure of signal complexity, 339 partial seizures in 45 patients with intracranial electrode arrays were analyzed. Segmentation procedures were applied to determine the timing and amplitude of GAD changes relative to the electrographic onset of the seizure. RESULTS: Three hundred and thirty out of 339 seizures have significant complexity level changes, with 319 (97%) having an increase in complexity. GAD increases occur within seconds of the onset of the partial seizure but are not observed in  channels remote from the focus. The complexity increase is similar for seizures from mesial temporal origin, neocortical temporal and extra-temporal origin. CONCLUSIONS: Partial onset seizures are associated with early increases in signal complexity as measured by GAD. This increase is independent of the location of the seizure focus. SIGNIFICANCE: Despite the often predominant rhythmic activity that characterizes  onset and early evolution of epileptic seizures, partial seizure onset is associated with an early increase in complexity. These changes are common to partial seizures originating from different brain regions, indicating a similar seizure dynamic.

http://www.ncbi.nlm.nih.gov/pubmed/19910249

Clin Neurophysiol. 2010 Jan;121(1):21-38. Epub 2009 Oct 23.

Neurophysiological changes with age probed by inverse modeling of EEG spectra.

van Albada SJ, Kerr CC, Chiang AK, Rennie CJ, Robinson PA.

School of Physics, The University of Sydney, NSW 2006, Australia. s.van.albada@fz-juelich.de

OBJECTIVE: To investigate age-associated changes in physiologically-based EEG spectral parameters in the healthy population. METHODS: Eyes-closed EEG spectra of 1498 healthy subjects aged 6-86 years were fitted to a mean-field model of thalamocortical dynamics in a cross-sectional study. Parameters were synaptodendritic rates, cortical wave decay rates, connection strengths (gains), axonal delays for thalamocortical loops, and power  normalizations. Age trends were approximated using smooth asymptotically linear functions with a single turning point. We also considered sex differences and relationships between model parameters and traditional quantitative EEG measures. RESULTS: The cross-sectional data suggest that changes tend to be most rapid in childhood, generally leveling off at age 15-20 years. Most gains decrease in magnitude with age, as does power normalization. Axonal and dendritic delays decrease in childhood and then increase. Axonal delays and gains show small but significant sex differences. CONCLUSIONS: Mean-field brain modeling allows interpretation of age-associated EEG trends in terms of physiological processes, including the growth and regression of white matter, influencing axonal delays, and the establishment and  pruning of synaptic connections, influencing gains. SIGNIFICANCE: This study demonstrates the feasibility of inverse modeling of EEG  spectra as a noninvasive method for investigating large-scale corticothalamic dynamics, and provides a basis for future comparisons.

http://www.ncbi.nlm.nih.gov/pubmed/19854102

Conf Proc IEEE Eng Med Biol Soc. 2010;2010:3723-6.

Analysis of the relationship between interictal electrical source imaging and PET hypometabolism.

Person C, Koessler L, Louis-Dorr V, Wolf D, Maillard L, Marie PY.

Centre de Recherche en Automatique de Nancy (CRAN, UMR 7039), Nancy-Université, CNRS, France. christophe.person@ensem.inpl-nancy.fr

The aim of this paper is to compare interictal EEG source localizations with statistical analysis of hypometabolisms in PET brain imaging. Both methods are currently used in the pre-surgical evaluation of drug-resistant partial epilepsy, but the relationship between electrical source localizations and hypometabolic areas has not been well defined yet. At the present time, these two methods have  been performed on five patients in order to develop a comparative quantitative study with these first results which should be then extended to a larger patient  database.

http://www.ncbi.nlm.nih.gov/pubmed/21096861

Conf Proc IEEE Eng Med Biol Soc. 2010;2010:2690-3.

Using ERPs for assessing the (sub) conscious perception of noise.

Porbadnigk AK, Antons JN, Blankertz B, Treder MS, Schleicher R, Moller S, Curio G.

Machine Learning Laboratory, Berlin Institute of Technology, 10587 Berlin, Germany. anne.k.porbadnigk@tu-berlin.de

In this paper, we investigate the use of event-related potentials (ERPs) as a quantitative measure for quality assessment of disturbed audio signals. For this  purpose, we ran an EEG study (N=11) using an oddball paradigm, during which subjects were presented with the phoneme /a/, superimposed with varying degrees of signal-correlated noise. Based on this data set, we address the question to which degree the degradation of the auditory stimuli is reflected on a neural level, even if the disturbance is below the threshold of conscious perception. For those stimuli that are consciously recognized as being disturbed, we suggest  the use of the amplitude and latency of the P300 component for assessing the level of disturbance. For disturbed stimuli for which the noise is not perceived  consciously, we show for two subjects that a classifier based on shrinkage LDA can be applied successfully to single out stimuli, for which the noise was presumably processed subconsciously.

http://www.ncbi.nlm.nih.gov/pubmed/21096200

Conf Proc IEEE Eng Med Biol Soc. 2010;2010:2447-50.

Assisted diagnosis of attention-deficit hyperactivity disorder through EEG bandpower clustering with self-organizing maps.

Alba-Sanchez F, Yanez-Suarez O, Brust-Carmona H.

Neuroimaging Laboratory, Universidad Autonoma Metropolitana - Iztapalapa, Mexico. chambridubri@gmail.com

The electroencephalogram is an attractive clinical tool given its non-invasive nature, its ability to reflect real-time changes in local cortical activity, and  the load of objective bioelectrical measurements that can be derived from it. For decades, the electroencephalogram has been successfully used for diagnosing epilepsy and schizophrenia, among other brain disorders. This paper focuses in the design and implementation of a computer-aided diagnostic tool for establishing the likelihood of presence of Attention-Deficit Hyperactivity Disorder in children, out of routine electroencephalographic recordings obtained  during a specific visual stimulation protocol. Classical bandpower features from  multiple differential recordings are computed and used as features in a classifier built from a cooperative ensemble of labeled self-organizing maps. Classification accuracy of the proposed system is 0,7 ± 0,11, as estimated from unseen data, a result that points to the idea that such a quantitative diagnostic aid could adequately support the diagnostic task of a clinical expert.

http://www.ncbi.nlm.nih.gov/pubmed/21095960

Crit Care. 2010;14(3):R81. Epub 2010 May 5.

Endotoxemia-induced inflammation and the effect on the human brain.

van den Boogaard M, Ramakers BP, van Alfen N, van der Werf SP, Fick WF, Hoedemaekers CW, Verbeek MM, Schoonhoven L, van der Hoeven JG, Pickkers P.

Department of Intensive Care Medicine, Radboud University Nijmegen Medical Centre, PO Box 9101, Nijmegen 6500HB, the Netherlands. m.vandenboogaard@ic.umcn.nl

Comment in     Crit Care. 2010;14(3):165.

INTRODUCTION: Effects of systemic inflammation on cerebral function are not clear, as both inflammation-induced encephalopathy as well as stress-hormone mediated alertness have been described. METHODS: Experimental endotoxemia (2 ng/kg Escherichia coli lipopolysaccharide [LPS]) was induced in 15 subjects, whereas 10 served as controls. Cytokines (TNF-alpha, IL-6, IL1-RA and IL-10), cortisol, brain specific proteins (BSP), electroencephalography (EEG) and cognitive function tests (CFTs) were determined. RESULTS: Following LPS infusion, circulating pro- and anti-inflammatory cytokines, and cortisol increased (P < 0.0001). BSP changes stayed within the normal range, in which neuron specific enolase (NSE) and S100-beta changed significantly. Except in one subject with a mild encephalopathic episode, without cognitive dysfunction, endotoxemia induced no clinically relevant EEG changes. quantitative EEG analysis showed a higher state of alertness detected by changes  in the central region, and peak frequency in the occipital region. Improved CFTs  during endotoxemia was found to be due to a practice effect as CFTs improved to the same extent in the reference group. Cortisol significantly correlated with a  higher state of alertness detected on the EEG. Increased IL-10 and the decreased  NSE both correlated with improvement of working memory and with psychomotor speed capacity. No other significant correlations between cytokines, cortisol, EEG, CFT and BSP were found. CONCLUSIONS: Short-term systemic inflammation does not provoke or explain the occurrence of septic encephalopathy, but primarily results in an inflammation-mediated increase in cortisol and alertness. TRIAL REGISTRATION: NCT00513110.

http://www.ncbi.nlm.nih.gov/pubmed/20444270

Curr Top Behav Neurosci. 2010;4:283-309.

Neurophysiological measures of sensory registration, stimulus discrimination, and selection in schizophrenia patients.

Rissling AJ, Light GA.

Department of Psychiatry, University of California, San Diego, CA 92093-0804, USA. ajrissling@ucsd.edu

Cortical Neurophysiological event related potentials (ERPs) are multidimensional  measures of information processing that are well suited to efficiently parse automatic and controlled components of cognition that span the range of deficits  exhibited in schizophrenia patients. Components following a stimulus reflect the  sequence of neural processes triggered by the stimulus, beginning with early automatic sensory processes and proceeding through controlled decision and response related processes. Previous studies employing ERP paradigms have reported deficits of information processing in schizophrenia across automatic through attention dependent processes including sensory registration (N1), automatic change detection (MMN), the orienting or covert shift of attention towards novel or infrequent stimuli (P3a), and attentional allocation following successful target detection processes (P3b). These automatic and attention dependent information components are beginning to be recognized as valid targets  for intervention in the context of novel treatment development for schizophrenia  and related neuropsychiatric disorders. In this review, we describe three extensively studied ERP components (N1, mismatch negativity, P300) that are consistently deficient in schizophrenia patients and may serve as genetic endophenotypes and as quantitative biological markers of response outcome.

http://www.ncbi.nlm.nih.gov/pubmed/21312404

Fiziol Cheloveka. 2010 Jan-Feb;36(1):5-17.

[Normative EEG spectral characteristics in healthy subjects from 7 to 89 years].

[Article in Russian]

Tereshchenko EP, Ponomarev VA, Muller A, Kropotov IuD.

EEGs were recorded at 885 healthy subjects of both sexes with age from 7 to 89 years in "eyes closed" and "eyes opened" conditions. Both average EEG power spectra and EEG independent component power spectra were computed for 20 age groups of subjects separately, and corresponding confidence intervals of average  power were estimated for four frequency bands: delta, theta, alpha and beta. These quantitative data can be useful as objective criteria for diagnostics of brain dysfunctions.

http://www.ncbi.nlm.nih.gov/pubmed/20196443

J Psychiatr Res. 2010 Jan;44(2):90-8. Epub 2009 Jul 24.

Antidepressant response trajectories and quantitative electroencephalography (QEEG) biomarkers in major depressive disorder.

Hunter AM, Muthén BO, Cook IA, Leuchter AF.

Semel Institute for Neuroscience and Human Behavior at UCLA, Department of Psychiatry and Biobehavioral Sciences, David Geffen School of Medicine at UCLA, Los Angeles, CA 90024-1759, United States. amhunter@ucla.edu

Individuals with Major Depressive Disorder (MDD) vary regarding the rate, magnitude and stability of symptom changes during antidepressant treatment. Growth mixture modeling (GMM) can be used to identify patterns of change in symptom severity over time. Quantitative electroencephalographic (QEEG) cordance  within the first week of treatment has been associated with endpoint clinical outcomes but has not been examined in relation to patterns of symptom change. Ninety-four adults with MDD were randomized to eight weeks of double-blinded treatment with fluoxetine 20mg or venlafaxine 150mg (n=49) or placebo (n=45). An  exploratory random effect GMM was applied to Hamilton Depression Rating Scale (Ham-D(17)) scores over 11 timepoints. Linear mixed models examined 48-h, and 1-week changes in QEEG midline-and-right-frontal (MRF) cordance for subjects in the GMM trajectory classes. Among medication subjects an estimated 62% of subjects were classified as responders, 21% as non-responders, and 17% as symptomatically volatile-i.e., showing a course of alternating improvement and worsening. MRF cordance showed a significant class-by-time interaction (F((2,41))=6.82, p=.003); as hypothesized, the responders showed a significantly  greater 1-week decrease in cordance as compared to non-responders (mean difference=-.76, Std. Error=.34, df=73, p=.03) but not volatile subjects. Subjects with a volatile course of symptom change may merit special clinical consideration and, from a research perspective, may confound the interpretation of typical binary endpoint outcomes. Statistical methods such as GMM are needed to identify clinically relevant symptom response trajectories.

http://www.ncbi.nlm.nih.gov/pubmed/19631948

Med Pregl. 2010 Jan-Feb;63(1-2):40-6.

[Visual vs. quantitative electroencephalographic analysis in patients with and without posttraumatic epilepsy].

[Article in Serbian]

Ljesević B, Martinović Z, Popović M, Jović S.

