Efficacy of a third or later antiepileptic drug regimen according to epilepsy syndrome among adult patients

Objective: To evaluate the efficacy of third or later antiepileptic drug (AED) regimens in adult patients with epilepsy according to epilepsy syndrome. Methods: The time courses of AEDs and their efficacy were evaluated in 449 adults with temporal lobe epilepsy (TLE, n = 153), juvenile myoclonic epilepsy (JME, n = 33), or extratemporal focal epilepsy (FE, n = 263) based mainly on clinical symptoms and EEG findings. Any change in AEDs after their initiation demarcated the end of one regimen, whereas changes in dose did not. Patients were judged to be seizure-free when they had no seizures for at least 1 year with no changes in AED regimen. Results: Only 55 of 153 patients in the TLE group were free of seizures at the last visit, and the rate was significantly lower in the TLE group than the extratemporal FE group. The rate of seizure freedom with the first regimen was lower in TLE group than in the other groups, whereas the rate at the third regimen or later was significantly higher in the TLE group than the JME group. In the TLE group, a greater proportion of patients who became seizure-free with the first regimen were first treated with carbamazepine (CBZ), whereas a greater proportion of patients who became seizure-free with the fourth regimen were first treated with valproate (VPA).