Interpreting seizure counts after temporal lobectomy: not just one-two-three.

PURPOSE: Temporal lobectomy is a well-established treatment for refractory temporal lobe epilepsy, yet many patients experience at least one seizure postoperatively. Little is known about the prognostic significance of the time from surgery to first seizure relapse in predicting long-term outcome. METHODS: In a retrospective analysis of patients who reported at least one complex partial seizure (CPS) or generalized tonic–clonic seizure (GTCS) after anterior temporal lobectomy (n = 268), we used a nominal response logistic model to predict the odds ratio (OR) of a seizure outcome based on length of the latency period from surgery to first postoperative seizure. A modified Engel outcome class scheme was used. We controlled for factors known to influence postoperative outcome, including history of tonic–clonic seizures, intelligence quotient (IQ), preoperative seizure frequency, magnetic resonance imaging (MRI) findings, and history of febrile convulsions. RESULTS: In the univariate analysis, the latency from surgery to the first postoperative disabling seizure was significantly associated with long-term outcome. Longer latency was associated with higher odds of being seizure-free or improved (modified Engel's classes 1, 2, and 3) relative to the unim-proved state (class 4) (p < 0.001, 0.001 and 0.004, respectively). Conversely, a shorter latency increased the likelihood of achieving the worst prognosis (class 4) relative to class 1 (p < 0.001). Multivariate analysis yielded similar results. DISCUSSION: Latency to the first postoperative seizure predicts long-term outcome, with short latencies portending poor prognosis and long latencies portending a good prognosis. This information can be used for patient counseling and may influence decisions regarding reoperation. PURPOSE: Up to one-half of epilepsy surgery patients will have at least one seizure after surgery. We aim to characterize the prognosis following a first postoperative seizure, and provide criteria allowing early identification of recurrent refractory epilepsy. METHODS: Analyzing 915 epilepsy surgery patients operated on between 1990 and 2007, we studied 276 who had ‡1 seizure beyond the immediate postoperative period. The probability of subsequent seizures was calculated using survival analysis. Patients were divided into seizure-free (no seizures for ‡1 year) and refractory (persistent seizures) and analyzed using multivariate regression analysis. RESULTS: After a first seizure, 50% had a recurrence within 1 month and 77% within a year before the risk slowed down to additional 2–3% increments every two subsequent years. After a second seizure, 50% had a recurrence within 2 weeks, 78% within 2 months, and 83% within 6 months. Having both the first and …