For a study, researchers aimed to examine transcranial motor-evoked potentials’ (Tc-MEP) validity in cervical spine surgery and to discover characteristics linked with Tc-MEP warnings’ positive predictive value. Tc-MEP has a high sensitivity and specificity for identifying motor paralysis; however, it can also produce false-positive results. Investigators evaluated patient demographics, spinal problem kinds, preoperative motor state, surgical variables, and Tc-MEP alert types in 2476 cervical spine surgeries. To trigger the Tc-MEP warning system, the amplitude must drop by more than 70% relative to the reference waveform. 

Items with significant differences were identified using univariate analysis, and they were then recognized using multivariate analysis, and the Tc-MEP results were divided into false-positive and true-positive categories. There was a 33% sensitivity for segmental paralysis and a 95.8% specificity for lower limb paralysis. There were 33 positive results from Tc-MEP and 233 false positives. The positive predictive value of general spine surgery increased from 6.7% to 19.5% in cases with a severe motor status (P=0.02), while it did not change from 20.8% to 19.4% in high-risk spine surgery. However, there was no discernible difference in the rate of rescue between those with and without motor impairment (48% versus 50%).  

In a multivariate logistic analysis, a preoperative severe motor status (P=0.041, odds ratio (OR): 2.46, ((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) were 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 in a multivariate logistic analysis. The benefits of Tc-MEP were maximized in patients with a severe motor status prior to surgery, regardless of whether they required high-risk spinal surgery. Interventions in response to Tc-MEP alarms may avoid postoperative paralysis regardless of motor function.

Source: journals.lww.com/spinejournal/Abstract/2022/12010/The_Utility_of_Transcranial_Stimulated.7.aspx