Surgical Outcomes in Degenerative Cervical Myelopathy: Correlation of Clinical Scores and Neurophysiological...

Degenerative cervical myelopathy (DCM) is the most common cause of adult spinal cord dysfunction and is associated with progressive neurological decline. While clinical outcome scales are routinely used to assess recovery after surgical decompression, their relationship with objective neurophysiological parameters remains incompletely defined. This study prospectively evaluated the correlation between clinical outcomes and neurophysiological recovery in patients undergoing surgery for DCM, with additional emphasis on severity-based stratification and predictive utility.

In this prospective observational study, 52 adult patients with DCM underwent standardized clinical assessment using the modified Japanese Orthopaedic Association (mJOA) score, Nurick grade, and Neck Disability Index, along with neurophysiological evaluation including median nerve somatosensory evoked potentials (SSEP) (N13 latency), M-wave, F-wave, and H-reflex studies. Assessments were performed preoperatively, at discharge, and at 6-month follow-up. Patients were stratified by baseline disease severity into mild, moderate, and severe DCM based on mJOA scores. Correlation analyses, multivariate regression, and receiver operating characteristic curve analyses were performed to evaluate the prognostic value of preoperative SSEP latency for functional recovery.

All clinical outcome measures demonstrated significant postoperative improvement over time (P < 0.001). Neurophysiological parameters showed significant recovery, with reductions in SSEP, F-wave, and H-reflex latencies and increases in M-wave amplitudes (all P < 0.001). Preoperative SSEP latency demonstrated a moderate and statistically significant correlation with mJOA score, Nurick grade, and Neck Disability Index, particularly in patients with mild-to-moderate DCM, whereas correlations were attenuated in severe disease. On multivariate analysis, preoperative SSEP latency emerged as an independent predictor of functional recovery after adjustment for age and baseline disease severity. Receiver operating characteristic analysis identified a clinically relevant SSEP latency threshold for predicting good neurological outcome, defined as an mJOA recovery ratio ≥ 50%.

Surgical decompression for DCM results in significant clinical and neurophysiological improvement. Among the neurophysiological parameters studied, SSEP latency demonstrates the most consistent association with functional outcomes and retains independent predictive value, particularly in mild-to-moderate disease. Severity-based stratification enhances the clinical applicability of neurophysiological assessment, supporting the role of SSEP latency as a practical adjunct in perioperative evaluation and surgical decision-making in DCM.