Klinika za rehabilitaciju "Dr Miroslav Zotović", Beograd. slavce@beotel.yu

INTRODUCTION: We investigated traces of EEG records from two groups of patients with brain trauma: with and without posttraumatic epilepsy (PTE) with respect to  the control group by means of two methods: visual and quantitative EEG (QEEG) analysis. The aim of this study was to compare these methods in their sensibility for traumatic and epileptic alterations of the brain tissue in the two experimental conditions: after hyperventilation (HV) and after photo stimulation  (FS), and in regard to the basic condition. MATERIAL AND METHODS: 36 patients with PTE and 33 without PTE, and the control group of 34 healthy subjects participated in this study. EEG was registered in three 1-min epochs: before activation, after HIV, and after FS on digital 32-channel EEG apparatus XLTEK. Mean amplitudes were calculated in 10 frequency ranges from 0 to 30 Hz on projections F7-C3, T5-O1, F8-C4 and T6-O2 from 16-s segments without artefacts. Data evaluation was performed using program package PERSYST Insight II (Persyst Development Co). Statistical package GRAPII-PAD was used for ANOVA test and Bonferroni post-test. RESULTS: Visual analysis used to distinguish between normal EEG, with pathological alterations, non-epileptiform and epileptiform transients showed that there was no statistically significant difference between patients with and  without post-traumatic epilepsy. On the contrary, QEEG of registered epochs before activation, after HV and after FS showed statistically significant differences between the control group and the patients without PTE and with PTE. CONCLUSION: These results indicate that quantitative analysis provides more subtle data about el ectrophysiological alterations after traumatic brain injury, which leads to better classification of patients.

http://www.ncbi.nlm.nih.gov/pubmed/20873308

Neonatology. 2010;97(2):175-82. Epub 2009 Oct 28.

Quantitative analysis of amplitude-integrated electroencephalogram patterns in stable preterm infants, with normal neurological development at one year.

Niemarkt HJ, Andriessen P, Peters CH, Pasman JW, Blanco CE, Zimmermann LJ, Bambang Oetomo S.

Neonatal Intensive Care Unit, Máxima Medical Centre, Veldhoven, The Netherlands.

BACKGROUND: The amplitude-integrated EEG (aEEG) is feasible for monitoring cerebral activity in preterm infants. However, quantitative data on normal patterns in these infants are limited. OBJECTIVE: To study maturational aEEG changes in a cohort of stable preterm infants by automated quantification. METHODS: In a cohort of stable preterm infants with gestational age (GA) <32 weeks and normal neurological follow-up at 1 year, weekly 4 h EEG recordings were performed. aEEG traces were obtained from channel C(3)-C(4). The upper margin amplitude (UMA), lower margin amplitude (LMA) and bandwidth (BW) were quantitatively calculated using an expert software system. In addition, the relative duration of discontinuous background pattern (discontinuous background defined as activity with LMA <5 microV, expressed as DC-%) was calculated. RESULTS: 79 aEEG recordings (4-6 recordings/infant) were obtained in 18 infants.  Analysis of the first week recordings demonstrated a strong positive correlation  between GA and LMA, while DC-% decreased significantly. Longitudinally, all infants showed increase of LMA. Multivariate analysis showed that GA and postnatal age (PA) both contributed independently and equally to LMA and DC-%. We found a strong correlation between postmenstrual age (GA + PA) and LMA and DC-%,  respectively. CONCLUSION: To our knowledge, this is the first study where aEEG development was  studied by automated quantification of aEEG characteristics in a cohort of stable preterm infants with a normal neurological development at 1 year of age. LMA and  DC-% are simple quantitative measures of neurophysiologic development and may be  used to evaluate neurodevelopment in infants.

http://www.ncbi.nlm.nih.gov/pubmed/19864923

Neuroimage. 2010 Jan 1;49(1):488-97. Epub 2009 Jul 24.

Quantitative imaging of spontaneous neuromagnetic activity for assessing cerebral ischemia using sLORETA-qm.

Sakamoto S, Tanaka H, Tsuyuguchi N, Terakawa Y, Ohata K, Inoue Y, Miki Y, Hara M, Takahashi Y, Nitta K, Sawa H, Satone A, Ide W, Hashimoto I, Kamada H.

Department of Neurosurgery, Hokuto Hospital, Obihiro, Japan. s-sakamoto@med.osaka-cu.ac.jp

To image cerebral neural activity in ischemic areas, we proposed a novel technique to analyze spontaneous neuromagnetic fields based on standardized low-resolution brain electromagnetic tomography modified for a quantifiable method (sLORETA-qm). Using a 160-channel whole-head-type magnetoencephalographic  system, cerebral magnetic fields were obtained pre- and postoperatively from 5 patients with unilateral internal carotid artery occlusive disease and 16 age-matched healthy volunteers. For quantitative imaging, voxel-based time-averaged intensities of slow waves in 4 frequency bands (0.3-2 Hz, 2-4 Hz, 4-6 Hz and 6-8 Hz) were obtained by the proposed technique based on sLORETA-qm. Positron emission tomography with (15)O gas inhalation ((15)O-PET) was also performed in these patients to evaluate cerebral blood flow and metabolism. In all 5 patients, slow waves in every frequency band were distributed in the area of cerebrovascular insufficiency, as confirmed by (15)O-PET preoperatively. In 4  patients, slow-wave intensities in theta bands (4-6 Hz, 6-8 Hz) decreased postoperatively along with improvements in cerebral blood flow and metabolism, whereas delta bands (0.3-2 Hz, 2-4 Hz) showed no significant differences between  pre- and postoperatively. One patient with deterioration of cerebral infarction after surgery showed marked increases in slow-wave intensities in delta bands (0.3-2 Hz, 2-4 Hz) postoperatively, with distribution close to the infarct region. The proposed quantitative imaging of spontaneous neuromagnetic fields enabled clear visualization and alternations of cerebral neural conditions in the ischemic area. This technique may offer a novel, non-invasive method for identifying cerebral ischemia, although further studies in a larger number of patients are warranted.

http://www.ncbi.nlm.nih.gov/pubmed/19632340

Vestn Otorinolaringol. 2010;(1):10-4.

[Clinical significance and functional outcomes of ligation of exterior carotid artery in surgical treatment of oropharyngeal cancer].

[Article in Russian]

Klochikhin AL, Trofimov EI, Gamilovskaia IuV, Chistiakov AL.

This work was designed to analyse outcomes of the treatment of 65 patients with advanced oropharyngeal cancer who had received combined treatment including radical resection of the tumour. Thirty three patients underwent surgery without  ligation of exterior carotid artery while the remaining 32 (control group) were operated after preceding ligation of this vessel. The influence of ligation of exterior carotid artery on cerebral circulation was evaluated by the following methods: estimation of the intraoperative blood loss from A.T. Staroverov's formula, ultrasound dopplerography of extracranial carotid segments, electroencephalography, measurement of the fields of vision using statistical quantitative perimetry, evaluation of the patients' neurologic status. It was shown that ligation of exterior carotid artery has no apparent effect on the intraoperative blood loss during radical surgery for the management of oropharyngeal cancer nor does it influence healing of the postoperative wound and oncological outcome of this treatment.

http://www.ncbi.nlm.nih.gov/pubmed/20436415

Zh Nevrol Psikhiatr Im S S Korsakova. 2010;110(12):9-12.

[Psychophysiological disturbances in attention-deficit hyperactivity disorder in  adolescents].

[Article in Russian]

Glushchenko VV.

We have studied 128 adolescents, aged 15-16 years, with attention-deficit hyperactivity disorder (ADHD) using clinico-psychopathological, psychometric and  electroencephalographic methods. Taking into account the age dynamics, the following components of ADHD have been singled out: motor (impulsivity-hyperactivity), subjective-cognitive (attention deficit) and somato-autonomic. The significance of subjective-cognitive disturbances, along with neurophysiological dysfunction, in the ADHD pathogenesis has been proved. Quantitative (productivity deficit) and qualitative (concentration deficit) disorders have been assessed. Author substantiated the deficit of emotional-motivational self-regulation measured by the M. Luscher test and the Self-assessment scale. The specific for ADHD pattern of alpha-rhythm reactivity has been found in EEG.

http://www.ncbi.nlm.nih.gov/pubmed/21311480

Zh Nevrol Psikhiatr Im S S Korsakova. 2010;110(3 Suppl 2):65-9.

[Evoked skin sympathetic potentials and electroencephalography in the differential diagnosis of temporal and frontal epilepsy].

[Article in Russian]

Deriaga IN, Karlov VA, Gnezditskiĭ VV.

An aim of the study was to investigate indices of autonomous regulation (evoked skin sympathetic potentials--ESSP) and EEG in temporal and frontal epilepsy (TE and FE) before and after functional tests (physical, psychoemotional, hyperventilation). The study included 24 patients with TE, 20 patients with FE and 20 healthy controls. The enhance of sympathetic component of reaction was seen in FE and that of parasympathetic component--in TE. The sympathetic response to physical load and hyperventilation was insufficient in both forms of epilepsy  that manifested itself in the reduced reaction amplitude and its longer duration. In the psychoemotional test, the reduction of sympathetic reaction amplitude and  its later development was more characteristic of TE compared to FE. In conclusion, resting ESSP is more significant for differential diagnosis of TE and FE while in the functional test only quantitative differences between these forms were observed.

http://www.ncbi.nlm.nih.gov/pubmed/20873477

J Neurosci Methods. 2009 Dec 15;185(1):99-107. Epub 2009 Sep 20.

'Weight of Evidence' analysis of neonatal sensory evoked potentials.

Stanley O, Wright M, Pike A, Marlow N, Pike R.

Centre for Child and Adolescent Health, University of Bristol, Bristol, UK. Oliver.Stanley@uhbristol.nhs.uk

Abnormalities in neonatal sensory evoked potentials (EPs) may indicate a poor developmental prognosis, but such EPs are highly variable, changing with development, and requiring subjective analysis. 'Weight of Evidence' (W), the logarithm of the ratio of the probability that a response has occurred to the probability that it has not, and 'Response Entropy' (S), the spread of the response over time and frequency bands, might provide objective and quantitative  measures of EP abnormalities and developmental changes, based on information processing characteristics. W and S were calculated from visual and somatosensory EPs recorded in 72 premature newborns over 2 sessions, separated by 6-9 weeks. Group 1 had normal brain ultrasound images at the time of recording, and a normal developmental outcome at age 2 years. Group 2 had abnormal brain ultrasound images but normal outcome. Group 3 had abnormal brain imaging and abnormal outcome.W values were lowest in Group 3 (visual p<0.001: somatosensory p<0.04). Entropy diminished between sessions (visual p<0.001: somatosensory p<0.015): it was highest in Group 2 (visual p<0.03). The low W in Group 3 implies a lower signal/noise ratio, reducing information capacity. Decreasing entropy suggests more efficient information encoding with maturation.

http://www.ncbi.nlm.nih.gov/pubmed/19772873

Anesth Analg. 2009 Dec;109(6):1811-5.

The correlation between bispectral index and observational sedation scale in volunteers sedated with dexmedetomidine and propofol.

Kasuya Y, Govinda R, Rauch S, Mascha EJ, Sessler DI, Turan A.

Department of Anesthesiology and Perioperative Medicine and Outcomes Research Consortium, University of Louisville, Louisville, Kentucky, USA.

BACKGROUND: Bispectral index (BIS) is a widely used quantitative parameter for evaluating anesthesia and sedation levels. Dexmedetomidine is a novel sedative, providing sedation while patients remain cooperative and can be easily aroused; as a consequence, BIS used with dexmedetomidine may poorly characterize sedation. Thus, we tested the hypothesis that BIS values are lower with dexmedetomidine than with propofol at comparable Observer's Assessment of Alertness and Sedation  (OAA/S) scores. METHODS: This was a randomized, 2-day, crossover study. On the first study day, healthy volunteers were randomly allocated to either propofol or dexmedetomidine  sedation. Drugs were administered using computer-controlled infusions targeting an effect-site concentration of 1, 2, and 4 microg/mL for propofol or a plasma concentration of 0.6, 1.2, and 2.4 ng/mL for dexmedetomidine. The relationship between BIS and OAA/S score was obtained 20 and 40 min after changing each drug concentration. BIS values at each OAA/S score were compared between drugs. The cutoff values of BIS for OAA/S score of < or =2 were obtained by analysis of receiver operating characteristic curves. RESULTS: Nine volunteers were included in our analysis. Heart rates decreased significantly with dexmedetomidine sedation. ETco(2) was significantly increased  with high doses of propofol but did not increase with high doses of dexmedetomidine. BIS values at OAA/S scores of 1, 2, 3, 4, and 5 during propofol  sedation were 95.5 (90-97), 78 (71-84.5), 67 (64-70), 57 (51.5-60), and 34 (30-37), respectively. BIS values at OAA/S scores of 1, 2, 3, 4, and 5 during dexmedetomidine sedation were 95 (79-98), 62 (53.5-68.5), 45.5 (45.3-52), 39.5 (34.3-41.8), and 24.5 (22.5-30.5), respectively. BIS values were significantly less with dexmedetomidine than propofol at OAA/S responsiveness scores of 2, 3, and 4. The calculated cutoff BIS values for OAA/S scores of < or =2 were 67 (sensitivity of 86%, specificity of 97%, and area under the curve of 0.98) for propofol and 46 (sensitivity of 84%, specificity of 91%, and area under the curve of 0.96) for dexmedetomidine. CONCLUSION: The combination of both BIS and sedative scales could provide different and complementary data to the clinician evaluating the patient's response to sedation than would either tool alone, especially when dexmedetomidine is used.

http://www.ncbi.nlm.nih.gov/pubmed/19923507

J Clin Monit Comput. 2009 Dec;23(6):369-90. Epub 2009 Sep 16.

Guidelines for intraoperative neuromonitoring using raw (analog or digital waveforms) and quantitative electroencephalography: a position statement by the American Society of Neurophysiological Monitoring.

Isley MR, Edmonds HL Jr, Stecker M; American Society of Neurophysiological Monitoring.

