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.