Atypical benign partial epilepsy of childhood.

Seven children with an unusual epileptic syndrome are reported. The main clinical features in each patient included onset between 2 1/2 and six years of age; the occurrence of several types of seizure, especially partial motor fits, atypical absences and myo-atonic seizures; and the persistence of normal neurological and mental function throughout the course. The EEG picture was characterized by a striking contrast between waking records, which usually displayed focal paroxysms, and sleep tracings which showed an almost continuous, diffuse, slow spike-wave activity. Although the electroclinical features suggested the diagnosis of Lennox-Gastaut syndrome or myoclonic epilepsy, the seizures remitted spontaneously in the five oldest patients and may well do so in the two youngest ones. The authors discuss the clinical and electroencephalographic features that permit these cases of atypical benign partial epilepsy to be distinguished from the more severe myo-atonic epileptic syndromes of childhood.