Intraoperative Neuromonitoring Department, Orlando Regional Medical Center, FL 32806, USA. Michael.Isley@OrlandoHealth.com

BACKGROUND CONTEXT: Electroencephalography (EEG) is one of the oldest and most commonly utilized modalities for intraoperative neuromonitoring. Historically, interest in the EEG patterns associated with anesthesia is as old as the discovery of the EEG itself. The evolution of its intraoperative use was also expanded to include monitoring for assessing cortical perfusion and oxygenation during a variety of vascular, cardiac, and neurosurgical procedures. Furthermore, a number of quantitative or computer-processed algorithms have also been developed to aid in its visual representation and interpretation. The primary clinical outcomes for which modern EEG technology has made significant intraoperative contributions include: (1) recognizing and/or preventing perioperative ischemic insults, and (2) monitoring of brain function for anesthetic drug administration in order to determine depth of anesthesia (and level of consciousness), including the tailoring of drug levels to achieve a predefined neural effect (e.g., burst suppression). While the accelerated development of microprocessor technologies has fostered an extraordinarily rapid  growth in the use of intraoperative EEG, there is still no universal adoption of  a monitoring technique(s) or of criteria for its neural end-point(s) by anesthesiologists, surgeons, neurologists, and neurophysiologists. One of the most important limitations to routine intraoperative use of EEG may be the lack of standardization of methods, alarm criteria, and recommendations related to its application. Lastly, refinements in technology and signal processing can be expected to advance the usefulness of the intraoperative EEG for both anesthetic  and surgical management of patients. OBJECTIVE: This paper is the position statement of the American Society of Neurophysiological Monitoring. It is the practice guidelines for the intraoperative use of raw (analog and digital) and quantitative EEG. METHODS: The following recommendations are based on trends in the current scientific and clinical literature and meetings, guidelines published by other organizations, expert opinion, and public review by the members of the American Society of Neurophysiological Monitoring. This document may not include all possible methodologies and interpretative criteria, nor do the authors and their  sponsor intentionally exclude any new alternatives. RESULTS: The use of the techniques reviewed in these guidelines may reduce perioperative neurological morbidity and mortality. CONCLUSIONS: This position paper summarizes commonly used protocols for recording and interpreting the intraoperative use of EEG. Furthermore, the American Society of Neurophysiological Monitoring recognizes this as primarily an educational service.

http://www.ncbi.nlm.nih.gov/pubmed/19757102

J Clin Neurophysiol. 2009 Dec;26(6):426-9.

The relationship between slowing EEGs and the progression of Parkinson's disease.

Morita A, Kamei S, Serizawa K, Mizutani T.

Division of Neurology, Department of Medicine, Nihon University School of Medicine, Tokyo, Japan.

The previous association study confirmed that diffuse slowing of EEGs was present in Parkinson's disease (PD), demonstrated with the use of the quantitative EEG technique. This study was the first to assess the relationship between progression of PD and quantitative EEG. A total of 106 patients with PD with a mean Hoehn-Yahr stage of 2.73 were serially enrolled. Lack of ischemic lesions was confirmed in all patients by magnetic resonance imaging. Absolute power values were measured for four frequency bands from delta to beta. The electrodes  were divided among six locations: frontal pole, frontal, central, parietal, temporal, and occipital locations. Spectral ratio was calculated as the sum of power values for the alpha and beta waves divided by the sum values for the slow  waves. The relationship between the progression of PD and spectral ratio was assessed by the Jonckheere-Terpstra trend test. At all electrode locations, spectral ratio significantly decreased with progression of Hoehn-Yahr stage (frontal pole, P = 0.007; frontal, P = 0.005; central, P = 0.031; parietal, P = 0.017; temporal, P = 0.005; occipital, P = 0.010). This shows that the slowing of EEGs became more obvious with PD progression.

http://www.ncbi.nlm.nih.gov/pubmed/19952568

J Clin Neurophysiol. 2009 Dec;26(6):401-6.

EEG power spectra at early stages of depressive disorders.

Grin-Yatsenko VA, Baas I, Ponomarev VA, Kropotov JD.

Laboratory of Neurobiology of Action Programming, Institute of the Human Brain of Russian Academy of Sciences, St Petersburg, ul Acad Pavlova, Russian Federation.  veragrin@yahoo.com

In previous quantitative EEG studies of depression, mostly patients with a lifetime history of depressive disorders were reported. This study examined quantitative EEG parameters obtained in the early stages of depression in comparison with age-matched healthy controls. EEG was recorded using two different montages in eyes closed and eyes open resting states. A significant increase in spectrum power in theta (4-7.5 Hz), alpha (7.5-14 Hz), and beta (14-20 Hz) frequency bands was found in depressed patients at parietal and occipital sites, both in eyes closed and eyes open conditions. These results suggest that an increase in slow (theta and alpha) activity in the EEG pattern may reflect a decreased cortical activation in these brain regions. Enhancement of beta power may correlate with anxiety symptoms that most likely play an important role on the onset of depressive disorder.

http://www.ncbi.nlm.nih.gov/pubmed/19952564

J Neurochem. 2009 Dec;111(5):1252-63. Epub 2009 Oct 3.

The microtubule interacting drug candidate NAP protects against kainic acid toxicity in a rat model of epilepsy.

Zemlyak I, Manley N, Vulih-Shultzman I, Cutler AB, Graber K, Sapolsky RM, Gozes I.

Department of Human Molecular Genetics and Biochemistry, Sackler Faculty of Medicine, Tel Aviv University, Tel Aviv, Israel.

NAP (NAPVSIPQ, generic name, davunetide), a neuroprotective peptide in clinical development for neuroprotection against Alzheimer's disease and other neurodegenerative indications, has been recently shown to provide protection against kainic acid excitotoxicity in hippocampal neuronal cultures. In vivo, kainic acid toxicity models status epilepticus that is associated with hippocampal cell death. Kainic acid toxicity has been previously suggested to involve the microtubule cytoskeleton and NAP is a microtubule-interacting drug candidate. In the current study, kainic acid-treated rats showed epileptic seizures and neuronal death. Injection of NAP into the dentate gyrus partially protected against kainic acid-induced CA3 neuron death. Microarray analysis (composed of > 31 000 probe sets, analyzing over 30 000 transcripts and variants  from over 25 000 well-substantiated rat genes) in the kainic acid-injured rat brain revealed multiple changes in gene expression, which were prevented, in part, by NAP treatment. Selected transcripts were further verified by reverse transcription coupled with quantitative real-time polymerase chain reaction. Importantly, among the transcripts regulated by NAP were key genes associated with proconvulsant properties and with long-lasting changes that underlie the epileptic state, including activin A receptor (associated with apoptosis), neurotensin (associated with proper neurotransmission) and the Wolfram syndrome 1 homolog (human, associated with neurodegeneration). These data suggest that NAP may provide neuroprotection in one of the most serious neurological conditions, epilepsy.

http://www.ncbi.nlm.nih.gov/pubmed/19799711

J Neurophysiol. 2009 Dec;102(6):3554-72. Epub 2009 Oct 7.

Quantitative analysis and biophysically realistic neural modeling of the MEG mu rhythm: rhythmogenesis and modulation of sensory-evoked responses.

Jones SR, Pritchett DL, Sikora MA, Stufflebeam SM, Hämäläinen M, Moore CI.

Massachusetts General Hospital, Athinoula A Martinos Center for Biomedical Imaging, Charlestown, MA 02129, USA. srjones@nmr.mgh.harvard.edu

Variations in cortical oscillations in the alpha (7-14 Hz) and beta (15-29 Hz) range have been correlated with attention, working memory, and stimulus detection. The mu rhythm recorded with magnetoencephalography (MEG) is a prominent oscillation generated by Rolandic cortex containing alpha and beta bands. Despite its prominence, the neural mechanisms regulating mu are unknown. We characterized the ongoing MEG mu rhythm from a localized source in the finger  representation of primary somatosensory (SI) cortex. Subjects showed variation in the relative expression of mu-alpha or mu-beta, which were nonoverlapping for roughly 50% of their respective durations on single trials. To delineate the origins of this rhythm, a biophysically principled computational neural model of  SI was developed, with distinct laminae, inhibitory and excitatory neurons, and feedforward (FF, representative of lemniscal thalamic drive) and feedback (FB, representative of higher-order cortical drive or input from nonlemniscal thalamic nuclei) inputs defined by the laminar location of their postsynaptic effects. The mu-alpha component was accurately modeled by rhythmic FF input at approximately 10-Hz. The mu-beta component was accurately modeled by the addition of approximately 10-Hz FB input that was nearly synchronous with the FF input. The relative dominance of these two frequencies depended on the delay between FF and  FB drives, their relative input strengths, and stochastic changes in these variables. The model also reproduced key features of the impact of high prestimulus mu power on peaks in SI-evoked activity. For stimuli presented during high mu power, the model predicted enhancement in an initial evoked peak and decreased subsequent deflections. In agreement, the MEG-evoked responses showed an enhanced initial peak and a trend to smaller subsequent peaks. These data provide new information on the dynamics of the mu rhythm in humans and the model  provides a novel mechanistic interpretation of this rhythm and its functional significance.

http://www.ncbi.nlm.nih.gov/pubmed/19812290

Paediatr Anaesth. 2009 Dec;19(12):1175-83.

Effects of dexmedetomidine sedation on the EEG in children.

Mason KP, O'Mahony E, Zurakowski D, Libenson MH.

Departments of Anesthesia, Perioperative and Pain Medicine, Children's Hospital Boston, Boston, MA 02115, USA.

OBJECTIVES: To examine the effects of dexmedetomidine sedation on EEG background  and epileptiform activity in children, comparing it to natural sleep. AIM: To provide quantitative and qualitative descriptions of the effect of dexmedetomidine sedation on the EEG of children. BACKGROUND: Children with intractable epilepsy admitted for surgery undergo 5 days of continuous EEG monitoring as well as nuclear medicine imaging studies with dexmedetomidine for sedation. Continuous EEG monitoring of each child during both natural sleep and dexmedetomidine-induced sedation provides a unique opportunity to evaluate the effects of dexmedetomidine on the EEG of children. MATERIALS/METHODS: Sixteen children undergoing dexmedetomidine sedation for nuclear medicine studies and simultaneous continuous EEG monitoring were studied. EEG segments during sedation were compared to samples of naturally occurring stage II sleep from the same child. Standard visual EEG analysis, quantification  of delta, theta, alpha, beta, and total RMS power, number and location of spike foci, and frequency of spike activity were compared. RESULTS: The EEG during dexmedetomidine sedation resembled stage II sleep. During sedation, statistically significant increases in power of 16% for theta (P = 0.01), 21% for alpha (P = 0.03), and 40% for beta (P < 0.01) were observed, but not for delta (P = 0.63) or total EEG power (P = 0.61). Spike frequency increased by 47% during sedation but no new spike foci or seizures were observed. CONCLUSION: Dexmedetomidine sedation elicited an EEG pattern similar to that of Stage II sleep with modest increases in theta, alpha, and beta activity. Dexmedetomidine does not hinder interpretation of the EEG, suggesting that it may be a uniquely useful agent for EEG sedation in children.

http://www.ncbi.nlm.nih.gov/pubmed/20017865

Schizophr Bull. 2009 Nov 23. [Epub ahead of print]

Delta EEG Band as a Marker of Left Hypofrontality for Language in Schizophrenia Patients.

Spironelli C, Angrilli A, Calogero A, Stegagno L.

2Department of General Psychology, University of Padova, via Venezia 8, 35131 Padova, Italy.

Frontal hypoactivation has consistently been demonstrated in schizophrenia patients. We hypothesized that this well-known deficit is asymmetrical, ie, centered over left frontal locations and, in-line with Crow's theory, associated  with both loss of linguistic asymmetry and correlated with positive symptoms. Electroencephalography delta band was used as a quantitative index of cortical inhibition in 17 paranoid schizophrenia patients with prevailing positive symptoms and 17 matched control subjects. Delta amplitude was measured by 38 electrodes, while participants performed 3 linguistic tasks, visuoperceptual, rhyming, and semantic judgment. Compared with control subjects, patients did not  show overall delta band differences, revealing no detrimental effects of pharmacological treatment. In healthy participants, analysis of 4 quadrants/regions of interest revealed higher delta amplitude in right vs left anterior sites, indicating significant left anterior disinhibition during linguistic processing. Instead, patients showed bilateral delta band distribution and, compared with control subjects, significant greater delta amplitude (ie, brain inhibition) in linguistic left anterior centers. Patients' left hypofrontality was functionally related to their lack of hemispheric specialization for language and was positively correlated with higher levels of delusions (P1) and conceptual disorganization (P2) Positive and Negative Syndrome Scale subscales. Results suggest, in schizophrenia patients, a functional deficit of Broca's area, a region playing a fundamental hierarchical role between and within hemispheres by integrating many basic processes in linguistic and conceptual organization. The significant correlation between lack of anterior asymmetry and increased positive symptoms is in-line with Crow's hypothesis postulating the etiological role of disrupted linguistic frontal asymmetry on the onset of the key symptoms of schizophrenia.

http://www.ncbi.nlm.nih.gov/pubmed/19933713

Br J Clin Pharmacol. 2009 Nov;68(5):721-30.

Evidence for oxazepam as an in vivo probe of UGT2B15: oxazepam clearance is reduced by UGT2B15 D85Y polymorphism but unaffected by UGT2B17 deletion.

He X, Hesse LM, Hazarika S, Masse G, Harmatz JS, Greenblatt DJ, Court MH.

Laboratory of Comparative and Molecular Pharmacogenomics and Department of Pharmacology and Experimental Therapeutics, Tufts University School of Medicine,  Boston, MA 02111, USA.

