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.