Abstracts

Rationale: Surgery in the insular region is considered challenging because of its vascular relationships, its deep location in the sylvian fissure and the close proximity to functional areas. This study was undertaken to establish safety and vascular consequences of operculo-insular cortectomies for refractory epilepsy. Methods: We retrospectively reviewed all our cases of operculo-insular cortectomies for refractory epilepsy between 1998 and 2012. Tumors and vascular lesions were excluded. All patients had postoperative MRI to document the location and extent of resections, and the occurrence and types of ischemic lesions (IL). Neurological exams were performed during the follow-up visits. Results: Seventeen patients (9 males, 4 dominant hemispheres, mean age 29) had insular cortex resections. This was combined with opercular/lobar resections in 15 cases. No IL from the lenticulo-sriate perforators was identified. IL occurred in 12 patients (70 %). Eleven IL were related to perforating branches from the M2 segments of the middle cerebral artery (MCA) at the surface of the insula. Two IL were related to perforating branches from the M3-4 segments of the MCA contouring the opercula. One IL was related to a distal temporal M4 branch after a combined temporal lobectomy. The IL from perforating branches were small and located in the corona radiata, running from the operculo-insular to the peri-ventricular region. Excluding a superior quadranopia related to a temporal lobectomy, 8 patients (47 %) had a postoperative neurological deficit: 7 hemiparesis and 1 dysphasia. All deficits were transient. Conclusions: In our series, operculo-insular cortectomies were associated with IL in 70 % of patients. However, this finding had limited clinical consequences given that no patient had a permanent postoperative deficit. We therefore consider that operculo-insular cortex resection is a safe procedure for the treatment of refractory epilepsy.