The risk of multiple recurrences after an initial seizure recurrence was assessed in a prospective study of 407 children, followed for a mean of 9.6 years at Montefiore Medical Center, The Albert Einstein College of Medicine, NY, and in private practices. Of the 407 with a first unprovoked seizure, 45% experienced a recurrence. At 1, 2, 5, and 10 years, the cumulative risk of a second seizure was 29%, 37%, 43%, and 46%, respectively. After 2 seizures, the risk of recurrence is 70% or higher, and after 3 seizures, the risk of further recurrence is 69%, 72%, and 81% at 1, 2, and 5 years, respectively. Children having a second seizure within 6 months of the first, and those with seizures of remote symptomatic etiology have an increased risk of additional recurrences, and are more likely to have 10 or more recurrences. An abnormal EEG and a seizure occurring during sleep were risk factors for the first seizure recurrence but not for further recurrences. Status epilepticus or multiple seizures at the first episode were not indicative of an increased risk of subsequent recurrences. Treatment after the second seizure is associated with a greater than 50% reduction in the risk of subsequent seizures, but only for the first 3 months. [1]

COMMENT. The findings confirm our present understanding that a second seizure, or one seizure recurrence, is sufficient for a diagnosis of epilepsy, and the need to consider counseling and therapy. In this long-term follow-up study, 45% of children with a single unprovoked seizure experienced a recurrence. Factors associated with multiple recurrent seizures include a second seizure within 6 months of the first, and a remote symptomatic etiology. As emphasized by Duchowny M, in an editorial, the etiology supercedes most risk factors when considering seizure prognosis, therapy, and long-term outcome [2]. In a child with a single new-onset seizure of remote symptomatic etiology, or cryptogenic/idiopathic etiology and an epileptiform EEG, the risk of recurrence may be comparable to that after a second seizure. In these circumstances, therapy may be appropriate after a first seizure.