Abstracts

Rationale: It has been well-established that children with intractable seizure disorders are at increased risk for a variety of negative outcomes including cognitive impairment and behavioral and emotional issues. Pediatric hemispherectomy has been demonstrated as a viable treatment option in cases with unilateral multi-lobe involvement to relieve seizure burden, reduce reliance on antiepileptic medications and improve overall quality of life. However, relatively few studies have systematically compared presurgical status with post-surgical impact of this procedure on intellectual and adaptive functioning in children undergoing functional hemispherectomy for intractable epilepsy. Methods: Twelve children and adolescents (50% male, range=1 to 13 years old, mean age=6) were referred for comprehensive neuropsychological assessment by a pediatric epilepsy neurosurgery team before and approximately 8 months following surgical intervention (6 right, 6 left). During these evaluations, participants completed age-appropriate measures of intellectual and adaptive functioning, from which three composite index scores were derived (Verbal Cognition, Nonverbal Cognition, Adaptive Behavior). Results: Following surgery, 11 out of 12 children obtained complete seizure freedom; one child continues to have occasional break-through seizures. Scores on test measures were analyzed at each time-point by comparing means to normative standards, using one-sample t-tests. These results indicated that patients fell significantly below the normative mean on verbal, nonverbal and adaptive functioning measures during both the pre- and post-surgical evaluation (p=.00). However, a series of paired-samples t-tests revealed no significant change in performance between evaluations with regards to Verbal Cognition (p=.18), Nonverbal Cognition (p=.08) and Adaptive Behavior (p=.15). Conclusions: While cognitive outcomes following focal resection surgery have been well described in the literature, our understanding of outcomes following pediatric hemispherectomy has been much more limited. These results suggest a relatively stable performance on measures of intellectual and adaptive functioning after functional hemispherectomy for intractable epilepsy. This area of research has important implications for understanding the impact of epilepsy surgery on cognitive and adaptive functioning. The relationships of these findings to various clinical factors including side of hemispherectomy, number of anti-epileptic medications (AEDs) and age at surgery will be discussed. Funding: N/A