QEEG and Brain Mapping Abstracts posted by "A Matter of Mind"
Last updated: April 2010.
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.
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.
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.
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.
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.
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.
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.
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.
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. Copyright 2009 Elsevier Ltd. All rights reserved.
Clin EEG Neurosci. 2009 Apr;40(2):84-112.
Evidence-based
medicine evaluation of electrophysiological studies of the anxiety disorders.
Clark CR, Galletly CA, Ash DJ, Moores KA, Penrose RA,
McFarlane AC.
Cognitive Neuroscience Laboratory, School of Psychology, Flinders
University , Adelaide, Australia, Adelaide, Australia. Richard.Clark@flinders.edu.au
We provide a systematic, evidence-based medicine (EBM)
review of the field of electrophysiology in the anxiety disorders. Presently,
electrophysiological studies of anxiety focus primarily on etiological aspects
of brain dysfunction. The review highlights many functional similarities across
studies, but also identifies patterns that clearly differentiate disorder
classifications. Such measures offer clinical utility as reliable and objective
indicators of brain dysfunction in individuals and indicate potential as
biomarkers for the improvement of diagnostic specificity and for informing
treatment decisions and prognostic assessments. Common to most of the anxiety
disorders is basal instability in cortical arousal, as reflected in measures of
quantitative electroencephalography (qEEG). Resting electroencephalographic
(EEG) measures tend to correlate with symptom sub-patterns and be exacerbated
by condition-specific stimulation. Also common to most of the anxiety disorders
are condition-specific difficulties with
sensory gating and the allocation and deployment of attention. These are
clearly evident from evoked potential (EP) and event-related potential (ERP)
electrical measures of information processing in obsessive compulsive disorder
(OCD), post-traumatic stress disorder (PTSD), panic disorder (PD), generalized
anxiety disorder (GAD) and the phobias. Other'ERP measures clearly
differentiate the disorders. However, there is considerable variation across
studies, with inclusion and exclusion criteria, medication status and control
group selection not standardized within condition or across studies. Study
numbers generally preclude analysis for confound removal or for the derivation
of diagnostic biomarker patterns at this time. The current trend towards
development of databases of brain and cognitive function is likely to obviate
these difficulties. In particular, electrophysiological measures of function
are likely to play a significant role in the development and subsequent adaptations of DSM-V and assist critically in
securing improvements in nosological and treatment specificity.
Clin EEG Neurosci. 2009 Apr;40(2):78-83.
Use of
clinical neurophysiology for the selection of medication in the treatment of major depressive disorder: the state of
the evidence.
Leuchter AF, Cook IA, Hunter A, Korb A.
Laboratory of Brain, Behavior, and Pharmacology, Semel
Institute for Neuroscience and Human Behavior at UCLA, Los Angeles, CA
90024-1759, USA. afl@ucla.edu
Approximately 50% of patients with Major Depressive Disorder
(MDD) respond to the first antidepressant medication prescribed, and fewer than
one-third experience remission of symptoms. The most significant challenge in
the management of MDD, therefore, is selection of the antidepressant medication
that is most likely to lead to response or to remission for an individual
patient. There is a growing body of evidence that certain clinical
neurophysiologic techniques may be useful
for selecting the medication that is most likely benefit each patient.
Use of low resolution electromagnetic tomography (LORETA), loudness dependent
auditory evoked potentials (LDAEP), and resting state quantitative
electroencephalography (QEEG) in the
clinical setting is increasingly supported by studies indicating that these
techniques may help identify particular medications that are most likely to
lead to response or remission. The current state of evidence supporting the use
of each technique is reviewed.
J Clin Exp Neuropsychol. 2009 May 29:1-18. [Epub ahead of
print]
Neuropsychological
effects of hostility and pain on emotion perception.
Mitchell GA, Harrison DW.
Adams State College, Alamosa, CO, USA.
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.
J Child Neurol. 2009 Apr;24(4):416-20.
Clinical and
EEG features of epilepsy in children and adolescents in Down syndrome.
Smigielska-Kuzia J, Sobaniec W, Kułak W,
Boćkowski L.
Department of Pediatric Neurology and Rehabilitation,
Medical University of Białystok, Waszyngtona 17, 15-274 Białystok,
Poland. jsmig1@poczta.onet.pl
Epilepsy is rarely considered as a major component of Down
syndrome. We evaluated the prevalence of epileptic seizures in 252 (97 girls
and 155 boys) children and adolescents
with Down syndrome evaluated at Department of Pediatric Neurology between 1994
and 2007. Results showed that 15 (6%) patients had epileptic seizures: 8
partial seizures; 1 infantile spasms, 1 Lennox-Gastaut syndrome, and 5 generalized tonic-clonic seizures.
Electroencephalography was performed on all
patients with Down syndrome. Focal changes, spikes, generalized slowing,
and hypsarrhythmia were recorded. The electroencephalography was found to be
abnormal in Down syndrome with epilepsy in 100%. Almost 60% of patients with
Down syndrome and epilepsy had seizures, but 40% of the patients were
seizures-free. Quantitative electroencephalography analysis revealed
significant differences between children with Down syndrome and the control
groups in the alpha, delta, and beta rhythms. Our findings are in accordance
with other reports.
Psychopharmacology (Berl). 2009 Jul;204(4):573-85. Epub
2009 Feb 25.
Caffeine
withdrawal, acute effects, tolerance, and absence of net beneficial effects of
chronic administration: cerebral blood flow velocity, quantitative EEG, and
subjective effects.
Sigmon SC, Herning RI, Better W, Cadet JL, Griffiths RR.
Department of Psychiatry, University of Vermont College of
Medicine, SATC-UHC, Room 1415, Burlington, VT, 05401, USA. stacey.sigmon@uvm.edu
RATIONALE: Although the subjective effects of caffeine
abstinence, acute and chronic administration, and tolerance are well described,
the corresponding neurophysiological effects are not. OBJECTIVES: Caffeine
withdrawal, acute caffeine effects, caffeine tolerance, and net beneficial
effects of chronic caffeine administration were investigated using cerebral blood
flow velocity, quantitative electroencephalography (EEG), and subjective
effects. MATERIALS AND METHODS: Sixteen
regular caffeine users participated in this double-blind, within-subject study
during which they received acute caffeine and placebo challenges (1) while
maintained on 400 mg caffeine daily for > or =14 days and (2) while
maintained on placebo for > or =14 days. Blood flow velocity was determined
for the middle (MCA) and anterior (ACA) cerebral arteries using pulsed
transcranial Doppler sonography. EEG was recorded from 16 scalp sites.
Subjective effects were assessed with questionnaires. RESULTS: Acute caffeine
abstinence (evaluated 24 h after placebo substitution) increased mean,
systolic, and diastolic velocity in the MCA and ACA and decreased pulsatility
index in the MCA. Acute caffeine abstinence increased EEG theta and decreased
beta 2 power. Acute caffeine abstinence also increased measures of Tired,
Fatigue, Sluggish, and Weary and decreased ratings of Energetic, Friendly,
Lively, and Vigor. Acute caffeine effects were demonstrated across a wide range
of measures, including cerebral blood flow, EEG, and subjective effects.
Tolerance and "complete" tolerance were observed on subjective but
not physiological measures. Chronic caffeine effects were demonstrated only on
the measure of EEG beta 2 power. CONCLUSION: Acute caffeine abstinence and
administration produced changes in cerebral blood flow velocity, EEG, and
subjective effects. Tolerance to subjective but not physiological measures was demonstrated.
There was almost no evidence for net effects of chronic caffeine administration
on these measures. Overall, these findings provide the most rigorous
demonstration to date of physiological effects of caffeine withdrawal.
Appl Psychophysiol Biofeedback. 2009 Mar;34(1):59-68. Epub
2009 Feb 6.
Traumatic
brain injury rehabilitation: QEEG biofeedback treatment protocols.
Thornton KE, Carmody DP.
Brain Foundation, 2 Ethel Road, Edison, NJ 08817, USA. ket@chp-neurotherapy.com
Interventions for improvement of cognitive problems in
patients with traumatic brain injury (TBI) include electroencephalography
biofeedback, also known as neurofeedback. Quantitative electroencephalography
(QEEG) patterns are assessed in TBI patients and then compared to a database
obtained from a normative population. Deviations in QEEG patterns from the
normative group are the basis for an intervention plan. While QEEG patterns,
obtained under an eyes closed, resting condition, provide information about
deviations at rest, QEEG patterns obtained while the patient engages in
cognitive tasks reflect specific deficiencies in brain functioning. This paper
reviews and assesses QEEG patterns
collected under both resting conditions as well as cognitive tasks. The
article provides a theoretical and empirical base for QEEG interventions with
TBI.
Dialogues Clin Neurosci. 2008;10(4):439-51.
Predictors,
moderators, and mediators (correlates) of treatment outcome in major depressive disorder.
Papakostas GI, Fava M.
Depression Clinical Research Program, Department of
Psychiatry, Massachusetts General Hospital, Harvard Medical School, Boston,
Massachusetts 02114, USA. gpapakostas@partners.org
Major Depressive Disorder (MDD) is a prevalent illness that
is frequently associated with significant disability, morbidity and mortality
Despite the development and availability of numerous treatment options for MDD,
studies have shown that antidepressant
monotherapy yields only modest rates of response and remission. Clearly, there
is an urgent need to develop more effective treatment strategies for patients
with MDD. One possible approach towards the development of novel
pharmacotherapeutic strategies for MDD involves identifying subpopulations of
depressed patients who are more likely to experience the benefits of a given
(existing) treatment versus placebo, or versus a second treatment. Attempts
have been made to identify such "subpopulations", specifically by
testing whether a given biological or clinical marker also serves as a
moderator, mediator (correlate), or predictor of clinical improvement following
the treatment of MDD with standard, first-line antidepressants. In the following article, we will attempt to
summarize the literature focusing on several major areas ("leads")
where preliminary evidence exists regarding clinical and biologic moderators,
mediators, and predictors of symptom improvement in MDD. Such clinical leads
will include the presence of hopelessness, anxious symptoms, or medical
comorbidity. Biologic leads will include gene polymorphisms, brain metabolism,
quantitative electroencephalography, loudness dependence of auditory evoked
potentials, and functional brain asymmetry.
Clin Neurophysiol. 2009 Mar;120(3):464-71. Epub 2009 Jan
20.
The occipital
alpha rhythm related to the "migraine cycle" and headache burden: a
blinded, controlled longitudinal study.
Bjørk MH, Stovner LJ, Nilsen BM, Stjern M, Hagen K, Sand T.
Department of Neuroscience, Norwegian University of Science
and Technology (NTNU), MTFS, N-7489 Trondheim, Norway. marte.bjork@ntnu.no
OBJECTIVE: Neurophysiological studies have shown a
fluctuating neural dysfunction in migraine. This pathophysiological feature has
not previously been investigated by quantitative electroencephalography (QEEG).
The alpha rhythm is especially interesting, because it is influenced by
ischemia and neuronal dysfunction within the posterior circulation area.
METHODS: We investigated alpha peak frequency, variability, peak power and
asymmetry in 41 migraineurs and 32 controls. Electroencephalography (EEG) was
recorded on three random days and retrospectively classified as preattack,
attack, postattack or interictal, based
on the patient's headache diaries. We also searched for correlations
between alpha rhythm parameters and disease duration, attack duration, attack
frequency, pain intensity and
photophobia. RESULTS: Peak frequency reduction correlated with increasing
disease- and attack duration. Frequency variability increased before the
attack, while peak power increased during the attack. Alpha peak width,
peak frequency and peak power were
similar for migraineurs and controls in the interictal period. CONCLUSION: The
accumulated burden of migraine caused slight alterations in the physiology of
the visual cortex. Small alpha rhythm changes were observed along the migraine
cycle. SIGNIFICANCE: This is a longitudinal, controlled study. It is the first
to report changes in alpha rhythm with increased migraine load, even when the
QEEG is not influenced by recent or imminent attacks.
Neurosci Lett. 2009 Feb 27;451(3):181-4. Epub 2009 Jan 6.
Effects of
bromazepam in frontal theta activity on the performance of a sensorimotor
integration task: a quantitative electroencephalography study.
Fridman S, Machado S, Cunha M, Velasques B, Pompeu F, Budde
H, Cagy M, Basile LF, Piedade R, Ribeiro P.
Brain Mapping and Sensory Motor Integration, Institute of
Psychiatry of Federal University of Rio de Janeiro, Brazil.
Our objective is to verify the modulatory effects of
bromazepam on EEG theta absolute power when subjects were submitted to a
visuomotor task (i.e., car driver task). Sample was composed of 14 students (9
males and 5 females), right handed, with ages varying between 23 and 42 years
(mean=32.5+/-9.5), absence of mental or physical impairments, no psychoactive
or psychotropic substance use and no neuromuscular disorders (screened by a
clinical examination). The results showed an interaction between condition and
electrodes (p=0.034) in favor of F8 electrode compared with F7 in both experimental
conditions (t-test; p=0.001). Additionally, main effects were observed for
condition (p=0.001), period (p=0.001) and electrodes (p=0.031) in favor of F4
electrode compared with F3. In
conclusion, Br 6mg of bromazepam may interfere in sensorimotor processes
in the task performance in an unpredictable scenario allowing that certain
visuospatial factors were predominant.
Therefore, the results may reflect that bromazepam effects influence the
performance of the involved areas because of the acquisition and integration of
sensory stimuli processes until the development of a motor behavior based on
the same stimuli.
BMC Neurol. 2008 Nov 24;8:44.
Quantitative
electroencephalography reveals different physiological profiles between benign
and remitting-relapsing multiple sclerosis patients.
Vazquez-Marrufo M, Gonzalez-Rosa JJ,
Vaquero E, Duque P, Borges M, Gomez C, Izquierdo G.
Laboratory of Psychophysiology, Department of Experimental
Psychology, University of Seville, Camilo Jose Cela s/n, 41018 Seville, Spain. marrufo@us.es
BACKGROUND: A possible method of finding physiological
markers of multiple sclerosis (MS) is the application of EEG quantification
(QEEG) of brain activity when the
subject is stressed by the demands of a cognitive task. In particular,
modulations of the spectral content that take place in the EEG of patients with
multiple sclerosis remitting-relapsing (RRMS) and benign multiple sclerosis
(BMS) during a visuo-spatial task need to be observed. METHODS: The sample
consisted of 19 patients with RRMS, 10 with BMS, and 21 control subjects. All
patients were free of medication and had not relapsed within the last month.
The power spectral density (PSD) of different EEG bands was calculated by
Fast-Fourier-Transformation (FFT), those analysed being delta, theta, alpha,
beta and gamma. Z-transformation was performed to observe individual profiles
in each experimental group for spectral
modulations. Lastly, correlation analyses was performed between QEEG values and
other variables from participants in the study
(age, EDSS, years of evolution and cognitive performance). RESULTS: Nearly
half (42%) the RRMS patients showed a statistically significant increase of two
or more standard deviations (SD) compared to the control mean value for the
beta-2 and gamma bands (F = 2.074, p = 0.004). These alterations were localized
to the anterior regions of the right hemisphere, and bilaterally to the
posterior areas of the scalp. None of
the BMS patients or control subjects had values outside the range of +/- 2 SD.
There were no significant correlations between these values and the other
variables analysed (age, EDSS, years of evolution or behavioural performance).
CONCLUSION: During the attentional processing, changes in the high EEG spectrum (beta-2 and gamma) in MS
patients exhibit physiological alterations
that are not normally detected by spontaneous EEG analysis. The
different spectral pattern between pathological and controls groups could
represent specific changes for the RRMS patients, indicative of compensatory
mechanisms or cortical excitatory states
representative of some phases during the RRMS course that are not present in
the BMS group.
BMC Psychiatry. 2008 Nov 11;8:89.
Quantitative
EEG findings in patients with acute, brief depression combined with other fluctuating psychiatric symptoms: a
controlled study from an acute psychiatric department.
Bjørk MH, Sand T, Bråthen G, Linaker OM, Morken G, Nilsen
BM, Vaaler AE.
Department of Neurology and Clinical Neurophysiology, St
Olavs Hospital, Trondheim, Norway. marte.bjork@ntnu.no
BACKGROUND: Patients with brief depressive episodes and
concurrent rapidly fluctuating psychiatric symptoms do not fit current
diagnostic criteria and they can be
difficult to diagnose and treat in an acute psychiatric setting. We wanted to
study whether these patients had signs of more epileptic or organic brain
dysfunction than patients with depression without additional symptomatology.
METHODS: Sixteen acutely admitted patients diagnosed with a brief depressive
episode as well as another concurrent psychiatric diagnosis were included.
Sixteen patients with major depression served as controls. Three
electroencephalographic studies (EEG) were visually interpreted and the
background activity was also analysed with quantitative electroencephalography
(QEEG). RESULTS: The group with brief depression and concurrent symptoms had
multiple abnormal features in their standard EEG compared to patients with
major depression, but they did not show
significantly more epileptiform activity. They
also had significantly higher temporal QEEG delta amplitude and
interhemispheric temporal delta
asymmetry. CONCLUSION: Organic brain dysfunction may be involved in the
pathogenesis of patients with brief depressive episodes mixed with rapidly
fluctuating psychiatric symptoms. This subgroup of depressed patients should be
investigated further in order to clarify the pathophysiology and to establish
the optimal evaluation scheme and treatment in an acute psychiatric setting.
Neurosci Lett. 2008 Nov 28;446(1):7-10. Epub 2008 Sep 19.
Integration of
cortical areas during performance of a catching ball task.
Machado S, Cunha M, Portella CE, Silva JG, Velasques B,
Bastos VH, Budde H, Pompeu F, Basile L, Cagy M, 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,
Brazil. secm80@yahoo.com.br
The study aimed to elucidate electrophysiological and
cortical mechanisms involved in anticipatory actions when healthy subjects had
to catch balls in free drop; specifically through quantitative electroencephalography
(qEEG) alpha absolute power changes. Our hypothesis is that during the
preparation of motor action (i.e., 2s before ball's drop) occurred integration
among left medial frontal, left primary somatomotor and left posterior parietal
cortices, showing a differentiated activity involving expectation, planning and
preparedness. This hypothesis supports a lateralization of motor function.
Although we contend that in
right-handers the left hemisphere takes on a dominant role for the
regulation of motor behavior. The sample
was composed of 23 healthy subjects (13 male and 10 female), right handed, with
ages varying between 25 and 40 years old (32.5+/-7.5), absence of mental and
physical illness, right handed, and do not make use of any psychoactive or psychotropic
substance at the time of the study. The
experiment consisted of a task of catching balls in free drop. The
three-way ANOVA analysis demonstrated an
interaction between moment and position in left medial frontal cortex (F3
electrode), somatomotor cortex (C3 electrode) and posterior parietal cortex (P3
electrode; p < 0.001). Summarizing, through experimental task employed, it
was possible to observe integration among frontal, central and parietal
regions. This integration appears to be more predominant in expectation, planning and motor preparation.
In this way, it established an absolute predominance of this mechanism under
the left hemisphere.
Curr Psychiatry Rep. 2008 Oct;10(5):432-8.
Quantitative
electroencephalography and attention-deficit/hyperactivity disorder:
implications for clinical practice.
Monastra VJ.
FPI Attention Disorders Clinic, Department of Psychology,
Binghamton University, 94 Marshall
Drive, Endicott, NY 13760, USA. poppidoc@aol.com
Although behavioral symptoms of inattention, impulsivity,
and hyperactivity serve as a foundation for the accurate diagnosis of
attention-deficit/hyperactivity disorder (ADHD), the low interrater reliability
and specificity of behavioral rating scales and the absence of comprehensive
screening for medical conditions that mimic ADHD have created a barrier to the
effective treatment of ADHD. Recently published studies using quantitative
electroencephalographic techniques have
identified abnormal patterns of cortical activation through power spectral
analysis, in event-related cortical potentials, and in slow cortical potentials
that may serve as a basis for overcoming these barriers. This paper reviews the
initial evidence indicating that power spectral analysis and event-related
cortical potentials may be useful in differentiating ADHD from other
psychiatric disorders, helping in
medication selection, evaluating medication response, and improving the rate of
treatment initiation and maintenance. Studies examining electroencephalogram
biofeedback (neurotherapy) are reviewed using published efficacy guidelines.
BMC Neurosci. 2008 Sep 15;9:86.
Serum
anticholinergic activity and cerebral cholinergic dysfunction: an EEG study in
frail elderly with and without delirium.
Thomas C, Hestermann U, Kopitz J, Plaschke K, Oster P,
Driessen M, Mundt C, Weisbrod M.
Centre for Psychosocial Medicine, Department of General
Psychiatry, University of Heidelberg, Vossstr, Heidelberg, Germany. Christine.Thomas@evkb.de
BACKGROUND: Delirium increases morbidity, mortality and
healthcare costs especially in the elderly. Serum anticholinergic activity
(SAA) is a suggested biomarker for anticholinergic burden and delirium risk,
but the association with cerebral
cholinergic function remains unclear. To clarify this relationship, we
prospectively assessed the correlation of SAA with quantitative
electroencephalography (qEEG) power, delirium occurrence, functional and
cognitive measures in a cross-sectional sample of acutely hospitalized elderly
(> 80 y) with high dementia and delirium prevalence. METHODS: 61
consecutively admitted patients over 80 years underwent an extensive clinical
and neuropsychological evaluation. SAA was determined by using radio receptor
assay as developed by Tune, and standard as well as quantitative EEGs were
obtained. RESULTS: 15 patients had dementia with additional delirium (DD)
according to expert consensus using DSM-IV criteria, 31 suffered from dementia
without delirium (D), 15 were cognitively unimpaired (CU). SAA was clearly
detectable in all patients but one (mean
10.9 +/- 7.1 pmol/ml), but was not associated with expert-panel approved
delirium diagnosis or cognitive functions. Delirium-associated EEG abnormalities
included occipital slowing, peak power and
alpha decrease, delta and theta power increase and slow wave ratio
increase during active delirious states. EEG measures correlated significantly
with cognitive performance and delirium severity, but not with SAA levels.
CONCLUSION: In elderly with acute disease, EEG parameters reliable indicate
delirium, but SAA does not seem to reflect cerebral cholinergic function as
measured by EEG and is not related to
delirium diagnosis.
Arch Gerontol Geriatr. 1998 Sep-Oct;27(2):115-26.
Quantitative
electroencephalography, with serial subtraction and odour detection in the differentiation of Alzheimer's disease
and vascular dementia.
Seal EC, van Hintum CJ, Pierson JM, Helme RD.
National Ageing Research Institute, PO Box 31, Parkville,
Victoria 3052, Australia.
The diagnosis of dementia can be difficult, yet diagnostic
accuracy has important prognostic and therapeutic implications. Nevertheless,
conventional electroencephalography (EEG) has always played a secondary role in
dementia investigation. More recently quantitative EEG (qEEG) has allowed more
detailed and objective analysis of EEG data, but there is still no clearly
defined clinical role for qEEG. We have used relative power qEEG measures made
during resting and active brain conditions (serial subtraction and odour
detection tasks) to differentiate between demented and non-demented subjects,
and between subjects with different forms of dementia. Electroencephalograms were
obtained from 15 subjects with clinically diagnosed Alzheimer's disease (AD),
16 with a clinical diagnosis of vascular dementia (VaD), and 16 non-demented
control subjects. Discriminate function analyses were used to differentiate
groups according to task, electrode site, and frequency bandwidth. Correct
classification, as demented or non-demented, was made for 93% of cases using
qEEG comparisons of resting states with eyes closed and eyes opened. Almost all
subjects with AD and VaD were correctly classified with qEEG recorded during
odour detection (95%). qEEG for serial subtraction correctly classified AD and
VaD in 91% of the dementia group. These results have important implications for
future qEEG research, and may be pertinent to the precision of diagnosis in
patients with dementia.
Arq Neuropsiquiatr. 2008 Jun;66(2B):341-3.
Posterior parietal cortex role in a sensorimotor task
performance.
Nader S, Machado S, Cunha M, Portella
CE, Silva JG, Velasques B, Bastos VH, Basile L, Cagy M, Piedade R, Ribeiro P.
Laboratório de Mapeamento Cerebral e
Integração Sensório-Motora, Programa de Pós-Graduação em Psiquiatria e Saúde
Mental, Instituto de Psiquiatria da Universidade do Brasil, Universidade
Federal do Rio de Janeiro, Brazil.
This study aimed to elucidate electrophysiological and
cortical mechanisms involved in anticipatory actions when individuals had to
catch balls in free drop; specifically through quantitative electroencephalography
(qEEG) alpha absolute power changes. The sample was composed for 23 health
subjects, both sexes, with ages varying between 25 and 40 years, absence of
mental and physical illness, right
handed and don't make use of any psychoactive or psychotropic substance at the
time of the study. The experiment consisted of a task of catching balls in free
drop. The three-way ANOVA analysis demonstrated an interaction between moment
and position factors in left parietal posterior cortex (PPC) (p=0.001). Through
the experimental task employed, this area demonstrated a differentiated
activity involving expectation, planning and preparedness in the ball's drop
task.
Alzheimers Dement. 2008 Jan;4(1 Suppl 1):S137-43. Epub 2007
Dec 21.
Electroencephalography
and event-related potentials as biomarkers of mild cognitive impairment and
mild Alzheimer's disease.
Jackson CE, Snyder PJ.
Department of Psychology, University of Connecticut,
Storrs, CT, USA.
BACKGROUND: Successful early detection of mild cognitive
impairment (MCI) and Alzheimer's disease demands the identification of
biomarkers capable of distinguishing individuals with prodromal or early
cognitive impairment from healthy aging adults. Many laboratories are engaged
in the discovery and validation of a wide array of potential genetic,
proteomic, cognitive, and other types of
biomarkers. METHODS: This review focuses on the application of quantitative electroencephalography
(qEEG) and event-related potential (ERP) technologies as markers of prodromal
impairment and early disease progression. It is the aim of this review to
critically assess where this field currently stands, as well as future
directions for EEG biomarker development. RESULTS: As a neuroimaging tool that
is relatively inexpensive, potentially portable, and capable of providing
high-density spatial mapping, qEEG offers a noninvasive, rapid, and replicable
method for assessing age-related and disease-related neurophysiologic change.
CONCLUSIONS: As different signature changes associated with particular stages
of disease burden are identified and validated, we anticipate expanded
application of qEEG as a reliable and sensitive biomarker(s) of MCI and early Alzheimer's disease.
J Altern Complement Med. 2008 Jun;14(5):505-13.
Effects of
verum acupuncture compared to placebo acupuncture on quantitative EEG and heart rate variability in healthy
volunteers.
Streitberger K, Steppan J, Maier C, Hill H, Backs J,
Plaschke K.
Clinic of Anesthesiology, University of Heidelberg,
Heidelberg, Germany.
