Abstract：
BACKGROUND: Transcranial muscle motor evoked potentials (Tc-mMEPs), a key component of intraoperative neurophysiologic monitoring (IONM), effectively reflect the changes in corticospinal tract integrity and are closely related to the occurrence of the postoperative motor deficit (PMD). Most institutions have applied a specified (fixed) alarm criterion for the heterogeneous groups in terms of etiologies or lesion location. However, given the high risk of PMD in ossification of the posterior longitudinal ligament (OPLL) surgery, it is essential to determine a tailored cutoff value for IONM.
OBJECTIVE: We aimed to establish the intraoperative cutoff value of Tc-mMEPs reduction for predicting PMD in OPLL according to lesion levels.
METHODS: Retrospective analysis using a review of electrical medical records.
METHODS: In this study, we included 126 patients diagnosed with OPLL, who underwent surgery and IONM.
METHODS: The occurrence of PMD immediately and 1 year after operation, as well as the decrement of intraoperative Tc-mMEPs amplitude.
METHODS: We analyzed OPLL surgery outcomes using Tc-mMEPs monitoring. Limbs with acceptable baseline Tc-mMEPs in the tibialis anterior or abductor hallucis were included in the final set. PMD was defined as a ≥1 decrease in Medical Research Council score in the legs, and it was evaluated immediately and 1year after operation. The reduction ratios of Tc-mMEPs amplitude compared with baseline value were calculated at the two time points: the maximal decrement during surgery and at the end of surgery. Receiver operating characteristic curve analysis was used to determine the cutoff value of Tc-mMEPs amplitude decrement for predicting PMDs.
RESULTS: In total, 203 limbs from 102 patients with cervical OPLL and 42 limbs from 24 patients with thoracic OPLL were included. PMD developed more frequently in thoracic lesions than in cervical lesions (immediate, 9.52% vs 2.46%; 1 year, 4.76% vs 0.99%). The Tc-mMEPs amplitude cutoff point at the end of surgery for PMD (both immediate and 1-year) was a decrease of 93% in cervical and 50% in thoracic OPLL surgeries. Similarly, the Tc-mMEPs amplitude cutoff point at the maximal decrement during surgery for PMD (both immediate and 1 year) was a reduction of 97% in cervical and 85% in thoracic OPLL surgeries.
CONCLUSIONS: The thoracic lesion exhibited a lower cutoff value than the cervical lesion for both immediate and long-term persistent PMD in OPLL surgery (Tc-mMEPs at the end of surgery measuring 93% vs 50%; and Tc-mMEPs at the maximal decrement measuring 97% vs 85% for cervical and thoracic lesions, respectively). To enhance the reliability of monitoring, considering the application of tailored alarm criteria for Tc-mMEPs changes based on lesion location in OPLL could be beneficial.
OBJECTIVE: We aimed to establish the intraoperative cutoff value of Tc-mMEPs reduction for predicting PMD in OPLL according to lesion levels.
METHODS: Retrospective analysis using a review of electrical medical records.
METHODS: In this study, we included 126 patients diagnosed with OPLL, who underwent surgery and IONM.
METHODS: The occurrence of PMD immediately and 1 year after operation, as well as the decrement of intraoperative Tc-mMEPs amplitude.
METHODS: We analyzed OPLL surgery outcomes using Tc-mMEPs monitoring. Limbs with acceptable baseline Tc-mMEPs in the tibialis anterior or abductor hallucis were included in the final set. PMD was defined as a ≥1 decrease in Medical Research Council score in the legs, and it was evaluated immediately and 1year after operation. The reduction ratios of Tc-mMEPs amplitude compared with baseline value were calculated at the two time points: the maximal decrement during surgery and at the end of surgery. Receiver operating characteristic curve analysis was used to determine the cutoff value of Tc-mMEPs amplitude decrement for predicting PMDs.
RESULTS: In total, 203 limbs from 102 patients with cervical OPLL and 42 limbs from 24 patients with thoracic OPLL were included. PMD developed more frequently in thoracic lesions than in cervical lesions (immediate, 9.52% vs 2.46%; 1 year, 4.76% vs 0.99%). The Tc-mMEPs amplitude cutoff point at the end of surgery for PMD (both immediate and 1-year) was a decrease of 93% in cervical and 50% in thoracic OPLL surgeries. Similarly, the Tc-mMEPs amplitude cutoff point at the maximal decrement during surgery for PMD (both immediate and 1 year) was a reduction of 97% in cervical and 85% in thoracic OPLL surgeries.
