Spinal Nerves Schwannomas: Experience on 367 Cases - Historic Overview on How Clinical, Radiological, and Surgical Practices Have Changed over a Course of 60 Years

Background. Spinal schwannomas are common benign spinal tumors. Their treatment has significantly evolved over the years, and preserving neurological functions has become one of the main treatment goals together with tumor resection. Study Design and Aims. Retrospective review focused on clinical assessment, treatment techniques, and outcomes. Methods. A retrospective study on our surgical series was performed. Clinical and operative data were analyzed. In regard to neurophysiologic monitoring, patients were retrospectively divided into two groups comparing the outcomes before and after introduction of routine intraoperative neurophysiology tests. Results. From 1951 to 2010, 367 patients overall were treated. Diagnosis was obtained using angiography and/or myelography (pre-CT era), MRI, or CT scan. A posterior spinal approach was used for most patients; complex approaches were adopted for treatment of giant/dumbbell tumors. A trend of neurophysiology monitoring decreasing the rate of post-op neurological deficits was observed but was not statistically significant enough to draft evidence-based conclusions. Conclusions. Clinical and radiological assessment of spinal schwannomas has markedly changed over the course of 50 years. Diagnostic tools have improved, and detection of recurrence has become way more sensitive. Neurophysiologic monitoring has become a useful intraoperative tool to guide resection and prevent post-op neurological impairment.