OBJECTIVES: The aim of this single-blind randomized crossover
study was to evaluate specific effects of manual acupuncture on central and
vegetative nervous system activity measured by quantitative
electroencephalography (qEEG) and heart
rate variability (HRV). DESIGN: Twenty (20) healthy volunteers (mean:
25.2 +/- 3.6 years) were monitored simultaneously using a qEEG system and a
12-channel electrocardiogram recorder during verum acupuncture (VA) at
acupuncture point Large Intestine 4 (Hegu) (LI4) or placebo acupuncture (PA) at
a sham point. RESULTS: In the EEG conduction of the occipital area, needle
stimulation in VA increased alpha1-frequency significantly, and the ratio
alpha1/theta was shifted to the benefit
of alpha1 over all electrodes. The HRV parameters showed a significant increase
of the low frequency/high frequency (HF) ratio during the first minute of
stimulation in VA, indicating an initial increase of sympathetic activation. However, an increase of HF power
in the minute after stimulation followed by a decrease in heart rate suggests
delayed vagal activation. De qi (a
sensation that is typical of acupuncture needling) occurred in 16
subjects during VA and in 9 volunteers during PA (80% versus 45%). CONCLUSIONS:
Manual stimulation on LI4 seems to lead to specific changes in alpha
EEG-frequency and in HRV parameters. A linear relationship between the HRV
parameters and the alpha EEG band might point to a specific modulation of
cerebral function by vegetative effects
during acupuncture.
Crit Care Med. 2008 Jun;36(6):1909-16.
Early
electrophysiologic markers predict functional outcome associated with
temperature manipulation after cardiac arrest in rats.
Jia X, Koenig MA, Nickl R, Zhen G, Thakor NV, Geocadin RG.
Department of Biomedical Engineering, Johns Hopkins
University School of Medicine, Baltimore, MD, USA. xjia1@jhmi.edu
OBJECTIVE: Therapeutic hypothermia after cardiac arrest improves
survival and functional outcomes, whereas hyperthermia is harmful. The optimal
method of tracking the effect of temperature on neurologic recovery after
cardiac arrest has not been elucidated. We studied the recovery of cortical
electrical function by quantitative
electroencephalography after 7-min asphyxial cardiac arrest, using information
quantity (IQ). DESIGN: Laboratory investigation. SETTING: University medical
school and animal research facility. SUBJECTS: A total of 28 male Wistar rats.
INTERVENTIONS: Using an asphyxial cardiac arrest rodent model, we tracked quantitative
electroencephalography of 6-hr immediate postresuscitation hypothermia (at 33
degrees C), normothermia (37 degrees C), or
hyperthermia (39 degrees C) (n = 8 per group). Neurologic recovery was
evaluated using the Neurologic Deficit
Score. Four rats were included as a sham control group. MEASUREMENTS AND MAIN
RESULTS: Greater recovery of IQ was found in rats treated with hypothermia (IQ
= 0.74), compared with normothermia (IQ = 0.60) and hyperthermia (IQ = 0.56) (p < .001).
Analysis at different intervals demonstrated a significant separation of IQ
scores among the temperature groups within the first 2 hrs postresuscitation (p
< .01). IQ values of >0.523 at 60 mins postresuscitation predicted good
neurologic outcome (72-hr Neurologic Deficit Score of > or = 60), with a
specificity of 100% and sensitivity of 81.8%. IQ was also significantly lower in rats that died
prematurely compared with survivors (p < .001). IQ values correlated
strongly with 72-hr Neurologic Deficit Score as early as 30 mins post-cardiac
arrest (Pearson's correlation 0.735, p < .01) and maintained a significant
association throughout the 72-hr experiment. No IQ difference was noted in sham
rats with temperature manipulation. CONCLUSIONS: The enhanced recovery provided
by hypothermia and the detrimental effect by hyperthermia were robustly
detected by early quantitative electroencephalographic markers. IQ values
during the first 2 hrs after cardiac arrest accurately predicted neurologic
outcome at 72 hrs.
Dev Neuropsychol. 2008;33(1):25-43.
Reduced verbal
learning associated with posterior temporal lobe slow wave activity.
Foster PS, Harrison DW, Crucian GP, Drago V, Rhodes RD,
Heilman KM.
Department of Neurology, University of Florida, Malcom
Randall Veterans Affairs Medical Center, Gainesville, Florida, USA. pfoster@mtsu.edu
Functional imaging has revealed that during verbal-word
learning there is activation of the left posterior temporo-parietal region
(PTPL). The purpose of this study was to learn if differences in the ability of
normal people to learn might be accounted for by differences in
electrophysiological (EEG) measures of activation of their left, but not right,
PTPL. The Rey Auditory Verbal Learning Test (RAVLT) was administered to 42 men
without neurological diseases. Delta magnitude, as measured by quantitative
electroencephalography (QEEG), was recorded from the left and right PTPL while
the participants sat quietly with their eyes closed. The magnitude of delta EEG
activity is inversely proportional to
cerebral activation. Based on delta magnitude, comparison groups were created by separating those with low and high delta
at the left and right PTPL. Cumulative word learning (CWL) on the RAVLT was
computed by subtracting the number of words recalled on the first learning
trial from the highest number of words recalled on the fourth or fifth trial
and multiplying this difference by the total words recalled during all 5
learning trials. The group with a greater magnitude of left PTPL delta activity
had a significantly poorer CWL scores than
those with less delta, but the CWL scores of the group with a greater
magnitude of delta of the right PTPL was no different that the group with less
right-sided delta. No significant
differences emerged at any frontal or parietal electrode site. Decreased
activation of the left, but not right, PTPL appears to be associated with a
decreased verbal leaning ability.
Part Fibre Toxicol. 2008 Mar 11;5:4.
Exposure to
diesel exhaust induces changes in EEG in human volunteers.
Crüts B, van Etten L, Törnqvist H, Blomberg A, Sandström T,
Mills NL, Borm PJ.
Centre of Expertise in Life Sciences, Zuyd University,
Heerlen, The Netherlands. p.borm@hszuyd.nl.
ABSTRACT: BACKGROUND: Ambient particulate matter and
nanoparticles have been shown to translocate to the brain, and potentially
influence the central nervous system. No
data are available whether this may lead to functional changes in the brain. METHODS: We exposed 10 human
volunteers to dilute diesel exhaust (DE, 300
mug/m3) as a model for ambient PM exposure and filtered air for one hour
using a double blind randomized
crossover design. Brain activity was monitored during and for one hour
following each exposure using quantitative electroencephalography (QEEG) at 8
different sites on the scalp. The frequency spectrum of the EEG signals was
used to calculate the median power frequency (MPF) and specific frequency bands
of the QEEG. RESULTS: Our data demonstrate a significant increase in MPF in
response to DE in the frontal cortex within 30 min into exposure. The increase
in MPF is primarily caused by an increase in fast wave activity (beta2) and continues to rise during the 1 hour
post-exposure interval. CONCLUSION: This
study is the first to show a functional effect of DE exposure in the
human brain, indicating a general cortical stress response. Further studies are
required to determine whether this effect is mediated by the nanoparticles in
DE and to define the precise pathways involved.
Vet J. 2009 May;180(2):221-30. Epub 2008 Mar 7.
Visual and
quantitative electroencephalographic analysis of healthy young and adult cats
under medetomidine sedation.
Wrzosek M, Nicpon J, Bergamasco L, Sammartano F,
Cizinauskas S, Jaggy A.
Division of Clinical Neurology, Department of Clinical
Veterinary Medicine, Vetsuisse Faculty, University of Bern, Länggassstrasse
128, CH-3001 Bern, Switzerland. marcin.wrzosek@itn.unibe.ch
A study was designed to investigate the effect of
medetomidine sedation on quantitative electroencephalography (q-EEG) in healthy
young and adult cats to determine objective guidelines for diagnostic EEG
recordings and interpretation.
Preliminary visual examination of EEG recordings revealed high-voltage
low-frequency background activity. Spindles, k-complexes and vertex sharp
transients characteristic of sleep or sedation were superimposed on a low
background activity. Neither paroxysmal activity nor EEG burst-suppression were
observed. The spectral analysis of q-EEG included four parameters, namely,
relative power (%), and mean, median and peak frequency (Hz) of all four frequency
bands (delta, theta, alpha and beta). The findings showed a prevalence of slow delta and theta rhythms as opposed to
fast alpha and beta rhythms in both young (group A) and adult (group B) cats. A
posterior gradient was reported for the theta band and an anterior gradient for
the alpha and beta bands in both groups, respectively. The relative power value
in group B compared to group A was significantly higher for theta, alpha and
beta bands, and lower for the delta band. The mean and median frequency values
in group B was significantly higher for delta, theta and beta bands and lower
for the alpha band. The study has shown that a medetomidine sedation protocol
for feline EEG may offer a method for investigating bio-electrical cortical
activity. The use of q-EEG analysis showed
a decrease in high frequency bands and increased activity of the low
frequency band in healthy cats under medetomidine sedation.
Psychiatry Investig. 2008 Mar;5(1):45-51. Epub 2008 Mar 31.
Comparison of
low resolution electromagnetic tomography imaging between subjects with mild and severe obstructive sleep apnea
syndrome: a preliminary study.
Lee HK, Park DH, Shin HS, Hong SC.
Department of Psychiatry, Seoul National Mental Hospital,
Seoul, Korea.
OBJECTIVE: The purpose of this study was to identify the
regions of the brain associated with recurrent nocturnal chronic hypoxic
episodes in patients with untreated obstructive sleep apnea syndrome (OSAS) using
low-resolution electromagnetic tomography (LORETA) and quantitative
electroencephalography (QEEG). METHODS: Nocturnal polysomnograph (NPSG) and
subsequent morning electroencephalograph (EEG) were measured in 20 subjects
with OSAS. Mild (n=10 ages 39.5+/-12.1 years) and severe (n=10 ages 41.7+/-13.6
years) right-handed male OSAS subjects were selected by interview and
questionnaires including the NPSG, Beck Depression Inventory, Beck Anxiety
Inventory, Epworth Sleepiness Scale, and Pittsburgh Sleep Quality Index. The
LORETA and QEEG were compared between the severe and mild OSAS groups by
frequency bands (delta 1-3 Hz, theta 4-7 Hz, alpha 8-12 Hz, beta1 13-18 Hz,
beta2 19-21 Hz, beta3 22-30 Hz, and total
1-30 Hz) made by spectral analysis during resting with the eyes closed.
RESULTS: The LORETA analysis showed
decreased alpha activity at the right posterior cingulate gyrus (Brodmann area
23) in cases with severe OSAS compared to mild OSAS (p<0.05). For the QEEG, the
absolute power of the alpha activity (8-12 Hz) was decreased in P3 (p=0.047),
PZ (p=0.039) and O2 (p=0.04) in cases with severe OSAS compared to mild OSAS cases. The LORETA
and QEEG analyses had similar results with regard to band, activation and
location. CONCLUSION: The decreased activity of the alpha frequency in the
right posterior cingulate gyrus, in patients with severe OSAS compared to those
with mild OSAS, suggests that chronic repeated short-term hypoxia during sleep,
in OSAS, could provoke cortical brain dysfunction associated with cognitive
dysfunction such as memory and attention.
Acta Psychiatr Scand. 2008 Apr;117(4):271-6. Epub 2008 Feb
26.
Pretreatment frontal EEG and changes in suicidal ideation
during SSRI treatment in major depressive disorder.
Iosifescu DV, Greenwald S, Devlin P, Perlis RH, Denninger
JW, Alpert JE, Fava M.
Depression Clinical and Research Program, Massachusetts
General Hospital, and Harvard Medical School, Boston, MA 02114, USA. diosifescu@partners.org
OBJECTIVE: We investigated frontal quantitative EEG
(QEEG) as predictor of changes in suicidal ideation (SI) during SSRI treatment
in major depressive disorder (MDD). METHOD: Eighty-two subjects meeting DSM-IV
criteria for MDD entered an 8-week, prospective, open-label treatment with
flexible dose SSRIs and completed at least 4 weeks of treatment. We assessed
MDD severity with the 17-item Hamilton Depression Rating Scale (HAM-D-17);
change in SI was measured with HAM-D item no. 3. We recorded four-channel EEGs
(F7-Fpz, F8-Fpz, A1-Fpz, A2-Fpz) before treatment. RESULTS: During the first 4
weeks of treatment 9 (11%) subjects
experienced worsening SI. Left-right asymmetry of combined theta + alpha power
correlated significantly with change in SI from baseline, even when adjusting
for changes in depression severity (HAM-D-17) and for the SSRI utilized.
CONCLUSION: Frontal QEEG parameters before treatment may predict worsening SI
during SSRI treatment in MDD.
Publication Types:
Clinical Trial Research
Support, Non-U.S. Gov't
Part Fibre Toxicol. 2008 Mar 11;5:4.
Exposure to diesel exhaust induces changes in EEG in human
volunteers.
Crüts B, van Etten L, Törnqvist H, Blomberg A, Sandström T,
Mills NL, Borm PJ.
Centre of Expertise in Life Sciences, Zuyd University,
Heerlen, The Netherlands. p.borm@hszuyd.nl.
ABSTRACT: BACKGROUND: Ambient particulate matter and
nanoparticles have been shown to translocate to the brain, and potentially
influence the central nervous system. No
data are available whether this may lead to functional changes in the brain. METHODS: We exposed 10 human
volunteers to dilute diesel exhaust (DE, 300
mug/m3) as a model for ambient PM exposure and filtered air for one hour
using a double blind randomized
crossover design. Brain activity was monitored during and for one hour
following each exposure using quantitative electroencephalography (QEEG) at 8
different sites on the scalp. The frequency spectrum of the EEG signals was
used to calculate the median power frequency (MPF) and specific frequency bands
of the QEEG. RESULTS: Our data demonstrate a significant increase in MPF in
response to DE in the frontal cortex within 30 min into exposure. The increase
in MPF is primarily caused by an increase in fast wave activity (beta2) and continues to rise during the 1 hour
post-exposure interval. CONCLUSION: This
study is the first to show a functional effect of DE exposure in the
human brain, indicating a general cortical stress response. Further studies are
required to determine whether this effect is mediated by the nanoparticles in
DE and to define the precise pathways involved.
J Neurol Neurosurg Psychiatry. 2008 Feb;79(2):119-25. Epub
2007 May 22.
Prolonged activation EEG differentiates dementia with and without
delirium in frail elderly patients.
Thomas C, Hestermann U, Walther S, Pfueller U, Hack M,
Oster P, Mundt C, Weisbrod M.
Centre for Psychosocial Medicine, Department of General
Psychiatry, University of Heidelberg, Germany. Christine.thomas@evkb.de
OBJECTIVE: Delirium in the elderly results in
increased morbidity, mortality and
functional decline. Delirium is underdiagnosed, particularly in
dementia. To increase diagnostic accuracy, we investigated whether maintenance
of activation assessed by EEG discriminates delirium in association with
dementia (D+D) from dementia without delirium (DP) and cognitively unimpaired
elderly subjects (CU). METHOD: Routine
and quantitative EEG (rEEG/qEEG) with additional prolonged activation (3 min
eyes open period) were evaluated in hospitalised elderly patients with acute
geriatric disease. Patients were assigned post hoc to three comparable groups
(D+D/DP/CU) by expert consensus based on DSM-IV criteria. Dementia diagnosis
was confirmed using cognitive and functional tests and caregiver rating
(IQCODE, Informed Questionnaire of Cognitive Decline in the Elderly). RESULTS:
While rEEG at rest showed low accuracy for a diagnosis of delirium, qEEG in DP
and CU revealed a specific activation pattern of high significance found to be
absent in the D+D group. Stepwise logistic regression confirmed that
differentiation of D+D from DP was best resolved using activated upper alpha
and delta power density which, compared with rEEG, enabled an 11% increase in
diagnostic correctness to 83%, resulting in 67% sensitivity and 91%
specificity. Among frail CU and D+D subjects, almost 90% were correctly
classified. CONCLUSION: Dementia associated with delirium can be discriminated
reliably from dementia alone in a meaningful clinical setting. Thus EEG
evaluation in chronic encephalopathy should be optimised by a simple activation
task and spectral analysis, particularly in the elderly with dementia.
Publication Types:
Research Support, Non-U.S. Gov't
Neuroimage. 2008 Feb 1;39(3):1257-65. Epub 2007 Oct 4.
Localizing epileptogenic regions in partial epilepsy using
three-dimensional statistical parametric maps of background EEG source spectra.
Alper K, Raghavan M, Isenhart R, Howard B, Doyle W, John R,
Prichep L.
Comprehensive Epilepsy Center, New York University School
of Medicine, New York, NY 10016, USA. kra1@nyu.edu
This preliminary study sought to localize
epileptogenic regions in patients with
partial epilepsy by analysis of interictal EEG activity utilizing
variable resolution electromagnetic tomography (VARETA), a three-dimensional
quantitative electroencephalographic
(QEEG) frequency-domain distributed source modeling technique. The very narrow
band (VNB) spectra spanned the frequency range 0.39 Hz to 19.1 Hz, in 0.39 Hz
steps. These VNB spectra were compared to normative data and transformed to
provide Z-scores for every scalp derivation, and the spatial distributions of
the probable EEG generators of the most abnormal values were displayed on
slices from a probabilistic MRI atlas. Each voxel was color-coded to represent
the significance of the deviation relative to age appropriate normative values.
We compared the resulting three-dimensional images to the localization of
epileptogenic regions based on invasive intracranial EEG recordings of seizure
onsets. The VARETA image indicated abnormal interictal spectral power values in
regions of seizure onset identified by invasive monitoring, mainly in delta and
theta range (1.5 to 8.0 Hz). The VARETA localization of the most abnormal voxel
was congruent with the epileptogenic regions identified by intracranial
recordings with regard to hemisphere in all 6 cases, and with regard to lobe in
5 cases. In contrast, abnormal findings with routine EEG agreed with invasive
monitoring with regard to hemisphere in 3 cases and with regard to lobe in 2
cases. These results suggest that analysis of background interictal EEG
utilizing distributed source models should be investigated further in clinical
epilepsy.
Publication Types:
Research Support, Non-U.S. Gov't
Brain Inj. 2008 Jan;22(1):61-74.
A QEEG index of level of functional dependence for people
sustaining acquired brain injury: the Seville Independence Index (SINDI).
Leon-Carrion J, Martin-Rodriguez JF, Damas-Lopez J, Martin
JM, Dominguez-Morales Mdel R.
Human Neuropsychology Laboratory, School of Psychology,
Department of Experimental Psychology, University of Seville, Seville, Spain. leoncarrion@us.es
PRIMARY OBJECTIVE: To find an easy-to-use, valid and
reliable tool for evaluating the level of functional dependence of an
individual with brain damage who seeks a diagnosis of his/her functional
dependence in daily activities. METHODS: Eighty-one patients with acquired
brain injury (ABI) in post-acute phase, 40 traumatic brain injury (TBI) and 41
cerebral vascular accident (CVA), were assessed using quantitative
electroencephalography (QEEG) and grouped according to the FIM + FAM scale.
Discriminant analysis was performed on QEEG variables to obtain a discriminant function with the best
discriminative capacity between functionality groups. RESULTS: Discriminant
analysis showed classification accuracy of 100% in the training set sample and
75% in an external cross-validation sample; 100% sensitivity and 100%
specificity were reached. Coherence measures were the most numerous variables
in the function. CONCLUSIONS: These results point out that the discriminant
function may be a useful tool in objective evaluations of patients seeking a
diagnosis of their level of dependence and that it could be included in current
functionality assessment protocols.
Publication Types:
Research Support, Non-U.S. Gov't
Dev Neuropsychol. 2008;33(1):25-43.
Reduced verbal learning associated with posterior temporal
lobe slow wave activity.
Foster PS, Harrison DW, Crucian GP, Drago V, Rhodes RD,
Heilman KM.
Department of Neurology, University of Florida, Malcom
Randall Veterans Affairs Medical Center, Gainesville, Florida, USA. pfoster@mtsu.edu
Functional imaging has revealed that during verbal-word
learning there is activation of the left posterior temporo-parietal region (PTPL).
The purpose of this study was to learn if differences in the ability of normal
people to learn might be accounted for by differences in electrophysiological
(EEG) measures of activation of their left, but not right, PTPL. The Rey
Auditory Verbal Learning Test (RAVLT) was administered to 42 men without
neurological diseases. Delta magnitude, as measured by quantitative
electroencephalography (QEEG), was recorded from the left and right PTPL while
the participants sat quietly with their eyes closed. The magnitude of delta EEG
activity is inversely proportional to
cerebral activation. Based on delta magnitude, comparison groups were
created by separating those with low and
high delta at the left and right PTPL. Cumulative word learning (CWL) on the RAVLT
was computed by subtracting the number of words recalled on the first learning
trial from the highest number of words recalled on the fourth or fifth trial
and multiplying this difference by the total words recalled during all 5
learning trials. The group with a greater magnitude of left PTPL delta activity
had a significantly poorer CWL scores than
those with less delta, but the CWL scores of the group with a greater
magnitude of delta of the right PTPL was no different that the group with less
right-sided delta. No significant
differences emerged at any frontal or parietal electrode site. Decreased
activation of the left, but not right, PTPL appears to be associated with a
decreased verbal leaning ability.
Lab Anim. 2008 Jan;42(1):45-61.
EEG power spectrum analysis for monitoring depth of
anaesthesia during experimental surgery.
Otto KA.
Institut für Versuchstierkunde und Zentrales
Tierlaboratorium, Medizinische Hochschule Hannover, Carl-Neuberg-Str. 1,
D-30625 Hannover, Germany. otto.klaus@mh-hannover.de
The first attempts to introduce computerized power
spectrum analysis of the electroencephalogram (EEG) as an intraoperative
anaesthesia monitoring device started approximately 30 years ago. Since that
time, the effects of various anaesthetic agents, sedative and analgesic drugs
on the EEG pattern have been addressed in numerous studies in human patients
and different animal species. These studies revealed dose-dependent changes in
the EEG power spectrum for many
intravenous and volatile anaesthetics. Moreover, EEG responses evoked by
surgical stimuli during relative light levels of surgical anaesthesia have been
classified as 'arousal' and 'paradoxical arousal' reaction, previously referred
to as 'desynchronization' and 'synchronization', respectively. Contrasting
reports on the correlation between quantitative EEG (QEEG) variables derived
from power spectrum analysis (i.e. spectral edge frequency, median frequency)
and simultaneously recorded clinical signs such as movement and haemodynamic
responses, however, limited the routine use of intraoperative EEG monitoring.
In addition, the appearance of EEG burst
suppression pattern and isoelectricity at clinically relevant
concentrations/doses of newer general anaesthetics (i.e. isoflurane,
sevoflurane, propofol) may have weakened the dose-related EEG changes
previously reported. Despite these findings, the EEG power spectrum analysis
may still provide valuable information
during intraoperative monitoring in the individual subject. The information
obtained from EEG power spectrum analysis may be further supplemented by newer
EEG indices such as bispectral index and approximate entropy or other
neurophysiological monitors including auditory evoked potentials or
somatosensory evoked potentials.
Comput Biol Med. 2008 Mar;38(3):348-60. Epub 2008 Jan 28.
A comparative
study of automatic techniques for ocular artifact reduction in spontaneous EEG
signals based on clinical target variables: a simulation case.
Romero S, Mañanas MA, Barbanoj MJ.
Department of Automatic Control (ESAII), Biomedical Engineering
Research Center, Technical University of
Catalonia (UPC), C/Pau Gargallo 5, Barcelona, Spain. sergio.romero-lafuente@upc.edu
Eye movement artifacts represent a critical issue for
quantitative electroencephalography (EEG) analysis and a number of mathematical
approaches have been proposed to reduce their contribution in EEG recordings.
The aim of this paper was to objectively and quantitatively evaluate the
performance of ocular filtering methods with respect to spectral target
variables widely used in clinical and functional EEG studies. In particular the
following methods were applied: regression analysis and some blind source
separation (BSS) techniques based on second-order statistics (PCA, AMUSE and
SOBI) and on higher-order statistics (JADE, INFOMAX and FASTICA). Considering
blind source decomposition methods, a completely automatic procedure of BSS
based on logical rules related to spectral and topographical information was
proposed in order to identify the components related to ocular interference.
The automatic procedure was applied in different montages of simulated EEG and
electrooculography (EOG) recordings: a full montage with 19 EEG and 2 EOG
channels, a reduced one with only 6 EEG leads
and a third one where EOG channels were not available. Time and
frequency results in all of them indicated that AMUSE and SOBI algorithms
preserved and recovered more brain activity than the other methods mainly at
anterior regions. In the case of full montage: (i) errors were lower than 5%
for all spectral variables at anterior sites; and (ii) the highest improvement
in the signal-to-artifact (SAR) ratio
was obtained up to 40dB at these anterior sites. Finally, we concluded that
second-order BSS-based algorithms (AMUSE and SOBI) provided an effective
technique for eye movement removal even when EOG recordings were not available
or when data length was short.
J Vet Intern Med. 2007 Nov-Dec;21(6):1299-306.
Electroencephalography
findings in healthy and Finnish Spitz dogs with epilepsy: visual and background quantitative analysis.
Jeserevics J, Viitmaa R, Cizinauskas S, Sainio K, Jokinen
TS, Snellman M, Bellino C, Bergamasco L.
Department of Clinical Veterinary Sciences, University of
Helsinki, Helsinki, Finland. janis.jeserevics@aisti.info
BACKGROUND: Qualitative and quantitative
electroencephalography (EEG) parameters
of healthy and Finnish Spitz dogs with epilepsy have not been
determined. OBJECTIVE: To determine if EEG can provide specific characteristics
to distinguish between healthy dogs and dogs with epilepsy. ANIMALS: Sixteen
healthy and 15 Finnish Spitz dogs with epilepsy. METHODS: A prospective
clinical EEG study performed under medetomidine sedation. Blinded visual and
quantitative EEG analyses were performed
and results were compared between study groups. RESULTS: Benign epileptiform transients of sleep and
sleep spindles were a frequent finding in a majority of animals from both
groups. The EEG analysis detected epileptiform activity in 3 Finnish Spitz dogs
with epilepsy and in 1 healthy Finnish Spitz dog. Epileptiform activity was
characterized by spikes, polyspikes, and spike slow wave complexes in
posterior-occipital derivation in dogs with epilepsy and with midline spikes in
control dog. The healthy dogs showed significantly less theta and beta activity
than did the dogs with epilepsy (P < .01), but the only significant
difference between healthy dogs and dogs with untreated epilepsy was in the
alpha band (P < .001). Phenobarbital treatment increased alpha, beta (P <
.001), and theta (P < .01), and decreased delta (P < .001) frequency
bands compared with dogs with untreated epilepsy. CONCLUSIONS AND CLINICAL
IMPORTANCE: Benign epileptiform transients of sleep could be easily
misinterpreted as epileptiform activity. Epileptiform activity in Finnish Spitz
dogs with epilepsy seems to originate from a posterior-occipital location. The
EEG of dogs with epilepsy exhibited a significant difference in background
frequency bands compared with the control dogs. Phenobarbital treatment
markedly influenced all background
activity bands. Quantitative EEG analysis, in addition to visual analysis, seems to be a useful tool
in the examination of patients with epilepsy.
