Abstracts

Rationale: Epilepsy surgery leads to significant seizure reduction and may lead to improvements in development. However, epilepsy surgery may also lead to deficits due to resection of eloquent cortex. Our objective was to assess neuropsychological outcome in children undergoing epilepsy surgery. Methods: Pediatric epilepsy surgery patients (3-20 years) with pre- and postoperative neuropsychological assessments were reviewed over a 5 year period, including demographics, seizure types and results of Wechsler Scales of Intelligence (WISC-IV and WAIS-III), Delis-Kaplan Executive Function System (D-KEFS), Wechsler Memory Scale, third edition (WMS-III), Children’s Memory Scale (CMS) and California Verbal Learning Test- Second Edition, and Children’s versions (CVLT-II and CVLT-C); and Behavior Rating Inventory of Executive Function (BRIEF). Results were compared to non-surgical epilepsy patients. Statistical analysis was performed using nonparametric tests. Results: 18 patients (9 females, median age at first assessment: 14.5 years; median age at seizure onset: 2 years) with temporal (12), frontal (1), occipital (2), hemispherectomy (2) and resection of hypothalamic hamartoma (HH) (1) were reviewed. Seizure types included auras (8), focal motor (13), dyscognitive (9), hypomotor (3), automotor (3), and gelastic (1) seizures. Etiologies included tumors (3), infarcts (3), malformation of cortical development (2), HH (1), hemorrhage (1), mesial temporal sclerosis (MTS) (7), and gliosis (1). 11 epilepsy patients (5 females, median age at first assessment: 10 years; median age of seizure onset: 2 years) with aura (5), focal (5) and generalized (2) motor, dyscognitive (6), and myoclonic (1) seizures were reviewed. MRI was normal (6), or showed stroke (2), hemorrhage (1), leukodystrophy (1) and periventricular leukomalacia (1). Test interval in the surgical group was 1.6 years and 2 years in comparison patients. Seizures significantly decreased from a median of 5.25/month to 0/month in the surgical group (p<0.05) and from 0.5/month to 0/month in the comparison group. 13/18 surgical and 6/11 comparison patients were seizure free on follow-up. Neuropsychological function remained largely unchanged at follow-up. In the surgical group, parent report of metacognitive aspects of executive function declined (3, -1) (p<0.05). Trends to improvement in the surgical group were seen in verbal reasoning (3:-3.5), verbal learning and memory (2.5, -3), and parent reported behavioral regulation (5, -2). There were also trends to worse nonverbal reasoning (4,-1.5), and nonverbal memory (2.5,0). Seizure frequency, laterality, age and seizure outcome did not predict change in neuropsychological outcome.