AIMS: Although in vitro studies indicate that oxazepam is an isoform-selective substrate probe for UDP-glucuronosyltransferase 2B15, the utility of this drug as an in vivo probe is uncertain. The main aim of this study was to determine whether common missense polymorphisms in the UGT2B15 gene (D85Y and K523T) are associated with altered oxazepam pharmacokinetics and pharmacodynamics. We also determined the possible influence of a common deletion polymorphism in the gene encoding UGT2B17, which shows substantial substrate specificity overlap with UGT2B15. METHODS: Thirty healthy male subjects were administered 15 mg of oxazepam by mouth followed by plasma oxazepam concentration monitoring for 36 h, and pharmacodynamic testing for 8 h. Genotypes were determined by genomic polymerase  chain reaction and commercial 5'-nuclease assays. RESULTS: Allele frequencies for D85Y, K523T, UGT2B17del were 47%, 23% and 19%, respectively. Median oxazepam apparent oral clearance was significantly lower in  85YY subjects (1.62 ml min(-1) kg(-1)) compared with 85DD subjects (3.35 ml min(-1) kg(-1); P= 0.003, Student-Newman-Keuls test), whereas 85DY subjects were  intermediate (2.34 ml min(-1) kg(-1); P= 0.018 vs. 85DD, P= 0.034 vs. 85YY). Regression analysis indicated that UGT2B15 D85Y genotype accounted for 34% of interindividual variability. However, neither UGT2B15 K523T nor UGT2B17del was associated with altered oxazepam disposition. Furthermore, no differences in pharmacodynamic measures, including quantitative electroencephalography, digit-symbol substitution test, self- or observer-rated visual analogue scales, could be demonstrated for any of the polymorphisms evaluated. CONCLUSIONS: These results identify UGT2B15 D85Y as a major determinant of oxazepam clearance, and indicate that oxazepam may be useful as an in vivo probe  for glucuronidation by UGT2B15.

http://www.ncbi.nlm.nih.gov/pubmed/19916996

Epilepsy Res. 2009 Nov;87(1):77-87. Epub 2009 Sep 5.

Quantitative brain surface mapping of an electrophysiologic/metabolic mismatch in human neocortical epilepsy.

Alkonyi B, Juhász C, Muzik O, Asano E, Saporta A, Shah A, Chugani HT.

Carman and Ann Adams Department of Pediatrics, Wayne State University School of Medicine, Detroit, MI, USA.

The spatial relationship between an intracranial EEG-defined epileptic focus and  cortical hypometabolism on glucose PET has not been precisely described. In order to quantitatively evaluate the hypothesis that ictal seizure onset and/or rapid seizure propagation, detected by subdural EEG monitoring, commonly involves normometabolic cortex adjacent to hypometabolic cortical regions, we applied a novel, landmark-constrained conformal mapping approach in 14 children with refractory neocortical epilepsy. The 3D brain surface was parcellated into finite cortical elements (FCEs), and hypometabolism was defined using lobe- and side-specific asymmetry indices derived from normal adult controls. The severity  and location of hypometabolic areas vs. ictal intracranial EEG abnormalities were compared on the 3D brain surface. Hypometabolism was more severe in the seizure onset zone than in cortical areas covered by non-onset electrodes. However, similar proportions of the onset electrodes were located over and adjacent to (within 2 cm) hypometabolic regions (46% vs. 41%, respectively), whereas rapid seizure spread electrodes preferred these "adjacent areas" rather than the hypometabolic area itself (51% vs. 22%). On average, 58% of the hypometabolic regions had no early seizure involvement. These findings strongly support that the seizure onset zone often extends from hypometabolic to adjacent normometabolic cortex, while large portions of hypometabolic cortex are not involved in seizure onset or early propagation. The clinical utility of FDG PET in guiding subdural electrode placement in neocortical epilepsy could be greatly  enhanced by extending grid coverage to at least 2 cm beyond hypometabolic cortex, when feasible.

http://www.ncbi.nlm.nih.gov/pubmed/19734012

Epilepsy Res. 2009 Nov;87(1):18-24. Epub 2009 Aug 20.

Intracranial EEG power and metabolism in human epilepsy.

Pan JW, Zaveri HP, Spencer DD, Hetherington HP, Spencer SS.

Department of Neurosurgery, Yale University School of Medicine, New Haven, CT 06520, USA. jullie.pan@yale.edu

EEG power and high frequency activity in the seizure onset zone has been increasingly considered for its relationship with seizures in animal and human studies of epilepsy. We examine the relationship between quantitative EEG measures and metabolic imaging in epilepsy patients undergoing intracranial EEG (icEEG) analysis for seizure localization. Patients with mesial temporal lobe epilepsy (MTLE) and neocortical epilepsy (NE) were studied. Metabolic imaging was performed with MR spectroscopic imaging using N-acetyl aspartate (NAA) and creatine (Cr). All data were acquired from the mesial temporal lobe such that a direct comparison of the same anatomical regions between the two groups could be  performed. While no difference was seen in the total power recorded from the mesial temporal lobe, the MTLE group had significantly greater power in the high  frequency bands. There was a significant positive exponential relationship between total icEEG power with NAA/Cr in MTLE, R=+0.84 and p<0.001, which was not seen in NE. There was also a significant negative relationship between fractional gamma power with NAA/Cr in MTLE, R=-0.66 and p<0.02, also not seen in NE. These data argue that within the seizure onset zone, the tight correlation between total power and NAA/Cr suggests that total electrical output is powered by available mitochondrial function. These data are also consistent with the hypothesis that high frequency activity is an abnormal manifestation of tissue injury.

http://www.ncbi.nlm.nih.gov/pubmed/19699059

PLoS One. 2009 Oct 29;4(10):e7613.

Applying an attentional set to perceived and remembered features.

Astle DE, Nobre AC, Scerif G.

Department of Experimental Psychology, University of Oxford, Oxford, United Kingdom. Duncan.astle@psy.ox.ac.uk

Previous research has examined our ability to attend selectively to particular features of perceptual objects, as well as our ability to switch from attending to one type of feature to another. This is usually done in the context of anticipatory attentional-set control, comparing the neural mechanisms involved as participants prepare to attend to the same stimulus feature as on the previous trial ("task-stay" trials) with those required as participants prepare to attend  to a different stimulus feature to that previously attended ("task-switch" trials). We wanted to establish how participants maintain or switch attentional set retrospectively, as they attend to features of objects held in visual short-term memory (VSTM). We found that switching, relative to maintaining attentional set retrospectively, was associated with a performance cost, which can be reduced over time. This control process was mirrored by a large parietal and frontal amplitude difference in the event-related brain potentials (ERPs) and significant differences in global field power (GFP) between switch and stay trials. However, when taking into account the switch/stay GFP differences, thereby controlling for this difference in amplitude, we could not distinguish these trial types topographically. By contrast, we found clear topographic differences between preparing an anticipatory feature-based attentional set versus applying it retrospectively within VSTM. These complementary topographical and amplitude analyses suggested that anticipatory and retrospective set control  recruited a qualitatively different configuration of underlying neural generators. In contrast, switch/stay differences were largely quantitative, with  them differing primarily in terms of amplitude rather than topography.

http://www.ncbi.nlm.nih.gov/pubmed/19898613

PLoS One. 2009 Oct 26;4(10):e7601.

Functional structure of spontaneous sleep slow oscillation activity in humans.

Menicucci D, Piarulli A, Debarnot U, d'Ascanio P, Landi A, Gemignani A.

Institute of Clinical Physiology, CNR, Pisa, Italy.

BACKGROUND: During non-rapid eye movement (NREM) sleep synchronous neural oscillations between neural silence (down state) and neural activity (up state) occur. Sleep Slow Oscillations (SSOs) events are their EEG correlates. Each event has an origin site and propagates sweeping the scalp. While recent findings suggest a SSO key role in memory consolidation processes, the structure and the propagation of individual SSO events, as well as their modulation by sleep stages and cortical areas have not been well characterized so far. METHODOLOGY/PRINCIPAL FINDINGS: We detected SSO events in EEG recordings and we defined and measured a set of features corresponding to both wave shapes and event propagations. We found that a typical SSO shape has a transition to down state, which is steeper than the following transition from down to up state. We show that during SWS SSOs are larger and more locally synchronized, but less likely to propagate across the cortex, compared to NREM stage 2. Also, the detection number of SSOs as well as their amplitudes and slopes, are greatest in  the frontal regions. Although derived from a small sample, this characterization  provides a preliminary reference about SSO activity in healthy subjects for 32-channel sleep recordings. CONCLUSIONS/SIGNIFICANCE: This work gives a quantitative picture of spontaneous SSO activity during NREM sleep: we unveil how SSO features are modulated by sleep stage, site of origin and detection location of the waves. Our measures on SSOs shape indicate that, as in animal models, onsets of silent states are more synchronized than those of neural firing. The differences between sleep stages could be related to the reduction of arousal system activity and to the breakdown of functional connectivity. The frontal SSO prevalence could be related to a greater homeostatic need of the heteromodal association cortices.

http://www.ncbi.nlm.nih.gov/pubmed/19855839

Neuroimage. 2009 Oct 15;48(1):50-62. Epub 2009 Jun 30.

Detection of EEG transients in neonates and older children using a system based on dynamic time-warping template matching and spatial dipole clustering.

Aarabi A, Kazemi K, Grebe R, Moghaddam HA, Wallois F.

GRAMFC, EFSN Péd., C.H.U. Nord, Place V. Pauchet, F-80054 Amiens, France. ardalan.aarabi@u-picardie.fr

We present a novel system for detecting electroencephalographic transient events  in neonates and older children. The detection system consists of three major elements: (i) a preprocessing stage for filtering EEG and detecting artifacts, (ii) a hierarchical course-to-fine temporal event detection stage and (iii) a hierarchical course-to-fine spatial event selection stage to incorporate spatial  contextual information for rejection of spurious events. The output consists of homogeneous EEG events and their corresponding dipole clusters. The system was evaluated on EEG signals recorded in four neonates and six older children. There  was a high degree of correlation between system-detected and expert-marked events for all patients. Mean sensitivities of 84.9% and 91.9% and mean selectivities of 86.3% and 90.6% were obtained for the neonates and the older children, respectively. This tool is appropriate for the detection and selection of homogeneous EEG events prior to source localization. Quantitative spatial analysis of dipoles may facilitate the physician's assessment of patients' brain  dysfunction.

http://www.ncbi.nlm.nih.gov/pubmed/19573612

Biol Psychol. 2009 Oct;82(2):133-48. Epub 2009 Jul 5.

Ictal hallucination and hemispheric specialization: findings from 217 cases with  a unilateral epileptic focus.

Guimond A, Braun CM, Daigneault R.

Department of Psychology, Université du Québec à Montréal, Canada.

Epileptic populations are generally considered inappropriate to investigate hemispheric specialization. However, (1) because hallucination occurs in the early stage of the ictus during which activation is observed in and around the focus, the former could be a direct result of the latter (hypothesis 1), and (2)  the type of psychological content of ictal hallucination could depend on which hemisphere is ictally activated (hypothesis 2). It was predicted that, on the basis of quantitative analysis of previously published singles case reports, unilateral ictal hallucinations should occur in the visual field, ear or hemibody contralateral to the side of the ictal focus (test of hypothesis 1). It was also  predicted that verbal ictal auditory hallucinations should result more often from left hemisphere foci, and non-verbal auditory ictal hallucinations from right hemisphere foci (test of hypothesis 2). Previously published cases (N=217) of ictal hallucination from a unilateral epileptic focus were reviewed and analyzed  with multivariate statistics. Both predictions were strongly supported.

http://www.ncbi.nlm.nih.gov/pubmed/19583992

Epilepsy Res. 2009 Oct;86(2-3):183-90. Epub 2009 Jul 16.

Working memory in children with epilepsy: an event-related potentials study.

Myatchin I, Mennes M, Wouters H, Stiers P, Lagae L.

Department of Woman and Child, Section Paediatric Neurology, K.U.Leuven, Leuven,  Belgium.

PURPOSE: The aim of this study was to find out whether children with idiopathic epilepsy did show different cortical activation patterns compared to non-epileptic children during performance of a working memory task. To this end event-related potentials (ERPs) were measured during a visual 1-backmatching task. A quantitative analysis technique to analyze the ERP data, without any 'a priori' decisions on 'peak' presence, amplitudes or latencies, is used. METHODS: 46 children were tested (6-16 years old): 21 children with well-controlled "benign" epilepsy (benign rolandic epilepsy, n=9, idiopathic generalized epilepsy, n=12) and a control group of 25 non-epileptic children. Behavioral task performance and ERPs following both target and nontarget stimuli  were compared across both study groups. RESULTS: No differences were found in the number of omission errors or commission errors or in the reaction times between groups. However, ERPs following target stimuli showed significantly higher amplitude in the epilepsy group compared to the control group over frontal and central regions within the time window between 250 and 425 ms poststimulus, what coincides with the time window of target-nontarget stimulus discrimination. DISCUSSION: Our study shows that children with benign, well-controlled epilepsy show a different cortical activation pattern during a visual working memory task. We hypothesize that they need more brain processing effort to achieve the same performance level as their age matched controls.

http://www.ncbi.nlm.nih.gov/pubmed/19615862

J Clin Neurophysiol. 2009 Oct;26(5):316-25.

Increasing the diagnostic value of evoked potentials in multiple sclerosis by quantitative topographic analysis of multichannel recordings.

Lascano AM, Brodbeck V, Lalive PH, Chofflon M, Seeck M, Michel CM.

Functional Brain Mapping Laboratory, Department of Clinical and Fundamental Neuroscience, University and University Hospital of Geneva, Switzerland.