J Neuropsychiatry Clin Neurosci. 2007 Fall;19(4):453-7.
Electrode
placement and ictal EEG indices in electroconvulsive therapy.
Rasmussen KG, Varghese R, Stevens SR, Ryan DA.
Department of Psychiatry and Psychology, Mayo Clinic, 200
First Street SW, Rochester, MN 55905, USA. rasmussen.keith@mayo.edu
The authors determine whether quantitative
electroencephalography (EEG) indices in electroconvulsive therapy (ECT)
seizures correlate with stimulus electrode placement. The authors analyzed data
from ECT seizures involving three electrode
placements on 37 different quantitative EEG measures. Though there were
a few statistically significant comparisons, no consistent pattern of
differences was discerned among the three electrode placements. Though many
different EEG analytical indices are available on modern ECT machines, the
clinical or neurophysiologic relevance has yet to be established. These data
provide a groundwork for future research on the neurophysiological aspects of
ECT.
There are few clinical or biologic predictors of response
to treatments for depression. This article reviews growing evidence that
electrophysiologic and neurocognitive measures of brain function may be of
value as predictors of therapeutic response to antidepressants. Initial studies
using dichotic listening, quantitative electroencephalography, or event-related
brain potential measures have found
differences between treatment responsive and nonresponsive subgroups of
depressed patients. The neurophysiologic basis for these differences and the
potential clinical utility of electrophysiologic and dichotic predictors of treatment outcome remain to be determined
in future studies.
Neurosci Lett. 2007 Oct 22;426(3):155-9. Epub 2007 Sep 5.
Electrophysiological
analysis of a sensorimotor integration task.
Velasques B, Machado S, Portella CE,
Silva JG, Basile LF, Cagy M, Piedade R, Ribeiro P.
Brain Mapping and Sensory Motor Integration, Institute of
Psychiatry, Federal University of Rio de Janeiro, Brazil. bruna_velasques@yahoo.com.br
The present experiment aimed at investigating
electrophysiologic changes observed as beta band asymmetry, by Quantitative
Electroencephalography (qEEG), when individuals performed a reaching motor task
(catching a ball in free fall). The sample was composed of 23 healthy
individuals, of both sexes, with ages varying between 25 and 40 years old. All
the subjects were right handed. A two-way ANOVA
was applied for the statistical analysis, to verify the interaction
between task moment (i.e., 2s before and
2s after ball's fall) and electrode (i.e., frontal, central and temporal
regions). The first analysis compared electrodes placed over the somatosensory
cortex. Central sites (C3-C4) were compared with temporal regions (T3-T4). The
results showed a main effect for moment and position. The second analysis was
focused over the premotor cortex, which was represented by the electrodes
placed on the frontal sites (F3-F4 versus F7-F8), and a main effect was
observed for position. Taken together, these results show a pattern of
asymmetry in the somatosensory cortex, associated with a preparatory mechanism
when individuals have to catch an object during free fall. With respect to task
moment, after the ball's fall, the asymmetry was reduced. Moreover, the
difference in asymmetry between the observed regions were related to a supposed
specialization of areas (i.e., temporal and central). The temporal region was
associated with cognitive processes involved in the motor action (i.e.,
explicit knowledge). On the other hand,
the central sites were related to the motor control mechanisms per se (i.e.,
implicit knowledge). The premotor cortex, represented by two frontal regions
(i.e., F3-F4 versus F7-F8), showed a decrease
on neural activity in the contralateral hemisphere (i.e., to the right
hand). This result is in agreement with other experiments suggesting a
participation of the frontal cortex in
the planning of the apprehension task. This sensorimotor paradigm may
contribute to the repertoire of tasks used to study clinical conditions such as
depression, alzheimer and Parkinson diseases.
Am J Pathol. 2007 Oct;171(4):1258-68. Epub 2007 Aug 16.
Bcl-w protects
hippocampus during experimental status epilepticus.
Murphy B, Dunleavy M, Shinoda S, Schindler C, Meller R,
Bellver-Estelles C, Hatazaki S, Dicker P, Yamamoto A, Koegel I, Chu X, Wang W,
Xiong Z, Prehn J, Simon R, Henshall D.
Department of Physiology and Medical Physics, Royal College
of Surgeons in Ireland, 123 St. Stephen's Green, Dublin 2, Ireland.
Experimentally evoked seizures can activate the intrinsic
mitochondrial cell death pathway, components of which are modulated in the
hippocampus of patients with temporal lobe epilepsy. Bcl-2 family proteins are
critical regulators of mitochondrial dysfunction, but their significance in
this setting remains primarily untested. Presently, we investigated the
mitochondrial pathway and role of anti-apoptotic Bcl-2 proteins using a mouse
model of seizure-induced neuronal death.
Status epilepticus was evoked in mice by intra-amygdala kainic acid, causing
cytochrome c release, processing of caspases 9 and 7, and death of ipsilateral
hippocampal pyramidal neurons. Seizures caused a rapid decline in hippocampal
Bcl-w levels not seen for either Bcl-2 or Bcl-xl. To test whether endogenous
Bcl-w was functionally significant for neuronal survival, we investigated
hippocampal injury after seizures in Bcl-w-deficient mice. Seizures induced significantly more hippocampal CA3
neuronal loss and DNA fragmentation in Bcl-w-deficient mice compared with
wild-type mice. Quantitative electroencephalography analysis also revealed that
Bcl-w-deficient mice display a neurophysiological phenotype whereby there was
earlier polyspike seizure onset. Finally, we detected higher levels of Bcl-w in
hippocampus from temporal lobe epilepsy patients compared with autopsy
controls. These data identify Bcl-w as an endogenous neuroprotectant that may
have seizure-suppressive functions.
Neuropsychobiology. 2007;55(3-4):176-83. Epub 2007 Aug 14.
Psychotropic
profile of S 17092, a prolyl endopeptidase inhibitor, using quantitative EEG in
young healthy volunteers.
Morain P, Boeijinga PH, Demazières A,
De Nanteuil G, Luthringer R.
IRIS, Institut de Recherches
Internationales SERVIER, Courbevoie, France. philippe.morain@fr.netgrs.com
The central activity of S 17092, a prolyl endopeptidase (PEP)
inhibitor, was investigated by quantitative electroencephalography (qEEG) in 48
young healthy men participating in a double-blind, randomized,
placebo-controlled, cross-over study. S 17092 (100, 200, 400 or 600 mg) and
placebo were administered once daily for 10 days in a rising multiple-dose
scheme. EEG recordings were performed before and repeatedly from 0.5 to 24 h
after dose on day 1 and day 10. PEP activity in plasma was also measured for
the same periods. S 17092 appeared as a
potent inhibitor of PEP activity at all doses, after both single and
repeated administrations. EEG changes after acute doses were slight and of
short duration, mainly characterized by increased relative alpha 1 power,
suggesting a vigilance-promoting EEG profile. After repeated doses and more
strikingly after a superimposed dose, increases in relative alpha 1 power were
still present with additional increase in relative delta power and decreases in
absolute fast alpha, fast beta, theta powers and total power at all doses. These
EEG findings suggest that S 17092 might
possess some mood-stabilizing potential in addition to its cognition-enhancing
properties. (c) 2007 S. Karger AG, Basel.
Int Tinnitus J. 2007;13(1):29-39.
Clear
Tinnitus, middle-ear pressure, and tinnitus relief: a prospective trial.
Goldstein B, Shulman A, Avitable MJ.
Department of Otolaryngology, Health Science Center at
Brooklyn, State University of New York, Downstate Medical Center, Brooklyn,
USA. metrc@inch.com
GOAL: Our goal was to establish the efficacy, in a 12-week
period, of Clear Tinnitus for tinnitus relief in patients with tinnitus of the
severe, disabling type. HYPOTHESIS: We hypothesized that tinnitus relief with
Clear Tinnitus reflects improvement in the sensory component of the tinnitus
complaint by controlling the factor of aeration of the middle ears and
improving eustachian tube function. METHOD: In a prospective clinical trial of
a homeopathic preparation--Clear Tinnitus--we attempted to identify in 15
tinnitus patients (14 male, 1 female; mean age, 47.6 years) its clinical
efficacy for establishing tinnitus relief for a 3-month period. We employed a
descriptive data analysis method across dimensions of risk to evaluate a base
of multidimensional evidence and
establish support for our hypothesis. A medical-audiological tinnitus patient
protocol completed by each patient identified the clinical type of tinnitus as predominantly
cochlear, with a central and middle-ear component bilaterally. We identified
fluctuation in middle-ear pressure (MEP) via patients' clinical history,
supported by physical examination and established with tympanometry, as a factor influencing the clinical course of
the tinnitus in each patient. RESULTS: Eleven of 15 patients completed the
study. Seven responders reported tinnitus relief; four did not respond.
Descriptive data analysis failed to detect any trends in a change in response
with audiometric tests across the hearing spectrum; thus, we could derive no
coefficients of hearing change. Evaluation revealed high-frequency tinnitus in
11 patients. The Feldmann masking curve comparison at the start and end of the
study showed no significant change in the
11 patients. There was no significant alteration in the minimum masking
levels or loudness discomfort levels before and after the study. Tympanometry
and MEP measurement indicated a significant difference in MEP with an
improvement on average of -58.18 in the right ear and -40.90 in the left ear
for the 11 patients. Quantitative electroencephalography analysis revealed a
marked difference in the number of significant abnormal recordings between the
different frequency bands, with the delta band significantly higher than the
theta, alpha, and beta bands for both
the overall cohort of patients (n = 11) and those reporting tinnitus relief (n
= 7). The tinnitus outcome questionnaires--the tinnitus intensity index, the
tinnitus annoyance index, and the tinnitus reaction questionnaire--revealed a
significant difference for the patients (7 of 11) obtaining tinnitus relief.
Results of the tinnitus stress test, the tinnitus handicap index, and the
measurement of depression scale before and after the study were not
statistically significant. CONCLUSIONS: Patients who completed the study
demonstrated with tympanometry a statistical and clinical significance in MEP
improvement or maintenance of MEP (or both). Patients with tinnitus of the
severe disabling type selected for this study and responding to Clear Tinnitus
reported tinnitus relief accompanied by improvement in or maintenance of MEP of
the middle ears. The statistical and clinical significance of Clear Tinnitus
for establishing tinnitus relief remains
to be established with a larger cohort of tinnitus patients.
Arq Neuropsiquiatr. 2007 Jun;65(2A):327-31.
[Changes in
cortical interhemispheric coherence produced by functional electrical
stimulation (FES)]
[Article in Portuguese]
Ecard L, Silva AP, Peçanha Neto M,
Cagy M, Piedade R, Ribeiro P.
Laboratório de Mapeamento Cerebral e
Integração Sensório-Motora, Instituto de Psiquiatria, Universidade Federal do
Rio de Janeiro, Brazil. leticiaecard@bol.com.br
The aim of the present study was to observe cortical
alterations produced by functional electrical stimulation (FES), through
quantitative electroencephalography (qEEG). Electrostimulation was performed on
the right forearm to stimulate the extension of the index finger. EEG activity
was recorded simultaneously. The sample consisted of 45 subjects randomly
divided into 3 groups of 15 subjects each. The control group was submitted to
24 blocks of stimulation at a current intensity of zero. Group 1 was submitted
to 24 blocks and group 2 to 36 blocks. Interhemispheric coherence between
F3-F4, C3-C4 and P3-P4 was assessed through a statistical analysis. Results
pointed out to increased coherence values after stimulation.
Stroke. 2007 Aug;38(8):2303-8. Epub 2007 Jun 21.
Cognitive and
neurophysiological outcome of cardiac arrest survivors treated with therapeutic
hypothermia.
Tiainen M, Poutiainen E, Kovala T,
Takkunen O, Häppölä O, Roine RO.
Department of Neurology, Meilahti Hospital, Haartmaninkatu
4, Finland. marjaana.tiainen@hus.fi
BACKGROUND AND PURPOSE: Cognitive deficits are common in
survivors of cardiac arrest (CA). The aim of this study was to examine the
effect of therapeutic hypothermia after CA on cognitive functioning and
neurophysiological outcome. METHODS: A cohort of 70 consecutive adult patients
resuscitated from out-of-hospital ventricular fibrillation CA were randomly
assigned to therapeutic hypothermia of 33 degrees C for 24 hours accomplished
by external cooling or normothermia. Neuropsychological examination was
performed to 45 of the 47 conscious survivors of CA (27 in hypothermia and 18
in normothermia group) 3 months after the incident. Quantitative
electroencephalography (Q-EEG) and auditory P300 event-related potentials were
studied on 42 patients at the same time point. RESULTS: There were no
differences between the 2 treatment groups in
demographic variables, depression, or delays related to the
resuscitation. No differences were found in any of the cognitive functions
between the 2 groups. 67% of patients in hypothermia and 44% patients in
normothermia group were cognitively intact or had only very mild impairment.
Severe cognitive deficits were found in 15% and 28% of patients, respectively.
All Q-EEG parameters were better in the hypothermia-treated group, but the
differences did not reach statistical significance. The amplitude of P300
potential was significantly higher in hypothermia-treated group. CONCLUSIONS:
The use of therapeutic hypothermia was not associated with cognitive decline or
neurophysiological deficits after out-of-hospital CA.
Methods. 2007 May;42(1):100-8.
Current
methodology and methods in psychophysiological studies of creative thinking.
Bechtereva NP, Danko SG, Medvedev SV.
Institute of the Human Brain, Russian Academy of Sciences,
ul.acad.Pavlova 9, Sankt-Peterburg 197376, Russia. bechtrv@ihb.spb.ru
Important points on methodology and detailed description of
methods used in polymodal psychophysiological studies of human verbal creative
thinking are presented. The psychophysiological studies were conducted with
healthy volunteers during implementations of specially developed and adapted
psychological tests aimed to bring the subjects into states of verbal creative
thinking. Four different task sets ("story composition",
"associative chains", "original definitions", "proverb
sense flipping") were developed and applied. Positron emission tomography
of regional cerebral blood flow (rCBF) and state-related quantitative
electroencephalography (power and coherence evaluated) were used. The
effectiveness of the methods is illustrated with figures.
Ann N Y Acad Sci. 2007 Feb;1097:156-67.
Quantitative
EEG and electromagnetic brain imaging in aging and in the evolution of dementia.
Prichep LS.
Brain Research Laboratories, Department of Psychiatry, New
York University School of Medicine, New York 10016, USA. leslie.prichep@med.nyu.edu
Electroencephalographic (EEG) changes with normal aging
have long been reported. Departures from
age-expected changes have been observed in mild cognitive impairment and
dementia, the magnitude of which correlates with the degree of cognitive
impairment. Such abnormalities include increased delta and theta activity,
decreased mean frequency, and changes in coherence. Similar findings have been
reported using magnetoencephalography (MEG) at rest and during performance of
mental tasks. Electrophysiological features have also been shown to be
predictive of future decline in mild cognitive impairment (MCI) and Alzheimer's
disease (AD). We have recently reported results from initial quantitative
electroencephalography (QEEG) evaluations of normal elderly subjects (with only
subjective reports of memory loss), predicting future cognitive decline or
conversion to dementia, with high prediction accuracy (approximately 95%). In this
report, source localization algorithms were used to identify the mathematically
most probable underlying generators of abnormal features of the scalp-recorded
EEG from these patients with differential outcomes. Using this QEEG method,
abnormalities in brain regions identified in studies of AD using MEG, MRI, and
positron emission tomography (PET) imaging were found in the premorbid
recordings of those subjects who go on to decline or convert to dementia.
Psychopharmacology (Berl). 2007 May;191(4):995-1004. Epub
2007 Feb 27.
A pharmaco-EEG
study on antipsychotic drugs in healthy volunteers.
Yoshimura M, Koenig T, Irisawa S, Isotani T, Yamada K,
Kikuchi M, Okugawa G, Yagyu T, Kinoshita T, Strik W, Dierks T.
Department of Psychiatric Neurophysiology, University
Hospital of Psychiatry, Bern, Switzerland. yoshimum@takii.kmu.ac.jp
RATIONALE: Both psychotropic drugs and mental disorders have
typical signatures in quantitative electroencephalography (EEG). Previous
studies found that some psychotropic drugs had EEG effects opposite to the EEG
effects of the mental disorders treated with these drugs (key-lock principle).
OBJECTIVES: We performed a placebo-controlled pharmaco-EEG study on two
conventional antipsychotics (chlorpromazine and haloperidol) and four atypical
antipsychotics (olanzapine, perospirone, quetiapine, and risperidone) in
healthy volunteers. We investigated
differences between conventional and atypical drug effects and whether
the drug effects were compatible with the key-lock principle. METHODS: Fourteen
subjects underwent seven EEG recording sessions, one for each drug (dosage
equivalent of 1 mg haloperidol). In a time-domain analysis, we quantified the
EEG by identifying clusters of
transiently stable EEG topographies (microstates). Frequency-domain analysis
used absolute power across electrodes and the location of the center of gravity (centroid) of the spatial distribution
of power in different frequency bands. RESULTS: Perospirone increased duration
of a microstate class typically shortened in schizophrenics. Haloperidol
increased mean microstate duration of all classes, increased alpha 1 and beta 1
power, and tended to shift the beta 1 centroid posterior. Quetiapine decreased
alpha 1 power and shifted the centroid anterior in both alpha bands. Olanzapine
shifted the centroid anterior in alpha 2 and beta 1. CONCLUSIONS: The increased
microstate duration under perospirone and
haloperidol was opposite to effects previously reported in schizophrenic
patients, suggesting a key-lock mechanism. The opposite centroid changes
induced by olanzapine and quetiapine
compared to haloperidol might characterize the difference between conventional
and atypical antipsychotics.
Clin Neurophysiol. 2007 Nov;118(11):2525-32. Epub 2007 Sep
21.
Quantitative EEG indices of sub-acute ischaemic stroke
correlate with clinical outcomes.
Finnigan SP, Walsh M, Rose SE, Chalk JB.
Centre for Magnetic Resonance, The University of
Queensland, Brisbane, Australia. finnigan.simon@gmail.com
OBJECTIVE: We investigated the ability of
quantitative electroencephalography (QEEG) measures in sub-acute stroke to
assist monitoring or prognostication of stroke evolution. QEEG indices and
National Institutes of Health Stroke Scale (NIHSS) scores were compared.
METHODS: Ischaemic cortical stroke patients were studied. Resting, 62-channel
EEG and NIHSS score were acquired at 49+/-3h post-symptom onset, and NIHSS
administered at 30+/-2 days post-stroke. Mean power was calculated for delta
(1-4 Hz), theta (4.1-8 Hz), alpha (8.1-12.5 Hz) and beta (12.6-30 Hz) frequency
bands, using a 62-channel electrode array and a 19-channel subset. RESULTS:
Thirteen patients (6 male, median age 66, range 54-86 years) were studied.
Sub-acute delta:alpha power ratio (DAR; r=0.91, P<0.001), relative alpha power (r=-0.82, P<0.01), and NIHSS
score (r=0.92, P<0.001) each were significantly correlated with 30-day NIHSS
score. The former two significant correlations were upheld in 19-channel EEG
data. QEEG measures involving theta or beta power were not significantly correlated
with NIHSS scores. CONCLUSIONS: QEEG measures such as DAR demonstrate potential
to augment bedside assessment of cerebral pathophysiology and prognostication
of stroke evolution. A standard, 19-channel array seems adequate for these
purposes. Future studies in larger samples should investigate the potential
effects on these measures of sleep state and possible causes of artefacts.
SIGNIFICANCE: QEEG measures from a standard number of electrodes, if available
rapidly and robust to potential artefacts, may inform future management of
stroke patients.
Publication Types:
Research Support, Non-U.S. Gov't
Neurosci Lett. 2007 Oct 22;426(3):155-9. Epub 2007 Sep 5.
Electrophysiological analysis of a sensorimotor integration
task.
Velasques B, Machado S, Portella CE,
Silva JG, Basile LF, Cagy M, Piedade R, Ribeiro P.
Brain Mapping and Sensory Motor Integration, Institute of
Psychiatry, Federal University of Rio de Janeiro, Brazil. bruna_velasques@yahoo.com.br
The present experiment aimed at investigating
electrophysiologic changes observed as beta band asymmetry, by Quantitative Electroencephalography
(qEEG), when individuals performed a reaching motor task (catching a ball in
free fall). The sample was composed of 23 healthy individuals, of both sexes,
with ages varying between 25 and 40 years old. All the subjects were right handed.
A two-way ANOVA was applied for the
statistical analysis, to verify the interaction between task moment (i.e., 2s before and 2s after ball's
fall) and electrode (i.e., frontal, central and temporal regions). The first
analysis compared electrodes placed over the somatosensory cortex. Central
sites (C3-C4) were compared with temporal regions (T3-T4). The results showed a
main effect for moment and position. The second analysis was focused over the
premotor cortex, which was represented by the electrodes placed on the frontal
sites (F3-F4 versus F7-F8), and a main effect was observed for position. Taken
together, these results show a pattern of asymmetry in the somatosensory
cortex, associated with a preparatory mechanism when individuals have to catch an
object during free fall. With respect to task moment, after the ball's fall,
the asymmetry was reduced. Moreover, the difference in asymmetry between the
observed regions were related to a supposed specialization of areas (i.e.,
temporal and central). The temporal region was associated with cognitive
processes involved in the motor action (i.e., explicit knowledge). On the other hand, the central
sites were related to the motor control mechanisms per se (i.e., implicit
knowledge). The premotor cortex, represented by two frontal regions (i.e.,
F3-F4 versus F7-F8), showed a decrease
on neural activity in the contralateral hemisphere (i.e., to the right
hand). This result is in agreement with other experiments suggesting a
participation of the frontal cortex in
the planning of the apprehension task. This sensorimotor paradigm may
contribute to the repertoire of tasks used to study clinical conditions such as
depression, alzheimer and Parkinson diseases.
Neurosci Lett. 2007 Oct 9;426(1):23-8. Epub 2007 Aug 22.
High frequency localised "hot spots" in temporal
lobes of patients with intractable tinnitus: a quantitative
electroencephalographic (QEEG) study.
Ashton H, Reid K, Marsh R, Johnson I, Alter K, Griffiths T.
School of Neurology, Neurobiology and Psychiatry,
University of Newcastle upon Tyne, Newcastle upon Tyne NE2 4HH, United Kingdom.
Tinnitus, the perception of noise in the absence of an
external auditory stimulus, is common, frequently distressing and often
intractable. It is associated with a number of conditions including deafness
but may arise spontaneously. Brain imaging studies indicate increased neuronal
excitability and decreased density of benzodiazepine receptors in temporal
(auditory) cortex but the source and mechanism of such changes are unknown.
Various electroencephalographic (EEG) abnormalities involving temporal lobe and
other brain areas have been described but recordings have been limited to
standard EEG wave bands up to
frequencies of 22Hz. This clinical study of otherwise healthy patients with
intractable unilateral tinnitus, using quantitative EEG power spectral mapping
(QEEG), identified discrete localised unilateral foci of high frequency
activity in the gamma range (>40-80Hz) over the auditory cortex in eight
patients experiencing tinnitus during recording. These high frequency
"hot spots" were not present
in 25 subjects without tinnitus. The results suggest that further EEG
investigations should include recordings in the gamma frequency range since
such high frequency oscillations are believed to be necessary for perception.
Identification of "hot spots" in tinnitus patients would provide a
means for monitoring the effects of new treatments. These findings may also
provide a model for exploration of more complex phenomena such as verbal and
musical hallucinations.
Clin Neurophysiol. 2007 Oct;118(10):2162-71. Epub 2007 Aug
31.
Reliability of quantitative EEG features.
Gudmundsson S, Runarsson TP, Sigurdsson S, Eiriksdottir G,
Johnsen K.
Department of Computer Science, University of Iceland,
Reykjavik, Iceland.
OBJECTIVE: To investigate the reliability of several
well-known quantitative EEG (qEEG)
features in the elderly in the resting, eyes closed condition and study the
effects of epoch length and channel derivations on reliability. METHODS:
Fifteen healthy adults, over 50 years of age, underwent 10 EEG recordings over
a 2-month period. Various qEEG features
derived from power spectral, coherence, entropy and complexity analysis of the
EEG were computed. Reliability was quantified using an intraclass correlation
coefficient. RESULTS: The highest reliability was obtained with the average
montage, reliability increased with epoch length up to 40s, longer epochs gave
only marginal improvement. The reliability of the qEEG features was highest for
power spectral parameters, followed by regularity measures based on entropy and
complexity, coherence being least
reliable. CONCLUSIONS: Montage and epoch length had considerable effects on
reliability. Several apparently unrelated regularity measures had similar
stability. Reliability of coherence measures was strongly dependent on channel
location and frequency bands. SIGNIFICANCE: The reliability of regularity
measures has until now received limited attention. Low reliability of coherence
measures in general may limit their usefulness in the clinical setting.
Publication Types:
Research Support, Non-U.S. Gov't
Arq Neuropsiquiatr. 2007 Sep;65(3A):637-41.
Beta and alpha electroencephalographic activity changes
after acute exercise.
Moraes H, Ferreira C, Deslandes A,
Cagy M, Pompeu F, Ribeiro P, Piedade R.
Laboratório de Mapeamento Cerebral e
Integração Sensório-Motora, Instituto de Psiquiatria, Universidade Federal do
Rio de Janeiro, 22290-140 Rio de Janeiro, RJ, Brazil.
Exercise has been widely related to changes in cortical
activation and enhanced brain functioning. Quantitative electroencephalography
(qEEG) is frequently used to investigate
normal and pathological conditions in the brain cortex. Therefore, the aim of
the present study was to observe absolute power alterations in beta and alpha
frequency bands after a maximal effort exercise. Ten healthy young volunteers
were submitted to an eight-minute resting EEG (eyes closed) followed by a
maximal exercise test using a mechanical cycle ergometer. Immediately
after the exercise, another identical
eight-minute EEG was recorded. Log transformation and paired student's t-test
compared the pre and post exercise values (p<0.05). Results indicated a
significant absolute power increase in beta after exercise at frontal (Fp1, F3
and F4) and central (C4) areas, which might be related to increased cortical
activation.
Arq Neuropsiquiatr. 2007 Sep;65(3A):633-6.
Changes in quantitative EEG absolute power during the task
of catching an object in free fall.
Machado S, Portella CE, Silva JG,
Velasques B, Terra P, Vorkapic CF, Silva VF, Miana L, Basile L, Cagy M, Piedade
R, Ribeiro P.
Laboratório de Mapeamento Cerebral e Integração
Sensório-Motor, Instituto de Psiquiatria, Universidade Federal do Rio de
Janeiro, 22430-130 Rio de Janeiro, RJ, Brazil. secm80@ig.com.br
The aim of this study was to verify changes in absolute
power (qEEG), in theta, during the catch of a free falling object. The sample
consisted of 10 healthy individuals, of both genders, with ages between 25 and
40 years. A three-way ANOVA followed by Post-Hoc analysis was applied. The
results demonstrated main effects for time and position. In conclusion, a motor
task that involves expectation produces deactivation of non-relevant areas in
the ipsilateral hemisphere of the active limb. On the other hand, the patterns
of results showed activation in areas
responsible for planning and selection of motor repertoires in the
contralateral hemisphere.
