Spine - 2026-06-15 - Journal Article; Multicenter Study; Observational Study; Comparative Study
Comparative Analysis of Fusion and Decompression Surgery in Degenerative Cervical Myelopathy: A Multicenter Observational Study of Transcranial Motor-Evoked Potentials.
Funaba M, Kanchiku T, Yoshida G, Ushirozako H, Kurosu K, Segi N, Ando M, Kawabata S, Yamada K, Iwasaki H, Taniguchi S, Shigematsu H, Tadokoro N, Takahashi M, Yamamoto N, Wada K, Yasuda A, Hashimoto J, Morito S, Seki S, Kobayashi K, Takatani T, Fujiwara Y, Nakanishi K, Matsuyama Y, Imagama S, Sakai T, Takeshita K
Topics
Key Takeaway
In 3,813 DCM patients, Tc-MEP monitoring demonstrated an NPV of 99.4% across all surgical approaches, but PPV was only 10.6% overall, with fusion surgery carrying a 4.62-fold higher odds of true-positive alerts versus decompression alone.
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Summary
This multicenter observational study evaluated Tc-MEP diagnostic performance for predicting postoperative paralysis in DCM patients undergoing fusion versus decompression surgery. Postoperative motor paralysis occurred in 1.36% of cases; Tc-MEP sensitivity was 57.7%, specificity 93.2%, PPV 10.6%, and NPV 99.4%. Posterior decompression with fusion carried a 3.7% paralysis rate versus 0.8% for decompression alone, and fusion was an independent predictor of true-positive alerts (OR=4.62, 95% CI: 1.69–12.66).
Key Limitation
The low overall PPV of 10.6% limits the actionability of positive alerts, and without granular data on alert-to-intervention protocols or surgeon response patterns across centers, the clinical impact of true-positive detection on final neurological outcomes cannot be determined.
Original Abstract
STUDY DESIGN
A multicenter observational study.
OBJECTIVE
To evaluate and compare the diagnostic performance and clinical value of transcranial motor-evoked potentials (Tc-MEPs) in predicting postoperative paralysis in degenerative cervical myelopathy (DCM), specifically on stratifying true-positive alerts in fusion versus decompression surgeries.
SUMMARY OF BACKGROUND DATA
Tc-MEP monitoring is widely used to detect intraoperative motor deficits, but its accuracy and predictive value in different surgical approaches remain unclear.
MATERIALS AND METHODS
A total of 3813 patients with DCM who underwent cervical spine surgery were analyzed. Tc-MEP alerts were defined as a ≥70% reduction in amplitude. Postoperative paralysis was categorized as upper limb palsy or lower limb palsy. The sensitivity, specificity, positive predictive value (PPV), and negative predictive value (NPV) of Tc-MEP alerts were calculated. Multivariate logistic regression analysis identified independent predictors of true-positive alerts.
RESULTS
Postoperative motor paralysis occurred in 1.36% (52/3778) of cases. The Tc-MEP sensitivity was 57.7%, specificity 93.2%, PPV 10.6%, and NPV 99.4%. Fusion surgery had a significantly higher postoperative paralysis rate [3.7% in posterior decompression with fusion (PDF) vs. 0.8% in posterior decompression alone]. Fusion surgery was an independent predictor of true-positive alerts (OR=4.62, 95% CI: 1.69-12.66), while nonattributed alerts were the primary cause of false positives (OR=0.036, 95% CI: 0.004-0.37).
CONCLUSION
Tc-MEP alerts showed higher PPV in fusion surgery, reflecting the greater risk profile in these procedures. However, the consistently high NPV across all surgical approaches supports the broad utility of Tc-MEP in ensuring intraoperative neurological safety. This study provides the first large scale, stratified analysis of Tc-MEP alert outcomes in fusion versus decompression surgery, offering actionable insights for intraoperative neuromonitoring in complex DCM cases.