SUMMARY: This study presents a method to record and analyze multichannel visual-evoked potential (VEP) and somatosensory-evoked potential (SEP) in an objective, automatic, and quantitative manner. The intention of this study was to assess their diagnostic value in multiple sclerosis (MS). A 256-channel VEP and SEP were recorded in 44 healthy subjects, 26 patients with MS, and 20 patients with other neurologic diseases. Topographic pattern recognition methods were applied and a normative database was established. Z-score statistics allowed identifying the number of subjects with significant abnormal values in each group. These values were compared with conventional single-channel waveform analysis. The diagnostic value of the new measures for MS reached a sensitivity of 72% and a specificity of 100% for the VEP, which was significantly higher than the conventional analysis. For the SEP, the specificity was also high (93%) but the sensitivity remained low as in the conventional analysis (30%). The quantitative topographic analysis of multichannel VEP revealed high-diagnostic sensitivity and specificity for MS. Moreover, the method reliably identified the  most dominant VEP and SEP components in the healthy subject group. The results indicate that objective topographic analysis of multichannel recordings increase  the value of VEP as surrogate marker for MS.

http://www.ncbi.nlm.nih.gov/pubmed/19752740

J Headache Pain. 2009 Oct;10(5):331-9. Epub 2009 Aug 25.

Interictal quantitative EEG in migraine: a blinded controlled study.

Bjørk MH, Stovner LJ, Engstrøm M, Stjern M, Hagen K, Sand T.

Department of Neuroscience, Norwegian University of Science and Technology (NTNU), MTFS, 7489, Trondheim, Norway. marte.bjork@ntnu.no

Comment in     J Headache Pain. 2009 Oct;10(5):327-9.

Abnormal electroencephalography (EEG) in migraineurs has been reported in several studies. However, few have evaluated EEG findings in migraineurs during a time period when neither the last attack nor the next attack may interact with the results. We, therefore, compared interictal EEG in migraineurs and headache-free  subjects with a design controlled for interference by pre-ictal changes. Pre-ictal EEG findings in the painful cranial side during the next attack after registration were also investigated. Correlations between clinical variables and  EEG are reported as well. Interictal EEGs from 33 migraineurs (6 with and 27 without aura) and 31 controls were compared. Absolute power, asymmetry and relative power were studied for delta, theta and alpha frequency bands in parieto-occipital, temporal and fronto-central areas. EEG variables were correlated to attack frequency, headache duration, attack duration, pain intensity, photo- and phonophobia. Compared with controls, migraineurs had increased relative theta power in all cortical regions and increased delta activity in the painful fronto-central region. Absolute power and asymmetry were  similar among groups. In age-adjusted analyses, headache intensity correlated with increased delta activity. In this blinded controlled study, we found globally increased relative theta activity in migraineurs. A slight interictal brain dysfunction is probably present between attacks.

http://www.ncbi.nlm.nih.gov/pubmed/19705061

Psychiatry Res. 2009 Sep 30;169(2):124-31. Epub 2009 Aug 27.

Comparative effectiveness of biomarkers and clinical indicators for predicting outcomes of SSRI treatment in Major Depressive Disorder: results of the BRITE-MD  study.

Leuchter AF, Cook IA, Marangell LB, Gilmer WS, Burgoyne KS, Howland RH, Trivedi MH, Zisook S, Jain R, McCracken JT, Fava M, Iosifescu D, Greenwald S.

Semel Institute for Neuroscience and Human Behavior at UCLA, Los Angeles, CA 90024-1759, USA. afl@ucla.edu

Patients with Major Depressive Disorder (MDD) may not respond to antidepressants  for 8 weeks or longer. A biomarker that predicted treatment effectiveness after only 1 week could be clinically useful. We examined a frontal quantitative electroencephalographic (QEEG) biomarker, the Antidepressant Treatment Response (ATR) index, as a predictor of response to escitalopram, and compared ATR with other putative predictors. Three hundred seventy-five subjects meeting DSM-IV criteria for MDD had a baseline QEEG study. After 1 week of treatment with escitalopram, 10 mg, a second QEEG was performed, and the ATR was calculated. Subjects then were randomly assigned to continue with escitalopram, 10 mg, or change to alternative treatments. Seventy-three evaluable subjects received escitalopram for a total of 49days. Response and remission rates were 52.1% and 38.4%, respectively. The ATR predicted both response and remission with 74% accuracy. Neither serum drug levels nor 5HTTLPR and 5HT2a genetic polymorphisms were significant predictors. Responders had larger decreases in Hamilton Depression Rating Scale (Ham-D(17)) scores at day 7 (P=0.005), but remitters did  not. Clinician prediction based upon global impression of improvement at day 7 did not predict outcome. Logistic regression showed that the ATR and early Ham-D(17) changes were additive predictors of response, but the ATR was the only  significant predictor of remission. Future studies should replicate these results prior to clinical use.

http://www.ncbi.nlm.nih.gov/pubmed/19712979

Psychiatry Res. 2009 Sep 30;169(2):132-8. Epub 2009 Aug 26.

Effectiveness of a quantitative electroencephalographic biomarker for predicting  differential response or remission with escitalopram and bupropion in major depressive disorder.

Leuchter AF, Cook IA, Gilmer WS, Marangell LB, Burgoyne KS, Howland RH, Trivedi MH, Zisook S, Jain R, Fava M, Iosifescu D, Greenwald S.

Semel Institute for Neuroscience and Human Behavior at UCLA, Los Angeles, CA 90024-1759, USA. afl@ucla.edu

We examined the Antidepressant Treatment Response (ATR) index as a predictor of differential response and remission to escitalopram, bupropion, or a combination  of the two medications, in subjects with major depressive disorder (MDD). Three hundred seventy-five subjects had a baseline quantitative electroencephalographic (QEEG) study preceding 1 week of treatment with escitalopram, 10 mg, after which  a second QEEG was performed and the ATR index was calculated. Subjects then were  randomized to continue escitalopram, switch to bupropion, or receive a combination of the two. Clinical response was assessed using the 17-item Hamilton Depression Rating Scale at 49 days of treatment. Accuracy of ATR in predicting response and remission was calculated. There were no significant differences between response and remission rates in the three treatment groups. A single ATR  threshold was useful for predicting differential response to either escitalopram  or bupropion monotherapy. Subjects with ATR values above the threshold were more  than 2.4 times as likely to respond to escitalopram as those with low ATR values  (68% vs. 28%). Subjects with ATR values below the threshold who were switched to  bupropion treatment were 1.9 times as likely to respond to bupropion alone as those who remained on escitalopram treatment (53% vs. 28%). The ATR index did not provide a useful prediction of response to combination treatment. The ATR index may prove useful in predicting responsiveness to different antidepressant medications.

http://www.ncbi.nlm.nih.gov/pubmed/19709754

Anesthesiology. 2009 Sep;111(3):574-83.

Effects of remifentanil on the spectrum and quantitative parameters of electroencephalogram in propofol anesthesia.

Kortelainen J, Koskinen M, Mustola S, Seppänen T.

Department of Electrical and Information Engineering, University of Oulu, Finland. jukka.kortelainen@ee.oulu.fi

BACKGROUND: A high dose of opioids associated with a low dose of propofol has become a popular anesthetic technique. However, the influence of opioids on the electroencephalographic phenomenon related to induction of anesthesia and, thereby, on the quantitative parameters used in the depth-of-anesthesia estimation is not well known. METHODS: Twenty-seven patients were divided into three groups to receive saline,  low-dose remifentanil (7.5 microg x kg x h) or high-dose remifentanil (30 microg  x kg x h) during induction of anesthesia with propofol (30 mg . kg . h). Electroencephalogram was recorded from Fz electrode, and its time-frequency properties in the patient groups were analyzed from the induction of anesthesia to the occurrence of burst suppression pattern. The group differences in 14 quantitative spectral parameters used in the depth-of-anesthesia estimation were  examined as well. RESULTS: The time-frequency properties of electroencephalogram were different between groups. The high-frequency (greater than 14 Hz) activity during light anesthesia was decreased in remifentanil groups; whereas, increased activity in extended alpha band (7-14 Hz) and decreased activity in delta band (0.5-4 Hz) was observed during deep anesthesia. This resulted in statistically significant changes in all 14 quantitative parameters. CONCLUSIONS: The effect of remifentanil on the spectrum and quantitative parameters of electroencephalogram is significant and strongly dependent on the level of anesthesia. Coadministration of opioids therefore challenges the reliability of the spectral properties of electroencephalogram in the depth-of-anesthesia estimation by using a frontal montage. Furthermore, the finding has implications for design of opioid coadministration studies.

http://www.ncbi.nlm.nih.gov/pubmed/19672187

Epilepsy Res. 2009 Sep;86(1):23-31. Epub 2009 May 22.

Single-subject voxel-based relaxometry for clinical assessment of temporal lobe epilepsy.

Kosior RK, Lauzon ML, Frayne R, Federico P.

Department of Electrical and Computer Engineering, University of Calgary, Alberta, Canada.

PURPOSE: T2 relaxometry, quantitative assessment of T2 relaxation time in magnetic resonance (MR) data, typically uses manually drawn regions of interest (ROIs). This approach is limited by its subjectivity and its restricted scope of  investigation. A recently developed approach called voxel-based relaxometry (VBR) provides an unbiased statistical analysis of the whole brain. Our objective was to assess the clinical utility of single-subject VBR for patients with temporal lobe epilepsy (TLE). METHODS: Forty-five patients with TLE confirmed by history, EEG, and structural MRI and 25 control subjects were scanned at 3T using a modified Carr-Purcell-Meiboom-Gill MR sequence. ROIs were drawn for each patient and control subject, and measurements were made on unregistered T2 maps. VBR was performed on a single-subject basis at a significance level of alpha=0.05. Patients were grouped according to seizure focus (left mesial, right mesial, other), and whether structural MR imaging was normal or abnormal. RESULTS: Up to 85% of patients in the temporal lobe groups demonstrated T2 abnormalities. VBR detected abnormalities either in equal numbers or in more patients (up to 23% more) than ROI analysis for each group. The number of detected abnormalities per patient was higher using VBR (3.38 versus 2.04, p<0.05). VBR also identified abnormalities that were missed by ROI analysis. The  rate of VBR detection of abnormalities was higher for patients than controls (76% versus 36%). CONCLUSIONS: VBR can be performed on single subjects with TLE and it detects considerably more abnormalities than ROI analysis. VBR may be a clinically useful tool for the detection of T2 abnormalities at the seizure focus and sites remote  from it.

http://www.ncbi.nlm.nih.gov/pubmed/19464852

Epileptic Disord. 2009 Sep;11(3):232-43. Epub 2009 Sep 1.

Gene expression changes in an animal model of in utero irradiation-induced Cortical Dysplasia.

Hiremath GK, Tilelli CQ, Xu Y, Gopalan B, Najm IM.

Department of Neurosurgery, Cleveland Clinic, Cleveland, Ohio 44195, USA.

PURPOSE: Cortical Dysplasia (CD) is the histopathological substrate in almost half of all drug-resistant focal epilepsies. Little is known about the gene expression profile of CD. As such information may help target therapeutics more effectively, our aim was to perform a gene expression analysis of an animal model of cortical dysplasia induced by in utero irradiation. METHODS: Nine offspring from irradiated animals, and nine age-matched controls were sacrificed at post-natal day 60. Cortical and hippocampal regions were separated, and total ribonucleic acid (RNA) was extracted using a commercially available kit (Qiagen). RNA was then subjected to a gene expression analysis using an oligonucleotide microarray platform (Illumina). After statistical analysis, genes were considered differentially expressed when a p value less than 0.001 was observed. Real-time, quantitative polymerase chain reaction (RT-qPCR) was used to confirm microarray results for three genes via the Livak method. RESULTS: Twenty three genes from cortical tissue met criteria for altered gene expression. Six genes from cortex seemed relevant to the pathogenesis of CD. Two  genes that promoted cell survival (connective tissue growth factor and peroxiredoxin) were upregulated. One gene that promoted excitotoxic neurodegeneration (latrophilin-2) was downregulated. Two genes involved in glutamate (protein kinase C-alpha) and AMPA receptor recycling (NEEP-21) were downregulated. One gene, (Shank-1) involved in the control of dendritic maturation, was downregulated. CONCLUSION: Gene expression analysis in this animal model revealed some of the potential mechanisms by which CD may lead to the phenotype of intractable epilepsy. The downregulation of genes that are involved in glutamate and AMPA receptor recycling may lead to increased excitability. Disinhibition of aberrant  dendritic branching, resulting from a downregulation of Shank-1, may also result  in an increase in sprouting, excitation and/or hypersynchrony. Finally, genes promoting cell survival, either directly (connective tissue growth factor, peroxiredoxin) or indirectly (latrophilin-2) may allow CD tissue to survive the excitotoxic injury that it produces, thus allowing it to perpetuate the epileptic condition over time.

http://www.ncbi.nlm.nih.gov/pubmed/19720584

IEEE Trans Inf Technol Biomed. 2009 Sep;13(5):703-10. Epub 2009 Mar 16.

Epileptic seizure detection in EEGs using time-frequency analysis.

Tzallas AT, Tsipouras MG, Fotiadis DI.

