Intramedullary Schwannoma of the Spinal Cord: A Nationwide Analysis by the Neurospinal Society of Japan

Objective: This study was aimed to report the clinical characteristics of intramedullary schwannomas and discuss imaging findings and treatment strategies.Methods: The inclusion criterion was consecutive patients with intramedullary schwannomas who were surgically treated at 8 centers between 2009 and 2020. Clinical characteristics included age, sex, clinical presentation, disease duration, and follow-up period. The modified McCormick scale was used to compare the preoperative and postoperative conditions. Pre-and postoperative magnetic resonance images (MRI) of each case were analyzed. Results: The mean age of the total 11 patients at the operation was 50.2 years. The mean duration of the symptoms was 23 months, with limb paresthesia being the most common clinical presentation. The cervical spine was the most common localization level of the tumor in 6 cases. The mean follow-up duration was 49.4 months. Gross total resection (GTR) and subtotal resection (STR) was achieved in 9 and 2 cases, respectively. According to the modified McCormick scale at 6 months postoperatively, 7 cases (63. 6%) had improved and 4 cases (36. 3%) had unchanged grades. Typical MRI findings of the intramedullary schwannoma included ring-like enhancement, syringomyelia, cystic formation, intramedullary edema, and hemosiderin deposition. Gadolinium enhancement was homogenous in 8 cases (72.7%). The tumor margins were well demarcated in all cases.Conclusion: Intramedullary schwannoma should be considered when sharp margins and well-enhanced tumors are present at the cervical spine level and the initial symptoms are relatively mild, such as dysesthesia. When GTR cannot be achieved, STR for tumor decompression is recommended.

Automated summary

This study reports on the clinical characteristics, imaging findings, and treatment strategies of intramedullary schwannomas. The study analyzed patients who underwent surgical treatment for intramedullary schwannomas at 8 centers between 2009 and 2020. The findings showed that the most common clinical presentation was limb paresthesia and the cervical spine was the most common location for the tumors. The study also discussed the MRI findings of intramedullary schwannomas and suggested treatment strategies based on the extent of tumor resection and symptom improvement.