Abstracts

To evaluate a novel method for localization of subdural electrodes in presurgical assessment of patients with drug-resistant focal epilepsy., We studied eight consecutive patients with posterior epilepsy in whom subdural electrodes were implanted for presurgical evaluation. Electrodes were detected on post-implantation brain CT scans through a semiautomated procedure based on a MATLAB routine. Then, post-implantation CT scans were fused with pre-implantation MRI to localize the electrodes in relation to the underlying cortical structures. Two independent raters tested the reliability of this procedure by comparing 3D-rendered MR images of the electrodes with electrode position as determined by intraoperative digital photography., In each patient, all electrodes could be correctly localized and visualized in a stereotactic space, thus allowing optimal surgery planning. For both raters, the agreement between the procedure-generated images and the digital photographs was good in all patients., While our findings need confirmation on larger samples including patients with anterior epilepsy, this procedure allowed to localize subdural electrodes and to establish the spatial relationship of each electrode to the underlying brain structure, either normal or damaged, on brain convessity, basal and medial cortex.[table1][figure1],