EEG-vigilance and response to stimulants in paediatric patients with attention deficit/hyperactivity disorder.

OBJECTIVE In a pilot study it was investigated whether assessment of EEG-vigilance is useful for the prediction of treatment outcome in ADHD patients. METHODS Resting EEG recordings of 49 unmedicated ADHD patients and 49 age-matched controls were analyzed. Vigilance level was determined for 1-s segments with a computer-based algorithm, distinguishing six stages from higher vigilance stages A1, A2 and A3 with dominant alpha activity to lower stages B1 and B2/3 with low amplitude non-alpha and increasing theta and delta activity and further onto stage C characterizing sleep onset. Treatment outcome was measured as changes in continuous performance test (CPT) results from baseline after at least 4 weeks of medication. RESULTS ADHD patients spend less time in higher A1-stages (ADHD=66%, controls=81%) and showed more switching between vigilance stages (ADHD=26.02%, controls=19.09%), indicating a more unstable vigilance regulation. Patients with less stable vigilance showed a worse pre-treatment CPT performance but achieved a better post-treatment result compared to patients with more stable vigilance regulation. These differences did not reach statistical significance. CONCLUSIONS Signs of vigilance instability where found in ADHD patients compared to controls. Those patients with a higher degree of vigilance instability seemed to benefit more from stimulant medication. SIGNIFICANCE This is the first investigation of EEG-vigilance in ADHD-patients. Results are limited by a short recording time but the results strongly suggest further investigation of the vigilance regulation in ADHD patients.