Multimodal Intraoperative Neuromonitoring in Intradural Spinal Tumors: A Detailed Case Series Highlighting the Role of D‑Wave Monitoring

Background: Surgical management of intradural spinal tumors carries a significant risk of postoperative neurological deficits due to the compact organization of neural pathways within the spinal cord. Multimodal intraoperative neuromonitoring (IONM), including motor evoked potentials (MEP), somatosensory evoked potentials (SSEP), and D‑wave monitoring, has emerged as an essential adjunct for functional preservation. Objective: To evaluate the role of multimodal IONM in guiding tumor resection and predicting postoperative neurological outcomes in patients undergoing surgery for intradural spinal tumors. Methods: A retrospective analysis of four patients undergoing intradural spinal tumor resection with multimodal IONM was performed. Intraoperative neuromonitoring changes were correlated with immediate and follow‑up neurological outcomes. Results: Transient MEP changes were observed in three patients. Preservation or recovery of D‑wave amplitude strongly correlated with favorable long‑term motor outcomes. Conclusion: Multimodal IONM, particularly D‑wave monitoring, plays a critical role in safe resection of intradural spinal tumors and in predicting postoperative neurological recovery.