The Value of Intraoperative Neurophysiological Monitoring During Patient Positioning in Spine Surgery: A Preventive Strategy.

Cervical spine surgery in patients with myelopathy poses a substantial anesthetic challenge, primarily due to the risk of secondary spinal cord injury (SCI). Traditionally, concerns have centered around cervical movements during intubation. However, limited evidence supports a direct link between intubation and SCI, so anesthesiologists must consider other factors, including patient positioning, spinal perfusion pressure, and direct surgical complications. In this context, multimodal intraoperative neurophysiological monitoring, including somatosensory (SSEPs) and motor evoked potentials (MEPs), is important for real-time assessment of spinal cord integrity. We present a 73-year-old male with cervical spondylotic myelopathy following a fall. The patient exhibited left-sided hemiparesis and sensory deficits at the C6 level. Imaging revealed significant C4-C5 and C5-C6 spinal cord deformation, leading to the decision for anterior cervical discectomy and fusion. Given the risk of SCI, anesthesia was managed with multimodal neurophysiological monitoring, including bilateral processed electroencephalogram, bilateral cerebral oximetry via near-infrared spectroscopy (NIRS), and nociception monitoring (ANI®). Awake fiberoptic intubation was performed under sedation to minimize cervical movement. Anesthesia was maintained with propofol and remifentanil infusions, without muscle relaxants. Neurophysiological monitoring, including SSEPs and MEPs, began before positioning to establish baseline neural function. The patient was positioned for surgery without significant changes in evoked potentials. A transient hypotensive episode post-intubation was corrected with ephedrine. The surgery proceeded uneventfully, and the patient awoke with no additional neurological deficits. At three-month follow-up, he had recovered normal muscle strength. Cervical myelopathy increases the risk of SCI due to the cord's heightened sensitivity to minor insults. Recognizing this risk foresees the need for heightened vigilance and advanced intraoperative neurophysiological monitoring to prevent the exacerbation of pre-existing lesions and mitigate the risk of secondary injury from positioning and controlled hypotension. This case highlights the necessity of broadening anesthetic vigilance beyond intubation to include patient positioning and spinal perfusion management. Multimodal intraoperative neurophysiological monitoring, initiated before critical phases such as patient positioning, is vital in the management of cervical spine surgeries in patients with myelopathy. This proactive approach minimizes the risk of secondary spinal cord injury and improves postoperative outcomes by enabling early detection of neural compromise and timely adjustments during surgery.