Surgery for epilepsy due to cortical malformations: ten-year follow-up.

Children with malformations of cortical development represent a significant proportion of pediatric epilepsy surgery candidates. From a cohort of 40 children operated on between 1980 and 1992 with malformation of cortical development, 38 were alive and had data 10 years after surgery. Age at surgery ranged from 6 months to 18 years (mean, 9.6 years). Thirty-six had partial seizures, and two had infantile spasms; 20 were nonlesional. Pathologic diagnoses were cortical dysplasia (n = 31) and developmental tumor (n = 7). At 10-year follow-up, 15 (40%) were seizure free, 10 (26%) had >90% seizure reduction, and 13 (34%) were improved or unchanged. Children seizure free at two-year follow-up were likely to remain seizure free. Ten-year seizure freedom was 72% in children with developmental tumors and 32% in the cortical dysplasia group. Complete resection was statistically significant for favorable outcome, and no patient with an incomplete resection was seizure free.