Abstracts

RATIONALE: Adult studies suggest that dominant frontal topectomy (DFT) results in diminished language functions, including verbal fluency and verbal IQ, with deficits more likely following larger resections. This study was aimed at assessing cognitive outcome following DFT in a pediatric epilepsy population.
METHODS: Patients included six children and adolescents ranging in age from 8 to 16 years (mean = 13) at the time of surgery. Four evidenced cryptogenic epilepsy and two experienced seizures secondary to low grade tumor. In patients with cryptogenic seizures, the frontal region anterior to language was resected, except one patient whose frontal pole was spared. Surgery was limited to tumor resection in the two tumor patients. All patients underwent cortical mapping of language and motor areas via stimulation of a subdural electrode array prior to resection. Patients underwent neuropsychological testing prior to and three to 13 months following DFT (mean = 9 months). Changes in confrontation naming, verbal fluency, verbal intelligence, and problem solving were analyzed.
RESULTS: Both tumor patients evidenced stable or improved verbal IQ, verbal fluency, and problem-solving post-operatively; one experienced a mild (1 SD) decline in confrontation naming. A 1-2 SD decline in verbal fluency was noted in all four patients with cryptogenic epilepsy. A mild (.5-1 SD) decline was noted in problem solving in two of these patients and mild declines in VIQ and confrontation naming were noted in the other two individuals. By parent report, cryptogenic seizure patients who experienced decreased problem-solving on formal testing were nonetheless described as having improved self-awareness or social judgment post-operatively. No patient was reported by parents to have experienced an adverse behavioral change.
CONCLUSIONS: Neuropsychological outcome in pediatric patients is similar to that observed in adults. Diminished verbal fluency and, less frequently, diminished problem-solving and verbal IQ were observed primarily in patients undergoing extensive frontal topectomy for cryptogenic epilepsy. Patients undergoing limited resection for tumor removal experienced minimal cognitive changes and often improved verbal functioning. Parent report suggests that improved seizure control may result in nonspecific improvements in mental efficiency and social behavior that may offset mild declines in executive abilities observed on formal testing. Seizure outcome and postoperative medication changes will be reported.