Evaluation of different antiepileptic drug strategies in medically refractory epilepsy patients following epilepsy surgery

Abstract

Purpose: This study aimed to explore the most appropriate antiepileptic drug strategies after successful epilepsy surgery.

Methods: A total of 131 refractory epilepsy patients who underwent epilepsy surgery from January 2005 to December 2008 in the Department of Neurosurgery, West China Hospital, were retrospectively reviewed. Patients were divided into three groups (monotherapy, duotherapy, and polytherapy) according to drug combinations used immediately after epilepsy surgery. Seizure outcomes were followed up for more than 2 years. Engel classification was used to evaluate seizure outcomes.

Results: The mean postoperative follow-up period was 3.7±1.0 years. Preoperative baseline data among the three groups were comparable. Seizure recurrence rate in monotherapy was obviously higher than in other groups (34.1% vs. 15.1%, 7.1%) at 6-month follow-up, which showed a statistically significant difference (p=0.02). Seizure outcomes for 2 years were assessed using Engel classification. In the duotherapy group, the rate of Engel class I was definitely higher than in the other two groups (69.9% vs. 47.7%, 57.1%, p=0.02). Seizure relapse rates at the 2-year follow-up, after planned reduction or withdrawal, were 46.4% for monotherapy, 16.9% for duotherapy, and 25.0% for polytherapy (p=0.01).

Conclusions: Monotherapy may be not sufficient enough to control seizures completely. It appears to have a higher risk for seizure relapse when considering drug reduction. It suggests that duotherapy may be more effective and safer than monotherapy. Even after successful epilepsy surgery, duotherapy seems preferable to monotherapy or polytherapy for control of residual seizures.