Investigators from Harvard Medical School, Boston, present the case of a 6-year-old girl with ADHD taking valproic acid for behavioral problems who had a generalized tonic-clonic convulsion shortly after a first dose of methylphenidate. She was known to have staring spells and an abnormal EEG with left centroparietal spikes but no history of electrographic seizures. A repeat EEG demonstrated continuous spike and slow wave during sleep. CSWS in sleep may be a risk factor for methylphenidate-induced seizure. 
COMMENT. This article corroborates previous reports of the utility of the EEG in children with ADHD and the increased risk of methylphenidate-induced seizures in patients with EEG centrotemporal (rolandic) spikes  and CSWS in sleep. Sleep deprivation in preparation for a sleep EEG is essential to exclude epileptiform abnormalities; one quarter of nonepileptic children with ADHD have epileptiform discharges in the sleep-deprived EEG compared to only 7% in awake only EEG, and slightly more than half discharges are focal.