Arq Neuropsiquiatr. 2007 Sep;65(3A):628-32.
Changes in cortical relative power in patients submitted to
a tendon transfer: a pre and post surgery
study.
Silva JG, Knackfuss IG, Portella CE, Machado S, Velasques
B, Bastos VH, Queiroz Rde A, Neves MA, Pacheco M, Vorkapic CF, Cagy M, Piedade
R, Ribeiro P.
Laboratory of Brain Mapping and Sensory-Motor Integration,
Institute of Psychiatry, Federal University of Rio de Janeiro, Rua Filgueiras
Lima 68, 20950-050 Rio de Janeiro, RJ, Brazil. jgsilva@hucff.ufrj.br
The aim of this study is analyze possible
modifications in the cerebral cortex, through quantitative
electroencephalography (qEEG) in patients submitted to a tendon transfer
procedure (posterior tibialis) by the Srinivasan's technique. Four subjects (2
men and 2 women), 49.25 age average (SD +/ 21.4) were studied. All subjects
have been through surgical procedure due to leprosy and had, at least, two
years of drop foot condition. The qEEG measured the electrocortical activity
(relative power) between 8 and 25 Hz frequencies pre and post surgery. A paired
t test analyzed all data (p< or =0,05). The results show significant
alterations in the alpha relative power, electrodes F7 (p=0.01) and F8
(p=0.021). Altogether, based on findings of the current literature, we can
conclude that the tendon transfer procedure suggests electrocortical
alterations sensitive to specific qEEG bands.
Arq Neuropsiquiatr. 2007 Sep;65(3A):623-7.
Cortical asymmetry: catching an object in free fall.
Velasques B, Machado S, Portella CE,
Silva JG, Terra P, Ferreira C, Basile L, Cagy M, Piedade R, Ribeiro P.
Laboratório de Mapeamento Cerebral e
Integração Sensório-Motor, Instituto de Psiquiatria, Universidade Federal do
Rio de Janeiro, 20541-190 Rio de Janeiro, RJ, Brazil. bruna_velasques@yahoo.com.br
The main goal of the present study was to analyze
theta asymmetry through quantitative electroencephalography (qEEG) when
individuals were exposed to a sequential motor task, i.e. catching a ball. The
sample was composed of 23 healthy subjects, male and female, between 25 and 40
years of age. A two-way factor Anova was applied to compare pre and post
moments related to the balls' drop and scalp regions (i.e., frontal and
parieto-occipital cortices). The first
analysis of the frontal region compared electrodes in the left, right
and left/right hemispheres combined, with the frontal midline electrode (FZ)
included in the analysis. The results showed moment and region main effects.
The second analysis compared left versus right hemisphere without the FZ site.
The findings demonstrated an interaction
effect between moment and region. The first parieto-occipital analysis,
comparing left, right and central regions, with PZ included in all regions,
showed main effects of moment and region. The second analysis, comparing left,
right (without Pz) and central regions strictly demonstrated a region main
effect. Thus, we observed an asymmetric pattern in the frontal cortex (i.e.,
planning and response selection) when the subjects were waiting for the balls'
drop. Moreover, the left hemisphere seems to engage differently from the other
regions when the central nervous system needs to prepare for a motor action. On
the other hand, the parieto-occipital cortex, which is related to attentive
processes, demonstrated a more asymmetric activity towards the right region which implies a
participation of this area in cognitive
strategies in this particular task. Taken together, we concluded that
the adopted experimental approach can be useful to explore several others
directions combining sensorimotor integration tasks with different pathologies,
such as depression, Alzheimer's and Parkinson's diseases.
Int J Neurosci. 2007 Sep;117(9):1257-79.
Mismatch negativity correlates with delta and theta EEG
power in schizophrenia.
Kirino E.
Department of Psychiatry, Juntendo University School of
Medicine, Koshigaya-shi Saitama, Japan. ekirino@med.juntendo.ac.jp
The goal of the present study was to investigate the
correlation of mismatch negativity (MMN) to other biological and clinical
measures in schizophrenic patients using Quantitative electroencepharography
(QEEG), computed tomography (CT), and psychopathological ratings. MMN was
recorded during an auditory oddball paradigm. QEEG was recorded in the resting
condition. Additionally, areas of the
lateral ventricles and Sylvian fissure were measured using CT. Although
the authors could not obtain a significant difference in MMN amplitudes between
controls and the schizophrenic patients, MMN deflection inversely correlated
with slow wave QEEG power and dilation of the lateral ventricles. Furthermore,
the longer the duration of illness, the lower the MMN amplitudes and the larger
the SF-BR in the patients. However there was no significant correlation between
illness duration and QEEG. In this view, a correlation between MMN and the
delta power in QEEG might usefully suggest
a progression in pathology of first manifestation of psychosis. The patients
with reduced MMN accompanied by greater
slow waves even at their first manifestation might have severely
progressing pathological process and poor prognosis of disease outcome.
J Clin Neurophysiol. 2007 Aug;24(4):348-51.
Comparison of a parent-rated DSM-IV measure of
attention-deficit/hyperactivity disorder and quantitative EEG parameters in an
outpatient sample of children.
Coolidge FL, Starkey MT, Cahill BS.
Department of Psychology, University of Colorado at
Colorado Springs, Colorado 80933-7150, USA. fcoolidg@uccs.edu
Attention-deficit/hyperactivity disorder (ADHD) was
investigated using the parent-as-respondent, 200-item, Coolidge Personality and
Neuropsychology Inventory (CPNI) and a quantitative electroencephalograph
(QEEG). Parents of 183 children (mean
age = 12.2 years) brought to an outpatient private clinic for behavioral and/or
emotional problems completed the CPNI including the 18-item DSM-IV-based ADHD
scale and their children were also evaluated by QEEG. The correlation between
the CPNI ADHD scale T score and the categorical QEEG parameter (based on the
beta-theta power ratio) for the identification of ADHD was r = -0.15. Using a
dichotomous ADHD CPNI measure (positive/negative) and the QEEG beta-theta power ratio resulted in an r
value of -0.09. The sensitivity of the QEEG ADHD parameter and the CPNI ADHD
scale was 50% and the specificity was 36%. The results stand in contrast to
those of who found 90% sensitivity and 94%
specificity between behavioral measures of ADHD and the QEEG scanning
procedure. The lack of correspondence
between the two measures is discussed.
Publication Types:
Comparative Study
Acta Psychiatr Scand. 2007 Jul;116(1):17-35.
Erratum in: Acta Psychiatr
Scand. 2007 Jul;116(1):35.
Electrophysiological subtypes of psychotic states.
John ER, Prichep LS, Winterer G, Herrmann WM, diMichele F,
Halper J, Bolwig TG, Cancro R.
Brain Research Laboratories, Department of Psychiatry, New
York University School of Medicine, New York, NY 10016, USA. johnr01@med.nyu.edu
OBJECTIVE: This research sought neurobiological
features common to psychotic states displayed by patients with different
clinical diagnoses. METHOD: Cluster analysis with quantitative
electroencephalographic (QEEG) variables was used to subtype drug-naïve,
non-medicated, and medicated schizophrenic, depressed and alcoholic patients
with psychotic symptoms, from the USA and Germany. QEEG source localization
brain images were computed for each cluster. RESULTS: Psychotic patients with
schizophrenia, depression and alcoholism, and drug- naïve schizophrenic
patients, were distributed among six clusters. QEEG images revealed one set of
brain regions differentially upregulated in each cluster and another group of
structures downregulated in the same way in every cluster. CONCLUSION: Subtypes
previously found among 94 schizophrenic patients were replicated in a sample of
390 non-schizophrenic as well as schizophrenic psychotics, and displayed common
neurobiological abnormalities. Collaborative longitudinal studies using these
economical methods might improve differential understanding and treatment of
patients based upon these features rather than clinical symptoms.
Clin EEG Neurosci. 2007 Jul;38(3):175-9.
Multimodality imaging in a depressed patient with violent
behavior and temporal lobe seizures.
Poprawski TJ, Pluzyczka AN, Park Y, Chennamchetty VN,
Halaris A, Crayton JW, Konopka LM.
Edward Hines Jr. VA Hospital, Hines, Illinois 60141, USA.
Patients suffering from epilepsy commonly experience
behavioral symptoms. Behavioral manifestations are especially prevalent in
patients with seizures originating in the limbic system. This case report
illustrates how an objective,
multimodality work-up can guide the clinician in the diagnosis and the
treatment of a patient with a complex
presentation. After the discontinuation of some medications, the patient
underwent a multimodality work-up that consisted of MRI, SPECT, and
conventional and quantitative EEG (LORETA). In this case, the functional
imaging studies showed a convergence of findings across the three modalities:
MRI, SPECT and qEEG. Because of these findings, we supported more aggressive
treatment of the seizure disorder. Ultimately this treatment resulted in resolution of the aggression and the
depression. In summary, when applied routinely, a comprehensive, systematic,
diagnostic approach will minimize treatment false starts and failures, may
reduce costs, and also, potentially decrease the severity and the duration of
symptoms.
Publication Types:
Case Reports Research Support,
U.S. Gov't, Non-P.H.S.
J Neurol Sci. 2007 Jun 15;257(1-2):11-6. Epub 2007 Mar 6.
Does EEG (visual and quantitative) reflect mental
impairment in subcortical vascular dementia?
Gawel M, Zalewska E, Szmidt-Sałkowska E, Kowalski J.
Department of Neurology, Medical University of
Warsaw, Poland. mgawel@amwaw.edu.pl
The aim of this study was to determine if the results of
visual and quantitative EEG (QEEG)
parameters reveal a correlation with mental impairment in subcortical vascular dementia (SVD), one of the most
frequent causes of cognitive impairment
in the elderly. In SVD, like in Alzheimer's disease disturbances were
found in cholinergic transmission. The cholinergic deficit as manifested in
changes of synaptic potentials is reflected in EEG signals. MATERIAL: 31
patients with probable SVD (according to NINCDS-AIREN and T. Erkinjuntii's
criteria) and mean age 72.3 yrs;(M--43%, F--57%) and 14 healthy control
subjects with mean age of 72.3 yrs (M-57%, F-43%). According to the Mini Mental
Scale Examination (MMSE) the SVD group was divided into two subgroups with mild
and moderate dementia, their EEGs being recorded with a Medelec and Neuroscan
4.2 system. Visual EEG findings were classified with the use of eight-degree scale
of pathological changes by the presence of slow waves. Then QEEGs were made.
The following parameters were calculated: alpha/slow wave power ratios, the
mean wave frequency in all and in some selected derivations. RESULTS: A
significant difference was found between QEEGs in SVD subgroups with mild and
moderate dementia (p<0.05), but there was no significant difference between
visual EEGs. A significant correlation between QEEG parameters such as
alpha/slow wave ratio or mean wave frequency and mental impairment (according
to MMSE results) was found (p<0.001),
but there was no significant correlation between degree of EEG
abnormalities in visual analysis and MMSE results. CONCLUSION: Only QEEGs are
correlated with mental impairment in SVD. Visual EEG technique as a less
precise tool does not reflect the mental impairment in SVD due to cholinergic
deficit.
Arq Neuropsiquiatr. 2007 Jun;65(2A):327-31.
[Changes in cortical interhemispheric coherence produced by
functional electrical stimulation (FES)]
[Article in Portuguese]
Ecard L, Silva AP, Peçanha Neto M,
Cagy M, Piedade R, Ribeiro P.
Laboratório de Mapeamento Cerebral e
Integração Sensório-Motora, Instituto de Psiquiatria, Universidade Federal do
Rio de Janeiro, Brazil. leticiaecard@bol.com.br
The aim of the present study was to observe cortical
alterations produced by functional electrical stimulation (FES), through
quantitative electroencephalography (qEEG). Electrostimulation was performed on
the right forearm to stimulate the extension of the index finger. EEG activity
was recorded simultaneously. The sample consisted of 45 subjects randomly divided
into 3 groups of 15 subjects each. The control group was submitted to 24 blocks
of stimulation at a current intensity of zero. Group 1 was submitted to 24
blocks and group 2 to 36 blocks. Interhemispheric coherence between F3-F4,
C3-C4 and P3-P4 was assessed through a statistical analysis. Results pointed
out to increased coherence values after stimulation.
Publication Types:
English Abstract Randomized
Controlled Trial
Clin Neurophysiol. 2007 Jun;118(6):1213-22. Epub 2007 Apr
23.
Cortical sources of awake scalp EEG in eating disorders.
Rodriguez G, Babiloni C, Brugnolo A, Del Percio C, Cerro F,
Gabrielli F, Girtler N, Nobili F,
Murialdo G, Rossini PM, Rossi DS, Baruzzi C, Ferro AM.
Section of Clinical Neurophysiology (DISEM), Department of
Endocrinological and Metabolic Sciences, University of Genoa, Genoa, Italy. guido@unige.it
OBJECTIVE: To investigate quantitative EEG (qEEG) in
anorexia nervosa (AN) and bulimia nervosa (BN) in comparison with healthy
controls. METHODS: Resting EEG was recorded in 30 healthy females (age:
27.1+/-5.5), 16-AN females (age: 26.4+/-9.5) and 12-BN females (age:
27.0+/-6.3). Cortical EEG sources (delta, theta, alpha 1, alpha 2, beta 1, beta
2) were modeled by LORETA solutions. The statistical analysis was performed
considering the factors Group, power Band, and region of interest (central,
frontal, parietal, occipital, temporal, limbic). RESULTS: Alpha 1 sources in
central, parietal, occipital and limbic areas showed a greater amplitude in Controls versus AN and
BN groups. Alpha 2 sources in parietal, occipital and limbic areas showed a
greater amplitude in Controls than in
both AN and BN groups. Alpha 1 sources in temporal area showed a greater
amplitude in Controls compared to both the BN and AN groups as well as in the
BN group compared to AN group. Central
alpha 1 source correlated significantly with
BMI in patients. CONCLUSIONS: These results support the hypothesis that
eating disorders are related to altered mechanisms of cortical neural
synchronization, especially in rolandic alpha rhythms. SIGNIFICANCE: To our
knowledge this is the first study by
LORETA able to detect modifications of cortical EEG activity in eating
disorders.
J Integr Neurosci. 2007 Jun;6(2):279-307.
Variability of model-free and model-based quantitative
measures of EEG.
Van Albada SJ, Rennie CJ, Robinson PA.
School of Physics, University of Sydney, NSW 2006,
Australia. albada@physics.usyd.edu.au
Variable contributions of state and trait to the
electroencephalographic (EEG) signal affect the stability over time of EEG
measures, quite apart from other experimental uncertainties. The extent of
intraindividual and interindividual variability is an important factor in
determining the statistical, and hence possibly clinical significance of
observed differences in the EEG. This study investigates the changes in
classical quantitative EEG (qEEG) measures, as well as of parameters obtained
by fitting frequency spectra to an existing continuum model of brain electrical
activity. These parameters may have extra variability due to model selection
and fitting. Besides estimating the levels of intraindividual and
interindividual variability, we determined approximate time scales for change
in qEEG measures and model parameters. This provides an estimate of the recording
length needed to capture a given percentage of the total intraindividual
variability. Also, if more precise time scales can be obtained in future, these
may aid the characterization of physiological processes underlying various EEG
measures. Heterogeneity of the subject group was constrained by testing only
healthy males in a narrow age range (mean = 22.3 years, sd = 2.7). Eyes-closed
EEGs of 32 subjects were recorded at weekly intervals over an approximately
six-week period, of which 13 subjects were followed for a year. QEEG measures,
computed from Cz spectra, were powers in five frequency bands, alpha peak
frequency, and spectral entropy. Of these, theta, alpha, and beta band powers
were most reproducible. Of the nine model parameters obtained by fitting model predictions to
experiment, the most reproducible ones quantified the total power and the time
delay between cortex and thalamus. About
95% of the maximum change in spectral parameters was reached within
minutes of recording time, implying that repeat recordings are not necessary to
capture the bulk of the variability in
EEG spectra.
Publication Types:
Comparative Study Research
Support, Non-U.S. Gov't
Epilepsy Behav. 2007 May;10(3):463-9. Epub 2007 Mar 6.
Topiramate effects on the EEG and alertness in healthy
volunteers: a different profile of antiepileptic drug neurotoxicity.
Salinsky M, Storzbach D, Oken B, Spencer D.
Oregon Health and Science University Epilepsy Center, 3181
SW Sam Jackson Park Road, CDW-3, Portland, OR 97201, USA. Salinsky@OHSU.edu
OBJECTIVE: Previous quantitative EEG (QEEG) studies of
carbamazepine (CBZ), oxcarbazepine (OXC), and phenytoin (PHT) revealed a
pattern of EEG slowing and an increase in drowsiness on the awake maintenance
task (AMT). EEG slowing has been shown
to correlate with negative effects on cognitive tests. Topiramate (TPM) is a novel AED with relatively large negative
effects on cognitive function. We tested the hypothesis that TPM would induce
significant slowing of EEG background rhythms and an increase in AMT
drowsiness. METHODS: Forty healthy volunteers were randomized to TPM,
gabapentin (GBP), or placebo. Doses were escalated as tolerated to a maximum of
400mg/day for TPM or 3600 mg/day for GBP, over a 10-week period, followed by a
minimum 2-week plateau period. Volunteers underwent an EEG, cognitive tests, and
the AMT prior to starting an AED and again 12 weeks later. The EEG was captured using a
structured recording protocol and quantified
using the fast Fourier transform. Four target measures were derived from
the averaged occipital electrodes (peak frequency of the dominant posterior
rhythm, median frequency, percentage theta, and percentage delta). Test-retest
changes for all measures were scored against similar test-retest distributions
previously obtained from untreated healthy volunteers. RESULTS: TPM produced no
significant change in any of the four
target EEG measures or on the AMT, even though several target cognitive tests revealed moderate or
greater negative effects. There were
also no significant changes in the placebo group. GBP slowed the peak
and median frequency EEG measures and
increased the percentage of theta and delta activity. Neither TPM, GBP, nor placebo caused a
significant increase in drowsiness on the
AMT. CONCLUSIONS: TPM has a unique neurotoxicity profile. It has no
effect on EEG background measures or on the AMT, but induces moderate to large
negative changes in many cognitive test scores. This profile differs from those
of CBZ, OXC, PHT, and GBP.
Publication Types:
Clinical Trial Randomized
Controlled Trial
J Neurosci Methods. 2007 Apr 15;161(2):205-11. Epub 2007
Jan 3.
Transformation of arbitrary distributions to the normal
distribution with application to EEG test-retest reliability.
van Albada SJ, Robinson PA.
School of Physics, University of Sydney, New South Wales
2006, Australia. albada@physics.usyd.edu.au
Many variables in the social, physical, and
biosciences, including neuroscience, are
non-normally distributed. To improve the statistical properties of such data,
or to allow parametric testing, logarithmic or logit transformations are often
used. Box-Cox transformations or ad hoc methods are sometimes used for
parameters for which no transformation is known to approximate normality.
However, these methods do not always give good agreement with the Gaussian. A
transformation is discussed that maps
probability distributions as closely as possible to the normal distribution,
with exact agreement for continuous distributions. To illustrate, the
transformation is applied to a theoretical distribution, and to quantitative
electroencephalographic (qEEG) measures from repeat recordings of 32 subjects
which are highly non-normal. Agreement with the Gaussian was better than using
logarithmic, logit, or Box-Cox transformations. Since normal data have
previously been shown to have better test-retest reliability than non-normal
data under fairly general circumstances, the implications of our transformation
for the test-retest reliability of parameters were investigated. Reliability
was shown to improve with the transformation, where the improvement was
comparable to that using Box-Cox. An advantage of the general transformation is
that it does not require laborious optimization over a range of parameters or a
case-specific choice of form.
Publication Types:
Evaluation Studies Research
Support, Non-U.S. Gov't
J Psychiatr Res. 2007 Apr-Jun;41(3-4):319-25. Epub 2006 Aug
4.
Changes in QEEG prefrontal cordance as a predictor of
response to antidepressants in patients with treatment resistant depressive
disorder: a pilot study.
Bares M, Brunovsky M, Kopecek M, Stopkova P, Novak T,
Kozeny J, Höschl C.
Prague Psychiatric Centre, Ustavni 91, Prague 8 - Bohnice,
181 03, Czech Republic; 3rd Faculty of Medicine, Charles University, Ruska 87,
Prague 10, 100 00, Czech Republic. bares@pcp.lf3.cuni.cz
INTRODUCTION: Previous studies of patients with unipolar
depression have shown that early decreases of EEG cordance (a new quantitative
EEG method) can predict clinical
response. We examined whether early QEEG decrease represents a phenomenon
associated with response to treatment with different antidepressants in
patients with treatment resistant depression. METHOD: The subjects were 17
inpatients with treatment resistant depression. EEG data and response to
treatment were monitored at baseline and after 1 and 4 weeks on an
antidepressant treatment. QEEG cordance was computed at three frontal
electrodes in theta frequency band. The prefrontal cordance combines
complementary information from absolute and relative power of EEG spectra. Recent
studies have shown that cordance correlates with cortical perfusion. Depressive
symptoms were assessed using Montgomery-Asberg Depression Rating Scale (MADRS).
RESULTS: All 17 patients completed the 4-week study. All five responders showed
decreases in prefrontal cordance after the first week of treatment. Only 2 of
the 12 nonresponders showed early prefrontal cordance decrease. The decrease of
prefrontal QEEG cordance after week 1 in responders as well as the increase in
nonresponders were both statistically significant (p-value 0.03 and 0.01,
respectively) and the changes of prefrontal cordance values were different
between both groups (p-value 0.001). CONCLUSION: Our results suggest that
decrease in prefrontal cordance may indicate early changes of prefrontal
activity in responders to antidepressants. QEEG cordance may become a useful
tool in the prediction of response to antidepressants.
Publication Types:
Clinical Trial Comparative
Study Research Support, Non-U.S.
Gov't
Acta Psychiatr Scand. 2007 Jul;116(1):17-35.
Electrophysiological subtypes of psychotic states.
John ER, Prichep LS, Winterer G, Herrmann WM, diMichele F,
Halper J, Bolwig TG, Cancro R.
Brain Research Laboratories, Department of Psychiatry, New
York University School of Medicine, New York, NY 10016, USA.
johnr01@med.nyu.edu
OBJECTIVE: This research sought neurobiological features
common to psychotic states displayed by patients with different clinical
diagnoses. METHOD: Cluster analysis with quantitative electroencephalographic
(QEEG) variables was used to subtype drug-naive, non-medicated, and medicated schizophrenic,
depressed and alcoholic patients with psychotic symptoms, from the USA and Germany.
QEEG source localization brain images were computed for each cluster. RESULTS:
Psychotic patients with schizophrenia, depression and alcoholism, and drug-
naive schizophrenic patients, were distributed among six clusters. QEEG images
revealed one set of brain regions differentially upregulated in each cluster
and another group of structures down-regulated in the same way in every
cluster. CONCLUSION: Subtypes previously found among 94 schizophrenic patients
were replicated in a sample of 390 non-schizophrenic as well as schizophrenic
psychotics, and displayed common neurobiological abnormalities. Collaborative
longitudinal studies using these economical methods might improve differential
understanding and treatment of patients based upon these features rather than
clinical symptoms.
PubMed
Link [PubMed - in process]
J Neurol Neurosurg Psychiatry. 2007 Jun 19; [Epub ahead of
print]
Prolonged activation EEG differentiates dementia with and
without delirium in frail elderly.
Thomas C, Hestermann U, Walther S, Pfueller U, Hack M,
Oster P, Mundt C, Weisbrod M.
Centre for Psychosocial Medicine, Department of General
PsychiatrEvangelisches Krankenhaus Bielefeld, Germany.
OBJECTIVE: Delirium in the elderly results in increased
morbidity, mortality, and functional decline. Particularly in dementia delirium
is underdiagnosed. To increase diagnostic accuracy, we investigated whether the
maintenance of activation assessed by EEG discriminates delirium concomitant
with dementia(D+D) from dementia without delirium(DP) and cognitively
unimpaired elderly(CU). METHOD: Routine and quantitative EEG (rEEG/qEEG) with
additional prolonged activation (3min eyes-open-period) were evaluated in
hospitalized elderly with acute geriatric disease. Patients were assigned post
hoc to three comparable groups (D+D/DP/CU) by expert consensus based on DSM-IV
criteria. Dementia diagnosis was confirmed with cognitive and functional tests
and caregiver rating (IQCODE). RESULTS: While rEEG at rest showed low accuracy
of delirium diagnosis, in qEEG DP and CU revealed a specific activation pattern
of high significance found to be absent in D+D. Stepwise logistic regression confirmed
that the differentiation of D+D from DP is best resolved using activated upper
alpha and delta powerdensity, which, compared to rEEG, enables an 11% increase
of diagnostic correctness to 83%, resulting in 67% sensitivity and 91%
specificity. Among frail CU and D+D almost 90% were correctly classified.
CONCLUSION: Dementia associated delirium can be discriminated reliably from
dementia alone in a meaningful clinical setting. Thus, EEG evaluation in
chronic encephalopathy should be optimized by a simple activation task and
spectral analysis especially in the demented elderly.
J Neurol Sci. 2007 Jun 15;257(1-2):11-6. Epub 2007 Mar 6.
Does EEG (visual and quantitative) reflect mental
impairment in subcortical vascular dementia?
Gawel M, Zalewska E, Szmidt-Saokowska E, Kowalski J.
Department of Neurology, Medical University of Warsaw,
Poland.
The aim of this study was to determine if the results of
visual and quantitative EEG (QEEG) parameters reveal a correlation with mental
impairment in subcortical vascular dementia (SVD), one of the most frequent
causes of cognitive impairment in the elderly. In SVD, like in Alzheimer's
disease disturbances were found in cholinergic transmission. The cholinergic
deficit as manifested in changes of synaptic potentials is reflected in EEG
signals. MATERIAL: 31 patients with probable SVD (according to NINCDS-AIREN and
T. Erkinjuntii's criteria) and mean age 72.3 yrs;(M-43%, F-57%) and 14 healthy
control subjects with mean age of 72.3 yrs (M-57%, F-43%). According to the
Mini Mental Scale Examination (MMSE) the SVD group was divided into two
subgroups with mild and moderate dementia, their EEGs being recorded with a
Medelec and Neuroscan 4.2 system. Visual EEG findings were classified with the
use of eight-degree scale of pathological changes by the presence of slow
waves. Then QEEGs were made. The following parameters were calculated:
alpha/slow wave power ratios, the mean wave frequency in all and in some
selected derivations. RESULTS: A significant difference was found between QEEGs
in SVD subgroups with mild and moderate dementia (p<0.05), but there was no
significant difference between visual EEGs. A significant correlation between
QEEG parameters such as alpha/slow wave ratio or mean wave frequency and mental
impairment (according to MMSE results) was found (p<0.001), but there was no
significant correlation between degree of EEG abnormalities in visual analysis
and MMSE results. CONCLUSION: Only QEEGs are correlated with mental impairment
in SVD. Visual EEG technique as a less precise tool does not reflect the mental
impairment in SVD due to cholinergic deficit.
