2021 Volume 12 Issue 6 Pages 859-863
Introduction: Removal of intradural extramedullary spinal cord tumors in thoracolumbar spine with total or partial laminectomy has been extensively utilized; however, new neurological symptoms often develop. Motor evoked potential (MEP) monitoring during surgery has been found to be useful for decreasing postoperative neurological complications in the prediction of postoperative neurological complications. Therefore, use of multimodality intraoperative monitoring, including MEP monitoring for surgery has been recommended. This study aimed to investigate the prognosis of new-onset or worsening neurological symptoms following the removal of intradural extramedullary tumors in the thoracolumbar spine on MEP monitoring.
Method: Fifty-five patients (29 men, and 26 women; mean age, 61.8 years: mean follow-up duration, 33.1 months) who had undergone removal of intradural extramedullary tumors in the thoracolumbar spine at our hospital between January 2006 and September 2019 were retrospectively reviewed. Transcranial electrical stimulation was used for MEP monitoring of all patients. Data pertaining to age, sex, follow-up duration, histology, location, and neurological deficits from the medical charts of these patients were reviewed. New-onset or worsening neurological symptoms included motor and sensory deficit and bladder dysfunction.
Results: The histopathological diagnoses were schwannomas in 35 patients, meningioma in 17, ependymoma in 1, epidermoid tumor in 1, hemangioma in 1, and glomus tumor in 1. New-onset or worsening neurological symptoms were observed in 19 patients (34.5%) after the surgery; 17 patients exhibited a new-onset sensory disorder, 3 had a worsening motor deficit, and 3 had new-onset bladder dysfunction. In the patient who developed postoperative bladder dysfunction, the tumor was localized to the ventral side of the conus medullaris. The MEP amplitude of all three patients did not decrease by >50% from that observed at baseline.
Conclusion: The present study demonstrated that the incidence of new-onset or worsening neurological symptoms after the removal of intradural extramedullary tumors was 34.5% on MEP monitoring. Three patients had new-onset bladder dysfunction. Care should be taken when treating the ventral side tumor of the conus medullaris.
