Preoperative factors associated with antiepileptic drug withdrawal following surgery for intractable temporal lobe epilepsy

Abstract

The outcomes of postoperative antiepileptic drug (AED) cessation after temporal lobe epilepsy surgery were investigated to identify the preoperative factors associated with seizure-free status without drug treatment in 40 patients who underwent resective epilepsy surgery between 2000 and 2007 for the treatment of complex partial seizures of the type typically associated with temporal lobe epilepsy. All patients were followed up for at least 3.5 years after surgery. After the numbers and types of AEDs used as preoperative and postoperative treatments were determined, the patients who obtained seizure-free outcome for at least 2 years after AED cessation were analyzed. Sex, age at surgery, age at seizure onset, time to operation, seizure frequency, operation side, invasive study, pathological types (hippocampal sclerosis or others), history of generalized convulsive seizures, and number of preoperative AEDs were analyzed as factors potentially associated with seizure-free status without drug treatment. In total, 35% of the patients who underwent temporal lobe epilepsy surgery achieved seizure-free status without drugs. The mean number AEDs fell from 2.1 preoperatively to 1.2 after the surgery. Seizures recurred in 18% of the patients after AED withdrawal. A shorter duration from seizure onset to surgery was found to be significantly related to successful withdrawal of postoperative AED treatment. Our results suggested that early surgical intervention after seizure onset is an important precondition for achieving seizure-free status without drugs after temporal lobe epilepsy surgery.