Reduced long-term mortality after successful resective epilepsy surgery: a population-based study

BACKGROUND: We investigated all-cause and epilepsy-related mortality in patients operated with resective epilepsy surgery and in non-operated patients with drug-resistant epilepsy. Our hypothesis was that patients who proceed to surgery have lower mortality over time compared with non-operated patients. METHOD: Data from 1329 adults and children from the Swedish National Epilepsy Surgery Register and 666 patients with drug-resistant epilepsy who had undergone presurgical work-up but not been operated were analysed. The operated patients had follow-ups between 2 and 20 years. We used the Swedish Cause of Death Register to identify deaths. Autopsy reports were collected for patients with suspected sudden unexpected death in epilepsy (SUDEP). Kaplan-Meier and Cox regression analyses were performed to identify predictors for mortality and SUDEP. RESULTS: SUDEP accounted for 30% of all deaths. Surgery was associated with lower all-cause mortality (HR 0.7, 95% CI 0.5 to 0.9), also when adjusted for age, sex and tonic-clonic seizures at inclusion. The benefit of surgery seemed to persist and possibly even increase after 15 years of follow-up. Risk factors of mortality for operated patients were persisting seizures and living alone. Of the operated patients, 37% had seizures, and these had a higher risk of mortality (HR 2.1, 95% CI 1.4 to 3.0) and SUDEP (HR 3.5, 95% CI 1.7 to 7.3) compared with patients with seizure freedom at last follow-up. CONCLUSIONS: In this large population-based epilepsy surgery cohort, operated patients had a lower all-cause mortality compared with non-operated patients with drug-resistant epilepsy. Seizure freedom was the most important beneficial factor for both all-cause mortality and SUDEP among operated patients.