CONCLUSIONS: The thoracic lesion exhibited a lower cutoff value than the cervical lesion for both immediate and long-term persistent PMD in OPLL surgery (Tc-mMEPs at the end of surgery measuring 93% vs 50%; and Tc-mMEPs at the maximal decrement measuring 97% vs 85% for cervical and thoracic lesions, respectively). To enhance the reliability of monitoring, considering the application of tailored alarm criteria for Tc-mMEPs changes based on lesion location in OPLL could be beneficial.
摘要：
背景：经颅肌肉运动诱发电位（Tc-mMEPs），术中神经生理学监测（IONM）的关键组成部分，能有效反映皮质脊髓束完整性的变化,并与术后运动缺陷(PMD)的发生密切相关。大多数机构在病因或病变位置方面对异质组应用了指定的（固定的）警报标准。然而,考虑到后纵韧带骨化（OPLL）手术中PMD的高风险，确定IONM的定制截止值至关重要。
目的：我们旨在根据病变水平建立Tc-mMEPs降低的术中临界值，以预测OPLL中的PMD。
方法：回顾电子病历进行回顾性分析。
方法：在本研究中，我们纳入了126例诊断为OPLL的患者，他接受了手术和IONM。
方法：术后即刻和术后1年发生PMD，以及术中Tc-mMEPs振幅的减小。
方法：我们使用Tc-mMEPs监测分析了OPLL手术结果。最终组中包括胫骨前肌或外展肌中具有可接受的基线Tc-mMEP的肢体。PMD定义为腿部医学研究委员会评分下降≥1，并在手术后立即和1年进行评估。在两个时间点计算Tc-mMEPs振幅与基线值相比的降低比率:手术期间和手术结束时的最大衰减。接收器工作特征曲线分析用于确定Tc-mMEPs振幅衰减的截止值，以预测PMD。
结果：总计，包括102例颈椎OPLL患者的203条肢体和24例胸椎OPLL患者的42条肢体。PMD在胸椎病变中比在宫颈病变中更常见（立即，9.52%vs.2.46%；1年，4.76%vs.0.99%）。PMD手术结束时（立即和1年）的Tc-mMEPs振幅截止点在颈椎手术中降低了93％，在胸椎OPLL手术中降低了50％。同样，在PMD手术期间(即刻和1年)最大衰减时,Tc-mMEPs振幅截止点在颈椎和胸椎OPLL手术中分别减少97%和85%.
结论：对于OPLL手术中的即刻和长期持续性PMD，胸廓病变的临界值均低于宫颈病变（手术结束时的Tc-mMEPs为93％vs.50%；和Tc-mMEP在最大减量时测量97%与85%为颈部和胸部病变，分别)。提高监测的可靠性,考虑根据OPLL中的病变位置对Tc-mMEPs变化应用量身定制的警报标准可能是有益的。
目的：我们旨在根据病变水平建立Tc-mMEPs降低的术中临界值，以预测OPLL中的PMD。
方法：回顾电子病历进行回顾性分析。
方法：在本研究中，我们纳入了126例诊断为OPLL的患者，他接受了手术和IONM。
方法：术后即刻和术后1年发生PMD，以及术中Tc-mMEPs振幅的减小。
方法：我们使用Tc-mMEPs监测分析了OPLL手术结果。最终组中包括胫骨前肌或外展肌中具有可接受的基线Tc-mMEP的肢体。PMD定义为腿部医学研究委员会评分下降≥1，并在手术后立即和1年进行评估。在两个时间点计算Tc-mMEPs振幅与基线值相比的降低比率:手术期间和手术结束时的最大衰减。接收器工作特征曲线分析用于确定Tc-mMEPs振幅衰减的截止值，以预测PMD。
结果：总计，包括102例颈椎OPLL患者的203条肢体和24例胸椎OPLL患者的42条肢体。PMD在胸椎病变中比在宫颈病变中更常见（立即，9.52%vs.2.46%；1年，4.76%vs.0.99%）。PMD手术结束时（立即和1年）的Tc-mMEPs振幅截止点在颈椎手术中降低了93％，在胸椎OPLL手术中降低了50％。同样，在PMD手术期间(即刻和1年)最大衰减时,Tc-mMEPs振幅截止点在颈椎和胸椎OPLL手术中分别减少97%和85%.
结论：对于OPLL手术中的即刻和长期持续性PMD，胸廓病变的临界值均低于宫颈病变（手术结束时的Tc-mMEPs为93％vs.50%；和Tc-mMEP在最大减量时测量97%与85%为颈部和胸部病变，分别)。提高监测的可靠性,考虑根据OPLL中的病变位置对Tc-mMEPs变化应用量身定制的警报标准可能是有益的。
