Seizure outcome after temporal lobectomy for temporal lobe epilepsy: a Kaplan-Meier survival analysis

Abstract

Objective: To determine seizure outcome and its predictors in patients with medically refractory temporal lobe epilepsy (TLE) after temporal lobectomy (TL).

Background: TL is the most common surgical procedure performed in adolescents and adults for the treatment of medically refractory TLE. Seizure outcome has been reported extensively during the first few postoperative years, but little is known beyond that time.

Methods: The authors analyzed seizure outcome in 79 patients who underwent TL for epilepsy at the Duke University Medical Center from 1962 through 1984. Patients with less than 2 years of follow-up and degenerative disorders were excluded. Predictors of seizure outcome were analyzed using Kaplan-Meier survival analyses.

Results: The mean follow-up was 14 years (range, 2.1 to 33.6 years). Using Engel's classification, 65% of patients were class I, 15% were class II, 11% were class III, and 9% were class IV. At least one postoperative seizure occurred in 55% of subjects. The majority of recurrences (86%) took place within 2 years of surgery. Later recurrences tended not to lead to medical intractability. Higher monthly preoperative seizure frequency was associated with poor seizure outcome. A seizure-free state at 2 years was found to be a better predictor of long-term outcome than the 6-, 12-, and 18-month landmarks.

Conclusions: TL provides sustained, long-term benefit in patients with medically refractory TLE. Seizure-free status at 2 years from the time of surgery is predictive of long-term remission.