Unit of Medical Technology and Intelligent Information Systems, Department of Material Science and Technology, University of Ioannina, Ioannina 45110, Greece.  atzallas@cc.uoi.gr

The detection of recorded epileptic seizure activity in EEG segments is crucial for the localization and classification of epileptic seizures. However, since seizure evolution is typically a dynamic and nonstationary process and the signals are composed of multiple frequencies, visual and conventional frequency-based methods have limited application. In this paper, we demonstrate the suitability of the time-frequency (t-f) analysis to classify EEG segments for epileptic seizures, and we compare several methods for t-f analysis of EEGs. Short-time Fourier transform and several t-f distributions are used to calculate  the power spectrum density (PSD) of each segment. The analysis is performed in three stages: 1) t-f analysis and calculation of the PSD of each EEG segment; 2)  feature extraction, measuring the signal segment fractional energy on specific t-f windows; and 3) classification of the EEG segment (existence of epileptic seizure or not), using artificial neural networks. The methods are evaluated using three classification problems obtained from a benchmark EEG dataset, and qualitative and quantitative results are presented.

http://www.ncbi.nlm.nih.gov/pubmed/19304486

 J Pharm Pharmacol. 2009 Sep;61(9):1219-28.

Rapid absorption of sumatriptan powder and effects on glyceryl trinitrate model of headache following intranasal delivery using a novel bi-directional device.

Luthringer R, Djupesland PG, Sheldrake CD, Flint A, Boeijinga P, Danjou P, Demazières A, Hewson G.

Forenap FRP, 27 rue du 4ème RSM, B.P. 27, 68250 Rouffach, France. remy.luthringer@forenap.com

OBJECTIVES: The aim was to investigate the pharmacokinetics of intranasal sumatriptan (administered using a novel bi-directional powder delivery device) and study its effects on quantitative electroencephalography in patients with migraine. The safety profiles of the two formulations were also compared. METHODS: The pharmacokinetics of intranasal sumatriptan (10 mg and 20 mg) administered using a novel breath-actuated bi-directional powder delivery device  were compared with subcutaneous sumatriptan (6 mg), along with an investigation of their effects on the electroencephalogram (EEG) following glyceryl trinitrate  (GTN) challenge in 12 patients with migraine using a randomized, three-way cross-over design. KEY FINDINGS: Following intranasal delivery, median t(max) was 20 min with both doses compared with 10 min after the subcutaneous dose. Mean +/- SD values for C(max) were 96 +/- 25, 11 +/- 7 and 16 +/- 6 ng/ml for subcutaneous, intranasal 10 mg and intranasal 20 mg formulations, respectively. Values for area under the  curve were also lower with the intranasal doses. Intranasal and subcutaneous sumatriptan induced similar EEG changes characterized by reduced theta-power and  increased beta-power. The majority of study participants were free of pain according to the headache severity score with all treatments from 15 min through  to 8 h post-dose. All treatments were well tolerated and there were no reports of bitter aftertaste after intranasal delivery. Sumatriptan was rapidly absorbed after intranasal administration using the new device. Using the GTN challenge, sumatriptan powder delivered intranasally at a dose of 20 mg by the new device had effects similar to those of subcutaneous sumatriptan on EEG and reported headache pain, despite much lower systemic exposure. CONCLUSIONS: Administration of sumatriptan intranasally at doses of 10 mg and 20  mg by the breath actuated bi-directional powder delivery device results in rapid  absorption. Delivery to target sites beyond the nasal valve induced a similar EEG profile to subcutaneous sumatriptan 6 mg and prevented migraine attacks in patients following GTN challenge. Intranasal administration of sumatriptan powder with the breath actuated bi-directional powder delivery device was well tolerated.

http://www.ncbi.nlm.nih.gov/pubmed/19703372

BMC Neurosci. 2009 Aug 19;10:100.

From upright to upside-down presentation: a spatio-temporal ERP study of the parametric effect of rotation on face and house processing.

Jemel B, Coutya J, Langer C, Roy S.

Research Laboratory in Neuroscience and Cognitive Electrophysiology, Hôpital Rivière-des-Prairies, 7070 Blv Perras, Montreal, Canada. boutheina.jemel@umontreal.ca

BACKGROUND: While there is a general agreement that picture-plane inversion is more detrimental to face processing than to other seemingly complex visual objects, the origin of this effect is still largely debatable. Here, we address the question of whether face inversion reflects a quantitative or a qualitative change in processing mode by investigating the pattern of event-related potential (ERP) response changes with picture plane rotation of face and house pictures. Thorough analyses of topographical (Scalp Current Density maps, SCD) and dipole source modeling were also conducted. RESULTS: We find that whilst stimulus orientation affected in a similar fashion participants' response latencies to make face and house decisions, only the ERPs  in the N170 latency range were modulated by picture plane rotation of faces. The  pattern of N170 amplitude and latency enhancement to misrotated faces displayed a curvilinear shape with an almost linear increase for rotations from 0 degrees to  90 degrees and a dip at 112.5 degrees up to 180 degrees rotations. A similar discontinuity function was also described for SCD occipito-temporal and temporal  current foci with no topographic distribution changes, suggesting that upright and misrotated faces activated similar brain sources. This was confirmed by dipole source analyses showing the involvement of bilateral sources in the fusiform and middle occipital gyri, the activity of which was differentially affected by face rotation. CONCLUSION: Our N170 findings provide support for both the quantitative and qualitative accounts for face rotation effects. Although the qualitative explanation predicted the curvilinear shape of N170 modulations by face misrotations, topographical and source modeling findings suggest that the same brain regions, and thus the same mechanisms, are probably at work when processing upright and rotated faces. Taken collectively, our results indicate that the same processing mechanisms may be involved across the whole range of face orientations, but would operate in a non-linear fashion. Finally, the response tuning of the N170 to rotated faces extends previous reports and further demonstrates that face inversion affects perceptual analyses of faces, which is reflected within the time range of the N170 component.

http://www.ncbi.nlm.nih.gov/pubmed/19691846

J Neurol Sci. 2009 Aug 15;283(1-2):127-33. Epub 2009 Mar 6.

The value of quantitative EEG in differential diagnosis of Alzheimer's disease and subcortical vascular dementia.

Gawel M, Zalewska E, Szmidt-Sałkowska E, Kowalski J.

Department of Neurology, Medical University of Warsaw, Poland. mgawel@amwaw.edu.pl

OBJECTIVE: To investigate whether quantitative EEG may be useful in differential  diagnosis of AD and SVD and to determine the correlation between dementia and abnormalities in EEG. MATERIALS AND METHODS: The group under study was consisted of 62 patients with AD (mean age: 73.6 yrs; M 51%), 31 with SVD (mean age: 75.2 yrs, M 43%) and a control group of 14 healthy subjects (mean age: 69.5 yrs, M 43%). The patients were divided into subgroups of those with mild, moderate and marked dementia. EEG findings were classified using eight-degree scale according to the presence of slow waves, and then quantitative analysis was carried out by calculating the alpha/slow wave power ratios and the mean frequencies in all and some selected derivations. RESULTS: A significant difference between visual EEGs and QEEGs in AD and SVD was found. Only QEEG parameters differed in AD and SVD subgroups with the same degree of cognitive impairment: the mean wave frequencies of waves in temporal derivations in subgroups with mild and moderate dementia and alpha/delta waves power ratio in subgroups with moderate dementia. CONCLUSIONS: Visual EEGs and QEEGs could be used in addition to the differential  diagnosis between AD and SVD, but only selected parameters of QEEG could be useful in differentiating between AD and SVD subgroups with the same degree of dementia.

http://www.ncbi.nlm.nih.gov/pubmed/19268969

Science. 2009 Aug 14;325(5942):866-70.

The transcriptional repressor DEC2 regulates sleep length in mammals.

He Y, Jones CR, Fujiki N, Xu Y, Guo B, Holder JL Jr, Rossner MJ, Nishino S, Fu YH.

Department of Neurology, University of California at San Francisco, Mission Bay,  1550 Fourth Street, San Francisco, CA 94158, USA.

Comment in     Science. 2009 Aug 14;325(5942):825-6.

Sleep deprivation can impair human health and performance. Habitual total sleep time and homeostatic sleep response to sleep deprivation are quantitative traits  in humans. Genetic loci for these traits have been identified in model organisms, but none of these potential animal models have a corresponding human genotype and phenotype. We have identified a mutation in a transcriptional repressor (hDEC2-P385R) that is associated with a human short sleep phenotype. Activity profiles and sleep recordings of transgenic mice carrying this mutation showed increased vigilance time and less sleep time than control mice in a zeitgeber time- and sleep deprivation-dependent manner. These mice represent a model of human sleep homeostasis that provides an opportunity to probe the effect of sleep on human physical and mental health.

http://www.ncbi.nlm.nih.gov/pubmed/19679812

Anesth Analg. 2009 Aug;109(2):539-50.

Practical use of the raw electroencephalogram waveform during general anesthesia: the art and science.

Bennett C, Voss LJ, Barnard JP, Sleigh JW.

Waikato Clinical School, Waikato Hospital, Hamilton, New Zealand.

Quantitative electroencephalogram (QEEG) monitors are often used to estimate depth of anesthesia and intraoperative recall during general anesthesia. As with  any monitor, the processed numerical output is often misleading and has to be interpreted within a clinical context. For the safe clinical use of these monitors, a clear mental picture of the expected raw electroencephalogram (EEG) patterns, as well as a knowledge of the common EEG artifacts, is absolutely necessary. This has provided the motivation to write this tutorial. We describe,  and give examples of, the typical EEG features of adequate general anesthesia, effects of noxious stimulation, and adjunctive drugs. Artifacts are commonly encountered and may be classified as arising from outside the head, from the head but outside the brain (commonly frontal electromyogram), or from within the brain (atypical or pathologic). We include real examples of clinical problem-solving processes. In particular, it is important to realize that an artifactually high QEEG index is relatively common and may result in dangerous anesthetic drug overdose. The anesthesiologist must be certain that the QEEG number is consistent with the apparent state of the patient, the doses of various anesthetic drugs, and the degree of surgical stimulation, and that the QEEG number is consistent with the appearance of the raw EEG signal. Any discrepancy must be a stimulus for the immediate critical examination of the patient's state using all the available information rather than reactive therapy to "treat" a number.

http://www.ncbi.nlm.nih.gov/pubmed/19608830

Anesth Analg. 2009 Aug;109(2):506-23.

Continuous electroencephalogram monitoring in the intensive care unit.

Friedman D, Claassen J, Hirsch LJ.

Department of Neurology, Comprehensive Epilepsy Center, Columbia University, NewYork City, New York, USA.

Because of recent technical advances, it is now possible to record and monitor the continuous digital electroencephalogram (EEG) of many critically ill patients simultaneously. Continuous EEG monitoring (cEEG) provides dynamic information about brain function that permits early detection of changes in neurologic status, which is especially useful when the clinical examination is limited. Nonconvulsive seizures are common in comatose critically ill patients and can have multiple negative effects on the injured brain. The majority of seizures in  these patients cannot be detected without cEEG. cEEG monitoring is most commonly  used to detect and guide treatment of nonconvulsive seizures, including after convulsive status epilepticus. In addition, cEEG is used to guide management of pharmacological coma for treatment of increased intracranial pressure. An emerging application for cEEG is to detect new or worsening brain ischemia in patients at high risk, especially those with subarachnoid hemorrhage. Improving quantitative EEG software is helping to make it feasible for cEEG (using full scalp coverage) to provide continuous information about changes in brain function in real time at the bedside and to alert clinicians to any acute brain event, including seizures, ischemia, increasing intracranial pressure, hemorrhage, and even systemic abnormalities affecting the brain, such as hypoxia, hypotension, acidosis, and others. Monitoring using only a few electrodes or using full scalp  coverage, but without expert review of the raw EEG, must be done with extreme caution as false positives and false negatives are common. Intracranial EEG recording is being performed in a few centers to better detect seizures, ischemia, and peri-injury depolarizations, all of which may contribute to secondary injury. When cEEG is combined with individualized, physiologically driven decision making via multimodality brain monitoring, intensivists can identify when the brain is at risk for injury or when neuronal injury is already  occurring and intervene before there is permanent damage. The exact role and cost-effectiveness of cEEG at the current time remains unclear, but we believe it has significant potential to improve neurologic outcomes in a variety of settings.

http://www.ncbi.nlm.nih.gov/pubmed/19608827

Clin Neurophysiol. 2009 Aug;120(8):1433-40. Epub 2009 Jul 8.

Use of quantitative EEG in infants with port-wine birthmark to assess for Sturge-Weber brain involvement.

Ewen JB, Kossoff EH, Crone NE, Lin DD, Lakshmanan BM, Ferenc LM, Comi AM.

Department of Neurology and Developmental Medicine, Kennedy Krieger Institute, Baltimore, MD 21205, USA. Ewen@kennedykrieger.org

OBJECTIVE: Many infants born with a facial port-wine (PW) birthmark will not develop brain involvement of Sturge-Weber syndrome (SWS). Previous studies have shown asymmetry in quantitative EEG (QEEG) correlates with degree of clinical impairment in children and adults with known SWS. We hope to determine if quantitative QEEG can be used as a method to predict which infants are most likely to develop SWS brain involvement on MRI. The current study looks at the ability of QEEG to differentiate between infants with radiographically demonstrated SWS and those without. METHODS: We first performed an observational study of QEEG results on eight infants with facial PW birthmark (four had SWS brain involvement). We recorded standard clinical EEGs and then derived a measure of asymmetry. We subsequently validated this threshold through a study of an additional nine infants with PW birthmark (five with SWS brain involvement). RESULTS: quantitative EEG correctly identified infants with SWS brain involvement in all cases in the Validation cohort. This technique was at least as good as a pediatric electroencephalographer with extensive experience reading SWS EEGs. CONCLUSIONS: This study demonstrates the ability for QEEG to discriminate between those infants with SWS brain involvement and those with neurologically asymptomatic PW birthmark. SIGNIFICANCE: This study represents an important step toward the development of a QEEG technique able to predict which infants with PW birthmark will develop SWS brain involvement.

http://www.ncbi.nlm.nih.gov/pubmed/19589723

Crit Care Med. 2009 Aug;37(8):2427-35.

