Impact of Intraoperative Neurophysiological Monitoring on the Extent of Resection and Postoperative Neurological Outcomes in Patients with Spinal Cord Ependymoma: A Retrospective Multicenter Comparative Study

Abstract

Background Data: Spinal cord ependymomas can arise in different locations throughout the spinal cord, with the most frequent location being the cervical spine. Ependymomas usually grow slowly, compressing rather than infiltrating spinal tumors. Among different prognostic and predictor factors, the extent of resection has been the strongest predictor of outcomes. Multimodal intraoperative neurophysiological monitoring (IONM) helps maximize the extent of resection with minimal postoperative neurological complications. Purpose: To assess the impact of IONM on the extent of surgical resection and outcomes of spinal cord ependymomas. Study Design: A retrospective cohort study. Patients and Methods: Twenty-five patients who underwent spinal cord ependymoma resection in 4 centers between March 2014 and February 2018 were eligible for the inclusion criteria of this study. Patients were divided into two groups: the IONM group and the non-IONM group. IONM consisted of electromyography (EMG), transcranial motor evoked potentials (tcMEP), and somatosensory evoked potentials (SSEP). All patients were submitted for full neurological examination and MRI of the spine both preoperatively and at the postoperative routine follow-up. Postoperative radiotherapy was conducted routinely by our radiotherapists. The secondary outcomes were the correlation between the warning criteria of IONM and postoperative neurological outcomes and their impact on the extent of tumor resection. Also, a recurrence rate during the follow-up period was reported.