Monitoring and Mapping of the Spinal Cord

  • Christopher J. PaceEmail author


Surgical treatment of intramedullary spinal cord tumors (IMSCTs) comes with an inherent risk of postoperative neurologic complications. Intraoperative neurophysiologic monitoring (IONM), including evoked potentials transmitted in the tracts of the spinal cord and the mapping of those tracts, is an essential tool for the surgeon whose goal is thorough and safe resection. Somatosensory evoked potentials (SSEPs), transcranial myogenic and myelogenic motor evoked potentials (TcMEPs and D-waves, respectively) and dorsal column and corticospinal tract (CST) mapping are important adjuncts to the surgical treatment of IMSCTs as each improves sensory and motor functional outcomes and contributes to greater resection. In particular, multimodality monitoring and combining multimodality monitoring with mapping reduce morbidity. SSEPs and TcMEPs serve to protect the spinal cord in general, and also give feedback directly on the function of each respective pathway. D-wave monitoring, an additional test of the motor pathway, adds functional predictive value over TcMEPs alone. Spinal cord mapping aids the surgeon in localizing the sensory and motor tracts and mitigates the risk of injury to them. Dorsal column mapping, physiologically localizing the sulcus separating the left and right dorsal columns, identifies a low-risk trajectory into the spinal cord for access to the tumor. CST mapping aids in differentiating normal from tumor tissue, and allows the surgeon to localize, determine the proximity, or determine specific muscle targets of the CST. In this chapter on neurophysiological applications for IMSCT surgery, the practical aspects of spinal cord monitoring and spinal cord mapping are described to inform the surgical neurophysiologist on how best to assist the surgeon in achieving the safest and most complete surgical resection.


Intramedullary Astrocytoma Ependymoma Hemangioblastoma D-Waves SSEP TcMEP Dorsal Columns Mapping Spinal Cord Corticospinal Tracts IONM 



The author thanks Christopher Martin CNIM, Rose Tash CNIM, Christopher Solotaroff CNIM, Gregory Jason CNIM and Debbie Davy PhD, for their contributions to this manuscript and for their assistance with its preparation.


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Copyright information

© Springer Nature Switzerland AG 2020

Authors and Affiliations

  1. 1.Neuro Alert and Center for ElectroneurodiagnosticsWhite PlainsUSA

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