General Session: Tumor, Trauma, Infection - Hall F

Presented by: S. Yi


S. Yi(1), J. Kang(1)

(1) Spine and Spinal Cord Institute,Yonsei University, College of Medicine, Neurosurgery, Seoul, Korea, Republic of


Objective: To evaluate the feasibility and the accuracy of D-wave monitoring in spinal cord tumor surgery comparing to motor evoked potential(MEP) monitoring.

Introduction: Accurate intraoperative neurophysiologic monitoring in spinal cord tumor surgery is important for decision of spinal surgeon and the predictive outcome of the patients. SSEP or MEP is a typical modality for intraoperative neurophysiologic monitoring in Korea. Concept of D-wave monitoring was introduced in 1980s.

Materials and Methods: From March, 2016 to May, 2017, 24 cases of spinal cord tumor (intradural tumor) were monitored MEP and D-wave simultaneously. No musculoskeletal blocker was used except anesthetic induction. Real time monitoring was undergone during operation. Each proportion of successful measuring was represented to monitorability. Measured significant wave changes of amplitude and frequency of each modality were collected and transcribed to abnormal or not. Also reports of abnormality of each modality were compared with patients' real neurologic deficit during immediate post-operation and discharge using Mccormick scale. We analyzed MEP and D-wave immediately after tumor removal and MEP and D-wave after dural repair.

Results: Monitorabilty was 95.83% in MEP (23 successes of 24) and 83.33% in D-wave (20 successes of 24). However, D-wave has higher specificity, positive predictive values of 100% than MEP. Also in univariate study, D-wave has significant difference in the change of Mccormick scale after immediate post-operation. (p=0.033) By the way, 1month follow up of Mccormick scale after operation is not statistically significant with D-wave and MEP. (p=0.152 vs p=0.754)

Conclusion: D-wave showed higher positive predictive value and specificity compared to MEP. There was no difference in the predictive value of the neurological symptoms of the patient 1 month later.