Abstracts

Rationale: This study was designed to evaluate surgical outcomes and prognostic factors that expect more favorable postoperative seizure outcomes after hemispherotomy in catastrophic epilepsy of unilateral hemispheric pathology. Methods: We performed a retrospective analysis of 26 patients with medically intractable epilepsy undergoing hemipherotomy or functional hemispherotomy at Severance Children s Hospital between 2003 and 2009. Preoperative evaluation included video-EEG monitoring, MRI and FDG-PET. And we also reviewed medical records and postoperative routine EEG findings and confirmative pathologic findings. Results: Overall mean follow up duration was 2.5 1.9 years and mean duration of epilepsy was 4.6 6.2 years. Mean age of surgery was 5.9 6.3 years and, mean age of seizure onset was 1.4 2.0 years. Sixteen patients (61.5%) showed Engel Class I outcome, 6 patients (23.1%) showed Engel Class II and 4 patients (15.4%) showed Engel Class III outcomes. Preoperative evaluation revealed concordance in 18 patients (69.2%) on MRI and 17 patients (63.0%) on FDG-PET. Malformation of cortical development was the most common etiology (12 patients, 46.2%). Other etiologies included Sturge-Weber syndrome, hemorrhage, infarction, Rasmussen encephalitis, hypoxic ischemic encephalopathy. Overall number of antiepileptic drugs was decreased from 3.38 to 2.15 postoperatively. Among many variables, complete resection was most reliable prognostic factor of favorable seizure outcome (p=0.0040) and unilateral abnormality on FDG-PET can be a possible predictor of seizure outcome on univariate analysis(p=0.0135). Conclusions: Surgical outcomes of hemispherotomy were favorable. To improve postoperative seizure outcomes, it is most recommended to select optimal candidates of complete lateralized hemispheric pathology through utilization of advanced neurodiagnostic modalities including video EEG monitoring and neuroradiologic studies, especially FDG-PET. With well defined surgery resulted in complete resection, we can achieve more favorable postoperative seizure outcomes in hemispherotomy.