Natural history of recurrent seizures after resective surgery for epilepsy.

Seizures persist or recur in 20-60% of patients after resective surgery for intractable partial epilepsy. Further information about the natural course of these seizures is lacking in the literature. During one decade of epilepsy surgery at a single institution, we identified 72 patients with recurrent postoperative seizures after resective procedures for epilepsy. Prospectively compiled seizure diaries, hospital records, and outpatient office records were reviewed and supplemented by telephone communications to assess subsequent seizure frequency. Follow-up data was available ranging from 6 months to 7 years 5 months (mean 3 years 5 months). The likelihood of persistent seizures and recurrent intractability was examined with life-tables. Seizures recurred within the first postoperative year in 86% of patients and were similar to preoperative events in 74% of patients. After the first seizure recurrence, there was 80% likelihood of persistent seizures in the next 6 years and 40% likelihood of intractability (more than one seizure a month despite optimal medical therapy). The interval until recurrence within the first postoperative year did not affect the likelihood of subsequent seizures or intractability. Late seizure recurrence (after the first year) was not associated with any instances of subsequent intractability. Recurrent seizures after extratemporal resections were more likely to become persistent and intractable than seizures recurring after temporal resections. This information provides rational prognostication and assists in counseling patients with recurrent seizures after resective surgery for intractable epilepsy.