Prognosis after grand mal seizures: a study of 187 children with three-year remissions.

From a total group of 640 children with grand mal seizures, 187 who became seizure-free for three consecutive years on monotherapy which was then discontinued have been followed for between one and 14 years. Relapse occurred in 22 children (12 per cent) and was related to age at presentation: only four of 89 children with primary grand mal seizures who had presented after the age of three years relapsed, compared with 12 of 45 who had presented before their third birthday. Children who had had more seizures were at greater risk of relapse. EEGs were not useful in predicting prognosis, whether taken at presentation or before withdrawal of treatment.