Purpose: To investigate the feasibility of antiepileptic drug (AED) withdrawal following anterior temporal lobectomy (ATL) and to identify the predictors of post withdrawal seizure recurrence.
Methods: We prospectively studied the seizure outcome of 310 consecutive patients, who were followed for a minimum of 5 years following ATL for medically refractory mesial temporal lobe epilepsy. In seizure-free patients, we started AED tapering at 3 months in patients on duotherapy/polytherapy and at 1 year after ATL for those on monotherapy. We used Kaplan-Meier survival curves to estimate the probability of seizure recurrence and complete AED discontinuation, and compared the attributes of recurred and nonrecurred groups of patients by univariate and multivariate logistic regression analyses.
Key findings: Immediately after ATL, 197 patients were on duotherapy and 101 were on monotherapy. We attempted AED withdrawal in 258 patients (83.2%). Sixty-four patients (24.8%) had seizure recurrence while reducing AEDs. Of 26 patients who had seizure recurrence after complete AED withdrawal, 24 (92.3%) again became seizure-free after restarting the AEDs. Absence of hippocampal sclerosis on pathologic examination and abnormal postoperative electroencephalogram (EEG) predicted seizure recurrence on multivariate analysis. At the end of follow-up duration of 8.0 ± 2.0 years, 163 patients (52.6%) were AED free. The cumulative probability of achieving AED-free status among patients in whom AED withdrawal was attempted, was 44% at fourth year, 65% at sixth year, 71% at eighth year, and 77% at 10th year after ATL.
Significance: AED withdrawal can be safely attempted following successful ATL. Seizure recurrences are few and can be managed easily.
Wiley Periodicals, Inc. © 2011 International League Against Epilepsy.