Alarm criteria for motor-evoked potentials - What's wrong with the "Presence-or-Absence" approach?
Alarm criteria for motor-evoked potentials - What's wrong with the "Presence-or-Absence" approach?
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DOI：
10.1097/brs.0b013e3181642a2f
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发表时间：
2008-02-15
期刊：
影响因子：
3
通讯作者：
Molano, Maria R.
中科院分区：
文献类型：
--
作者：
Calancie, Blair;Molano, Maria R.
研究设计。前瞻性和回顾性相结合。客观。评估 2 个已发布的解释手术期间重复经颅电刺激 (rTES) 的运动诱发电位 (MEP) 的标准。背景数据摘要。关于如何解释 rTES 引发的 MEP 存在争议。许多中心仅在 MEP 完全丢失时才向手术团队发出警告（“存在或不存在”方法）。或者，我们监测引发最小诱发肌电图反应所需的刺激能量；这种能量的显着增加反映了即将发生的运动束损伤，并作为警告手术团队的基础（“阈值水平”方法）。方法。我们记录了每个受试者整个手术过程中 rTES 的目标肌肉阈值。确定术中阈值变化和 (a) 完全失去反应或 (b) 直到手术结束之间的时间（以小时为单位）。通过直接体检或图表审查记录术后短期运动状态。结果。我们招募了 903 名受试者，其中 859 名受试者可以从术中 rTES 诱发反应。其中，93 名受试者在术中遭受中枢运动通路损伤。目标肌肉阈值的显着增加通常会在信号完全丧失之前的几分钟甚至几小时内出现。在其他情况下，阈值显着增加而不会失去肌肉反应。结论。阈值方法对中枢运动功能恶化具有高度敏感性和特异性，并提供此类事件的早期预警。相反，在某些情况下，存在或不存在方法可能无法检测部分丢失的事件，而在其他情况下，通常会在运动功能障碍开始发生和响应丢失（此时触发警报）之间引入延迟。我们的结论是，在手术期间使用存在或不存在警报标准来解释 MEP 通常与对中枢运动通路即将发生的损伤进行准确和早期预警的要求不相容，应该避免。
Study Design. Combined prospective and retrospective.Objective. Evaluate 2 published criteria for interpreting motor-evoked potentials (MEP) in response to repetitive transcranial electrical stimulation (rTES) during surgery.Summary of Background Data. There is controversy regarding how to interpret MEPs elicited by rTES. Many centers warn the surgical team only if the MEP is lost entirely ("Presence-or-Absence" method). Alternatively, we monitor the stimulus energy needed to elicit a minimal evoked EMG response; significant increases in this energy reflect impending motor tract injury and serve as the basis for warning the surgical team ("Threshold-Level" method).Methods. We documented target muscle thresholds for rTES throughout each subject's surgical procedure. The time (in hours) between intraoperative threshold change and (a) complete loss of response or (b) until the end of the surgical procedure was determined. Shortterm postoperative motor status was documented by either direct physical examination or by chart review.Results. We enrolled 903 subjects, from whom intraoperative rTES-evoked responses could be elicited in 859 subjects. Of these, 93 subjects sustained intraoperative damage to central motor pathways. Significant increases in target muscle thresholds were often noted many minutes, and sometimes hours before complete signal loss. In other cases, thresholds increased significantly without ever losing the muscle response.Conclusion. The Threshold-Level method is highly sensitive and specific to deterioration in central motor function, and provides early warning of such an event. Conversely, in some cases the Presence-or-Absence method may fail to detect episodes of partial loss, and in other cases typically introduces a delay between the times when motor dysfunction begins to occur and when the response is lost (at which time an alarm is triggered). We conclude that use of the Presence-or-Absence alarm criteria for interpreting MEPs during surgery is often incompatible with the requirement for accurate and early warning of impending injury to central motor pathways, and should be avoided.