Multimodal Neuromonitoring Improves Detection of Deficits in Thoracic Spine Surgery

Multimodal intraoperative neuromonitoring (IONM) provides high diagnostic accuracy for detecting neurological injury during non-tumor thoracic spine surgeries, according to findings published in the Journal of Clinical Neuroscience.

Thoracic spine surgeries are associated with a greater risk for neurologic complications compared with cervical or lumbar procedures because of the narrow spinal canal and limited vascular supply in this region. To address this risk, researchers evaluated the effectiveness of IONM, which uses somatosensory-evoked potentials (SSEP), transcranial motor-evoked potentials (TcMEP), or a multimodal combination, to detect intraoperative neurological compromise.

The researchers conducted a systematic review, analyzing 19 studies encompassing 3261 patients. Eligible studies included more than 10 patients undergoing thoracic spine surgery for non-tumor indications and reported both intraoperative monitoring data and postoperative neurological outcomes. Study quality was assessed with the QUADAS-2 tool, and diagnostic accuracy was evaluated using a bivariate random-effects model.

Overall, 9.3% of patients experienced new postoperative neurological deficits. Multimodal IONM achieved the highest sensitivity (82.0%; 95% CI, 66.7-91.2) and specificity (94.7%; 95% CI, 88.4-97.6), with an area under the curve of 94.5%. By comparison, SSEP alone demonstrated lower sensitivity (65.5%) despite high specificity (93.0%), while TcMEP achieved intermediate sensitivity (79.7%) and specificity (92.1%).

Further, in patients whose IONM alerts reversed following intraoperative interventions, postoperative deficit rates were 13.8% for SSEP and 10.7% for TcMEP. Among the 1343 patients with no alerts or reversible alerts under multimodal monitoring, however, only 0.8% developed postoperative deficits.

Bayesian analysis further supported the advantage of multimodal IONM, showing a 94% probability of superiority over SSEP and a 76% probability of superiority over TcMEP. Subgroup analysis restricted to thoracic decompression procedures demonstrated similar trends, reinforcing the robustness of the findings.

Study limitations include heterogeneous patient populations and surgical techniques, differing diagnostic thresholds, limited long-term follow-up data, and potential detection bias due to unblinded postoperative neurological assessments.

“The importance of timely intervention in response to IONM alerts cannot be overstated, as it offers the best chance for preserving neurological function,” the study authors concluded. “Integrating these insights into clinical protocols can reduce postoperative deficits and improve outcomes in thoracic spine surgeries.”