A reappraisal of mortality after epilepsy surgery

To assess whether epilepsy surgery is associated with a reduction in mortality rate and if postoperative seizure frequency and severity affect mortality.

A total of 1,110 patients were evaluated (1,006 surgically and 104 nonsurgically treated) for a total follow-up of 8,126.62 person-years from 1986 to 2013. Deaths were ascertained through database and Social Security Death Index query. Patients were grouped by surgery type and seizure status; standardized mortality ratio and deaths per 1,000 person-years were calculated. Survival analysis and Cox proportional hazard regression were performed.

Eighty-nine deaths were observed. Surgically treated patients had a lower mortality rate (8.6 per 1,000 person-years [95% confidence interval (CI) 6.58-11.15]) than nonsurgically treated patients (25.3 per 1,000 person-years [14.50-41.17]; p < 0.001). Seizure-free patients had a lower mortality rate (5.2 per 1,000 person-years [95% CI 2.67-9.02]) than non-seizure-free patients (10.4 per 1,000 person-years [95% CI 7.67-13.89] p = 0.03). More frequent postoperative tonic-clonic seizures (>2 per year) were associated with increased mortality (p = 0.006) whereas complex partial seizure frequency was not related to death rate. Mortality was similar in temporal and extratemporal epilepsy patients (p = 0.7).

Brain surgery is associated with a reduction in mortality rate in drug-resistant epilepsy, both when seizures are abolished and when it results in significant palliation of tonic-clonic seizure frequency. These observations provide further rationale for earlier consideration of epilepsy surgery.