The Use of Intraoperative Neuromonitoring in Anterior Cervical Spine Procedures for Myelopathy: Alert Incidence, Interventions, and Prognostic Value.

Abstract

Study design: Retrospective review.

Objective: Examine the utility of intraoperative neuromonitoring (IONM) in anterior cervical spine procedures for myelopathy in informing intraoperative interventions.

Summary of background data: The routine use of IONM in anterior cervical spine procedures for myelopathy remains controversial, with poorly defined indications and limited evidence validating protocols for managing intraoperative alerts.

Methods: One hundred ninety-one anterior cervical spine cases with continuous IONM from 2021 to 2025 were included, excluding revisions and nondegenerative conditions. The incidence of IONM alert was recorded for both myelopathic (n=111) and non-myelopathy (n=80) groups. Alerts were characterized by associated surgical event, intraoperative interventions, duration and resolution, and correlation with new postoperative deficit. Patient demographic and procedural variables, including total monitoring time and blood pressure fluctuations, were assessed for confounding.

Results: Intraoperative alerts occurred in 42 patients, with a higher incidence of alert in the myelopathic group (28, 25.2%) than the non-myelopathic group (14, 17.5%) (P = 0.220). The most common event at the time of alert was instrumentation (30%) followed by decompression (27%) and patient positioning (21%). Intraoperative interventions in response to alerts included increased stimulation parameters, anesthetic adjustment, patient repositioning, or reversal of last surgical maneuver. Alerts in the myelopathic group were more likely to remain unresolved at closing [P = 0.007159; OR = 5.718, 95% CI (1.369, 29.523)] and associated with a lower positive predictive value for new postoperative deficit (0.29 vs. 0.50). Total monitoring time was the only variable significantly associated with alert incidence (P = 0.0004).

Conclusions: Myelopathic patients experienced a higher incidence of IONM alerts and were significantly more likely to have unresolved alerts at closure. However, alerts demonstrated limited predictive value for new postoperative deficits.