Arq Neuropsiquiatr. 2007 Jun;65(2A):327-31.
[Changes in cortical interhemispheric coherence produced by
functional electrical stimulation (FES)]
[Article in Portuguese]
Ecard L, da Silva AP, Pesanha Neto M,
Cagy M, Piedade R, Ribeiro P.
Laboratorio de Mapeamento Cerebral e
Integracao Sensorio-Motora, Instituto de Psiquiatria, Universidade Federal do
Rio de Janeiro, Brazil. leticiaecard@bol.com.br
The aim of the present study was to observe cortical
alterations produced by functional electrical stimulation (FES), through
quantitative electroencephalography (qEEG). Electrostimulation was performed on
the right forearm to stimulate the extension of the index finger. EEG activity
was recorded simultaneously. The sample consisted of 45 subjects randomly
divided into 3 groups of 15 subjects each. The control group was submitted to
24 blocks of stimulation at a current intensity of zero. Group 1 was submitted
to 24 blocks and group 2 to 36 blocks. Interhemispheric coherence between
F3-F4, C3-C4 and P3-P4 was assessed through a statistical analysis. Results
pointed out to increased coherence values after stimulation.
Publication Types:
English Abstract
Clin Neurophysiol. 2007 Jun;118(6):1213-22. Epub 2007 Apr
23.
Cortical sources of awake scalp EEG in eating disorders.
Rodriguez G, Babiloni C, Brugnolo A, Del Percio C, Cerro F,
Gabrielli F, Girtler N, Nobili F, Murialdo G, Rossini PM, Rossi DS, Baruzzi C,
Ferro AM.
Section of Clinical Neurophysiology (DISEM), Department of
Endocrinological and Metabolic Sciences, University of Genoa, Genoa, Italy.
guido@unige.it
OBJECTIVE: To investigate quantitative EEG (qEEG) in
anorexia nervosa (AN) and bulimia nervosa (BN) in comparison with healthy controls.
METHODS: Resting EEG was recorded in 30 healthy females (age: 27.1+/-5.5),
16-AN females (age: 26.4+/-9.5) and 12-BN females (age: 27.0+/-6.3). Cortical
EEG sources (delta, theta, alpha 1, alpha 2, beta 1, beta 2) were modeled by
LORETA solutions. The statistical analysis was performed considering the
factors Group, power Band, and region of interest (central, frontal, parietal,
occipital, temporal, limbic). RESULTS: Alpha 1 sources in central, parietal,
occipital and limbic areas showed a greater amplitude in Controls versus AN and
BN groups. Alpha 2 sources in parietal, occipital and limbic areas showed a
greater amplitude in Controls than in both AN and BN groups. Alpha 1 sources in
temporal area showed a greater amplitude in Controls compared to both the BN
and AN groups as well as in the BN group compared to AN group. Central alpha 1
source correlated significantly with BMI in patients. CONCLUSIONS: These
results support the hypothesis that eating disorders are related to altered
mechanisms of cortical neural synchronization, especially in rolandic alpha
rhythms. SIGNIFICANCE: To our knowledge this is the first study by LORETA able
to detect modifications of cortical EEG activity in eating disorders.
Int J Neurosci. 2007 Jun;117(6):869-82.
Relationship of working memory and EEG to academic
performance: a study among high school students.
Aguirre-Perez DM, Otero-Ojeda GA,
Pliego-Rivero FB, Ferreira-Martenez AA.
Centro de Investigacion en Ciencias
Medicas, Universidad Autonoma del Estado de Mexico, Toluca, Mexico.
Some biological and behavioral elements which could explain
differences between high and low academic attainment (HA/LA) students were
identified. The qEEG of subjects under the 10-20 derivation system was recorded
at rest and while completing a 3-back working memory (WM) task. While
completing the task LA students showed more theta and total absolute potency at
rest, and HA individuals showed more energy in delta and theta frequencies in
frontal regions; LA students made a higher number of mistakes while executing
the WM task with no differences in reaction time between groups. We conclude
that a diminished WM capacity is present in LA students.
Publication Types:
Research Support, Non-U.S. Gov't
J Integr Neurosci. 2007 Jun;6(2):279-307.
Variability of model-free and model-based quantitative
measures of EEG.
VAN Albada SJ, Rennie CJ, Robinson PA.
School of Physics, University of Sydney, NSW 2006,
Australia. albada@physics.usyd.edu.au.
Variable contributions of state and trait to the
electroencephalographic (EEG) signal affect the stability over time of EEG
measures, quite apart from other experimental uncertainties. The extent of
intraindividual and interindividual variability is an important factor in
determining the statistical, and hence possibly clinical significance of
observed differences in the EEG. This study investigates the changes in
classical quantitative EEG (qEEG) measures, as well as of parameters obtained
by fitting frequency spectra to an existing continuum model of brain electrical
activity. These parameters may have extra variability due to model selection
and fitting. Besides estimating the levels of intraindividual and
interindividual variability, we determined approximate time scales for change
in qEEG measures and model parameters. This provides an estimate of the
recording length needed to capture a given percentage of the total
intraindividual variability. Also, if more precise time scales can be obtained
in future, these may aid the characterization of physiological processes
underlying various EEG measures. Heterogeneity of the subject group was constrained
by testing only healthy males in a narrow age range (mean = 22.3 years, sd =
2.7). Eyes-closed EEGs of 32 subjects were recorded at weekly intervals over an
approximately six-week period, of which 13 subjects were followed for a year.
QEEG measures, computed from Cz spectra, were powers in five frequency bands,
alpha peak frequency, and spectral entropy. Of these, theta, alpha, and beta
band powers were most reproducible. Of the nine model parameters obtained by
fitting model predictions to experiment, the most reproducible ones quantified
the total power and the time delay between cortex and thalamus. About 95% of
the maximum change in spectral parameters was reached within minutes of
recording time, implying that repeat recordings are not necessary to capture
the bulk of the variability in EEG spectra.
Epilepsy Behav. 2007 May;10(3):463-9. Epub 2007 Mar 6.
Topiramate effects on the EEG and alertness in healthy
volunteers: a different profile of antiepileptic drug neurotoxicity.
Salinsky M, Storzbach D, Oken B, Spencer D.
Oregon Health and Science University Epilepsy Center, 3181
SW Sam Jackson Park Road, CDW-3, Portland, OR 97201, USA. Salinsky@OHSU.edu
OBJECTIVE: Previous quantitative EEG (QEEG) studies of
carbamazepine (CBZ), oxcarbazepine (OXC), and phenytoin (PHT) revealed a
pattern of EEG slowing and an increase in drowsiness on the awake maintenance
task (AMT). EEG slowing has been shown to correlate with negative effects on
cognitive tests. Topiramate (TPM) is a novel AED with relatively large negative
effects on cognitive function. We tested the hypothesis that TPM would induce
significant slowing of EEG background rhythms and an increase in AMT
drowsiness. METHODS: Forty healthy volunteers were randomized to TPM,
gabapentin (GBP), or placebo. Doses were escalated as tolerated to a maximum of
400mg/day for TPM or 3600 mg/day for GBP, over a 10-week period, followed by a
minimum 2-week plateau period. Volunteers underwent an EEG, cognitive tests,
and the AMT prior to starting an AED and again 12 weeks later. The EEG was
captured using a structured recording protocol and quantified using the fast
Fourier transform. Four target measures were derived from the averaged occipital
electrodes (peak frequency of the dominant posterior rhythm, median frequency,
percentage theta, and percentage delta). Test-retest changes for all measures
were scored against similar test-retest distributions previously obtained from
untreated healthy volunteers. RESULTS: TPM produced no significant change in
any of the four target EEG measures or on the AMT, even though several target
cognitive tests revealed moderate or greater negative effects. There were also
no significant changes in the placebo group. GBP slowed the peak and median
frequency EEG measures and increased the percentage of theta and delta
activity. Neither TPM, GBP, nor placebo caused a significant increase in
drowsiness on the AMT. CONCLUSIONS: TPM has a unique neurotoxicity profile. It
has no effect on EEG background measures or on the AMT, but induces moderate to
large negative changes in many cognitive test scores. This profile differs from
those of CBZ, OXC, PHT, and GBP.
J Neurosci Methods. 2007 Apr 15;161(2):205-11. Epub 2007
Jan 3.
Transformation of arbitrary distributions to the normal
distribution with application to EEG test-retest reliability.
van Albada SJ, Robinson PA.
School of Physics, University of Sydney, New South Wales
2006, Australia. albada@physics.usyd.edu.au
Many variables in the social, physical, and biosciences,
including neuroscience, are non-normally distributed. To improve the
statistical properties of such data, or to allow parametric testing,
logarithmic or logit transformations are often used. Box-Cox transformations or
ad hoc methods are sometimes used for parameters for which no transformation is
known to approximate normality. However, these methods do not always give good agreement
with the Gaussian. A transformation is discussed that maps probability
distributions as closely as possible to the normal distribution, with exact
agreement for continuous distributions. To illustrate, the transformation is
applied to a theoretical distribution, and to quantitative
electroencephalographic (qEEG) measures from repeat recordings of 32 subjects
which are highly non-normal. Agreement with the Gaussian was better than using
logarithmic, logit, or Box-Cox transformations. Since normal data have
previously been shown to have better test-retest reliability than non-normal
data under fairly general circumstances, the implications of our transformation
for the test-retest reliability of parameters were investigated. Reliability
was shown to improve with the transformation, where the improvement was
comparable to that using Box-Cox. An advantage of the general transformation is
that it does not require laborious optimization over a range of parameters or a
case-specific choice of form.
Publication Types:
Evaluation Studies Research
Support, Non-U.S. Gov't
J Psychiatr Res. 2007 Apr-Jun;41(3-4):319-25. Epub 2006 Aug
4.
Changes in QEEG prefrontal cordance as a predictor of
response to antidepressants in patients with treatment resistant depressive
disorder: a pilot study.
Bares M, Brunovsky M, Kopecek M, Stopkova P, Novak T,
Kozeny J, Hãschl C.
Prague Psychiatric Centre, Ustavni 91, Prague 8 - Bohnice,
181 03, Czech Republic; 3rd Faculty of Medicine, Charles University, Ruska 87,
Prague 10, 100 00, Czech Republic. bares@pcp.lf3.cuni.cz
INTRODUCTION: Previous studies of patients with unipolar
depression have shown that early decreases of EEG cordance (a new quantitative
EEG method) can predict clinical response. We examined whether early QEEG
decrease represents a phenomenon associated with response to treatment with
different antidepressants in patients with treatment resistant depression.
METHOD: The subjects were 17 inpatients with treatment resistant depression.
EEG data and response to treatment were monitored at baseline and after 1 and 4
weeks on an antidepressant treatment. QEEG cordance was computed at three
frontal electrodes in theta frequency band. The prefrontal cordance combines
complementary information from absolute and relative power of EEG spectra.
Recent studies have shown that cordance correlates with cortical perfusion.
Depressive symptoms were assessed using Montgomery-Asberg Depression Rating
Scale (MADRS). RESULTS: All 17 patients completed the 4-week study. All five
responders showed decreases in prefrontal cordance after the first week of
treatment. Only 2 of the 12 nonresponders showed early prefrontal cordance
decrease. The decrease of prefrontal QEEG cordance after week 1 in responders
as well as the increase in nonresponders were both statistically significant
(p-value 0.03 and 0.01, respectively) and the changes of prefrontal cordance
values were different between both groups (p-value 0.001). CONCLUSION: Our
results suggest that decrease in prefrontal cordance may indicate early changes
of prefrontal activity in responders to antidepressants. QEEG cordance may
become a useful tool in the prediction of response to antidepressants.
Publication Types:
Clinical Trial Comparative
Study Research Support, Non-U.S.
Gov't
Acta Psychiatr
Scand. 2007 Mar;115(3):237-42.
Toward a better understanding of the pathophysiology of OCD
SSRI responders: QEEG source localization.
Bolwig TG, Hansen ES, Hansen A, Merkin H, Prichep LS.
Department of Psychiatry, The Neuroscience Center,
Copenhagen University Hospital Rigshospitalet, Copenhagen, Denmark.
bolwigtg@rh.dk
OBJECTIVE: To demonstrate the utility of three-dimensional
source localization of the scalp-recorded electroencephalogram (EEG) for the
identification of the most probable underlying brain dysfunction in patients
with obsessive-compulsive disorder (OCD). METHOD: Eyes-closed resting EEG data
was recorded from the scalp locations of the International 10/20 System.
Variable resolution electromagnetic tomography (VARETA) was applied to
artifact-free EEG data. This mathematical algorithm estimates the source generators
of EEG recorded from the scalp. RESULTS: An excess in the alpha range was found
with sources in the corpus striatum, in the orbito-frontal and temporo-frontal
regions in untreated OCD patients. This abnormality was seen to decrease
following successful treatment with paroxetine. CONCLUSION: The VARETA findings
of an activation/deactivation pattern in cortical and subcortical structures in
paroxetine-responsive patients are in good accordance with data obtained in
previously published positron emission tomography studies related to current
hypotheses of a thalamo-striatal-frontal feedback loop being relevant for
understanding the pathophysiology of OCD.
Publication Types:
Research Support, Non-U.S. Gov't
Appl Psychophysiol Biofeedback. 2007 Mar;32(1):11-7. Epub
2007 Feb 27.
A quantitative electroencephalographic correlate of
sustained attention processing.
Arruda JE, Amoss RT, Coburn KL, McGee H.
University of West Florida, 11000 University Pkwy.,
Pensacola, FL 32514, USA. jarruda@uwf.edu
The objective of the present investigation was to develop a
quantitative electroencephalographic measure (qEEG) that is sensitive and
specific to changes in sustained human performance. A principal components
analysis (PCA) was performed on the qEEG obtained from participants during a
continuous performance test. Measures of sensitivity (proportion of correctly
identified correct responses, or hits) and specificity (proportion of correctly
identified incorrect responses, or misses) were calculated to assess the
classification accuracy of each newly derived component. PCA solutions produced
a right hemisphere component comprised of beta-wave activity measured from four
unipolar sites (F8, C6a, C6, and T4) that appeared to be sensitive and specific
to changes in human performance. Results provide evidence for the validity of a
right hemisphere qEEG measure that is sensitive and specific to changes in
sustained human performance. Consistent with the findings of previous research,
the present findings implicate the right cerebral hemisphere in the sustained
attention process.
Arq Neuropsiquiatr. 2007 Mar;65(1):63-7.
EEG spectral coherence inter- and intrahemispheric during
catching object fall task.
Portella CE, Silva JG, Machado S, Velasques B, Bastos VH,
Ferreira-Vorkapic C, Terra P, Lopes V, Cagy M, Carvalho E, Orsini M, Basile L,
Piedade R, Ribeiro P.
Laboratorio de Mapeamento Cerebral e
Integracao Sensorio-motor, Instituto de Psiquiatria, Universidade Federal do
Rio de Janeiro, Rua Silva Teles 30A/208, 20541-110 Rio de Janeiro, RJ, Brazil.
itoito@click21.com.br
The aim of the present study was to evaluate coherence
measures at Theta through qEEG during the accomplishment of a specific motor
task. The sample consisted of 23 healthy individuals, both sexes, with ages
varying between 25 and 40 years old. All subjects were submitted to a specific
motor task of catching sequences of falling balls. A three-way ANOVA was
employed for the statistical analysis, which demonstrated main effects for the
following factors: time, block and position. However, there was no interaction
between the factors. A significant and generalized coherence reduction was
observed during the task execution time. Coherence was also diminished at the
left frontal cortex and contralateral hemisphere of the utilizing limb
(comparing to the right frontal cortex). In conclusion, these findings suggest
a certain specialization of the neural circuit, also according to previous
investigations. The inter-coherence reduction suggests a spatial
inter-electrode dependence during the task, rather than a neuronal
specialization.
J Integr Neurosci. 2007 Mar;6(1):175-90.
Different brain activation patterns in dyslexic children:
evidence from EEG power and coherence patterns for the double-deficit theory of
dyslexia.
Arns M, Peters S, Breteler R, Verhoeven L.
The Brain Resource Company B.V./Brainquiry B.V. Nijmegen,
6525 EC, The Netherlands. marns@qeeg.nl
AIMS: QEEG and neuropsychological tests were used to
investigate the underlying neural processes in dyslexia. METHODS: A group of
dyslexic children were compared with a matched control group from the Brain
Resource International Database on measures of cognition and brain function
(EEG and coherence). RESULTS: The dyslexic group showed increased slow activity
(Delta and Theta) in the frontal and right temporal regions of the brain.
Beta-1 was specifically increased at F7. EEG coherence was increased in the
frontal, central and temporal regions for all frequency bands. There was a
symmetric increase in coherence for the lower frequency bands (Delta and Theta)
and a specific right-temporocentral increase in coherence for the higher
frequency bands (Alpha and Beta). Significant correlations were observed
between subtests such as Rapid Naming Letters, Articulation, Spelling and Phoneme
Deletion and EEG coherence profiles. DISCUSSION: The results support the
double-deficit theory of dyslexia and demonstrate that the differences between
the dyslexia and control group might reflect compensatory mechanisms.
INTEGRATIVE SIGNIFICANCE: These findings point to a potential compensatory
mechanism of brain function in dyslexia and helps to separate real dysfunction
in dyslexia from acquired compensatory mechanisms.
Publication Types:
Research Support, Non-U.S. Gov't
J Integr Neurosci. 2007 Mar;6(1):35-74.
Brain structure and function correlates of general and
social cognition.
Rowe DL, Cooper NJ, Liddell BJ, Clark CR, Gordon E,
Williams LM.
The Brain Dynamics Center, Westmead Millennium Institute,
Westmead Hospital and Western Clinical School, University of Sydney, NSW 2145,
Australia. donrowe@med.usyd.edu.au
AIMS: To examine how general (e.g., memory, attention) and
social (emotional and interpersonal processes) cognition relate to measures of
brain function and structure. METHODS: PCA was used to identify general and
social cognitive factors from Brain Resource International Database in 1,316
subjects. The identified factors were correlated with each subject's
corresponding brain structure (MRI) and function (EEG/ERP) data. RESULTS: Seven
core cognitive factors were identified for general and three for social.
General cognition was correlated with global grey matter, while social
cognition was negatively correlated with grey matter in
fronto-temporal-somatosensory regions. Executive function, information
processing speed and verbal memory performance were correlated with delta-theta
qEEG, while most general cognitive factors negatively correlated with beta
qEEG. Faster information processing speed was correlated with alpha qEEG.
Executive function and information processing speed was correlated with
negative-going ERP amplitude and slower ERP latency at frontal sites, but at
posterior sites negative correlations were found. DISCUSSION: In contrast to
general cognition, social cognition is identified by different functional
(automated) activity and more localized neural structures. Only general
cognition, requiring more effortful, controlled processing is related to brain
function measures, particularly in frontal cortices. INTEGRATIVE SIGNIFICANCE:
Recording measures from multiple modalities including MRI, EEG/ERP, social and
general cognition within the same subject provides a method of brain profiling
for use in cognitive-neurotherapy and pharmacological studies.
Publication Types:
Research Support, Non-U.S. Gov't
Psychiatr Clin North Am. 2007 Mar;30(1):105-24.
The promise of the quantitative electroencephalogram as a
predictor of antidepressant treatment outcomes in major depressive disorder.
Hunter AM, Cook IA, Leuchter AF.
Laboratory of Brain, Behavior, and Pharmacology, 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, USA. amhunter@ucla.edu
Recent studies have shown overall accuracy rates of 72% and
88% using baseline and/or 1-week change in QEEG biomarkers to predict clinical
outcome to treatment with various antidepressant medications. In some cases,
findings have been replicated across academic institutions and have been
studied in the context of randomized, placebo-controlled trials. Recent EEG
findings are corroborated by studies that use techniques with greater spatial
resolution (eg, PET, MEG) in localizing brain regions pertinent to clinical
response. As such, EEG measurements increasingly are validated by other physiologic
measurements that have the ability to assess deeper brain structures. Continued
progress along these lines may lead to the realized promise of QEEG biomarkers
as predictors of antidepressant treatment outcome in routine clinical practice.
In the larger context, use of QEEG technology to predict antidepressant
response in major depression may mean that more patients will achieve response
and remission with less of the trial-and-error approach that currently
accompanies antidepressant treatment.
Publication Types:
Research Support, N.I.H., Extramural
Research Support, Non-U.S. Gov't
Review
Ann N Y Acad Sci. 2007 Feb;1097:156-67.
Quantitative EEG and electromagnetic brain imaging in aging
and in the evolution of dementia.
Prichep LS.
Brain Research Laboratories, Department of Psychiatry, New
York University School of Medicine, New York 10016, USA.
leslie.prichep@med.nyu.edu
Electroencephalographic (EEG) changes with normal aging
have long been reported. Departures from age-expected changes have been
observed in mild cognitive impairment and dementia, the magnitude of which
correlates with the degree of cognitive impairment. Such abnormalities include
increased delta and theta activity, decreased mean frequency, and changes in
coherence. Similar findings have been reported using magnetoencephalography
(MEG) at rest and during performance of mental tasks. Electrophysiological features
have also been shown to be predictive of future decline in mild cognitive
impairment (MCI) and Alzheimer's disease (AD). We have recently reported
results from initial quantitative electroencephalography (QEEG) evaluations of
normal elderly subjects (with only subjective reports of memory loss),
predicting future cognitive decline or conversion to dementia, with high
prediction accuracy (approximately 95%). In this report, source localization
algorithms were used to identify the mathematically most probable underlying
generators of abnormal features of the scalp-recorded EEG from these patients
with differential outcomes. Using this QEEG method, abnormalities in brain
regions identified in studies of AD using MEG, MRI, and positron emission
tomography (PET) imaging were found in the premorbid recordings of those
subjects who go on to decline or convert to dementia.
Publication Types:
Research Support, Non-U.S. Gov't
Maturitas. 2007 Jan 20;56(1):54-60. Epub 2006 Jul 10.
Neurophysiologic changes during estrogen augmentation in
perimenopausal depression.
Morgan ML, Cook IA, Rapkin AJ, Leuchter AF.
Laboratory of Brain, Behavior, and Pharmacology, Department
of Psychiatry and Biobehavioral Sciences, UCLA Neuropsychiatric Institute, 760
Westwood Plaza, Suite 37-439, Los Angeles, CA 90024-1759, United States.
melinda@ucla.edu
BACKGROUND: Estrogen augmentation of antidepressant
medication has been an effective treatment in a subgroup of women experiencing
affective symptoms during perimenopause. It has been suggested that estrogen
facilitates serotonergic transmission in brain regions involved in mood
disorders. We investigated differences in physiologic brain changes with
estrogen augmentation in women with perimenopausal depression who reached
remission compared to those who did not reach remission. We also assessed
whether such changes were correlated with serum hormone levels. METHODS:
Quantitative electroencephalography (QEEG) was used to examine neurophysiologic
brain changes in remission and non-remission of depressive symptoms. Women with
major depressive disorder (MDD) in partial remission who were taking
antidepressant medication for a minimum of 8 weeks and were experiencing two or
more perimenopausal symptoms (hot flashes, night sweats, irregular periods,
memory impairment, vaginal dryness) were recruited from the community. Absolute
power, relative power, and QEEG cordance, a measure that has moderately strong
associations with cerebral perfusion, were obtained before and after 6 weeks of
treatment with 0.625 mg of conjugated estrogen per day. RESULTS: Women who
experienced remission of depressive symptoms (Ham-D< or =7) had a
significant decrease in right frontal QEEG cordance (p=0.008, t((8))=-3.54)
which was not present in non-remitters. No significant correlations were found
between hormone levels and QEEG cordance. CONCLUSION: In women with
perimenopausal depression, physiologic brain changes in the right frontal region
during estrogen augmentation were associated with remission of depression.
Publication Types:
Clinical Trial Research
Support, N.I.H., Extramural Research
Support, Non-U.S. Gov't
Rev Neurol. 2007 Jan 16-31;44(2):81-8.
[Quantitative electroencephalography features and cognitive
impairment in alcoholic patients]
[Article in Spanish]
de Quesada-Martinez ME, Doaz-Pacrez
GF, Herrera-Ramos A, Tamayo-Porras M, Rubio-Lopez R.
Escuela de Medicina J.M.Vargas,
Caracas, Venezuela. medequesada@yahoo.com
AIM: To determine the exact relation between the
characteristics of quantitative electroencephalogram analyses and the
estimators of the cognitive status in alcoholic patients undergoing withdrawal.
SUBJECTS AND METHODS: The study examined 49 patients diagnosed with alcoholism
(DSM-IV) after 10 days of withdrawal, as well as the correlation between the
bandwidth measures from the quantitative electroencephalogram (qEEG) analysis and
the characteristics of the visual and auditory cognitive evoked potentials
(P300) and from the findings of the attention and memory tests. RESULTS: The
patients were divided into two groups: group one, which displayed an overall
increase in the delta and theta absolute powers with frontal predominance, and
group two, with reduced delta and theta absolute powers. Latency of the P300
wave was delayed in patients, particularly in those in group one, but regional
absence of the P300 wave was more frequent in group two. Results of attention
and memory tests were abnormal in patients, especially those in group one.
CONCLUSIONS: The findings in the two groups appear to reflect different stages
in the progression of alcoholism: the first only involved cortical dysfunction
due to metabolic causes and the second possibly had added cortical atrophy.
They might also represent two types of biological response by their nervous
systems to the same pathogenic agent. These findings suggest that it is
advisable to conduct follow-up studies involving qEEG, cognitive tests and
magnetic resonance imaging of the brain in this kind of patient.
Publication Types:
Comparative Study English
Abstract Research Support, Non-U.S.
Gov't
Clin Neurophysiol. 2007 Jan;118(1):31-52. Epub 2006 Nov 7.
The effect of hypobaric hypoxia on multichannel EEG signal
complexity.
Papadelis C, Kourtidou-Papadeli C,
Bamidis PD, Maglaveras N, Pappas K.
Aristotle University of Thessaloniki, School of Medicine,
Laboratory of Medical Informatics, Thessaloniki, Greece. cpapad@med.auth.gr
OBJECTIVE: The objective of this study was the development
and evaluation of nonlinear electroencephalography parameters which assess
hypoxia-induced EEG alterations, and describe the temporal characteristics of
different hypoxic levels' residual effect upon the brain electrical activity.
METHODS: Multichannel EEG, pO2, pCO2, ECG, and respiration measurements were
recorded from 10 subjects exposed to three experimental conditions (100%
oxygen, hypoxia, recovery) at three-levels of reduced barometric pressure. The
mean spectral power of EEG under each session and altitude were estimated for
the standard bands. Approximate Entropy (ApEn) of EEG segments was calculated,
and the ApEn's time-courses were smoothed by a moving average filter. On the
smoothed diagrams, parameters were defined. RESULTS: A significant increase in
total power and power of theta and alpha bands was observed during hypoxia.
