Kim David H, Zaremski Jason, Kwon Brian, Jenis Louis, Woodard Eric, Bode Robert, Banco Robert J
Department of Orthopaedic Surgery, Tufts University Medical School, New England Baptist Hospital, Boston, MA, USA.
Spine (Phila Pa 1976). 2007 Dec 15;32(26):3041-6. doi: 10.1097/BRS.0b013e31815d0072.
Retrospective consecutive series review.
To examine performance of transcranial motor-evoked potential (TcMEP) monitoring in patients undergoing surgery for cervical myelopathy and potential risk factors for false positive alerts.
Although use of TcMEP monitoring has been increasing and has been specifically recommended in patients with cervical myelopathy, rates and risk factors for false positive alerts have not been established.
Intraoperative neuromonitoring data for 52 consecutive patients undergoing surgery for cervical myelopathy were reviewed. All major TcMEP alerts were identified. Comprehensive demographic and clinical data, preoperative imaging studies, operative, and anesthesia records were reviewed.
Six of 52 patients (12%) experienced a major TcMEP alert consisting of sustained >80% loss of amplitude. There were no somatosensory-evoked potential (SSEP)-related alerts. In 2 cases, an intraoperative wake-up test was negative and in 3 cases, surgery was completed without a wake-up test and without recovery of TcMEP signals. No new postoperative neurologic deficits were observed in these patients. One patient with new postoperative weakness was correctly predicted by loss of TcMEP signals. No new deficit was observed in the remaining 46 patients. Statistical analysis revealed significantly higher body mass index (28.8 vs. 35.0; P = 0.032) and length of surgery (191 vs. 283 minutes; P = 0.019) in patients with false positive alerts.
In this series of cervical myelopathy patients, sensitivity and specificity of TcMEP for detection of clinically significant intraoperative cord injury were 100% and 90%, respectively. Sensitivity and specificity of SSEP were 0% and 100%, respectively. The positive predictive value of a TcMEP alert was 17%. Possible risk factors for false positive TcMEP alerts include obesity and increased length of surgery. This study supports superior sensitivity of TcMEP compared with SSEP monitoring but identifies a relatively high false positive rate even in a selected high-risk cervical myelopathy population when this modality is applied in practice.
回顾性连续病例系列研究。
探讨经颅运动诱发电位（TcMEP）监测在颈椎病手术患者中的应用效果以及假阳性警报的潜在危险因素。
尽管TcMEP监测的应用日益增多，且特别推荐用于颈椎病患者，但假阳性警报的发生率及危险因素尚未明确。
回顾了52例连续接受颈椎病手术患者的术中神经监测数据。识别出所有主要的TcMEP警报。审查了全面的人口统计学和临床数据、术前影像学检查、手术及麻醉记录。
52例患者中有6例（12%）出现主要的TcMEP警报，表现为波幅持续下降>80%。未出现与体感诱发电位（SSEP）相关的警报。2例患者术中唤醒试验为阴性，3例患者未进行唤醒试验且TcMEP信号未恢复但手术完成。这些患者术后均未出现新的神经功能缺损。1例术后出现新的肌无力患者通过TcMEP信号消失得到正确预测。其余46例患者未出现新的神经功能缺损。统计分析显示，出现假阳性警报的患者体重指数（28.8对35.0；P = 0.032）和手术时间（191对283分钟；P = 0.019）显著更高。
在这组颈椎病患者中，TcMEP检测术中具有临床意义的脊髓损伤的敏感性和特异性分别为100%和90%。SSEP的敏感性和特异性分别为0%和100%。TcMEP警报的阳性预测值为17%。TcMEP假阳性警报的可能危险因素包括肥胖和手术时间延长。本研究支持TcMEP比SSEP监测具有更高的敏感性，但也表明即使在选定的高危颈椎病患者群体中，实际应用该方法时假阳性率相对较高。
