Historical Risk Factors Associated with Seizure Outcome After Surgery for Drug-Resistant Mesial Temporal Lobe Epilepsy

OBJECTIVE: To investigate the possible influence of risk factors on seizure outcome after surgery for drug-resistant temporal lobe epilepsy (TLE) and mesial temporal sclerosis (MTS). METHODS: This retrospective study recruited patients with drug-resistant MTS-TLE who underwent epilepsy surgery at Jefferson Comprehensive Epilepsy Center and were followed for a minimum of 1 year. Patients had been prospectively registered in a database from 1986 through 2014. After surgery outcome was classified into 2 groups: seizure-free or relapsed. The possible risk factors influencing long-term outcome after surgery were investigated. RESULTS: A total of 275 patients with MTS-TLE were studied. Two thirds of the patients had Engel's class 1 outcome and 48.4% of the patients had sustained seizure freedom, with no seizures since surgery. Patients with a history of tonic-clonic seizures in the year preceding surgery were more likely to experience seizure recurrence (odds ratio, 2.4; 95% confidence interval 1.19-4.80; P = 0.01). Gender, race, family history of epilepsy, history of febrile seizure, history of status epilepticus, duration of disease before surgery, intelligence quotient, and seizure frequency were not predictors of outcome. CONCLUSIONS: Many patients with drug-resistant MTS-TLE respond favorably to surgery. It is critical to distinguish among different types and etiologies of TLE when predicting outcome after surgery.