Partial motor epilepsy with "negative myoclonus".

Three children had both nocturnal unilateral motor seizures and daytime ipsilateral "negative myoclonus" which occurred so frequently that it resembled asterixis. Neurophysiologic studies demonstrated lateralized spike discharges that were time-locked to postural lapse in the contralateral outstretched arm. The clinical course was characterized by good seizure control with benzodiazepines.