Incidence of spikes and paroxysmal rhythmic events in overnight ambulatorycomputer-assisted EEGs of normal subjects: A multicenter study

The incidences of spikes and paroxysmal rhythmic events (PREs) in 10-h over night EEGs of normal adult volunteers (n = 135) were studied at 11 sites wi th a computer-assisted ambulatory EEG monitoring system with automatic spik e and PRE detection. Spikes were evident in the overnight EEG of 1 subject (0.7%), and PREs were apparent in the overnight EEG of the same subject (0. 7%). The incidences of spikes of 24 other subjects with a history of migrai ne and/or a family history of epilepsy were 12.5 and 13.3%, respectively. T he overnight EEGs of these subjects were significantly more likely to show spikes than the overnight EEGs of subjects without migraine or a family his tory of epilepsy.