EEG coherence and symptom profiles of children with Attention-Deficit/Hyperactivity Disorder.

OBJECTIVE: We compared EEG coherence in children with and without AD/HD, and sought to relate observed anomalies to AD/HD symptoms. METHODS: Forty children with AD/HD and 40 age- and sex-matched controls had eyes-closed resting EEG coherence calculated for eight interhemispheric electrode pairs and eight intrahemispheric pairs (four within each hemisphere) in the delta, theta, alpha, beta and "40 Hz" gamma bands. RESULTS: At short-medium inter-electrode distances, the AD/HD group had increased intrahemispheric coherence in delta and theta, and reduced (L>R) laterality in delta, alpha, beta and gamma. Over longer inter-electrode distances, the AD/HD group had reduced intrahemispheric coherence in alpha. In interhemispheric comparisons, the AD/HD group had reduced frontal coherence in delta, alpha and gamma, increased temporal theta and reduced temporal alpha coherences, and increased central/parietal/occipital coherence in theta. Smaller left-lateralized coherences in AD/HD correlated negatively with DSM Inattentive and DSM Total scores, and smaller frontal interhemispheric coherence in alpha correlated negatively with DSM Hyperactive/Impulsive score. CONCLUSIONS: The negative correlations between AD/HD coherence anomalies and symptoms suggest that several anomalies reflect compensatory brain function. SIGNIFICANCE: Coherence differences in AD/HD may reflect anomalous frontal right-hemisphere linkages that help compensate functional brain anomalies in the left frontal regions in this disorder.