Hemispherectomy for catastrophic epilepsy in infants

Purpose: To report our experience with hemispherectomy in the treatment of catastrophic epilepsy in children younger than 2 years. Methods: In a single-surgeon series, we performed a retrospective analysis of 18 patients with refractory epilepsy undergoing hemispherectomy (22 procedures). Three different surgical techniques were performed: anatomic hemispherectomy, functional hemispherectomy, and modified anatomic hemispherectomy. Pre- and postoperative evaluations included extensive video-EEG monitoring, magnetic resonance imaging, and positron emission tomography scanning. Seizure outcome was correlated with possible variables associated with persistent postoperative seizures. The Generalized Estimation Equation (GEE) and the Barnard's exact test were used as statistical methods. Results: The follow-up was 12-74 months (mean, 34.8 months). Mean weight was 9.3 kg (6-12.3 kg). The population age was 3-22 months (mean, 11.7 months). Thirteen (66%) patients were seizure free, and four patients had > 90% reduction of the seizure frequency and intensity. The overall complication rate was 16.7%. No deaths occurred. Twelve (54.5%) of 22 procedures resulted in incomplete disconnection, evidenced on postoperative images. Type of surgical procedure, diagnosis categories, persistence of insular cortex, and bilateral interictal epileptiform activity were not associated with persistent seizures after surgery. Incomplete disconnection was the only variable statistically associated with persistent seizures after surgery (p < 0.05). Conclusions: Hemispherectomy for seizure control provides excellent and dramatic results with a satisfactory complication rate. Our results support the concept that early surgery should be indicated in highly selected patients with catastrophic epilepsy. Safety factors such as an expert team in the pediatric intensive care unit, neuroanesthesia, and a pediatric epilepsy surgeon familiar with the procedure are mandatory.