Abstracts

Rationale: Corpus callosotomy is a palliative disconnection procedure that consists of microsurgically sectioning the corpus callosum which is to disrupt the bilateral propagation of epileptic discharges, thereby decreasing frequency and severity of seizure. The overall goal of the current study is to evaluate the preoperative lateralizing values in patients of corpus callostomy. Methods: A total 105 patients (male: 63, female 42) underwent corpus callosotomy at the Severance Children's Hospital between October 2003 and July 2011. Lennox-Gastuat syndrome was the most diagnosis, and was 86 patients (81.9%). The medical records were retrospectively reviewed for all patients. Clinical characteristics, surgical outcomes, etiologies, and EEG profiles (background, asymmetric slowing, independent sharp wave discharges, generalized slow sharp and wave discharges, generalized paroxysmal fast activities, localized paroxysmal fast activities, subclinical seizure, clinical seizure, and dominancy) were reviewed. Statistical analyses were performed using the SAS (version 9.2, Institute, Cary, NC, USA). For analyzing differences of EEG profiles between preoperative and postoperative features, McNemar's test and logistic regression were used. The probability value less than 0.05 we defined as statistically significant. Results: The age at seizure onset was 2.5 years (range, 0.5 month-15.5 year). The age at surgery was 8.0 years (range, 3.6 month-20.7 year). The period between seizure onset and surgery was 5.5 years (range, 2.4 month-17.5 year). Total corpus callosotomy was the most common procedure, and was performed in 96 patients (91.4%). Partial corpus callosotomy was performed in 9 patients (8.6%). Twenty-nine patients (27.6%) demonstrated an Engel class I outcome at least 12 months after callosotomy. The mean follow-up duration after surgery was 4.0 years (range, 1.1-9.2 years). Significant lateralization in post-callostomy patients were found in 29 (27.6%) patients. Preoperative asymmetric slowing on EEG could predict lateralization (OR: 3.77, CI: 1.45-9.78). Twenty-five patients had done secondary resective surgery due to lateralization on postoperative follow-up EEG findings. Ten patients (40.0%) demonstrated an Engel class I outcome after secondary resective surgery. Conclusions: Corpus callosotomy could be an possible lateralizing method for patients suffering from intractable generalized pediatric epilepsy that are not candidates for resective surgery with generalized EEG features.