Intraoperative neurophysiological monitoring in spinal deformity surgery

The role of intraoperative neurophysiological monitoring (IOM) during spinal deformity surgery is to continuously evaluate the integrity of the nervous system, providing the surgeon with an early warning in the event of an adverse change and the opportunity to take corrective action in order to avoid neurological injuries. Strong evidence supports the association between multimodal IOM and a significantly reduced risk of iatrogenic injury to the nervous system and in recent years this has become the gold standard of care in most spinal deformity centres. In this chapter, we provide an overview of the development of IOM and its role in major spinal surgery describing its efficacy, limitations and the importance of effective communication in the event of an adverse neurophysiological change. We also provide a summary of the basic neurophysiological principles and techniques, with clinical examples illustrating true-positive and false-positive events.