Visual interpretation of ApEn time-courses revealed a characteristic pattern
(decreasing during hypoxia and recovering after oxygen re-administration). The
introduced qEEG parameters S1 and K1 distinguished successfully the three hypoxic
conditions. CONCLUSIONS: The introduced parameters based on ApEn time-courses
are assessing reliably and effectively the different hypoxic levels. ApEn
decrease may be explained by neurons' functional isolation due to hypoxia since
decreased complexity corresponds to greater autonomy of components, although
this interpretation should be further supported by electrocorticographic animal
studies. SIGNIFICANCE: The introduced qEEG parameters seem to be appropriate
for assessing the hypoxia-related neurophysiological state of patients in the
hyperbaric chambers in the treatment of decompression sickness, carbon dioxide
poisoning, and mountaineering.
Epilepsia. 2007 Jan;48(1):191-5.
Quantitative EEG asymmetry correlates with clinical
severity in unilateral Sturge-Weber syndrome.
Hatfield LA, Crone NE, Kossoff EH, Ewen JB, Pyzik PL, Lin
DD, Kelley TM, Comi AM.
Department of Neurology, Kennedy Krieger Institute,
Baltimore, MD 21205, USA.
PURPOSE: Sturge-Weber syndrome (SWS) is a neurocutaneous
disorder with vascular malformations of the skin, brain, and eye. SWS results
in ischemic brain injury, seizures, and neurologic deficits. We hypothesized
that a decrease in quantitative EEG (qEEG) power, on the affected side,
correlates with clinical severity in subjects with SWS. METHODS: Fourteen
subjects had 16-channel scalp EEG recordings. Data were analyzed using fast
Fourier transform and calculation of power asymmetry. Blinded investigators assigned
scores for clinical neurological status and qualitative assessment of MRI and
EEG asymmetry. RESULTS: The majority of subjects demonstrated lower total power
on the affected side, usually involving all four frequency bands (delta, theta,
alpha, and beta). qEEG asymmetry correlated strongly with neurologic clinical
severity scores and MRI asymmetry scores. qEEG data generally agreed with the
MRI evidence of regional brain involvement. In MRI-qEEG comparisons that did
not agree, decreased power on qEEG in a brain region not affected on MRI was
more likely to occur in subjects with more severe neurologic deficits.
CONCLUSIONS: qEEG provides an objective measure of EEG asymmetry that
correlates with clinical status and brain asymmetry seen on MRI. These findings
support the conclusion that qEEG reflects the degree and extent of brain
involvement and dysfunction in SWS. qEEG may potentially be a useful tool for
early diagnosis and monitoring of disease progression in SWS. qEEG may prove
useful, in severely affected individuals with SWS, for determining regions of
brain dysfunction.
Publication Types:
Comparative Study Research
Support, N.I.H., Extramural Research
Support, Non-U.S. Gov't
Neuropsychology. 2007 Jan;21(1):74-81.
Quantitative electroencephalographic profiles for children
with autistic spectrum disorder.
Chan AS, Sze SL, Cheung MC.
Department of Psychology, Chinese University of Hong Kong,
Shatin, Hong Kong, China. aschan@psy.cuhk.edu.hk
The present study examined quantitative
electroencephalographic (QEEG) profile for children with autistic spectrum
disorder (ASD). Five-minute QEEG data were obtained from 90 normal controls
(NCs) and 66 children with ASD. Spectrum analyses revealed that ASD children
showed significantly less relative alpha and more relative delta than NC.
Specifically, 26% of ASD children and 2% of NCs showed 1.5 SDs of relative
alpha below the normative mean. Children with this QEEG profile had 17 times
the risk of having ASD than those without such a profile. Sensitivity and
specificity of relative alpha were 91% and 73%, respectively. Split-half
cross-validation yielded a sensitivity of 76%. (c) 2007 APA, all rights
reserved.
Publication Types:
Comparative Study Research
Support, Non-U.S. Gov't
Aviat Space Environ Med. 2007 Feb;78(2):156.
Quantitative
electroencephalography for the assessment of performance.
Cardillo C, Russo M.
Neuroscience. 2006 Dec;143(3):793-803. Epub 2006 Oct 13.
Conversion
from mild cognitive impairment to Alzheimer's disease is predicted by sources and coherence of brain
electroencephalography rhythms.
Rossini PM, Del Percio C, Pasqualetti P, Cassetta E,
Binetti G, Dal Forno G, Ferreri F, Frisoni G, Chiovenda P, Miniussi C, Parisi
L, Tombini M, Vecchio F, Babiloni C.
IRCCS "Centro S. Giovanni di
Dio-F.B.F.," Brescia, Italy. paolomaria.rossini@afar.it
Objective. Can quantitative electroencephalography (EEG)
predict the conversion from mild cognitive impairment (MCI) to Alzheimer's
disease (AD)? Methods. Sixty-nine subjects fulfilling criteria for MCI were
enrolled; cortical connectivity (spectral coherence) and (low resolution brain
electromagnetic tomography) sources of EEG rhythms (delta=2-4 Hz; theta=4-8 Hz;
alpha 1=8-10.5 Hz; alpha 2=10.5-13 Hz: beta 1=13-20 Hz; beta 2=20-30 Hz; and
gamma=30-40) were evaluated at baseline (time of MCI diagnosis) and follow up
(about 14 months later). At follow-up, 45 subjects were still MCI (MCI Stable)
and 24 subjects were converted to AD (MCI Converted). Results. At baseline,
fronto-parietal midline coherence as well as delta (temporal), theta (parietal,
occipital and temporal), and alpha 1 (central, parietal, occipital, temporal,
limbic) sources were stronger in MCI Converted than stable subjects (P<0.05).
Cox regression modeling showed low midline coherence and weak temporal source
associated with 10% annual rate AD conversion, while this rate increased up to
40% and 60% when strong temporal delta source and high midline gamma coherence
were observed respectively. Interpretation. Low-cost and diffuse computerized
EEG techniques are able to statistically predict MCI to AD conversion.
J Head Trauma Rehabil. 2006 Sep-Oct;21(5):388-97.
Multimodal
neuroimaging approaches to disorders of consciousness.
Schiff ND.
Department of Neurology and Neuroscience, Weill Medical
College of Cornell University, New York, NY 10021, USA. nds2001@med.cornell.edu
Advances in neuroimaging techniques hold significant
promise for improving understanding of disorders of consciousness arising from
severe brain injuries. We review neuroimaging studies of the vegetative state
(VS) and minimally conscious state (MCS), and findings in an unusual case of
late emergence from MCS. Multimodal neuroimaging studies using positron
emission tomography techniques, functional magnetic resonance imaging, and
quantitative electroencephalography and magnetoencephalography quantify
variations of residual cerebral activity across these patient populations. The
results suggest models to distinguish the pathophysiologic basis of VS and MCS.
Less clear are potential brain mechanisms underlying late recovery of
communication in rare MCS patients.
Diffusion tensor magnetic resonance imaging studies and recent
experimental findings suggest that structural remodeling of the brain following
severe injury may play a role in late
functional recoveries. More generally, relatively long time courses of recovery
following severe brain injury emphasize the need to develop markers for
identifying patients who may harbor potential for further meaningful recovery.
Introduction of neuroimaging into the clinical evaluation process will require
developing frameworks for longitudinal assessments of cerebral function.
Although limited in number, available studies already provide important insights into underlying brain
mechanisms that may help guide development of such assessment strategies.
Ann N Y Acad Sci. 2006 Jul;1071:438-41.
Ecological
study of sleep disruption in PTSD: a pilot study.
Germain A, Hall M, Katherine Shear M, Nofzinger EA, Buysse
DJ.
Department of Psychiatry, University of Pittsburgh School
of Medicine, 3811 O'Hara Street, Room E-1124, Pittsburgh, PA 15213, USA. germaina@upmc.edu
Laboratory-based sleep studies have yielded inconsistent
results regarding the presence and nature of objective sleep anomalies in
posttraumatic stress disorder (PTSD). This pilot study aimed at assessing sleep
in adult crime victims with PTSD by using in-home polysomnography. Compared to
healthy archival subjects, PTSD subjects showed longer sleep latency, reduced
total sleep time, and increased duration of nocturnal awakening. Quantitative
electroencephalography (EEG) measures of delta and beta activity also differed
in PTSD and healthy subjects. These preliminary findings suggest that ambulatory
methods can capture objective signs of
sleep disruption, and corroborate subjective complaints of disrupted sleep in
PTSD.
J Cardiothorac Vasc Anesth. 2006 Aug;20(4):520-5. Epub 2006
Apr 4.
Anesthetic
technique (sufentanil versus ketamine plus midazolam) and quantitative
electroencephalographic changes after cardiac surgery.
Smith FJ, Bartel PR, Hugo JM, Becker PJ.
Department of Anaesthesiology, Pretoria Academic Hospital,
School of Medicine, University of Pretoria, Pretoria, South Africa. fjsmith@medic.up.ac.za
OBJECTIVES: Cardiac surgery involving cardiopulmonary
bypass is associated with neurologic deterioration. Several interventions,
including anesthetic techniques, have been designed to limit ischemic brain
damage and have been evaluated in animals. Markers of neurologic injury may
facilitate the assessment of these interventions in humans. DESIGN: A blinded
randomized prospective study comparing 2 anesthetic techniques (one
sufentanil-based, the other ketamine and midazolam-based) in patients
undergoing cardiac surgery. Quantitative electroencephalography was used to
detect postoperative neurologic injury. SETTING: Major teaching hospital.
PARTICIPANTS: Forty-two patients aged 18 to 70
years undergoing cardiac surgery. INTERVENTIONS: Patients were
anesthetized with either a
sufentanil-based or a ketamine and midazolam-based technique for cardiac
surgery with cardiopulmonary bypass. Quantitative electroencephalography was
performed preoperatively as well as 5 to 6 days postoperatively. MEASUREMENTS
AND MAIN RESULTS: Quantitative electroencephalography outcome did not differ (p
> 0.05) between the 2 groups. It showed significant deterioration between
preoperative and postoperative assessments with a decrease in faster and an
increase in slower frequencies. In addition, the alpha attenuation index
decreased. This may reflect a decrease in alertness. Both the intergroup
comparisons and the assessment of individual changes failed to reveal
significant differences between the anesthetic techniques. The adjuvant use of
isoflurane correlated with less deterioration of quantitative
electroencephalographic variables. CONCLUSIONS: The use of either
sufentanil-based or ketamine and midazolam-based anesthetic techniques for
cardiac surgery with cardiopulmonary bypass had no effects on a marker of
postoperative neurologic injury (ie, quantitative electroencephalography).
Sud Med Ekspert. 2006 Mar-Apr;49(2):8-12.
[Forensic
medical differential diagnosis of craniocerebral trauma in children]
[Article in Russian]
Timchenko GP, Chukhlovina ML, Binat GN.
It is emphasized that history, complaints, a comprehensive
neurological examination, craniography are not often sufficient for
differentiation between brain concussion and mild brain contusion in children
because of specific characteristics of craniocerebral trauma (CCT) in such
patients. To make an adequate forensic medical diagnosis of CCT in children, it
is necessary to take into consideration anatomophysiological peculiarities of a
child, biomechanical conditions of the brain injury, to apply modern methods of
neurovisualization (ultrasonography, computed and MR imaging), to follow up
brain function with quantitative electroencephalography. Improvement of
differential forensic-medical assessment of CCT severity in childhood should be
made according to the principles of evidence-based medicine.
Artif Organs. 2006 Jun;30(6):447-51.
Quantitative
electroencephalography values of neonates during and after venoarterial
extracorporeal membrane oxygenation and permanent ligation of right common carotid artery.
Trittenwein G, Plenk S, Mach E, Mostafa G, Boigner H, Burda
G, Hermon M, Golej J, Pollak A.
Pediatric Intensive Care Unit, University Children's
Hospital, Vienna, Austria. gerhard.trittenwein@meduniwien.ac.at
Venoarterial extracorporeal membrane oxygenation (ECMO) in
neonates commonly needs neck vessel cannulation leading to ligation of right
common carotid artery (RCCA) in some
cases. Quantitative electroencephalography (EEG) measurements provide
reproducible data of cerebral function. The aim of this case-control study was
to test whether ligation of the RCCA results in EEG changes after ECMO weaning. Ten mechanically ventilated neonates
not treated with ECMO were eligible as control patients. Seven ECMO patients
receiving similar sedoanalgesia were investigated during and after ECMO and
RCCA ligation. Dominant frequency, absolute alpha, theta, delta, and total powers
of right and left frontocentral and temporooccipital derivations were
calculated. Dominant frequency did not differ among groups. Power was found to
be significantly decreased in all frequency bands during ECMO. After weaning
from ECMO, EEG differences between the ECMO and control groups disappeared in
spite of permanent RCCA ligation. It is concluded that ligation of the RCCA per
se does not result in quantitative EEG changes.
Neurol Sci. 2006 May;27 Suppl 2:S77-81.
Neurophysiological
features of the migrainous brain.
Schoenen J.
Department of Neurology-Headache Research Unit and Research
Center for Cellular and Molecular Neurobiology, University of Liège, Liège,
Belgium. jschoenen@ulg.ac.be
Migraine is a disorder in which central nervous system
(CNS) dysfunction might play a pivotal role. As there are no consistent
structural disturbances, clinical neurophysiology methods seem particularly
suited to study its pathophysiology. This chapter will focus on a review of
neurophysiological studies that have provided an insight into migraine
pathogenesis. The results are in part contradictory, which may be due to the
methodology, patient selection or timing of study. Nonetheless, quantitative
electroencephalography and magnetoencephalography recordings during migraine
attacks provide strong, though indirect,
evidence favouring the occurrence of spreading cortical depression during
attacks of migraine with, and possibly without, aura. Evoked cortical potential
and nociceptive blink reflex studies demonstrate that lack of habituation
during repetitive stimulation is a reproducible CNS dysfunction interictally in
both migraine with and without aura. Transcranial magnetic stimulations show
excitability changes of the visual cortex. The interictal migrainous CNS
dysfunction is likely to play a role in migraine pathogenesis, has a familial
character and undergoes periodic modulations with quasi-normalisation just before, during an attack and after
treatment with certain prophylactic agents. In addition, neurophysiological
methods have revealed subclinical abnormalities of cerebellar function and
neuromuscular transmission, which may improve phenotyping of migraineurs for
genetic and therapeutic studies.
Brain Cogn. 2006 Aug;61(3):286-97. Epub 2006 Apr 4.
Magnitude of
cerebral asymmetry at rest: covariation with baseline cardiovascular activity.
Foster PS, Harrison DW.
University of Florida, Gainesville, 32608, USA. paul.foster@neurology.ufl.edu
The cerebral regulation of cardiovascular functioning
varies along both a lateral and a longitudinal axis. The parasympathetic and
sympathetic nervous systems are
lateralized to the left and right cerebral hemispheres, respectively.
Further, the frontal lobes are known to be inhibitory in nature, whereas the
temporal lobes are excitatory. However, no systematic investigation has been
conducted to determine the nature and
strength of the relationship between the left and right frontal and temporal lobes in regulating
cardiovascular activity. The present investigation sought to examine these
relationships by testing the hypothesis that negative correlations would be
found between baseline heart rate and blood pressure and asymmetry of alpha
magnitude across the frontal lobes. Further, positive correlations were
hypothesized to exist across the temporal lobes. A total of 20 women were asked
to relax with their eyes closed while heart rate and blood pressure as well as
quantitative electroencephalography data were obtained. The results indicated
that, as hypothesized, significant negative correlations existed across the
frontal lobes and significant positive correlations existed across the temporal
lobes. The results provide further support for a division of responsibility between the left and right
frontal and temporal lobes in the regulation of heart rate and blood pressure.
Int J Psychophysiol. 2006 Oct;62(1):87-92. Epub 2006 Mar
22.
Symptom-specific
EEG power correlations in patients with obsessive-compulsive disorder.
Pogarell O, Juckel G, Mavrogiorgou P, Mulert C, Folkerts M,
Hauke W, Zaudig M, Möller HJ, Hegerl U.
Department of Psychiatry, Division of Clinical
Neurophysiology, Ludwig-Maximilians-University of Munich, Germany. oliver.pogarell@med.uni-muenchen.de
Neurophysiological studies in patients with
obsessive-compulsive disorder (OCD) consistently revealed frontal alterations
of cortical activity but otherwise showed inhomogeneous results, conceivably
due to variable subgroups with diverse
pathomechanisms involved. The aim of this study was to investigate
quantitative electroencephalography (EEG) in patients with OCD as compared to healthy
controls and to correlate neurophysiological data with clinical variables. EEGs
were digitally recorded from 18 unmedicated patients (8 male, mean age
32.4+/-11.8 years, Yale-Brown Obsessive-Compulsive Scale (Y-BOCS) 15.3+/-7.9)
and 18 matched healthy controls, and
analysed quantitatively. The mean frequency of EEG background activity and
absolute power in delta, theta, alpha and beta frequency bands were calculated. Mean frequency of
background activity was significantly lower in patients as compared to controls
(-1.44/s, p<0.01), predominantly for the frontal electrode positions. Power
spectra revealed increased delta- and decreased alpha-/beta-power in the group
of patients (p<0.05, patients vs. controls). Correlation analyses showed
significant positive correlations of EEG-power with the Y-BOCS sub-scores
"obsessions", and negative correlations with the sub-scores
"compulsions" (Spearman's correlations, r(s)=+0.48 to +0.70, and
-0.47 to -0.6, respectively, p<0.05). The data provide evidence of a dysfunction of frontal cortical activity in patients with
OCD. The opposite correlations of neurophysiological data and clinical
features, i.e. obsessions and compulsions, are suggestive of pathophysiological
differences based on the presence of the respective cardinal symptoms of OCD.
Appl Psychophysiol Biofeedback. 2006 Dec;31(4):331-8. Epub
2006 Nov 3.
Tongue piercing by a Yogi: QEEG observations.
Peper E, Wilson VE, Gunkelman J, Kawakami M, Sata M, Barton
W, Johnston J.
Institute for Holistic Healing Studies, San Francisco State
University, 1600 Holloway Avenue, San Francisco, 94132 CA, USA. epeper@sfsu.edu
This study reports on the QEEG observations recorded from a
yogi during tongue piercing in which he demonstrated voluntary pain control.
The QEEG was recorded with a Lexicor 1620 from 19 sites with appropriate
controls for impedance and artifacts. A neurologist read the data for
abnormalities and the QEEG was analyzed by mapping, single and multiple hertz
bins, coherence, and statistical comparisons with a normative database. The
session included a meditation baseline and tongue piercing. During the
meditative baseline period the yogi's QEEG maps suggesting that he was able to
lower his brain activity to a resting state. This state showed a predominance
of slow wave potentials (delta) during piercing and suggested that the yogi
induced a state that may be similar to those found when individuals are under
analgesia. Further research should be conducted with a group of individuals who
demonstrate exceptional self-regulation to determine the underlying mechanisms,
and whether the skills can be used to teach others how to manage pain.
Int J Neurosci. 2006 Nov;116(11):1359-73.
Spectral analysis of EEG in normal and sulfite oxidase
deficient rats under sulfite administration.
Ozkaya YG, et al
Akdeniz University, School of Physical Education and
Sports, Arapsuyu, Antalya, Turkey. gulozk@yahoo.com
This article investigated the possible neurotoxic effect of
sulfite in normal and sulfite oxidase (SOX) deficient rats by evaluating EEG
spectral analysis. Rats were divided into four groups: control (C), sulfite
treated (25 mg/kg) (ST), SOX deficient (SD), and sulfite treated SOX deficient
(STSD) groups. The qEEG spectral analyses of two spectral parameters including
power and relative power were performed. The mean power of SD group was found
to be increased compared to the all other groups and returned to control levels
after sulfite administration. The power of the four frequency bands (delta,
theta, alpha, beta) of the SD group corresponds to the mean power. EEG relative
power increased in the delta band with concomitant decreases in power measured
in the alpha frequency range. It was concluded that exogenous administration of
sulfite affected the brain electrical activity in SOX deficiency, and improved
neuroprotection.
Publication Types:
Research Support, Non-U.S. Gov't
Neurosci Lett. 2006 Oct 23;407(2):166-70. Epub 2006 Sep 7.
Neuromodulatory effect of bromazepam on motor learning: an
electroencephalographic approach.
Cunha M, Machado D, Bastos VH,
Ferreira C, Cagy M, Basile L, Piedade R, Ribeiro P.
Brain Mapping and Sensory Motor Integration, Institute of
Psychiatry of the Federal University of Rio de Janeiro (IPUB/UFRJ), Brazil.
marlo.marques@bol.com.br
To investigate the effects of bromazepam on motor
performance and electroencephalographic activity (qEEG) in healthy subjects,
during the process of learning a typewriting task, with a focused attention
demand. A randomized double-blind model was used to allocate subjects in one of
the following conditions: placebo (n=13), bromazepam 3 mg (n=13) or bromazepam
6 mg (n=13). Forty minutes after treatment administration, subjects were
submitted to the motor task. EEG activity was recorded simultaneously. The analyzed
variables were: number of errors and execution time, which were extracted from
each block of the typewriting task, and mean relative power values in the beta
band (13-35 Hz), extracted from the qEEG. A significantly lower number of
typing errors was observed in both bromazepam conditions (Br 3 mg and Br 6 mg)
when compared to the placebo. There was no difference between the two
bromazepam conditions. For the execution time variable, a better performance
was observed in the Br 3 mg condition, but with no statistical significance.
The highest degree of cortical activation during the task was observed in Br 3
mg and Br 6 mg when compared to placebo. The medication's anxiolytic effect
intensifies the attentional focus over predictable events occurring in reduced
perceptual fields. The qEEG's accentuated response in pre-motor and primary
motor areas suggests a greater effort directed to the most relevant aspects of
the task. In short, the doses employed (3 and 6 mg) seem to enhance the
learning of motor tasks that involve focused attention, such as typewriting.
Publication Types:
Randomized Controlled Trial
Research Support, Non-U.S. Gov't
J Clin Neurophysiol. 2006 Oct;23(5):440-55.
A meta-analysis of quantitative EEG power associated with
attention-deficit hyperactivity disorder.
Snyder SM, Hall JR.
Department of Psychology, University of North Texas Health
Science Center at Fort Worth, Fort Worth, Texas, USA.
A meta-analysis was performed on quantitative EEG (QEEG)
studies that evaluated attention-deficit hyperactivity disorder (ADHD) using
the criteria of the DSM-IV (Diagnostic and Statistical Manual of Mental
Disorders, 4th edition). The nine eligible studies (N = 1498) observed QEEG
traits of a theta power increase and a beta power decrease, summarized in the
theta/beta ratio with a pooled effect size of 3.08 (95% confidence interval,
2.90, 3.26) for ADHD versus controls (normal children, adolescents, and
adults). By statistical extrapolation, an effect size of 3.08 predicts a
sensitivity and specificity of 94%, which is similar to previous results 86% to
90% sensitivity and 94% to 98% specificity. It is important to note that the controlled
group studies were often with retrospectively set limits, and that in practice
the sensitivity and specificity results would likely be more modest. The
literature search also uncovered 32 pre-DSM-IV studies of ADHD and EEG power,
and 29 of the 32 studies demonstrated results consistent with the
meta-analysis. The meta-analytic results are also supported by the observation
that the theta/beta ratio trait follows age-related changes in ADHD symptom
presentation (Pearson correlation coefficient, 0.996, P = 0.004). In
conclusion, this meta-analysis supports that a theta/beta ratio increase is a
commonly observed trait in ADHD relative to normal controls. Because it is
known that the theta/beta ratio trait may arise with other conditions, a
prospective study covering differential diagnosis would be required to
determine generalizability to clinical applications. Standardization of the
QEEG technique is also needed, specifically with control of mental state,
drowsiness, and medication.
Publication Types: Comparative Study Meta-Analysis Research Support, Non-U.S. Gov't
J Neuropsychiatry Clin Neurosci. 2006 Fall;18(4):460-500.
The value of quantitative electroencephalography in
clinical psychiatry: a report by the Committee on Research of the American
Neuropsychiatric Association.
Coburn KL, Lauterbach EC, Boutros NN, Black KJ, Arciniegas
DB, Coffey CE.
Department of Psychiatry and Behavioral Sciences, Mercer
University School of Medicine, Macon, Georgia 31201, USA. Coburn_kl@Mercer.edu
The authors evaluate quantitative electroencephalography
(qEEG) as a laboratory test in clinical psychiatry and describe specific
techniques, including visual analysis, spectral analysis, univariate
comparisons to normative healthy databases, multivariate comparisons to
normative healthy and clinical databases, and advanced techniques that hold
clinical promise. Controversial aspects of each technique are discussed, as are
broader areas of criticism, such as commercial interests and standards of
evidence. The published literature is selectively reviewed, and qEEG's
applicability is assessed for disorders of childhood (learning and attentional
disorders), dementia, mood disorders, anxiety, panic, obsessive-compulsive
disorder, and schizophrenia. Emphasis is placed primarily on studies that use
qEEG to aid in clinical diagnosis, and secondarily on studies that use qEEG to
predict medication response or clinical course. Methodological problems are
highlighted, the availability of large databases is discussed, and specific
recommendations are made for further research and development. As a clinical
laboratory test, qEEG's cautious use is recommended in attentional and learning
disabilities of childhood, and in mood and dementing disorders of adulthood.
Publication Types:
Evaluation Studies Review
Brain Res. 2006 Sep 21;1111(1):166-75. Epub 2006 Aug 17.
Quantitative EEG and neurological recovery with therapeutic
hypothermia after asphyxial cardiac arrest in rats.
Jia X, Koenig MA, Shin HC, Zhen G, Yamashita S, Thakor NV,
Geocadin RG.
Department of Biomedical Engineering, Johns Hopkins
University School of Medicine, Baltimore, MD 21205, USA. xjia1@jhmi.edu
We test the hypothesis that quantitative
electroencephalogram (qEEG) can be used to objectively assess functional
electrophysiological recovery of brain after hypothermia in an asphyxial
cardiac arrest rodent model. Twenty-eight rats were randomly subjected to 7-min
(n = 14) and 9-min (n = 14) asphyxia times. One half of each group (n = 7) was
randomly subjected to hypothermia (T = 33 degrees C for 12 h) and the other
half (n = 7) to normothermia (T = 37 degrees C). Continuous physiologic
monitoring of blood pressure, EEG, and core body temperature monitoring and
intermittent arterial blood gas (ABG) analysis was undertaken. Neurological
recovery after resuscitation was monitored using serial Neurological Deficit Score
(NDS) calculation and qEEG analysis. Information Quantity (IQ), a previously
validated measure of relative EEG entropy, was employed to monitor electrical
recovery. The experiment demonstrated greater recovery of IQ in rats treated
with hypothermia compared to normothermic controls in both injury groups (P
< 0.05). The 72-h NDS of the hypothermia group was also significantly
improved compared to the normothermia group (P < 0.05). IQ values measured
at 4 h had a strong correlation with the primary neurological outcome measure,
72-h NDS score (Pearson correlation 0.746, 2-tailed significance <0.001). IQ
is sensitive to the acceleration of neurological recovery as measured NDS after
asphyxial cardiac arrest known to occur with induced hypothermia. These results
demonstrate the potential utility of qEEG-IQ to track the response to
neuroprotective hypothermia during the early phase of recovery from cardiac
arrest.
