Depression, Anxiety, and Resting Frontal EEG Asymmetry: A Meta-Analytic Review
Emotion-related disturbances, such as depression and anxiety, have been linked to relative right-sided resting frontal electroencephalograph (EEG) asymmetry among adults and infants of afflicted mothers. However, a somewhat inconsistent pattern of findings has emerged. A meta-analysis was undertaken to (a) evaluate the magnitude of effects across EEG studies of resting frontal asymmetry and depression, anxiety, and comorbid depression and anxiety and (b) determine whether certain moderator variables could help reconcile inconsistent findings. Moderate effects of similar magnitude were obtained for the depression and anxiety studies, whereas a smaller effect emerged for comorbid studies. Three moderating variables predicted effect sizes: (a) Shorter EEG recording periods were associated with larger effects among adults, (b) different operationalizations of depression yielded effects of marginally different magnitudes, and (c) younger infant samples showed larger effects than older ones. The current data support a link between resting frontal EEG asymmetry and depression and anxiety and provide a partial account of inconsistent findings across studies.
In-Clinic ERP for Sports Concussion: A 3-Year Study
We have collected baseline EEG with event-related potentials (ERP) on 364 athletes, aged 17-23, participating in contact and collision sports in order to assess the utility of EEG/ERP as an adjunct for assessing return to play following a sports-related concussion. Using a simple 4-min procedure, the 39 subsequent concussion events corresponded to significant changes in P300 amplitude, typically a reduction from baseline, with amplitudes normalizing back to baseline at a rate slower than that observed for performance markers in many cases. Our data confirm previous results suggesting that concussions cause measurable changes in the electrophysiological markers of brain activity, concussed participants often pass clinical tests while still displaying electrophysiological deficits, and that ERPs may constitute a useful adjunct in monitoring the clinical course and recovery of concussion in athletes.
Associations between EEG asymmetries and electrodermal lability in low vs. high depressive and anxious normal individuals
In order to investigate one aspect of cortical-autonomic control, cortical activation asymmetries, measured by EEG, were related to the activity of the sympathetic nervous system, measured by EDA (electrodermal lability, number of spontaneous fluctuations), in two large samples. Since it may help to explain the participation of psychological factors in the development of various somatic complaints and disorders, we examined whether inter-individual differences in autonomic nervous system regulation may exist that are related to stress/anxiety and depression within the normal range. Results demonstrate substantial modifications of functional hemisphere asymmetries in the modulation of EDA by these emotional factors and suggest that activation asymmetries in orbital and dorsolateral frontal regions reflect two different cortical sub-systems regulating electrodermal activity. The findings may, to some extent, provide an explanation for contradictory results in previous studies and may encourage research in psychosomatics and other clinical fields (e.g. schizophrenia).
A Meta-analysis of Quantitative EEG Power Associated With Attention-Deficit Hyperactivity Disorder
A meta-analysis was performed on quantitative EEG (QEEG) studies that evaluated attention-deficit hyperactivity disor- der (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.
DE NOVO CLASSIFICATION REQUEST FOR NEUROPSYCHIATRIC EEG-BASED ASSESSMENT AID FOR ADHD (NEBA) SYSTEM
FDA identifies this generic type of device as:
Neuropsychiatric Interpretive Electroencephalograph Assessment Aid. The Neuropsychiatric Interpretive Electroencephalograph Assessment Aid is a prescription device that uses a patient’s electroencephalograph (EEG) to provide an interpretation of the patient’s neuropsychiatric condition. The Neuropsychiatric Interpretive EEG Assessment Aid is used only as an assessment aid for a medical condition for which there exists other valid methods of diagnosis.