Hypothermia-treated cardiac arrest patients with good neurological outcome differ early in quantitative variables of EEG suppression and epileptiform activity.

Wennervirta JE, Ermes MJ, Tiainen SM, Salmi TK, Hynninen MS, Särkelä MO, Hynynen  MJ, Stenman UH, Viertiö-Oja HE, Saastamoinen KP, Pettilä VY, Vakkuri AP.

Intensive Care Units, Department of Anesthesiology and Intensive Care Medicine, Helsinki University Hospital, Helsinki, Finland. johanna.wennervirta@hus.fi

Comment in     Crit Care Med. 2009 Aug;37(8):2485-6.

OBJECTIVE: To evaluate electroencephalogram-derived quantitative variables after  out-of-hospital cardiac arrest. DESIGN: Prospective study. SETTING: University hospital intensive care unit. PATIENTS: Thirty comatose adult patients resuscitated from a witnessed out-of-hospital ventricular fibrillation cardiac arrest and treated with induced  hypothermia (33 degrees C) for 24 hrs. INTERVENTIONS: None. MEASUREMENTS AND MAIN RESULTS: Electroencephalography was registered from the arrival at the intensive care unit until the patient was extubated or transferred to the ward, or 5 days had elapsed from cardiac arrest. Burst-suppression ratio,  response entropy, state entropy, and wavelet subband entropy were derived. Serum  neuron-specific enolase and protein 100B were measured. The Pulsatility Index of  Transcranial Doppler Ultrasonography was used to estimate cerebral blood flow velocity. The Glasgow-Pittsburgh Cerebral Performance Categories was used to assess the neurologic outcome during 6 mos after cardiac arrest. Twenty patients  had Cerebral Performance Categories of 1 to 2, one patient had a Cerebral Performance Categories of 3, and nine patients had died (Cerebral Performance Categories of 5). Burst-suppression ratio, response entropy, and state entropy already differed between good (Cerebral Performance Categories 1-2) and poor (Cerebral Performance Categories 3-5) outcome groups (p = .011, p = .011, p = .008) during the first 24 hrs after cardiac arrest. Wavelet subband entropy was higher in the good outcome group between 24 and 48 hrs after cardiac arrest (p =  .050). All patients with status epilepticus died, and their wavelet subband entropy values were lower (p = .022). Protein 100B was lower in the good outcome  group on arrival at ICU (p = .010). After hypothermia treatment, neuron-specific  enolase and protein 100B values were lower (p = .002 for both) in the good outcome group. The Pulsatility Index was also lower in the good outcome group (p  = .004). CONCLUSIONS: Quantitative electroencephalographic variables may be used to differentiate patients with good neurologic outcomes from those with poor outcomes after out-of-hospital cardiac arrest. The predictive values need to be determined in a larger, separate group of patients.

http://www.ncbi.nlm.nih.gov/pubmed/19487928

Curr Opin Neurol. 2009 Aug;22(4):340-7.

Human brain networks in health and disease.

Bassett DS, Bullmore ET.

Department of Psychiatry, Behavioral and Clinical Neurosciences Institute, Addenbrooke's Hospital, Cambridge, UK.

PURPOSE OF REVIEW: Recent developments in the statistical physics of complex networks have been translated to neuroimaging data in an effort to enhance our understanding of human brain structural and functional networks. This review focuses on studies using graph theoretical measures applied to structural MRI, diffusion MRI, functional MRI, electroencephalography, and magnetoencephalography data. RECENT FINDINGS: Complex network properties have been identified with some consistency in all modalities of neuroimaging data and over a range of spatial and time scales. Conserved properties include small worldness, high efficiency of information transfer for low wiring cost, modularity, and the existence of network hubs. Structural and functional network metrics have been found to be heritable and to change with normal aging. Clinical studies, principally in Alzheimer's disease and schizophrenia, have identified abnormalities of network configuration in patients. Future work will likely involve efforts to synthesize  structural and functional networks in integrated models and to explore the interdependence of network configuration and cognitive performance. SUMMARY: Graph theoretical analysis of neuroimaging data is growing rapidly and could potentially provide a relatively simple but powerful quantitative framework to describe and compare whole human brain structural and functional networks under diverse experimental and clinical conditions.

http://www.ncbi.nlm.nih.gov/pubmed/19494774

Epilepsia. 2009 Aug;50 Suppl 7:13-7.

Guidelines for EEG in encephalopathy related to ESES/CSWS in children.

Scheltens-de Boer M.

Department of Clinical Neurophysiology, Erasmus Medical Center, Gravendijkwal 230, Rotterdam, The Netherlands. m.scheltens@erasmusmc.nl

Electrical status epilepticus during slow sleep (ESES) or continuous spikes and waves during slow sleep (CSWS) is a phenomenon characterized by strong activation of epileptiform activity in the electroencephalogram (EEG) during sleep. The literature contains several small series of patients and many case reports. Large prospective studies are lacking. Definitions of the syndromes and EEG criteria and methods vary, as does their classification. The fluctuating clinical course and EEG findings complicate the diagnostic process and evaluation of effect of therapy. Studies describing quantitative aspects of the epileptiform abnormalities in EEG are overrepresented in literature, whereas qualitative aspects are relatively undervalued. Guidelines for evaluation of the EEG in these syndromes, which focus on both aspects, are presented.

http://www.ncbi.nlm.nih.gov/pubmed/19682043

Epilepsy Behav. 2009 Aug;15(4):486-90. Epub 2009 Jul 23.

Educational problems related to quantitative EEG changes in benign childhood epilepsy with centrotemporal spikes.

Tedrus GM, Fonseca LC, Melo EM, Ximenes VL.

Department of Neurology, Pontificia Universidade Catolica de Campinas (PUC-Campinas), Av. John Boyd Dunlop, Campinas, Brazil.

The relationship between educational problems and clinical/electroencephalographic aspects was assessed in 38 children with benign  childhood epilepsy with centrotemporal spikes (BECTS). Children were assessed using the School Performance Test; questionnaires on learning difficulties administered to parents and teachers; the Wechsler Intelligence Scale for Children, Third Edition; and EEGs. Absolute and relative amplitudes in the classic bands (quantitative EEG) and characteristics of epileptiform activity on  the EEG were examined. Educational problems were observed in 7 (18.4%) children with BECTS. In this subgroup, relative alpha amplitudes at the central and parietal electrodes were lower as compared with those of the BECTS subgroup with  normal educational performance and a control group matched for age, gender, and socioeconomic status. The data indicated a possible relationship between alterations in background brain electrical activity and the tendency toward inferior educational performance in children with BECTS. This study suggested that quantitative EEGs are a possible physiological tool in the assessment of cognitive aspects in children with BECTS.

http://www.ncbi.nlm.nih.gov/pubmed/19631587

Clin EEG Neurosci. 2009 Jul;40(3):168-72.

Dementia, mild cognitive impairment and quantitative EEG in patients with Parkinson's disease.

Fonseca LC, Tedrus GM, Letro GH, Bossoni AS.

School of Medicine, Pontifícia Universidade Católica de Campinas (PUC-Campinas),  Campinas, SP, Brazil. lineu.fonseca@uol.com.br

The objective of this study was to evaluate relationships between quantitative EEG (QEEG) changes and cognitive disturbance (mild cognitive impairment or dementia) and the motor disturbance stage in Parkinson's disease (PD). Thirty-two PD patients (age = 67.2 +/- 10.0) and 26 normal subjects (age = 68.4 +/- 4.7) were assessed using a neurological evaluation, modified Hoehn and Yahr (HY) scale for PD, a Portuguese version of the CERAD neuropsychological battery (consortium  to establish a registry for Alzheimer's disease) incorporating the Mini-mental Status Examination, Clinical Dementia Rating and an EEG analysis of absolute and  relative band amplitude at rest. Four groups were compared: three with PD (7 patients with dementia, 10 with mild cognitive impairment and 15 with no cognitive disturbances) and the control group. The QEEG showed no significant differences between the control group and PD patients without cognitive disturbance. Abnormalities on the QEEG were essentially associated with the occurrence of mild cognitive impairment or dementia in patients with PD. There was an increase in the absolute and relative posterior theta amplitude in the groups with mild cognitive impairment or dementia and of the posterior absolute and relative delta amplitude in the group with dementia This study suggested QEEG as a possible physiological tool in the assessment of cognitive aspects in PD.

http://www.ncbi.nlm.nih.gov/pubmed/19715179

Clin EEG Neurosci. 2009 Jul;40(3):150-6.

Source analysis of alpha rhythm reactivity using LORETA imaging with 64-channel EEG and individual MRI.

Cuspineda ER, Machado C, Virues T, Martínez-Montes E, Ojeda A, Valdés PA, Bosch J, Valdes L.

Havana Institute of Neurology and Neurosurgery, Havana City, Cuba. cuspineda@yahoo.com

Conventional EEG and quantitative EEG visual stimuli (close-open eyes) reactivity analysis have shown their usefulness in clinical practice; however studies at the level of EEG generators are limited. The focus of the study was visual reactivity of cortical resources in healthy subjects and in a stroke patient. The 64 channel EEG and T1 magnetic resonance imaging (MRI) studies were obtained from 32 healthy subjects and a middle cerebral artery stroke patient. Low Resolution Electromagnetic Tomography (LORETA) was used to estimate EEG sources for both close eyes (CE) vs. open eyes (OE) conditions using individual MRI. The t-test was performed between source spectra of the two conditions. Thresholds for statistically significant t values were estimated by the local false discovery rate (lfdr) method. The Z transform was used to quantify the differences in cortical reactivity between the patient and healthy subjects. Closed-open eyes alpha reactivity sources were found mainly in posterior regions (occipito-parietal zones), extended in some cases to anterior and thalamic regions. Significant cortical reactivity sources were found in frequencies different from alpha (lower t-values). Significant changes at EEG reactivity sources were evident in the damaged brain hemisphere. Reactivity changes were also found in the "healthy" hemisphere when compared with the normal population.  In conclusion, our study of brain sources of EEG alpha reactivity provides information that is not evident in the usual topographic analysis.

http://www.ncbi.nlm.nih.gov/pubmed/19715176

Clin Neurophysiol. 2009 Jul;120(7):1273-81. Epub 2009 Jun 9.

Wavelet-denoising of electroencephalogram and the absolute slope method: a new tool to improve electroencephalographic localization and lateralization.

Leung H, Schindler K, Chan AY, Lau AY, Leung KL, Ng EH, Wong KS.

Division of Neurology, Department of Medicine and Therapeutics, Chinese University of Hong Kong, Prince of Wales Hospital, Shatin, NT, Hong Kong, China.  howanleung@hotmail.com

OBJECTIVE: In ictal scalp electroencephalogram (EEG) the presence of artefacts and the wide ranging patterns of discharges are hurdles to good diagnostic accuracy. Quantitative EEG aids the lateralization and/or localization process of epileptiform activity. METHODS: Twelve patients achieving Engel Class I/IIa outcome following temporal lobe surgery (1 year) were selected with approximately 1-3 ictal EEGs analyzed/patient. The EEG signals were denoised with discrete wavelet transform (DWT), followed by computing the normalized absolute slopes and spatial interpolation of scalp topography associated to detection of local maxima. For localization, the region with the highest normalized absolute slopes at the time  when epileptiform activities were registered (>2.5 times standard deviation) was  designated as the region of onset. For lateralization, the cerebral hemisphere registering the first appearance of normalized absolute slopes >2.5 times the standard deviation was designated as the side of onset. As comparison, all the EEG episodes were reviewed by two neurologists blinded to clinical information to determine the localization and lateralization of seizure onset by visual analysis. RESULTS: 16/25 seizures (64%) were correctly localized by the visual method and 21/25 seizures (84%) by the quantitative EEG method. 12/25 seizures (48%) were correctly lateralized by the visual method and 23/25 seizures (92%) by the quantitative EEG method. The McNemar test showed p=0.15 for localization and p=0.0026 for lateralization when comparing the two methods. CONCLUSIONS: The quantitative EEG method yielded significantly more seizure episodes that were correctly lateralized and there was a trend towards more correctly localized seizures. SIGNIFICANCE: Coupling DWT with the absolute slope method helps clinicians achieve a better EEG diagnostic accuracy.

http://www.ncbi.nlm.nih.gov/pubmed/19515612

Clin Neurophysiol. 2009 Jul;120(7):1245-51. Epub 2009 May 24.

Quantitative study of the sleep onset period via detrended fluctuation analysis:  normal vs. narcoleptic subjects.

Kim JW, Shin HB, Robinson PA.

