The surgical management of pediatric brain tumors causing epilepsy: consideration of the epileptogenic zone

Children suffering from epilepsy with suspected low-grade tumors may benefit from a surgical approach that considers the epileptogenic zone, which can be more extensive than the tumor region. This study aimed to determine the prevalence of epilepsy in children undergoing supratentorial tumor resection and the factors predictive of postoperative seizure freedom in children with low-grade tumors. Subjects 3 months to 21 years undergoing supratentorial brain tumor resection between 2007 and 2011 were included in this retrospective study. Children with supratentorial, cortically based tumors and a preoperative diagnosis of epilepsy were considered epilepsy surgery candidates. Pre- and postoperative MRI were reviewed and scored for extent of resection, adjacent dysplasia, and remaining abnormal cortex postoperatively. The prevalence of seizures in all cases of supratentorial tumors was 46/87 (53 %). Eighteen were epilepsy surgery candidates. Eight of 18 (44 %) were seizure-free postoperatively with a mean follow-up of 39 months. Children who were seizure free postoperatively had tried fewer anticonvulsants than those with continued seizures (1.7 v. 2.9, p = 0.01). Presurgical evaluation was nonstandardized, and a more extensive workup and resection were performed in children who continued to have seizures postoperatively. All epilepsy surgery candidates had low-grade tumors on histological evaluation, indicating that a surgical approach that takes into consideration the epileptogenic zone is reasonable in this population. Gross total resection should be the goal, with additional attention to resection of the epileptogenic zone when located in the noneloquent cortex.