Abstracts

Rationale: To assess outcome of executive function skills following surgery for treatment of temporal lobe epilepsy (TLE) in a pediatric sample. We hypothesize that TLE surgery will be associated with improvement in executive function skills following successful treatment of seizures. Methods: Patients were identified through archival record review. The final sample consisted of 50 patients (30 left, 20 right). Mean age at surgery was 14.9 years (SD=3.7) for the left TLE and 15.3 (SD=3.7) for the right TLE patients (p>0.86; ns). There were no group differences in age of seizure onset or duration of epilepsy at the time of surgery. Patients completed a neuropsychological battery that incorporated executive function tests including Digit Span from the Wechsler Intelligence Scale for Children and Adult Versions, the Letter and Category Verbal Fluency Test, Trail Making Test (TMT) and Tower Test of the Delis-Kaplan Executive Function System (DKEFS), and the parent report version of the Behavior Rating Inventory of Executive Function (BRIEF) prior to surgery and within the first year after surgery (presurgical assessment mean=4.7 months, SD=3; postsurgical assessment mean=8.4 months, SD=3.7). Analysis consisted of repeated measures ANOVA with pre/post surgery scores as within-subjects factor and surgery side as between-subjects factor. Paired sample t-tests that included all patients were conducted for exploratory analysis. Reliable change indices (RCI) corrected for practice effects were also calculated (90%CI). Results: All but four patients (3 left TLE) were seizure free following the surgery, including at the time of the post-surgical assessment (Engel Class I). No group differences in IQ before and after surgery were evident. There was no main effect or interaction with laterality of surgery and measures of executive function. As a group, mean scores comparison before and after surgery indicated nonsignificant increases in performance on Digit Span, Letter Verbal Fluency and TMT. Statistically significant improvement was evident on the Tower Test (p < .04). Individual patient score comparison using RCI (90%CI) revealed a decline in 1 patient (left) and improvement in 1 patient (right) on the TMT; improvement in 5 patients (3 left, 2 right) on Letter Verbal Fluency; improvement in 5 patients (2 left, 3 right) and decline in 7 patients (3 left, 4 right) on Category Verbal Fluency; and improvement in 5 patients (2 left, 3 right) on the Tower. Conclusions: Stability in executive function skills may be expected in most pediatric patients after temporal lobe surgery, and some may demonstrate improved performance. This study has implications for pre-surgical decision-making in pediatric populations. Longitudinal outcome data for these patients is necessary. Funding: No funding