School of Physics, The University of Sydney, Sydney, NSW 2006, Australia. jwkim@physics.usyd.edu.au

OBJECTIVE: To examine the process of the sleep onset quantitatively and explore differences between narcoleptics and controls during the sleep onset period (SOP). METHOD: Dynamic detrended fluctuation analysis (DFA) was applied to electroencephalograms recorded during multiple sleep latency tests of 11 drug-free narcoleptic patients (19.3+/-4.4 yrs; 8 males) and 9 healthy controls (23.8+/-6.3 yrs; 6 males). The SOP of each group was estimated by fitting the time courses of the DFA scaling exponents to a parametric curve. RESULTS: The sequence of DFA exponents showed that electrophysiological brain activity was changing rapidly across the SOP. This transition was also verified by a conventional method (i.e., dynamic spectral analysis). The SOP durations of  narcoleptics and controls were estimated as 239+/-25 s and 145+/-20 s, respectively. CONCLUSIONS: The significantly larger SOP of narcoleptics, compared to controls,  is consistent with the wake state of narcolepsy being more susceptible to sleep due to a lower barrier to transitioning to sleep. SIGNIFICANCE: Our results suggest that electrophysiological signatures of narcolepsy could be quantified by dynamic DFA, so the method may have promise as  a potential tool to help the diagnosis of narcolepsy despite the present study's  limited sample size.

http://www.ncbi.nlm.nih.gov/pubmed/19467617

Clin Neurophysiol. 2009 Jul;120(7):1235-44. Epub 2009 May 22.

An electro-encephalogram beta gap after induction with diazepam: a localization method in epileptogenic lesions.

Claus S, Leijten F, Kallansee P, Klepper J, Lopes da Silva FH, Ronner H, Velis D, Viergever MA, Kalitzin S.

Department of Clinical Neurophysiology, Stichting Epilepsy Instellingen Nederland (Epilepsy Institutes of The Netherlands Foundation), SEIN, Achterweg 5, 2103 SW,  Heemstede, The Netherlands. sclaus@sein.nl

OBJECTIVE: We clinically tested a quantitative EEG method to localize abnormal variations in benzodiazepine-induced fast rhythms to localize focal epileptogenic lesions, assuming altered quality/quantity of GABA receptors in the lesions. METHODS: During a 64-channel-EEG (sampled at 1 kHz) recording benzodiazepines were administered to five patients with localization related epilepsy associated  with an MRI visible focal lesion. We determined the post-injection dominant spectral modulation using Gabor wavelets and analysed the symmetry of spatial distribution. This was compared to the localization of the lesion on the MRI scan. RESULTS: The principal component was found in the beta/gamma band. In all patients one region of decreased change was associated with the lesional hemisphere, and overlapped with the site of the lesion in four. Three patients underwent surgery: interictal corticographic findings concurred with the area of  decreased benzodiazepine response. CONCLUSIONS: This simple method localized abnormal function associated with epileptogenic lesions. Further methodological validation is now justified. Final  clinical validation must be done in MRI-negative cases as well. SIGNIFICANCE: This research may lead to techniques for non-invasive easy localization of epileptogenic tissue that is not visible on a structural MRI scan.

http://www.ncbi.nlm.nih.gov/pubmed/19464946

J Neuropsychiatry Clin Neurosci. 2009 Summer;21(3):279-83.

Discrete shifts within the theta band between the frontal and parietal regions of the right hemisphere and the experiences of a sensed presence.

Booth JN, Persinger MA.

Behavioral Neuroscience Program, Laurentian University, Sudbury, Ontario P3E 2C6.

The attribution of personal cognition to another consciousness or sentient being  is strongly correlated with altered perfusion within the frontoparietal or frontotemporal regions. The authors applied weak complex magnetic fields that produce an increased incidence of these experiences in healthy volunteers. Quantitative monopolar electroencephalographic (QEEG) measurements for each of the four lobes of the two hemispheres found that intensity of the sensed presence was significantly correlated with increased power within only the theta range over the right parietal and frontal lobes. Successive 1 Hz incremental analyses indicated specific power increases for 4 Hz-5 Hz and 7 Hz-8 Hz bands over the right parietal and frontal lobes, respectively. These results are consistent with those of other measures for both schizophrenia patients and healthy volunteers; changes in activity within these regions are associated with attribution of one's thoughts and actions to another.

http://www.ncbi.nlm.nih.gov/pubmed/19776307

Dialogues Clin Neurosci. 2009;11(4):435-46.

A new paradigm for the prediction of antidepressant treatment response.

Leuchter AF, Cook IA, Hunter AM, Korb AS.

Laboratory of Brain Behavior, and Pharmacology, Semel Institute for Neuroscience and Human Behavior at UCLA, Los Angeles, CA 90024, USA. afl@ucla.edu

Current treatment of Major Depressive Disorder utilizes a trial-and-error sequential treatment strategy that results in delays in achieving response and remission for a majority of patients. Protracted ineffective treatment prolongs patient suffering and increases health care costs. In addition, long and unsuccessful antidepressant trials may diminish patient expectations, reinforce negative cognitions, and condition patients not to respond during subsequent antidepressant trials, thus contributing to further treatment resistance. For these reasons, it is critical to identify reliable predictors of antidepressant treatment response that can be used to shorten or eliminate lengthy and ineffective trials. Research on possible endophenotypic as well as genomic predictors has not yet yielded reliable predictors. The most reliable predictors identified thus far are symptomatic and physiologic characteristics of patients that emerge early in the course of treatment. We propose here the term "response endophenotypes" (REs) to describe this class of predictors, defined as latent measurable symptomatic or neurobiologic responses of individual patients that emerge early in the course of treatment, and which carry strong predictive power for individual patient outcomes. Use of REs constitutes a new paradigm in which medication treatment trials that are likely to be ineffective could be stopped within 1 to 2 weeks and other medication more likely to be effective could be started. Data presented here suggest that early changes in symptoms, quantitative electroencephalography, and gene expression could be used to construct effective REs. We posit that this new paradigm could lead to earlier recovery from depressive illness and ultimately produce profound health and economic benefits.

PubMed Link

Clin Physiol Funct Imaging. 2010 Mar;30(2):135-40. Epub 2010 Jan 20.

Brain electrical activity during food presentation in obese binge-eating women.

Tammela LI, Pääkkönen A, Karhunen LJ, Karhu J, Uusitupa MI, Kuikka JT.

Department of Clinical Nutrition, School of Public Health and Clinical Nutrition, University of Kuopio, and Kuopio University Hospital, Kuopio, Finland.

Binge-eating (BE) subjects have shown altered brain activity at frontal regions during food presentation. The aim of this study was to examine the frontal brain electrical activity in obese BE women (n = 12) and in obese women without BE (non-BE, n = 13). Brain electrical activity was measured using a quantitative electroencephalography during a resting state (eyes-closed) and when the subjects focused (eyes-open) their attention on a picture of a landscape (control experiment) or on a meal (food experiment). The BE showed greater frontal beta activity (14-20 Hz) than the non-BE in both the eyes-closed (on average 52%) and the eyes-open situations and independently of the stimulus (control experiment: 57% and food experiment: 71%). No significant differences between the groups were found in alpha, delta or theta amplitudes. Increased beta activity correlated positively with the disinhibition factor of the Three-Factor Eating Questionnaire. Thus, our results suggest that elevated frontal beta activity may be a marker of dysfunctional disinhibition-inhibition mechanism, which could make the obese BE women more vulnerable or sensitive to food and the environmental cues.

PubMed Link

Psychol Med. 2009 Dec 9:1-9. [Epub ahead of print]

Subanesthetic dose of ketamine decreases prefrontal theta cordance in healthy volunteers: implications for antidepressant effect.

Horacek J, Brunovsky M, Novak T, Tislerova B, Palenicek T, Bubenikova-Valesova V, Spaniel F, Koprivova J, Mohr P, Balikova M, Hoschl C.

Prague Psychiatric Centre, Prague, Czech Republic.

BACKGROUND: Theta cordance is a novel quantitative electroencephalography (QEEG) measure that correlates with cerebral perfusion. A series of clinical studies has demonstrated that the prefrontal theta cordance value decreases after 1 week of treatment in responders to antidepressants and that this effect precedes clinical improvement. Ketamine, a non-competitive antagonist of N-methyl-d-aspartate (NMDA) receptors, has a unique rapid antidepressant effect but its influence on theta cordance is unknown.MethodIn a double-blind, cross-over, placebo-controlled experiment we studied the acute effect of ketamine (0.54 mg/kg within 30 min) on theta cordance in a group of 20 healthy volunteers. RESULTS: Ketamine infusion induced a decrease in prefrontal theta cordance and an increase in the central region theta cordance after 10 and 30 min. The change in prefrontal theta cordance correlated with ketamine and norketamine blood levels after 10 min of ketamine infusion. CONCLUSIONS: Our data indicate that ketamine infusion immediately induces changes similar to those that monoamineric-based antidepressants induce gradually. The reduction in theta cordance could be a marker and a predictor of the fast-acting antidepressant effect of ketamine, a hypothesis that could be tested in depressive patients treated with ketamine.

PubMed Link

Neurosci Lett. 2010 Jan 18;469(1):145-9. Epub 2009 Nov 27.

Gamma band oscillations under influence of bromazepam during a sensorimotor integration task: an EEG coherence study.

Minc D, Machado S, Bastos VH, Machado D, Cunha M, Cagy M, Budde H, Basile L, Piedade R, Ribeiro P.

Brain Mapping and Sensory Motor Integration, Institute of Psychiatry of Federal University of Rio de Janeiro (IPUB/UFRJ), Rio de Janeiro, RJ, Brazil.

The goal of the present study was to explore the dynamics of the gamma band using the coherence of the quantitative electroencephalography (QEEG) in a sensorimotor integration task and the influence of the neuromodulator bromazepam on the band behavior. Our hypothesis is that the needs of the typewriting task will demand the coupling of different brain areas, and that the gamma band will promote the binding of information. It is also expected that the neuromodulator will modify this coupling. The sample was composed of 39 healthy subjects. We used a randomized double-blind design and divided subjects into three groups: placebo (n=13), bromazepam 3mg (n=13) and bromazepam 6 mg (n=13). The two-way ANOVA analysis demonstrated a main effect for the factors condition (i.e., C4-CZ electrode pair) and moment (i.e., C3-CZ, C3-C4 and C4-CZ pairs of electrodes). We propose that the gamma band plays an important role in the binding among several brain areas in complex motor tasks and that each hemisphere is influenced in a different manner by the neuromodulator. (c) 2009 Elsevier Ireland Ltd. All rights reserved.

PubMed Link

Br J Clin Pharmacol. 2009 Nov;68(5):721-30.

Evidence for oxazepam as an in vivo probe of UGT2B15: oxazepam clearance is reduced by UGT2B15 D85Y polymorphism but unaffected by UGT2B17 deletion.

He X, Hesse LM, Hazarika S, Masse G, Harmatz JS, Greenblatt DJ, Court MH.

Laboratory of Comparative and Molecular Pharmacogenomics and Department of Pharmacology and Experimental Therapeutics, Tufts University School of Medicine, Boston, MA 02111, USA.

AIMS: Although in vitro studies indicate that oxazepam is an isoform-selective substrate probe for UDP-glucuronosyltransferase 2B15, the utility of this drug as an in vivo probe is uncertain. The main aim of this study was to determine whether common missense polymorphisms in the UGT2B15 gene (D85Y and K523T) are associated with altered oxazepam pharmacokinetics and pharmacodynamics. We also determined the possible influence of a common deletion polymorphism in the gene encoding UGT2B17, which shows substantial substrate specificity overlap with UGT2B15. METHODS: Thirty healthy male subjects were administered 15 mg of oxazepam by mouth followed by plasma oxazepam concentration monitoring for 36 h, and pharmacodynamic testing for 8 h. Genotypes were determined by genomic polymerase chain reaction and commercial 5'-nuclease assays. RESULTS: Allele frequencies for D85Y, K523T, UGT2B17del were 47%, 23% and 19%, respectively. Median oxazepam apparent oral clearance was significantly lower in 85YY subjects (1.62 ml min(-1) kg(-1)) compared with 85DD subjects (3.35 ml min(-1) kg(-1); P= 0.003, Student-Newman-Keuls test), whereas 85DY subjects were intermediate (2.34 ml min(-1) kg(-1); P= 0.018 vs. 85DD, P= 0.034 vs. 85YY). Regression analysis indicated that UGT2B15 D85Y genotype accounted for 34% of interindividual variability. However, neither UGT2B15 K523T nor UGT2B17del was associated with altered oxazepam disposition. Furthermore, no differences in pharmacodynamic measures, including quantitative electroencephalography, digit-symbol substitution test, self- or observer-rated visual analogue scales, could be demonstrated for any of the polymorphisms evaluated. CONCLUSIONS: These results identify UGT2B15 D85Y as a major determinant of oxazepam clearance, and indicate that oxazepam may be useful as an in vivo probe for glucuronidation by UGT2B15.

PubMed Link

J Neuropsychiatry Clin Neurosci. 2009 Summer;21(3):254-8.

Quantitative EEG abnormalities are associated with memory impairment in recently abstinent methamphetamine-dependent individuals.

Kalechstein AD, De la Garza R 2nd, Newton TF, Green MF, Cook IA, Leuchter AF.

Baylor College of Medicine, Menninger Department of Psychiatry and Behavioral Sciences, Houston, TX 77030, USA. ari.kalechstein@bcm.tmc.edu

This study examined the association between brain electrical activity, measured using quantitative electroencephalography (QEEG), and performance on measures of episodic memory in a sample of nine methamphetamine-dependent individuals who were evaluated after 4 days of monitored abstinence and 10 non-drug-using comparison subjects. In methamphetamine users, but not in comparison subjects, increased theta power was correlated with poorer performance on the delayed recall subtests of the Rey Auditory Verbal Learning Test and the Rey-Osterrieth Complex Figure Test (p<0.05). There was no association between alpha, beta, and delta power and performance on the memory tests. These results complement previous findings by demonstrating that the electrophysiological abnormalities associated with methamphetamine dependence are likely to affect behavior in an observable and important manner (i.e., memory deficits) when users are not intoxicated.

PubMed Link