Ahead of Print: Intraoperative Neuromonitoring in Glioma Surgery

Background: Resection of gliomas in or adjacent to the motor system is widely performed using intraoperative neuromonitoring (IOM). Despite the fact that data on the safety of IOM are available, the significance and predictive value of the procedure is still under discussion. Moreover, cases of false negative monitoring affect the surgeon’s confidence in IOM.

Objective: To examine cases of false negative IOM to reveal structural explanations.

Methods: Between 2007 and 2010 we resected 115 consecutive supratentorial gliomas in or close to eloquent motor areas using direct cortical stimulation for monitoring of motor evoked potentials (MEPs). The monitoring data were reviewed and related to new postoperative motor deficit and postoperative imaging. Clinical outcomes were assessed during follow-up.