Abstracts

Rationale: Little is known regarding postoperative changes in functioning among pediatric patients undergoing nondominant frontal topectomy (NDFT). In a previous study, it was found that some pediatric patients undergoing NDFT experience a postoperative decline in judgment that appears to be of a transitory nature. In adults, those undergoing large NDFT can experience some diminishment of cognitive flexibility and IQ; however, to date, there is no published account such as this on changes specific to NDFT in children. The purpose of this study was to clarify postoperative changes in executive functions in pediatric NDFT patients. Methods: Five patients, age 7 to 11 years at the time of surgery, underwent NDFT for intractable seizures. Hemispheric dominance for language was established with the intracarotid amobarbital procedure (IAP) in all patients. The sample was limited to patients with IQ greater than 70, as those of lower ability were often unable to complete a formal test battery. Patients were seen for postoperative testing at intervals ranging from 5 months to 4 years, 4 months. Pre- and postoperative scores on measures of IQ, problem-solving (PS), verbal fluency (VF), and nonverbal fluency (NF) were reviewed retrospectively to assess for postoperative cognitive changes. Results: Three patients showed no postoperative decline in executive functions (PS, VF, NF). One patient, who did not experience improved seizure control postoperatively, displayed postoperative declines, from the normal to impaired range, on measures of PS, VF, and one of two indices of NF, although NF recovered to the normal range by the time of a subsequent postoperative follow-up (6.5 years post surgery). Postoperative IQ remained average in this patient. A similar decline in NF was seen in one other patient, and this patient’s performance also rebounded to the normal range during a subsequent postoperative evaluation (8 years, 8 months post surgery). Only a single patient displayed a decline in IQ, from the average to low average range, which appeared related to cognitive side effects of AED treatment. Conclusions: Results suggest that, within this small sample, most pediatric NDFT patients display stable performance on formal tests of executive problem solving and overall intellectual functioning. We did not observe a persistent adverse change specifically in nonverbal fluency, a purported nondominant frontal function, nor was cognitive flexibility more generally compromised by NDFT in most patients. These data suggest that risk of long term cognitive decline postoperatively in pediatric NDFT patients is relatively low.