Functional Outcome in Spinal Meningioma Surgery and Use of Intraoperative Neurophysiological Monitoring

SIMPLE SUMMARY: Spinal meningiomas are among the most common intradural spinal tumors. Although most of them are benign, they can cause serious neurological impairment due to spinal cord compression resulting in myelopathy. The main treatment is microsurgical gross total resection. So far, only a few small case series on functional outcome and the value of intraoperative neurophysiological monitoring have been published. In our single-center retrospective cohort, we analyzed functional outcome after surgical treatment with or without intraoperative neurophysiological monitoring. We found that preoperative functional impairment is associated with tumor extension. Most patients improved after surgical resection. The recurrence rate was low and perioperative complications were in the range reported in the published studies. Intraoperative neurophysiological monitoring was helpful in challenging cases and resulted in a change of operative strategy. These findings suggest that surgical treatment of spinal meningiomas is safe and that use of intraoperative neurophysiological monitoring is advisable in complex cases. ABSTRACT: Data on intraoperative neurophysiological monitoring (IOM) during spinal meningioma (SM) surgery are scarce. The aim of this study was to assess the role of IOM and its impact on post-operative functional outcome. Eighty-six consecutive surgically treated SM patients were included. We assessed pre and post-operative Modified McCormick Scale (mMCS), radiological and histopathological data and IOM findings. Degree of cord compression was associated with preoperative mMCS and existence of motor or sensory deficits (p < 0.001). IOM was used in 51 (59.3%) patients (IOM-group). Median pre and post-operative mMCS was II and I, respectively (p < 0.001). Fifty-seven (66.3%) patients showed an improvement of at least one grade in the mMCS one year after surgery. In the IOM group, only one patient had worsened neurological status, and this was correctly predicted by alterations in evoked potentials. Analysis of both groups found no significantly better neurological outcome in the IOM group, but IOM led to changes in surgical strategy in complex cases. Resection of SM is safe and leads to improved neurological outcome in most cases. Both complication and tumor recurrence rates were low. We recommend the use of IOM in surgically challenging cases, such as completely ossified or large ventrolateral SM.