Benign neonatal sleep myoclonus: clinical features and video-polygraphic recordings.

Benign neonatal sleep myoclonus is a syndrome characterized by the occurrence of repetitive myoclonic jerks of the extremities exclusively during non-rapid eye movement sleep in the early life of healthy newborns. No etiological factors are present. The onset is within the first 15 days of life with spontaneous disappearance within 3-4 months. These myoclonic events are commonly diagnosed as epileptic seizures. We observed 12 newborns with this clinical pattern; the follow-up ranges from 12 to 60 months. Long-term videopolygraphic electroencephalographic (EEG) monitoring demonstrated normal EEG activity, thus confirming that these unusual events were nonepileptic.