# Correlating the Preoperative Modified Japanese Orthopaedic Association Score With Baseline Motor Evoked Potential to Justify Neuromonitoring in Degenerative Cervical Myelopathy Surgery: A Pilot Study

## TL;DR

This pilot study explores how a preoperative score (mJOA) can predict baseline motor evoked potentials (MEP) in cervical myelopathy surgery, potentially reducing healthcare costs.

## Contribution

The study introduces a potential threshold for using the mJOA score to predict baseline MEP presence in DCM patients.

## Key findings

- MEP was indeterminate in 36% of patients.
- An mJOA score of 13 gives a 71% probability of MEP being present.
- Each point increase in mJOA score increases MEP likelihood by 21.76%.

## Abstract

Introduction

The ability to predict the measurable baseline motor evoked potential (MEP) in degenerative cervical myelopathy (DCM) condition using a preoperative clinical score such as the modified Japanese Orthopaedic Association (mJOA) score may allow savings in healthcare costs, as intraoperative neuromonitoring contributes significantly to the rise of healthcare costs.

Materials and methods

This is a retrospective case cohort of 22 patients looking at the ability of the preoperative mJOA score to predict baseline MEP in DCM patients undergoing surgery in three regional spine centers over one year, from July 2023 to July 2024.

Results

MEP was indeterminate in 36% of patients. Using univariate threshold analysis and ROC curves, a classification threshold of 71% was chosen, where the mJOA score was 13. Binary logistic regression analysis showed an odds ratio of 1.22 (p=0.22). Every point of increase in the mJOA score leads to 21.76% increase in the likelihood of MEP being present at baseline.

Conclusion

An mJOA score of 13 gives a 71% probability of MEP being present. Increasing the value of the mJOA score increases the likelihood of MEP being present in the lower limb but fails to reach statistical significance. We suggest a greater number of patients while including other preoperative neurologic markers to predict the presence of baseline MEP.