Publication Types:
Research Support, N.I.H., Extramural
Epilepsy Res. 2006 Aug;70(2-3):190-9. Epub 2006 Jun 9.
Quantitative EEG effects of carbamazepine, oxcarbazepine,
valproate, lamotrigine, and possible clinical relevance of the findings.
Clemens B, et al.
Kenoczy Gyula Memorial Hospital, Department of Neurology,
Epilepsy Center, Bartok Boca 3, 4031 Debrecen, Hungary. clemensdr@freemail.hu
Quantitative EEG (QEEG) effects of therapeutic doses of
carbamazepine (CBZ), oxcarbazepine (OXC), valproate (VA) and lamotrigine (LA)
monotherapy were investigated in patients with beginning epilepsy. Baseline
waking EEG (EEG1) was recorded in the untreated state, the second EEG (EEG2)
was done after 8 weeks of reaching the therapeutic dose. Left occipital data
were used for analysis. QEEG target parameters were absolute band-power (delta:
AD, theta: AT, alpha: AA, beta: AB), and alpha mean frequency (AMF). Group
effects (untreated versus treated condition in the CBZ, VA, OXC, LA groups)
were computed for each target parameter. One group with benign rolandic
epilepsy remained untreated for clinical reasons and served to estimate the
QEEG test-retest differences. In addition, the individual QEEG response to each
drug was calculated as (EEG2-EEG1). Results: statistically significant
(p<0.05) group differences indicated the QEEG domain systematically affected
by the drugs. CBZ caused AT increase and AMF decrease. OXC caused AMF decrease.
VA and LA did not decrease AMF (LA even increased it), but reduced broad-band
power. Individual power and AMF changes showed considerable variability in each
group. >0.5 Hz AMF decrease (that was reported to predict cognitive
impairment in prior studies) occurred in 10/41 patients in the CBZ group but
never in the OXC, VA, LA groups. The results may be utilized in planning
further studies addressing the relationship between antiepileptic drugs and
their CNS effects. In addition, the relationship of AED-related cognitive
impairment and AMF changes was discussed.
Publication Types:
Clinical Trial Comparative
Study Multicenter Study
Clin EEG Neurosci. 2006 Jul;37(3):193-7.
Benign childhood epilepsy with centro-temporal spikes:
quantitative EEG and the Wechsler intelligence scale for children (WISC-III).
Tedrus GM, Fonseca LC, Tonelotto JM, Costa RM, Chiodi MG.
Department of Neurology, PontifÃcia Universidade Católica
de Campinas, SP, Brazil. gmtedrus@uol.com.br
Benign childhood epilepsy with centro-temporal spikes
(BECTS) is a form of focal idiopathic epilepsy, with seizure remission by the
age of 18. Recent studies have suggested that some children with BECTS can
suffer from deficits of memory, attention and learning ability and in
auditory-verbal and performance sub-tests. On the other hand, alterations in
the baseline brain electrical activity determined by using the quantitative
electroencephalogram (qEEG) have been described. The objective of this study
was to evaluate the absolute and relative powers in the delta, theta, alpha and
beta bands of the qEEG in children with BECTS, and their relation to IQ
measurements (WISC-III). Twenty-six 8 to 11-year-old children with BECTS were
studied, paired with a control group of healthy children according to age and gender.
It was shown that the absolute delta and theta powers were statistically
greater in the children with BECTS than in the control group, at almost all the
electrodes. In the children with BECTS, a negative correlation (Pearson's
correlation test) was observed at various electrodes between the absolute delta
and theta powers and the performance IQ. These data indicate a possible
relationship between maturational disturbance in the brain electrical activity
development and the tendency for inferior cognitive performance in children
with BECTS.
Publication Types:
Controlled Clinical Trial
Neurophysiol Clin. 2006 Jul-Aug;36(4):195-205. Epub 2006
Sep 28.
Continuous EEG-SEP monitoring of severely brain injured
patients in NICU: methods and feasibility.
Fossi S, Amantini A, Grippo A, Innocenti P, Amadori A,
Bucciardini L, Cossu C, Scarpelli S, Bruni I, Sgalla R, Pinto F.
UO Neurophysiopatology, Department of Neurological and Psychiatric
Sciences, University of Florence, Azienda Ospedaliero-Universitaria Careggi,
V.le Morgagni 85, 50134 Firenze, Italy.
AIMS: To evaluate the feasibility of a continuous
neurophysiologic monitoring (electroencephalography (EEG)-somatosensory evoked potentials
(SEPs)) in the neuro-intensive care unit (NICU), taking into account both the
technical and medical aspects that are specific of this environment. METHODS:
We used an extension of the recording software that is routinely used in our
unit of clinical neurophysiology. It performs cycles of alternate EEG and SEP
recordings. Raw traces and trends are simultaneously displayed. Patient head
and stimulator box are placed behind the bed and linked to the ICU monitoring
terminal through optic fibers. The NICU staff has been trained to note directly
clinical events, main artefacts and therapeutic changes. The hospital local
area network (LAN) enables remote monitoring survey. RESULTS: Continuous EEG
(CEEG)-SEP monitoring was performed in 44 patients. Problems of needle
detachment were seldomly encountered, thanks to the use of a sterile plastic
dressing, which covers needles. We never had infection or skin lesions due to
needles or the electrical stimulator. The frequent administration of sedative
at high doses prevented us from having a clinically valuable EEG in several
cases but SEPs were always monitorable, independently of the level of EEG
suppression. The diagnosis of seizures and non-epileptic status was based on
raw EEG, while quantitative EEG (QEEG) was used to quantify ictal activity as a
guide to treatment. CONCLUSIONS: EEG and EP waveforms collected in NICU were of
comparable quality to routine clinical measurements and contained the same
clinical information. A continuous SEP monitoring in a comatose and sedated
patient in NICU is not technically more difficult and potentially less useful
than in operating room. This monitoring appears to be feasible provided the
observance of some requirement regarding setting, electrodes, montages,
personnel integration, consulting and software.
Behav Brain Funct. 2006 Jun 292:23.
Correlation of symptom clusters of schizophrenia with
absolute powers of main frequency bands in quantitative EEG.
Gross A, Joutsiniemi SL, Rimon R, Appelberg B.
Helsinki University Central Hospital, Department of
Psychiatry, Välskärinkatu 12 A, 00260 Helsinki, Finland/Tammiharju Hospital,
10600 Tammisaari, Finland. andres.gross@luukku.com.
ABSTRACT: BACKGROUND: Research of QEEG activity power
spectra has shown intriguing results in patients with schizophrenia. Different
symptom clusters have been correlated to QEEG frequency bands. The findings
have been to some extent inconsistent. Replication of the findings of previous
research is thus an important task. In the current study we investigated the
correlations between the absolute powers of delta, theta, alpha, and beta
frequency bands over the fronto-central scalp area (FC) with the PANSS
subscales and the Liddle's factors in 16 patients with schizophrenia.The
authors hypothesised a priori the correlations reported by Harris et al (1999)
of PANSS negative subscale with delta power, Liddle's psychomotor poverty with
delta and beta powers, disorganisation with delta power and reality distortion
with alpha power on the midline FC. METHODS: The sample consisted of 16
patients with chronic schizophrenia considered as having insufficient clinical
response to conventional antipsychotic treatment and evidencing a relapse. The
correlations between quantitative electroencephalography (QEEG) absolute powers
of delta (1.5-3.0 Hz), theta (3.0-7.5 Hz), alpha (7.5-12.5 Hz), and beta
(12.5-20.0 Hz) frequency bands over the fronto-central scalp area (FC) with
PANSS subscales and Liddle's factors (reality distortion, disorganisation,
psychomotor poverty) were investigated. RESULTS: Significant positive
correlations were found between the beta and psychomotor poverty (p < 0.05).
Trends towards positive correlations (p < 0.1) were observed between delta
and PANSS negative subscale and psychomotor poverty. Alpha did not correlate
with reality distortion and delta did not correlate with disorganisation.Post
hoc analysis revealed correlations of the same magnitude between beta and psychopathology
generally over FC. CONCLUSION: The a priori hypothesis was partly supported by
the correlation of the beta and psychomotor poverty. Liddle's factors showed
correlations of the same magnitude with PANSS subscales. Supplementary analysis
showed beta frequency correlating non-specifically over FC with a wide range of
psychiatric symptomatology in patients with schizophrenia having a relapse.
Arq Neuropsiquiatr. 2006 Jun;64(2B):478-84.
[Procedural learning and anxiolytic effects:
electroencephalographic, motor and attentional measures]
[Article in Portuguese]
Portella CE, Silva JG, Bastos VH,
Machado D, Cunha M, Cagy M, Basile L, Piedade R, Ribeiro P.
Laboratorio de Mapeamento Cerebral e
Integracao Sensorio-motor, IPUB, Universidade Federal do Rio de Janeiro, Rua
Filgueiras Lima 68/104, 20950-050 Rio de Janeiro RJ, Brazil.
The objective of the present study was to evaluate
attentional, motor and electroencephalographic (EEG) parameters during a
procedural task when subjects have ingested 6 mg of bromazepam. The sample
consisted of 26 healthy subjects, male or female, between 19 and 36 years of
age. The control (placebo) and experimental (bromazepam 6 mg) groups were
submitted to a typewriting task in a randomized, double-blind design. The
findings did not show significant differences in attentional and motor measures
between groups. Coherence measures (qEEG) were evaluated between scalp regions,
in theta, alpha and beta bands. A first analysis revealed a main effect for
condition (Anova 2-way--condition versus blocks). A second Anova 2-way
(condition versus scalp regions) showed a main effect for both factors. The
coherence measure was not a sensitive tool at demonstrating differences between
cortical areas as a function of procedural learning.
Publication Types:
English Abstract Randomized
Controlled Trial
Psychiatry Res. 2006 Apr 30;146(3):271-82. Epub 2006 Apr 5.
Correlation of PET and qEEG in normal subjects.
Alper KR, John ER, Brodie J, Gunther W, Daruwala R, Prichep
LS.
Brain Research Laboratories, Department of Psychiatry, New
York, University Medical Center, 550 First Avenue, New York, NY 10016, USA.
kra1@nyu.edu
Positron emission tomography (PET) and quantitative
electroencephalography (qEEG) were obtained in 15 normal male subjects with
eyes closed at rest. Correlations between qEEG variables and regional
metabolism were examined as an approach to investigating the metabolic and
neuroanatomical basis of the generation of the EEG. Analogous to the
neurometric approach to qEEG, a normative 2-fluoro-deoxyglucose voxel data base
was developed for the PET image. The PET image was transformed to an idealized
cylindrical set of coordinates to allow registration with the Talairach
stereotactic atlas. PET regions of interest for the thalamus, the left and
right temporal lobes, the medial frontal cortex and the dorsolateral prefrontal
cortex were defined using Talairach coordinates and correlated to the QEEG.
Salient findings included a negative correlation of thalamic metabolism to
alpha power and a positive correlation of medial frontal cortical metabolism to
delta EEG power. The significance of these findings is discussed with reference
to the existing literature on the physiology of the generation of the EEG.
Publication Types:
Validation Studies
Clin EEG Neurosci. 2006 Apr;37(2):135-43.
The relevance of QEEG to the evaluation of behavioral
disorders and pharmacological interventions.
John ER, Prichep LS.
Brain Research Laboratories, Department of Psychiatry, New
York University School of Medicine, NY, NY 10016, USA. roy.john@med.nyu.edu
It has become apparent that the electrical signals recorded
from the scalp of healthy individuals under standardized conditions are
predictable, and that patients with a wide variety of brain disorders display
activity with unusual features. It also early became apparent that centrally
active medications produced striking changes in this activity. The application
of computerized signal analysis to EEG recordings collected using standardized
procedures has made it possible to obtain quantitative descriptions of brain
electrical activity (QEEG) in normal individuals and patients with disorders of
brain function or structure, as well as quantitative description of the ways in
which centrally active medications alter this activity (Pharmaco-EEG or
"PEEG"). With the emergence of three-dimensional EEG source
localization techniques, it has recently become possible to visualize the
mathematically most probable generators of QEEG abnormalities within the brain
as well as the neuroanatomical regions where abnormal activity is most altered
by efficacious medication. As QEEG and PEEG have evolved, a vast body of facts
has been accumulated, describing changes in the EEG or event-related potentials
(ERPs). observed in a variety of brain disorders or after administration of a
variety of medications. With some notable exceptions, these studies have tended
to be phenomenological rather than analytic. There has not been a systematic
attempt to integrate these phenomena in order to build better understanding of
how the abnormal behaviors of a particular psychiatric patient might be related
to the specific pattern of the deviant electrical activity, nor just how
pharmacological reduction of that deviant activity may have resulted in more
normal behavior. This article is an endeavor to provide a more specific
theoretical framework for understanding the relationships between the
neuroanatomy and neurochemistry of the homeostatic system underlying the
regulation of the QEEG, and the mechanisms revealed by Pharmaco-EEG that aid in
correcting these illnesses.
Publication Types:
Review
Clin EEG Neurosci. 2006 Apr;37(2):81-98.
Pharmaco-EEG in psychiatry.
Mucci A, Volpe U, Merlotti E, Bucci P,
Galderisi S.
Department of Psychiatry, University of Naples SUN, Naples,
Italy. armucci@tin.it
In spite of its origins deeply rooted in the discipline,
pharmaco-EEG applications in psychiatry remain limited to its achievements in
the field of psychotropic drugs classification and, in few instances,
discovery. In the present paper two attempts to transfer pharmaco-EEG methods
to psychiatric clinical routine will be described: 1) monitoring of
psychotropic drug toxicity at the central nervous system level, and 2)
prediction of clinical response to treatment with psychotropic drugs. Both
applications have been the object of several investigations providing promising
and sometimes consistent findings which, however, had no impact on clinical
practice. For the first topic, the review is limited to antipsychotics, lithium
and recreational drugs, as for other psychotropic drugs mostly case studies are
available, while for the response prediction it will include antipsychotics,
antidepressants, anxiolytics, psychostimulants and nootropics. In spite of
several methodological limitations, pharmaco-EEG studies dealing with
monitoring of antipsychotic- and lithium-induced EEG abnormalities went close to,
but never became, a clinical routine. EEG studies of recreational drugs are
flawed by several limitations, and failed, so far, to identify reliable indices
of CNS toxicity to be used in clinical settings. Several QEEG studies on early
predictors of treatment response to first generation antipsychotics have
produced consistent findings, but had no clinical impact. For other
psychotropic drug classes few and inconsistent reports have appeared.
Pharmaco-EEG had the potential for important clinical applications, but so far
none of them entered clinical routine. The ability to upgrade theories and
methods and promote large scale studies represent the future challenge.
Publication Types:
Review
Clin EEG Neurosci. 2006 Apr;37(2):66-80.
EEG topography and tomography (LORETA) in the
classification and evaluation of the pharmacodynamics of psychotropic drugs.
Saletu B, Anderer P, Saletu-Zyhlarz GM.
Department of Psychiatry, University of Vienna, Austria.
bernd.saletu@meduniwien.ac.at
By multi-lead computer-assisted quantitative analyses of
human scalp-recorded electroencephalogram (QEEG) in combination with certain
statistical procedures (quantitative pharmaco-EEG) and mapping techniques
(pharmaco-EEG mapping or topography), it is possible to classify psychotropic
substances and objectively evaluate their bioavailability at the target organ,
the human brain. Specifically, one may determine at an early stage of drug
development whether a drug is effective on the central nervous system (CNS)
compared with placebo, what its clinical efficacy will be like, at which dosage
it acts, when it acts and the equipotent dosages of different galenic
formulations. Pharmaco-EEG maps of neuroleptics, antidepressants,
tranquilizers, hypnotics, psychostimulants and nootropics/cognition-enhancing
drugs will be described. Methodological problems, as well as the relationships
between acute and chronic drug effects, alterations in normal subjects and
patients, CNS effects and therapeutic efficacy will be discussed. Imaging of
drug effects on the regional brain electrical activity of healthy subjects by
means of EEG tomography such as low-resolution electromagnetic tomography
(LORETA) has been used for identifying brain areas predominantly involved in
psychopharmacological action. This will be shown for the representative drugs
of the four main psychopharmacological classes, such as 3 mg haloperidol for
neuroleptics, 20 mg citalopram for antidepressants, 2 mg lorazepam for
tranquilizers and 20 mg methylphenidate for psychostimulants. LORETA
demonstrates that these psychopharmacological classes affect brain structures
differently. By considering these differences between psychotropic drugs and
placebo in normal subjects, as well as between mental disorder patients and
normal controls, it may be possible to choose the optimum drug for a specific
patient according to a key-lock principle, since the drug should normalize the
deviant brain function. Thus, pharmaco-EEG topography and tomography are
valuable methods in human neuropsychopharmacology, clinical psychiatry and
neurology.
Publication Types:
Review
Clin Neurophysiol. 2006 Apr;117(4):740-51. Epub 2006 Feb
21.
Clinical correlates of quantitative EEG alterations in
alcoholic patients.
Coutin-Churchman P, Moreno R, Vergara F.
Hospital Psiquiátrico San Juan de Dios, Urb. Campo Claro. Los Curos, Edo. Mérida 5101, Venezuela. coutinpe@yahoo.com
OBJECTIVE: To evaluate the incidence and clinical
correlations of abnormal QEEG features in alcoholic patients. METHODS:
Quantitative EEG (frequency analysis, absolute and relative powers of the four
classical bands) was assessed in 191 male alcoholic patients admitted in our
facility for detoxification process. All underwent psychiatric, medical and
neurological examination prior to the EEG recording, in search for specific
clinical or paraclinical findings. The presence or absence of relevant clinical
features was codified as nominal dichotomic variables to be related to specific
QEEG features. RESULTS: Only 7 patients had normal QEEG. The most frequent
alteration (81 cases) was decreased power in slow (delta and theta) bands with
a concurrent increase in beta band, followed by decreased power only in slow
bands (33), increase only in beta band (29), decrease in both slow and alpha
bands without beta alterations (28), decrease only in alpha band (6) and
others. Alterations in slow and beta bands were uncorrelated. However, a
significant correlation was found between decreased power in slow bands and
cortical atrophy as revealed by MRI (especially in patients with early onset of
alcoholism), time elapsed from the beginning of alcoholic habits (but only in
younger or early onset subjects) and in a lesser degree arterial hypertension,
but neither with age nor any other clinical or psychiatric feature. On the
other hand, increased power in beta band correlated mainly with the use of
benzodiazepines, sensoperceptual alterations (hallucinations, illusions),
clinical seizures and family history of alcoholism. The effects of those
variables were strongly interrelated. CONCLUSIONS: Decreased power in slow
bands in alcoholic patients may be an indicator of brain atrophy or chronic
brain damage, while increase in beta band is related to medication use, family
history of alcoholism, hallucinations and seizures, suggesting a state of
cortical hyperexcitability. SIGNIFICANCE: This study show the relation of specific
QEEG alterations to certain clinical features found in alcoholics, in a further
attempt to elucidate the semiological value of those alterations in individual
patients.
Clin Neurophysiol. 2006 Apr;117(4):752-70. Epub 2006 Feb
21.
Quantitative multichannel EEG measure predicting the
optimal weaning from ventilator in ICU patients with acute respiratory failure.
Papadelis C, Maglaveras N, Kourtidou-Papadeli C, Bamidis P,
Albani M, Chatzinikolaou K, Pappas K.
Laboratory of Medical Informatics, School of Medicine,
Aristotle University of Thessaloniki, Thessaloniki, Greece.
christos@med.auth.gr
OBJECTIVE: The objective of this study was to develop a
novel quantitative multichannel EEG (qEEG) based analysis method, called Global
Field Damping Time (GFDT), in order to detect potential EEG changes of patients
admitted to the ICU with acute respiratory failure, and correlate them to the
patients' recovery outcome predicting the optimal time-point to disconnect the
patient from mechanical ventilation. METHODS: Twenty-nine adult patients with
acute respiratory failure out of 98 admitted to the Intensive Care Unit of
Saint Paul General Hospital were enrolled, and among them only 15 completed the
study. The patients were classified in 3 groups according to their outcome
after 3 months follow-up. The patients were intubated with fraction of inspired
oxygen (FiO2) of 100%. Neurological Deficit Scores (NDS) were measured 24 h
after intubation to assess patients' neurological condition. Twenty-four hours
after patient's intubation, FiO2 was decreased to 40% (weaning session),
followed by a 5 min early recovery session, a 5 min recovery 1 session and a 5
min recovery 2 session. EEG recordings were performed during this experimental
procedure. Multichannel EEG segments were processed and fitted into a
multivariate autoregressive (mAR) model, and single channel EEG segments into a
scalar autoregressive (sAR) model. The mAR and the sAR models of arbitrary
order p were decomposed into mp and p oscillators and relaxators, respectively.
Damping time of each oscillator and each relaxator, and the Global Field
Damping Time (GFDT) as a weighted damping time were estimated for both mAR and
sAR models. RESULTS: A statistically significant increase of mAR model's GFDT
during the weaning session was observed in the subjects of all groups.
Comparing the 3 patients' groups, statistically significant differences for mAR
model's GFDT were observed for the weaning and early recovery session. Linear
regression analysis between NDS and mean mAR model's GFDT showed statistical
significance during weaning session, early recovery session, and recovery 1
session. There was no statistical significance for SaO2 in the regression
analysis with NDS. The sAR model's GFDT presented worst results in comparison
with the mAR modelling GFDT in the identification of hypoxic conditions during
weaning session and in the discrimination of patients with acute respiratory
failure according to their neurological outcome. CONCLUSIONS: Global Field
Damping Time as correlated to the patients' neurological outcome appears to be
a simple, compact, and substantial novel indicator of cerebral hypoxia and a
potential predictor of the optimal time-point to disconnect the patient from
the ventilator. SIGNIFICANCE: Quantitative EEG seems to be an important tool
for ICU clinicians assisting them to decide for the patients' optimal
time-point to disconnect the patient from the ventilator.
Publication Types: Research Support, Non-U.S. Gov't
J Neuropsychiatry Clin Neurosci. 2006 Spring;18(2):208-16.
Variation in neurophysiological function and evidence of quantitative
electroencephalogram discordance: predicting cocaine-dependent treatment
attrition.
Venneman S, Leuchter A, Bartzokis G, Beckson M, Simon SL,
Schaefer M, Rawson R, Newton T, Cook IA, Uijtdehaage S, Ling W.
Medication Development Unit, Research Service, and
Psychiatry Service, West Los Angeles VA Medical Center, California, USA.
VennemanS@uhv.edu
Cocaine treatment trials suffer from a high rate of
attrition. We examined pretreatment neurophysiological factors to identify
participants at greatest risk. Twenty-five participants were divided into
concordant and discordant groups following electroencephalogram (EEG) measures
recorded prior to a double-blind, placebo-controlled treatment trial. Three
possible outcomes were examined: successful completion, dropout, and removal.
Concordant (high perfusion correlate) participants had an 85% rate of
successful completion, while discordant participants had a 15% rate of
successful completion. Twenty-five percent of dropouts and 50% of participants
removed were discordant (low perfusion correlate), while only 25% of those who
completed were discordant. Failure to complete the trial was not explained by
depression, craving, benzoylecgonine levels or quantitative
electroencephalogram (QEEG) power; thus cordance may help identify attrition
risk.
Publication Types:
Randomized Controlled Trial
Research Support, N.I.H., Extramural
Neuropsychopharmacology. 2006 Apr;31(4):872-84.
Topographic imaging of quantitative EEG in response to
smoked cocaine self-administration in humans.
Reid MS, Flammino F, Howard B, Nilsen D, Prichep LS.
Department of Psychiatry, New York University School of
Medicine, New York, NY, USA. malcolm.reid@med.va.gov
Quantitative electroencephalographic (qEEG) profiles were
studied in cocaine-dependent patients in response to an acute, single-blind,
self-administered dose of smoked cocaine base (50 mg) vs placebo. qEEG data
were averaged using neurometric analytical methods and the spectral power of
each primary bandwidth was computed and topographically imaged. Additional
measures included cocaine-induced high, craving, and related subjective
ratings, heart rate, blood pressure, and plasma cortisol and homovanillic acid
levels. In all, 13 crack cocaine-dependent subjects were tested. Cocaine
produced a rapid increase in subjective ratings of cocaine high and good drug
effect, and a more persistent increase in cocaine craving and nervousness.
Cocaine also produced a rapid rise in heart rate and a prolonged increase in
plasma cortisol. Placebo, administered in the context of cocaine cues and
dosing expectations, had no cocaine-like subjective or physiological effects.
Cocaine produced a rapid increase in absolute theta, alpha, and beta power over
the prefrontal cortex (FP1, FP2), lasting up to 25 min after dosing. The
increase in theta power was correlated with good drug effect, and the increase
in alpha power was correlated with nervousness. Cocaine also produced a similar
increase in delta coherence over the prefrontal cortex, which was positively
correlated with plasma cortisol, and negatively correlated with nervousness.
Placebo resulted in an increase in alpha power over the prefrontal cortex.
These data demonstrate the involvement of prefrontal cortex in the qEEG
response to acute cocaine. Evidence indicates slow wave qEEG, delta and theta
activity, involvement in the rewarding properties of cocaine.
Publication Types:
Clinical Trial Comparative Study Research Support, N.I.H., Extramural
Schizophr Res. 2006 Apr;83(2-3):111-9. Epub 2006 Mar 9.
Quantitative EEG and low resolution electromagnetic
tomography (LORETA) imaging of patients with persistent auditory
hallucinations.
Lee SH, Wynn JK, Green MF, Kim H, Lee KJ, Nam M, Park JK,
Chung YC.
Department of Psychiatry, Ilsanpaik Hospital, Inje
University College of Medicine, 2240 Daehwa-dong, Ilsan-gu, Goyang city,
Gyeonggi-do 411-706, Korea. lshpss@hanmail.net
Electrophysiological studies have demonstrated gamma and
beta frequency oscillations in response to auditory stimuli. The purpose of
this study was to test whether auditory hallucinations (AH) in schizophrenia
patients reflect abnormalities in gamma and beta frequency oscillations and to
investigate source generators of these abnormalities. This theory was tested
using quantitative electroencephalography (qEEG) and low-resolution
electromagnetic tomography (LORETA) source imaging. Twenty-five schizophrenia
patients with treatment refractory AH, lasting for at least 2 years, and 23
schizophrenia patients with non-AH (N-AH) in the past 2 years were recruited
for the study. Spectral analysis of the qEEG and source imaging of frequency
bands of artifact-free 30 s epochs were examined during rest. AH patients
showed significantly increased beta 1 and beta 2 frequency amplitude compared
with N-AH patients. Gamma and beta (2 and 3) frequencies were significantly
correlated in AH but not in N-AH patients. Source imaging revealed
significantly increased beta (1 and 2) activity in the left inferior parietal
lobule and the left medial frontal gyrus in AH versus N-AH patients. These
results imply that AH is reflecting increased beta frequency oscillations with
neural generators localized in speech-related areas.
