Importance of intraoperative dynamic spinal cord mapping (DSCM) during complex spinal deformity surgery

Study design: Case report and review of literature. Objective: To illustrate the importance of “dynamic spinal cord mapping” (DSCM) in locating the site of neurophysiologic data loss during severe spinal deformity correction. Summary of background data: During marked correction of severe spinal deformities, intra-operative neuromonitoring remains of paramount importance. This case illustrates the importance of a unique type of monitoring, particularly useful when obtaining correction at multiple sites. Methods: A patient with symptomatic, progressive, severe kyphoscoliosis underwent multiple periapical posterior column osteotomies, partial T8 and complete T9 vertebral column resections and T2 to L3 posterior segmental instrumented fusion. During correction maneuvers, complete loss of spinous process descending neurogenic evoked potentials occurred. A flexible epidural catheter was placed at different spinal levels to dynamically stimulate the spinal cord and map out the site of data loss corresponding to the area of neural compromise. Results: Using DSCM, the site of data loss was identified to the apex of the proximal thoracic region cephalad to the VCR site. This was rectified by releasing correction at the proximal end of the construct, and neurophysiologic data promptly returned to baseline. Postoperatively the patient was neurologically intact. Conclusion: Dynamic spinal cord mapping helps map areas of neurophysiologic data loss permitting focused attention to the site of compromise to reverse the offending agent. This improves the chance for return of baseline data, avoiding the potential for permanent neurologic catastrophe for the patient. LOE: IV.