Prognostic Value of Intraoperative MEP and SSEP Changes for Functional Recovery Following Posterior Cervical Decompression and Fusion

Background and/or Objectives: Intraoperative neurophysiological monitoring (IONM), including somatosensory evoked potentials (SSEPs) and motor evoked potentials (MEPs), is widely used during posterior cervical decompression and fusion to minimize intraoperative neural injury. However, its prognostic value in predicting postoperative functional recovery remains under investigation. This study aims to evaluate whether intraoperative improvements in SSEPs and MEPs during posterior cervical decompression and fusion correlate with enhanced postoperative recovery, assessed using functional outcome scales.

Design: Prospective cohort study conducted from June 2018 to July 2024.

Setting : Tertiary academic center

Participants : 71 patients with cervical compressive myelopathy undergoing posterior cervical decompression and fusion. Inclusion criteria included adults aged 18–75 with radiographic cervical spinal cord compression and clinical myelopathy. Exclusion criteria included prior cervical surgery and comorbid neurologic disorders.

Interventions: Not applicable.

Main Outcome Measures: Intraoperative SSEP and MEP amplitudes were recorded pre- and post-decompression. Functional recovery was assessed using the Functional Independence Measure (FIM) and Neck Disability Index (NDI) at baseline, and at 1 and 3 months postoperatively. Correlation analyses and multivariate regression were performed to assess the relationship between intraoperative neurophysiological changes and functional recovery.

Results: Patients with significant intraoperative MEP amplitude improvement showed greater gains in FIM and NDI scores at both 1 and 3 months postoperatively compared to those without MEP improvement. Mean FIM improvement was 16 points in the MEP improvement group vs. 8 points in the non-improvement group (p < 0.01). Mean NDI score decreased by 13 points vs. 6 points, respectively (p < 0.01). Intraoperative SSEP changes demonstrated weaker and non-significant correlations with functional outcomes.

Conclusions: Intraoperative improvements in MEPs during posterior cervical decompression and fusion are associated with superior short-term functional recovery, as reflected by gains in FIM and NDI scores. MEP monitoring may serve not only as an intraoperative safety tool but also as a prognostic indicator for postoperative recovery. Larger studies with longer follow-up are warranted.