Risk of recurrence after a first unprovoked seizure.

The risk of recurrence after a first unprovoked seizure has been examined in numerous observational studies and two large, high-quality randomized trials. Overall, in untreated individuals, 40-50% can expect a recurrence within 2 years of the initial seizure. Treatment may reduce this risk by as much as half. Those at the greatest risk of recurrence have either an abnormal EEG or an identifiable neurological condition or symptoms consistent with one ("symptomatic"). Status epilepticus and a history of febrile seizures may be associated with an increased risk of recurrence in individuals with symptomatic seizures. The great majority of people (approximately 90%) who are seen for a first unprovoked seizure attain a one to two year remission within 4 or 5 years of the initial event.