Long-Term Neurological Outcomes Following Significant Intraoperative Neuromonitoring Alarms: A Longitudinal Study of 115 Patients With Severe Spinal Deformities

Study DesignA retrospective cohort study.ObjectiveIntraoperative neurophysiological monitoring (IONM) is crucial for detecting impending iatrogenic neurological injury during high-risk scoliosis surgery. However, the implication of significant IONM alarms on long-term neurological function remains unknown for complex deformity correction. This study aims to report the longitudinal neurological outcomes and identify predictors of long-term neurological survivorship for patients with severe spinal deformities.MethodsA total of 115 patients who encountered significant intraoperative neuromonitoring alarms (excluding systematic and non-operative confounders) during high-risk surgical maneuvers were analyzed. A longitudinal clinical dataset containing baseline information, surgical details, multimodal IONM data, and follow-up neurological function was collected. Cox regression analysis was performed to identify prognostic factors that could predict long-term neurological survivorship. Kaplan-Meier curves were plotted for these predictors, and a nomogram facilitated the clinical prediction of 2-year neurological function.ResultsImmediately after surgery, 57 patients (49.6%) showed neurological deficits, which decreased to only 5 cases (4.3%) at the 2-year follow-up. Multivariate Cox regression analysis for long-term neurological survivorship identified decreased hazard ratios (HRs) for grade six osteotomy (HR, 0.311; <i>P</i> = 0.028), a positive wake-up test (HR, 0.216; <i>P</i> < 0.001), and no recovery of descending neurogenic evoked potentials (DNEPs) (HR, 0.162; <i>P</i> < 0.001). A nomogram based on osteotomy grade, wake-up test, and DNEP recovery status was established to predict 2-year neurological function.ConclusionsOverall, patients with severe spinal deformities who experienced significant IONM alarms demonstrated gradual neurological improvement over the 2-year follow-up. Osteotomy grade, wake-up test results, and DNEP recovery status were identified as valuable predictors that could facilitate surgical decision-making, prognostication, and counseling.