Quantitative EEG in Children with Attention Deficit Hyperactivity Disorder

Background: ADHD affects approximately 4-8% of children worldwide. EEG studies in children with ADHD search for data with respect to various aspects of brain function. Objective: To investigate if children with ADHD have a distinctive EEG pattern that reflects their alertness and behavior using quantitative EEG. Methods: Thirty children with ADHD and 33 control children were evaluated using digital EEG recordings. Power spectral analysis was carried out for the absolute and relative power of the frequency bands delta (1–3 Hz), theta (4–7 Hz), alpha (8–11 Hz), beta1 (12–15 Hz), beta2 (16–20 Hz). QEEG findings were correlated to the Conners’ Parent Rating Scale scores. Results: ADHD children showed more delta power and less alpha power mainly in frontal leads. Of the whole sample, children who scored >65 on the Conners’ DSM-IV Total had lower beta1 power in frontal, central and temporal leads. Regression analysis of the relative power across frequency bands at the midline leads showed that relative theta power at Cz positively predicted the score. At Cz as well, children scoring >65 on the DSM-IV Inattentive subscale had increased theta relative power and theta/beta ratio and children scoring >65 on the DSM-IV Hyperactive-Impulsive subscale had decreased beta1 relative power. The increased theta/beta ratio at Cz predicted both the scores of the inattention and hyperactivity/impulsivity scales of the DSM-IV. Conclusion: There is increased low frequency activity and decreased high frequency activity in children with ADHD. The increased theta/beta ratio at Cz may aid as an indicator in the diagnosis of ADHD. [Egypt J Neurol Psychiat Neurosurg. 2010; 47(3): 399-406]