Abstracts

Rationale: Approximately 1/3 of patients with epilepsy have pharmacoresistant seizures. For these patients surgery is an effective and potentially life-saving intervention. Several studies have revealed very favorable surgical outcomes in children and adolescents with temporal lobe epilepsy. The primary aim of this study was to evaluate the neuropsychological outcomes in pediatric patients undergoing temporal lobe epilepsy surgery. Secondarily, we compare the neuropsychological outcomes based upon age of onset and operating suite (iMRI vs standard). Methods: We retrospectively reviewed the neurosurgical and neuropsychological reports of patients (age 1-21 years) who had undergone a temporal lobe resection for treatment of intractable epilepsy at Cook Children's Medical Center since 2001. Of the 164 patients identified, 74 underwent baseline neuropsychological assessments and 47 had post-op assessment. Results: Seventy-three percent of patients had evidence of disease solely in the temporal lobe, 68% had unifocal disease, and 87% had radiological evidence of one or more lesions. At least 75% of patients were deemed to have significant seizure improvement with >50% reporting complete freedom from disabling seizures at each time point. Analysis of baseline and postoperative scores revealed decline in verbal memory (p = .04) and reading comprehension (p = .02), but improvement for word reading (p = .05) and working memory (p = .08). Evaluation of preoperative individual, disease, and therapeutic variables showed that verbal comprehension scores increased for patients with lesions in the right hemisphere or bilaterally (R² = .486, F_(2,18) = 8.53, p = .002). Attention improved over time for more than 50% of patients; though the presence of a lesion was a significant predictor of decline in attention (R² = .206, F_(1,21) = 5.19, p = .034). At baseline, patients with early onset of epilepsy (<7 years) had lower scores on intelligence (p = .007), perceptual reasoning (p = .005), processing speed (p = .059.), and attention (p = .017). At one-year follow-up, the early onset group demonstrated improvement and the late onset group declined over time for the response style domain of the attention measure (p = .03), intelligence (p = .06) and working memory (p = .08). No significant differences were observed between the iMRI and standard operating suite. Conclusions: This study demonstrated the predictive ability of several disease-specific variables on neurocognitive outcomes of temporal lobectomy in pediatric patients. Intelligence and attention scores improved following temporal lobectomy, while memory and achievement scores remained fairly stable. These results are consistent with prior research on intelligence and memory and contribute with the additional improvement of attention. Given the knowledge that aspects of memory, intelligence, and attention are impacted by epilepsy surgery, surgical candidates and their legal guardians could be better informed and advised on the outcomes of temporal lobe epilepsy surgery.