Intraoperative motor evoked potentials and pyramidal tractography for insular gliomas

Objective: This prospective study examines the ability of intraoperative motor evoked potentials (MEPs) to reflect ischemic involvement of the pyramidal tract, which is frequently observed with new paresis after insular glioma surgery. Methods: In a series of 45 insular gliomas, intraoperative MEP results were correlated with motor outcome and perioperative MR imaging including pyramidal tractography, FLAIR and diffusion-weighted studies. Results: MEP deterioration indicated new paresis in 13 patients, and was reversible with only transient new deficit in 9 of these cases. The grade of MEP attenuation matched th…