The Utility of Transcranial Stimulated Motor-Evoked Potential Alerts in Cervical Spine Surgery Varies Based on Preoperative Motor Status

Abstract

Study Design. A prospective multicenter observational study. Objective. The aim was to investigate the validity of transcranial motor-evoked potentials (Tc-MEP) in cervical spine surgery and identify factors associated with positive predictive value when Tc-MEP alerts are occurred. Summary of Background Data. The sensitivity and specificity of Tc-MEP for detecting motor paralysis are high; however, false-positives sometimes occur. Materials and Methods. The authors examined Tc-MEP in 2476 cases of cervical spine surgeries and compared patient backgrounds, type of spinal disorders, preoperative motor status, surgical factors, and the types of Tc-MEP alerts. Tc-MEP alerts were defined as an amplitude reduction of more than 70% from the control waveform. Tc-MEP results were classified into two groups: false-positive and true-positive, and items that showed significant differences were extracted by univariate analysis and detected by multivariate analysis. Results. Overall sensitivity was 66% (segmental paralysis: 33% and lower limb paralysis: 95.8%) and specificity was 91.5%. Tc-MEP outcomes were 33 true-positives and 233 false-positives. Positive predictive value of general spine surgery was significantly higher in cases with a severe motor status than in a nonsevere motor status (19.5% vs. 6.7%, P=0.02), but not different in high-risk spine surgery (20.8% vs. 19.4%). However, rescue rates did not significantly differ regardless of motor status (48% vs. 50%). In a multivariate logistic analysis, a preoperative severe motor status [P=0.041, odds ratio (OR): 2.46, 95% confidence interval (95% CI): 1.03–5.86] and Tc-MEP alerts during intradural tumor resection (P<0.001, OR: 7.44, 95% CI: 2.64–20.96) associated with true-positives, while Tc-MEP alerts that could not be identified with surgical maneuvers (P=0.011, OR: 0.23, 95% CI: 0.073–0.71) were associated with false-positives. Conclusion. The utility of Tc-MEP in patients with a preoperative severe motor status was enhanced, even in those without high-risk spine surgery. Regardless of the motor status, appropriate interventions following Tc-MEP alerts may prevent postoperative paralysis.

Role of Transcranial Motor Evoked Potential Monitoring During Traumatic Spinal Injury Surgery: A Prospective Multicenter Study of the Monitoring Committee of the Japanese Society for Spine Surgery and Related Research

“…22,23 Kobayashi et al reported that multimodal IONM is essential during high-risk spinal surgery, such as adult spinal deformity, spinal cord tumor, and OPLL. 24,25 In this study, the positive predictive value of cases with traumatic spinal surgery, cervical, and thoracic injury surgeries were 17.9%, 19.0%, and 25.0%, respectively, which were relatively lower than previous reports related to high-risk spinal surgeries. We understand that using TcMEP for non-high-risk spinal surgery with lower paralysis rates yields a lower positive predictive value as compared with that for high-risk spinal surgery.…”

“…Patients with greater spinal cord compression and those who undergo surgery at thoracic levels are prone to severe spinal cord compromise and are at high risk of intraoperative neurological complications 22,23 . Kobayashi et al reported that multimodal IONM is essential during high-risk spinal surgery, such as adult spinal deformity, spinal cord tumor, and OPLL 24,25 . In this study, the positive predictive value of cases with traumatic spinal surgery, cervical, and thoracic injury surgeries were 17.9%, 19.0%, and 25.0%, respectively, which were relatively lower than previous reports related to high-risk spinal surgeries.…”

“…In this study, the positive predictive value of cases with traumatic spinal surgery, cervical, and thoracic injury surgeries were 17.9%, 19.0%, and 25.0%, respectively, which were relatively lower than previous reports related to high-risk spinal surgeries. We understand that using TcMEP for non-high-risk spinal surgery with lower paralysis rates yields a lower positive predictive value as compared with that for high-risk spinal surgery 8,18,21,25 . In this study, the FP alerts occurred four times more frequently than the intended use of IONM (discovery of a TP alert).…”

“…We understand that using TcMEP for non-high-risk spinal surgery with lower paralysis rates yields a lower positive predictive value as compared with that for high-risk spinal surgery. 8,18,21,25 In this study, the FP alerts occurred four times more frequently than the intended use of IONM (discovery of a TP alert).…”

Determinants influencing intraoperative neuromonitoring quality during cervical spine treatment: A systematic review

“…Some conditions, such as herniated discs, may respond well to conservative treatments such as physical therapy or chiropractic care, while other conditions such as spinal tumors or fractures may require surgery. Funaba et al (2022) examined the individual techniques, their anatomical and physiological bases, and their use in spinal surgery as trustworthy indications of functional injury, their limitations, and their usage to particular surgically surgical procedures, such as the lateral transposes access for antibody fusion and the divergent trajectory for cortico-pedicular screws. To assess the effect of IONM departure disposal, medical expenditures, and hospital-based obstacles, a multivariate analysis with modifications for patient a factor was utilized (George et al (2019)).…”