Correlation of Intraoperative Neurophysiological Parameters and Outcomes in Patients with Intramedullary Tumors

INTRODUCTION: Intramedullary spinal cord tumors (IMSCT) account for about 2%–4% of all central nervous system tumors. Surgical resection is the main treatment step, but might cause damage to functional tissues. Intraoperative neuromonitoring (IONM) is an adopted measure to decrease surgical complications. Below, we describe the results of IMSCT submitted to surgery under IONM at a tertiary institution. METHODS: The sample consisted of consecutive patients with IMSCT admitted to the Neurological Institute of Curitiba from January 2007 to November 2016. A total of 47 patients were surgically treated. Twenty-three were male (48.9%) and 24 were female (51.1%). The mean age was 42.77 years. The mean follow-up time was 42.7 months. RESULTS: Neurological status improved in 29 patients (62%), stable in 6 (13%), and worse in 12 (25%). Patients who presented with motor symptoms at initial diagnosis had a worse outcome compared to patients with sensory impairment and pain (P = 0.026). Patients with a change in electromyography had worse neurological outcomes compared to patients who did not show changes in monitoring (P = 0.017). DISCUSSION AND CONCLUSION: No prospective randomized high evidence study has been performed to date to compare clinical evolution after surgery with or without monitoring. In our sample, surgical resection was well succeeded mainly in oligosymptomatic patients with low preoperative McCormick classification and no worsening of IONM during surgery. We believe that microsurgical resection of IMSCT with simultaneous IONM is the gold standard treatment and achieved with good results.