Beyond seizure freedom: Dissecting long‐term seizure control after surgical resection for drug‐resistant epilepsy

OBJECTIVE: This study was undertaken to better understand the long‐term palliative and disease‐modifying effects of surgical resection beyond seizure freedom, including frequency reduction and both late recurrence and remission, in patients with drug‐resistant epilepsy. METHODS: This retrospective database‐driven cohort study included all patients with >9 years of follow‐up at a single high‐volume epilepsy center. We included patients who underwent lobectomy, multilobar resection, or lesionectomies for drug‐resistant epilepsy; we excluded patients who underwent hemispherectomies. Our main outcomes were (1) reduction in frequency of disabling seizures (at 6 months, each year up to 9 years postoperatively, and at last follow‐up), (2) achievement of seizure remission (>6 months, >1 year, and longest duration), and (3) seizure freedom at last follow‐up. RESULTS: We included 251 patients; 234 (93.2%) achieved 6 months and 232 (92.4%) experienced 1 year of seizure freedom. Of these, the average period of seizure freedom was 10.3 years. A total of 182 (72.5%) patients were seizure‐free at last follow‐up (defined as >1 year without seizures), with a median 11.9 years since remission. For patients not completely seizure‐free, the mean seizure frequency reduction at each time point was 76.2%, and ranged from 66.6% to 85.0%. Patients decreased their number of antiseizure medications on average by .58, and 53 (21.2%) patients were on no antiseizure medication at last follow‐up. Nearly half (47.1%) of those seizure‐free at last follow‐up were not seizure‐free immediately postoperatively. SIGNIFICANCE: Patients who continue to have seizures after resection often have considerable reductions in seizure frequency, and many are able to achieve seizure freedom in a delayed manner.