(Re)Defining success in epilepsy surgery: The importance of relative seizure reduction in patient-reported quality of life.

In our high severity and complexity cohort, a substantial subset of patients (27%) reported improved QoL despite persistent seizures. Relative seizure reduction was at least as good a predictor of QoL as seizure freedom. A yes/no seizure freedom variable may be a suboptimal measure of surgical success, especially in high complexity cohorts.