Publication Types:
Comparative Study
Arq Neuropsiquiatr. 2006
Mar;64(1):112-7. Epub 2006 Apr 5.
[Neuromodulatory effects of bromazepam when individuals
were exposed to a motor learning task: quantitative electroencephalography
(qEEG)]
[Article in Portuguese]
Salles JI, Bastos VH, Cunha M, Machado
D, Cagy M, Furtado V, Basile LF, Piedade R, Ribeiro P.
Laboratorio de Mapeamento Cerebral e
Integracao Sensorio-Motora, Instituto de Psiquiatria, Universidade Federal do
Rio de Janeiro, Rio de Janeiro, RJ, Brazil.
The sedative effects of bromazepam on cognitive and
performance have been widely investigated. A number of different approaches
have assessed the influence of bromazepam when individuals are engaged to a
motor task. In this context, the present study aimed to investigate
electrophysiological changes when individuals were exposed to a typewriting
task after taking 6 mg of bromazepam. qEEG data were simultaneously recorded
during the task. In particular, relative power in delta band (0.5-3.5 Hz) was
analyzed. Time of execution and errors during the task were registered as
behavioral variables. The experimental group, bromazepam 6 mg, showed a better
motor performance and higher relative power than control individuals (placebo).
These results suggest that the use of bromazepam reduces anxiety levels as
expected and thus, produces an increment in motor performance.
Publication Types:
English Abstract
Int J Neurosci. 2006 Mar;116(3):223-46.
Dynamic spectral analysis findings in first episode and
chronic schizophrenia.
Harris A, Melkonian D, Williams L, Gordon E.
Brain Dynamics Centre, Westmead Hospital, Australia.
aharris1@mail.usyd.edu.au
The quantified analysis of the electroencephalogram (qEEG)
has enabled the extraction of additional psychophysiological information from
the raw EEG, but in turn has introduced a number of distortions. This study
compared Dynamic Spectral Analysis (DSA), a novel and mathematically stringent
technique for the evaluation of qEEG activity with conventional power spectral
analysis in subjects with both first episode and chronic schizophrenia and
matched controls. Advantages of the technique in the automated processing of
data, rejection of artefact, avoidance of artefact introduced by the mathematical
trans-formation of the data and the identification of irregular low frequency
artefactual activity "pi" are discussed in detail. Using this method,
the study has confirmed past observations of increased slow wave activity in
schizophrenia, and identified a decrease in peak frequency in the alpha band in
the subjects with chronic schizophrenia. The two clinical groups differed in
mean peak frequency in the delta band with the first episode schizophrenia
subjects having a raised mean peak frequency and the subjects with chronic
schizophrenia having a lowered mean peak frequency. The results suggest
continued change in the EEG with illness chronicity in schizophrenia. These
changes were most evident in the frequency domain emphasizing the importance of
routine measurement of mean band frequencies in qEEG studies.
Publication Types:
Comparative Study
Neurobiol Aging. 2006 Mar;27(3):471-81. Epub 2005 Oct 6.
Prediction of longitudinal cognitive decline in normal
elderly with subjective complaints using electrophysiological imaging.
Prichep LS, John ER, Ferris SH, Rausch L, Fang Z, Cancro R,
Torossian C, Reisberg B.
Brain Research Laboratories, Department of Psychiatry, New
York University School of Medicine, New York, NY 10016, USA.
leslie.prichep@med.nyu.edu
An extensive literature reports changes in quantitative
electroencephalogram (QEEG) with aging and a relationship between magnitude of
changes and degree of clinical deterioration in progressive dementia.
Longitudinal studies have demonstrated QEEG differences between mild
cognitively impaired (MCI) elderly who go on to decline and those who do not.
This study focuses on normal elderly with subjective cognitive complaints to
assess the utility of QEEG in predicting future decline within 7 years.
Forty-four normal elderly received extensive clinical, neurocognitive and QEEG
examinations at baseline. All study subjects (N = 44) had only subjective
complaints but no objective evidence of cognitive deficit (evaluated using the
Global Deterioration Scale [GDS] score, GDS stage = 2) at baseline and were
re-evaluated during 7-9 year follow-up. Baseline QEEGs of Decliners differed
significantly (p < 0.0001, by MANOVA) from Non-Decliners, characterized by
increases in theta power, slowing of mean frequency, and changes in covariance
among regions, especially on the right hemisphere. Using logistic regression,
an R2 of 0.93 (p < 0.001) was obtained between baseline QEEG features and
probability of future decline, with an overall predictive accuracy of 90%.
These data indicate high sensitivity and specificity for baseline QEEG as a
differential predictor of future cognitive state in normal, subjectively
impaired elderly.
Publication Types:
Controlled Clinical Trial
Research Support, N.I.H., Extramural
Research Support, Non-U.S. Gov't
J Nerv Ment Dis. 2006 Feb;194(2):83-90.
P300 is attenuated during dissociative episodes.
Kirino E.
Juntendo University School of Medicine Department of
Psychiatry, Juntendo Institute of Mental Health, Koshigaya-shi Saitama, Japan.
The present study examined the pathophysiology of
dissociative phenomena using the P300 component of event-related potentials,
quantitative electroencephalography (QEEG), and morphology measures of computed
tomography scan. Event-related potentials during an auditory oddball paradigm
and QEEG in resting state were recorded. Patients exhibited attenuation of P300
amplitudes compared with controls during dissociative episodes, but exhibited
recovery to control levels in remission. Patients had a larger Sylvian
fissure-brain ratio than did controls. QEEG findings revealed no significant
differences between the patients and controls or between episodes and remission
in the patient group. Attenuation of the P300 can be interpreted as the result
of a negative feedback loop from the medial temporal lobe to the cortex, which
decreases the amount of information flow, allocation of attentional resources,
and updating of working memory to avoid both excessive long-term memory system
activity in medial temporal lobe and resurgence of affect-laden memories.
Publication Types:
Comparative Study
Clin EEG Neurosci. 2006 Jan;37(1):54-9.
QEEG monitoring of Alzheimer's disease treatment: a
preliminary report of three case studies.
Sneddon R, Shankle WR, Hara J, Rodriquez A, Hoffman D, Saha
U.
University of California at Irvine, USA.
rsneddon@dslextreme.com
Previous research has shown that quantitative
electroencephalography (qEEG) can monitor treatment of Alzheimer's Disease
(AD). This study investigated the ability of a qEEG measure based on EEG
variance, combined with a delayed recognition memory task, to measure treatment
effects on patients with AD. Three AD patients with very mild AD (CDR=0.5, FAST
stage 3) were monitored with task specific EEG at multiple time points before
and after medication treatment. Patients had their EEG recorded while
performing a recognition memory task. A measure of (normalized) variance was
applied to the EEG data. To the extent possible, the subjects received this
treatment monitoring multiple times. These patients were monitored a total of
14 times, which yielded 11 measurements of qEEG change during the course of
treatment. The direction of change in patients' qEEG values agreed with
patients' medication treatment on 10 out of 11 occasions, p < 0.006
(binomial test) and was more accurate than monitoring with the relative theta
power, p < 0.05. The results of this monitoring also showed that the qEEG
measure accurately reflected treatment in a dose dependent manner. These results
were independent of the specific medication monitored; Galantamine, Memantine,
Nicotine, and Rivastigmine. In conclusion, this qEEG method may be useful for
measuring AD treatment responses.
Publication Types:
Case Reports Research Support,
Non-U.S. Gov't
Int Tinnitus J. 2006;12(2):121-31.
Quantitative electroencephalography power analysis in
subjective idiopathic tinnitus patients: a clinical paradigm shift in the understanding
of tinnitus, an electrophysiological correlate.
Shulman A, Avitable MJ, Goldstein B.
Martha Entenmann Tinnitus Research Center, Forest Hills,
New York, USA. metrc@inch.com
We report a descriptive analysis-interpretation of
quantitative electroencephalography (QEEG) data for the metric of power in
patients with tinnitus of the severe disabling type (N = 61). The results are
based on a statistical analysis of the data compared to a normative database as
calculated in Z scores, controlling for the factors of age, gender, IQ, and the
like. METHOD: We analyzed the QEEG data for the metric of power to measure (1)
the number of significant recordings, normal and abnormal; (2) the significant
recordings by electrode recording sites; (3) distribution of the
electroencephalographic (EEG) frequency bands; and (4) occurrence of the EEG
frequency bands correlated with the electrode recording sites. In the analysis
of the occurrence of the EEG frequency bands by electrode recording area, we
corrected for the number of recording sites. RESULTS: We recorded normal power
recordings in 20 of 61 patients (32.8%) and abnormal power recordings in 41 of
61 patients (67.2%); power distribution by frequency band in 41 of 61
patients,revealing the number of significant recordings of delta (119), alpha
(69), beta (91), and theta (17); and the power distribution by location for all
frequencies, which were revealed as recording site activity in the frontal
greater than in the temporal sites, which in turn was greater than in the
parietal site, and equal activity in parietal, occipital, and central sites.
The analysis of the occurrence of the EEG frequency bands by electrode
recording area as corrected for the number of recording sites reinforced our
initial results. CONCLUSIONS: Z-score analyses of QEEG recordings--based on a
large normative database--for the metric of power for patients having tinnitus
of the severe disabling type (N = 61) revealed statistically significant
abnormalities in frontal greater than temporal electrode recording sites. We
reported no difference between male and female tinnitus patients in the number
of abnormal power QEEG recordings. However, we observed significant differences
in the average Z scores between males and females in the alpha and theta bands.
The results suggest multiple central electrophysiological correlates for
different clinical types of tinnitus identifiable with QEEG, for the metric of
power, by frequencies of brain activity of delta greater than beta greater than
alpha greater than theta bands of activity, reflecting physiologically the
individuality of brain function and clinically the heterogeneity of the symptom
of tinnitus for tinnitus patients. Clinical interpretation of the QEEG data in
terms of brain function in a tinnitus patient, with a focus on theories of a
neuroanatomical homeostatic system that regulates baseline levels of local
synchrony in multiple neuronal assemblies and on theories of consciousness,
introduces a paradigm switch in our clinical understanding of the symptom of
tinnitus and an application for tinnitus diagnosis and treatment.
Int Tinnitus J. 2006;12(1):17-30.
Congenital atresia of the external ear and tinnitus: a new
syndrome.
Shulman A, Strashun AM, Goldstein B, Lenhardt ML.
Health Science Center at Brooklyn, State University of New
York, Downstate Medical Center, 450 Clarkson Avenue, Box 1239, Brooklyn, New
York 11203, USA. metrc@inch.com
Congenital atresia of the external ears and severe tinnitus
has been reported by two patients to be contralateral to the atretic ear. The
use of the nuclear medicine imaging technique of single-photon emission
computed tomography (SPECT) of brain has demonstrated hypoperfusion in brain areas
supplied by the middle cerebral artery on the side of the atretic ear.
Ultrahigh-frequency audiometry (UHFA) has revealed a bilateral loss of hearing
greater than expected for the age of affected patients. Quantitative
electroencephalography (QEEG) has shown a significant central nervous system
electrical dysfunction correlated with the SPECT of brain findings. One case is
reported in detail at this time. Completion of the medical audiological
tinnitus patient protocol, including SPECT of brain, UHFA, and QEEG, accurately
established the clinical tinnitus diagnosis of predominantly a central-type
tinnitus, a clinical hypothesis that the medical significance of the tinnitus
is a "soft" sign of cerebrovascular disease, and provided a rationale
for treatment directed to a presumed ischemia of brain based on a
receptor-targeted therapy targeted to the GABA-A receptor, resulting in
significant tinnitus relief. Questions that have arisen include (1) the
incidence of occurrence of hypoperfusion of the middle cerebral artery in
congenital atresia patients; (2) implications and long-term consequences of
this finding in this patient population for development of cerebrovascular
disease; (3) brain plasticity for tinnitus relief (i.e., neuronal
reprogramming, particularly in response to treatment recommendations for
complaints of the cochleovestibular system in general and specifically for
tinnitus); (4) the clinical significance of the UHFA thresholds of bilateral
hearing loss greater than expected for the age of the patient; and (5) whether
congenital atresia of the external ear may be part of a syndrome that includes
hypoperfusion in brain areas supplied by the middle cerebral artery on the side
of the atretic ear, ultra-high-frequency bilateral loss of hearing greater than
expected for the age of the patient, and significant central nervous system
electrical dysfunction. As far as we can determine, these findings, highlighted
by the brain SPECT, have not previously been reported in patients with
congenital atresia of the external ear.
Publication Types:
Case Reports Research Support,
Non-U.S. Gov't
J Neural Eng. 2006 Mar;3(1):71-7. Epub 2006 Mar 1.
Study on a
quantitative electroencephalography power spectrum typical of Chinese Han Alzheimer's disease patients by using
wavelet transforms.
Wan B, Ming D, Fu X, Yang C, Qi H, Chen B.
Department of Biomedical Engineering, Tianjin University,
Tianjin 300072, People's Republic of China.
Our objective was to investigate the quantitative
electroencephalogram (EEG) power spectrum typical of Chinese Han ethnic
Alzheimer's disease (AD) patients. A study on the resting EEG was carried out
on 103 local AD (NINCDS-ADRDA criteria)
patients, and 124 age-matched normal elderly subjects served as
controls. A novel multi-resolution decomposition algorithm based on Daubechies
wavelet transform was employed for EEG spectral analysis. This algorithm
decomposed recorded EEG signals into components with five frequency subbands,
which especially provided more electroneural activity details in comparison
with the conventional four subbands. A significant prevalence of an EEG
spectrum characterized by increased slow
activity with decreased fast activity was found in these patients. Moreover,
the spectral power increase/decrease was mainly centralized in the below-2
Hz/over-8 Hz band, whereas the 2-8 Hz band did not show any widespread change.
In conclusion, this study may provide some evidence of specific spectral
changes of EEG affected by AD in China.
Curr Opin Neurol. 2005 Dec;18(6):692-7.
Rehabilitation
interventions after mild head injury.
Ponsford J.
School of Psychology, Psychiatry and Psychological
Medicine, Monash University and Monash-Epworth Rehabilitation Research Centre,
Epworth Hospital, Melbourne, Australia. jennie.ponsford@med.monash.edu.au
PURPOSE OF REVIEW: This review examines current management
and rehabilitation strategies for mild traumatic brain injury, with emphasis on
the need to address multiple potential
causative factors in order to enhance outcomes and to conduct more controlled efficacy studies. RECENT
FINDINGS: Whilst most individuals who sustain mild traumatic brain injury make
a good recovery, a proportion experience significant ongoing disability. In
some cases this is due to diffuse axonal injury and cognitive impairment, but
in others symptoms are exacerbated by factors such as pain, stress, personality
issues or litigation, or in children, previous head injury, behavioural or
learning difficulties. Provision of information early after injury results in
reduced symptom reporting in adults and children. There is also a need,
however, to address these other factors in treatment. Psychological therapy
using a cognitive behavioural approach may be helpful, but controlled
evaluations of such interventions have been lacking. Recent uncontrolled studies
have examined the impact of computer-mediated interventions to remediate visual
and verbal processing and oculomotor problems and the impact of quantitative
electroencephalography. More rigorous efficacy studies of these approaches are
needed. Guidelines for management of sports-related concussion and timing of
return to play also require a more solid
scientific basis. SUMMARY: The evidence base for management of mild
traumatic brain injury is still very limited. There is a need to conduct more
carefully controlled prospective studies and examine the influence of factors
not directly related to the brain injury
as a basis for formulating more uniform management guidelines.
Arch Clin Neuropsychol. 2005 Jun;20(4):427-34. Epub 2004
Nov 19.
The Ruff
Figural Fluency Test: heightened right frontal lobe delta activity as a function of performance.
Foster PS, Williamson JB, Harrison DW.
Virginia Polytechnic Institute and State University, VA,
USA.
Research has indicated that the Ruff Figural Fluency Test
[RFFT; Ruff, R. M., Light, R. H., & Evans, R. W. (1987). The Ruff Figural
Fluency Test: A normative study with adults. Developmental Neuropsychology, 3,
37-51] is sensitive to right frontal lobe functioning. Indeed, research has
differentiated between patients with left or right frontal lobe lesions using
performance on the RFFT [Ruff, R. M., Allen, C. C., Farrow, C. E., Niemann, H.,
& Wylie, T. (1994). Figural fluency: Differential impairment in patients
with left versus right frontal lobe
lesions. Archives of Clinical Neuropsychology, 9, 41-55]. The present
investigation used quantitative electroencephalography to test further whether
the RFFT was sensitive to right frontal lobe functioning among a group of
individuals with no history of head injury. To meet this objective, the RFFT
was administered to a group of 45
right-handed men with no history of significant head injury or cerebral
dysfunction. Delta magnitude (muV) at three right frontal electrode sites (FP2,
F4, F8) was then used to compare those who performed the best (High Fluency)
with those who performed the worst (Low Fluency) on the RFFT. The findings
indicated heightened right frontal delta magnitude for the Low Fluency group
relative to the High Fluency group at the F2 and F8 right frontal electrode
sites. Thus, the present findings provide further support for the contention
that the RFFT is sensitive to right frontal lobe functioning, even among those
with no history of head injury.
Pediatr Neurol. 2005 Apr;32(4):248-56.
Resting EEG
theta activity predicts cognitive performance in attention-deficit
hyperactivity disorder.
Hermens DF, Soei EX, Clarke SD, Kohn MR, Gordon E, Williams
LM.
The Brain Dynamics Centre, Westmead Hospital, NSW,
Australia; School of Psychology, University of Sydney, NSW, Australia.
Quantitative electroencephalography has contributed
significantly to elucidating the neurobiologic
mechanisms of attention-deficit hyperactivity disorder. The most consistent and
robust electroencephalographic disturbance in attention-deficit hyperactivity
disorder has been abnormally increased theta band during resting conditions.
Separate research using attention-demanding tests has elucidated cognitive disturbances that
differentiate attention-deficit hyperactivity disorder. This study attempts to
integrate electroencephalographic and
neuropsychological indices to determine whether cognitive performance is
specifically related to increased theta. Theta activity was recorded during a
resting condition for 46 children/adolescents with attention-deficit
hyperactivity disorder and their sex- and age-matched control subjects.
Accuracy and reaction time during an
auditory oddball and a visual continuous performance test were then recorded. Compared with
control subjects, the attention-deficit hyperactivity disorder group manifested
significantly increased (primarily left)
frontal theta. Furthermore, the attention-deficit hyperactivity disorder
group scored significantly delayed reaction time and decreased accuracy in both
tasks. Correlation analysis revealed a
significant relationship between frontal (primarily left) theta and oddball
accuracy for the attention-deficit hyperactivity disorder group compared with a
significant relationship between posterior (primarily right) theta and reaction
time in the continuous performance test for the control group. These results
indicate that spatial neurophysiologic
deficits in attention-deficit hyperactivity disorder may be related to
disturbances in signal detection. This observation has important implications
for the role of trait-like biologic deficits in attention-deficit hyperactivity
disorder predicting performance in information processing.
Int Tinnitus J. 2004;10(2):127-31.
Quantitative
electroencephalography patterns in patients suffering from tinnitus.
Weiler EW, Brill K.
NeuroNet, GmbH, St Wendel, Germany. neuronet@t-online.de
We conducted this study in an attempt to determine whether
the electroencephalographic activity in patients suffering from tinnitus
exhibits tinnitus-typical electroencephalography features. Our results
indicated a significant increase in the average total power in female tinnitus
patients and a significant decrease in average total power in male tinnitus
patients. Furthermore, we noted a suppression of the alpha peaks or a split
alpha band (or both). The reactivity of
the alpha frequency was employed to evaluate the efficacy of noise generators,
a critical component of tinnitus-retraining therapy. In conclusion, tinnitus-typical
electroencephalography features can be extracted from the electroencephalogram.
Pharmacol Biochem Behav. 2005 Jan;80(1):161-71. Epub 2004
Dec 22.
Clonidine
pre-treatment fails to block acute smoking-induced EEG arousal/mood in cigarette smokers.
Knott VJ, Raegele M, Fisher D, Robertson N, Millar A,
McIntosh J, Ilivitsky V.
Department of Psychiatry, University of Ottawa and
Institute of Mental Health Research/Royal Ottawa Hospital, 1145 Carling Avenue,
Ottawa, Ontario, Canada K1Z 7K4. vknott@rohcg.on.ca
Given the arousal eliciting actions of smoking and
nicotine, and the contributing role of noradrenaline in brain arousal systems,
this study examined the neuroelectric and affective correlates of cigarette
smoking following acute pre-treatment with the alpha 2-noradrenergic
auto-receptor agonist, clonidine. In a double-blind placebo-controlled
crossover design, quantitative electroencephalography (EEG), mood, and smoking
withdrawal symptoms were assessed in 12 overnight smoking abstinence smokers,
before and after sham and cigarette smoking. Orally administered clonidine (0.1
mg) failed to alter overnight smoking abstinence symptoms or the EEG arousal
and mood-elevating response seen with the
smoking of a single cigarette. The results are discussed in relation to
neural mechanisms underlying the acute reinforcement maintaining nicotine use.
Neurosci Lett. 2005 Dec 31;391(1-2):43-7. Epub 2005 Sep 12.
A pre-task resting condition neither 'baseline' nor 'zero'.
Gonzalez-Hernandez JA, Campbell K, Scherbaum WA,
Bosch-Bayard J, Figueredo-Rodriguez P.
Section of Cognitive Research and Psychophysiology,
Department of Clinical Neurophysiology, Hermanos Ameijeiras Hospital, San
Lázaro 701, Havana 3, 10300, Cuba.
This study introduce the comparison of a 'reference state'
versus a resting condition (zero), defined upon normative developmental
equations. We compared pre-task 'resting' data from healthy individuals with
the Normative Cuban digital resting EEG-database recently calculated for VARETA
(qEEG/VARETA). The results allowed us to state that a 'pre-task resting
conditions' exists as a state beyond the 'zero' or 'baseline' condition. The
pre-task 'resting' condition is never truly 'at rest', however most of the
previous published fMRI/PET studies assumed such a pre-task condition as
reference/baseline condition. By defining different 'resting states' by
qEEG/VARETA analyses, we have a potential methodology which can define resting
state conditions and to be sure that they are consistent when comparing within
group analyses across tasks or between groups either void of task or for task
specific conditions.
Publication Types:
Clinical Trial Research
Support, Non-U.S. Gov't
Brain Res. 2005 Dec 7;1064(1-2):146-54. Epub 2005 Nov 11.
Effect of acute hypoxic preconditioning on qEEG and
functional recovery after cardiac arrest in rats.
Geocadin RG, Malhotra AD, Tong S, Seth A, Moriwaki G,
Hanley DF, Thakor NV.
Department of Neurology, The Johns Hopkins Medical
Institutions, Baltimore, MD 21205, USA.
Acute hypoxic preconditioning (AHPC) can confer
neuroprotection from global cerebral ischemia such as cardiac arrest. We
hypothesize that acute neuroprotection by AHPC will be detected early by
quantitative EEG (qEEG) entropy analysis after asphyxial cardiac arrest (aCA).
Cerebral ischemia lowers EEG signal randomness leading to low entropy. A qEEG
entropy index defined as the duration when the entropy measure is 15% below
uninjured baseline entropy is used as a measure of injury. We compared 3 groups
of adult Wistar rats: (1) untreated controls that were subjected to 5 min of
aCA and were resuscitated (n = 5); (2) AHPC-treated group with 10% FI O2 for 30
min, then 25 min of room air, 5 min of aCA followed by resuscitation (n = 5);
and (3) a surgical sham group (no aCA) (n = 3). Functional outcome was assessed
by neurodeficit score (NDS) which consisted of level of consciousness, cranial
nerve, motor-sensory function, and simple behavioral tests (best = 100 and
brain dead = 0). We found that increasing entropy index of injury at 0-5 h from
return of spontaneous circulation (ROSC) is associated with worsening NDS at 24
h (linear regression: r = 0.81, P < 0.001). The NDS of the group sham (84.7
+/- 2.8) (mean +/- SEM) and AHPC group (84.6 +/- 2.9, P > 0.05) was better
than control injury group (52.2 +/- 8.4, P < 0.05) (ANOVA with Tukey test).
We therefore conclude that AHPC confers acute neuroprotection at 24 h, which
was detected by qEEG entropy during the first 5 h after injury.
Publication Types:
Comparative Study
Int J Geriatr Psychiatry. 2005 Nov;20(11):1038-45.
The utility of EEG in dementia: a clinical perspective.
Adamis D, Sahu S, Treloar A.
Deptartment of Ageing and Health, Guy's and St Thomas' NHS
Foundation Trust, London, UK.
BACKGROUND: Despite being simple and cheap, the EEG is not
often used in clinical practice. METHODOLOGY: Literature search using PUBMED
and Medline. RESULTS: Quantitative EEG can help to identify mild dementia and
mild cognitive impairment and can increase diagnostic accuracy when used with
other imaging techniques. EEG helps differentiate organic from functional brain
disease and predict response to cholinesterase inhibitors and is central in the
diagnosis of Creutzfeldt Jacob disease. The accuracy of EEG may be greater than
that of CT or MRI scans alone. DISCUSSION: Quantitative EEG may save on
specialist interpretation time and enable more routine use of EEG in diagnosis
and care. More widespread use of EEG's is indicated. Agreement on the
parameters that are best measured on qEEG is still awaited. Copyright (c) 2005
John Wiley & Sons, Ltd.
Publication Types:
Review
Int J Geriatr Psychiatry. 2005 Oct;20(10):983-8.
The heterogeneity of frontotemporal dementia with regard to
initial symptoms, qEEG and neuropathology.
Passant U, Rosén I, Gustafson L, Englund E.
Department of Psychogeriatrics, Lund University Hospital,
Lund, Sweden. ulla.passant@skane.se
OBJECTIVES/METHODS: Ten patients with neuropathologically
verified frontotemporal dementia (FTD) were analysed for neuropathological
features in relation to first presenting and dominating symptoms, age at onset
and duration of dementia, as well as to EEG/quantitative EEG. RESULTS: Cases
with a late onset (> 65 years) initially presented language disturbances,
while the early onset group (< 65 years) showed predominantly behavioural
symptoms and mood alterations as early features. The late onset group presented
combined cortical-subcortical degeneration including white matter pathology,
while early onset cases showed pathology predominantly in the cortex. EEG was
normal in the late onset group, while it was mildly and variably abnormal in
those with early onset. CONCLUSIONS: Within this small sample of clinical and
neuropathological FTD, cases with late vs early onset differed with respect to
initial symptoms, EEG findings and regional distribution of brain pathology.
Copyright (c) 2005 John Wiley & Sons, Ltd.
Publication Types:
Research Support, Non-U.S. Gov't