Abstracts

Rationale: The ideal goal of successful epilepsy surgery would be life without seizures and free of seizure medication. However, few literature reports describe long term epilepsy surgery outcomes, especially in terms of seizure medication reduction post-surgery. Furthermore, there is no clear guideline on how and when to reduce seizure medications after epilepsy surgery. The aim of this study is to report our own experience on these issues. Methods: We retrospectively reviewed our pediatric epilepsy surgery database to identify all resective epilepsy surgery patients at the Children's of Alabama Hospital between December 2003 and June 2010 with at least 2 years follow up information. Individual seizure medication regimens before and after surgery were collected as well as the onset of seizure medication weaning after operation and seizure relapse date (if any). Clinical characteristics, magnetic resonance imaging (MRI) and surgical resection margin were analyzed for their potential impact on seizure medication reduction and seizure relapse. Statistical significance of differences was assessed using Chi-square, Fischer Exact test and Kaplan-Meier survival analysis for each group. Results: A total of 72 patients were identified. Forty-eight had an attempt to wean off seizure medications after epilepsy surgery and twenty-four patients remained on their seizure medications with no attempt to wean. There was no significant difference in demographic data between the groups. For the wean group, the seizure relapse rate was 31.25% (15/48) and for the no wean group, the seizure relapse rate was 62.5% (15/24). The mean onset of wean of the whole cohort was 8.33 month after operation (SD 11.5 months) and the median onset of wean of the whole cohort was 5 months after operation. The timing of medication wean after surgery did not affect the seizure relapse. The duration of epilepsy was significantly longer in the no wean group than the wean group. Even though the overall class-I outcome rate for the whole cohort was 66.67%, only four patients (5.55% of 72 patients) were seizure-free without medication. Conclusions: The decision to wean off seizure medications after epilepsy surgery should be considered on a case-by-case basis. When to wean the medication may not be as important as who should be weaned.