自由描记肌电图监测腰椎手术中脊神经根功能的有效性分析

Free-run electromyogram for nerve root function monitoring during lumbar surgery

中文关键词:  自由描记肌电图  术中监测  腰椎手术  脊神经根

英文关键词:Free-run electromyogram  Intraoperative neurophysiology monitoring  Lumbar surgery  Nerve root

中文摘要:

  【摘要】 目的：探讨单独应用自由描记肌电图监测腰椎手术中脊神经根功能的有效性。方法：2014年10月～2015年10月共纳入246例腰椎病变在L2～S1节段之间且≤2个连续运动节段行单独自由描记肌电图监测的手术患者，男129例，女117例；年龄16～75岁，平均50.3±16.4岁。记录术中发生爆发性肌电活动、连续性肌电活动和自发性肌电活动的患者、相对应的手术操作、处理方法和转归。比较术前和术后神经功能状态，统计所有患者中真阳性、假阳性、真阴性和假阴性的病例，计算敏感性、特异性、阳性预测值和阴性预测值，分析自由描记肌电图监测的有效性。结果：术中监测时间80～140min，平均115.0±17.7min。所有患者中共有49例监测报警，爆发性肌电活动19例，连续性肌电活动27例，自发性肌电活动3例。其中，神经根牵拉过度28例，停止牵拉或减轻牵拉力度，肌电活动逐渐恢复正常；椎间融合器或植骨块植入挤压神经根8例，移除并改变植入角度避免挤压神经根，其中6例肌电活动逐渐恢复正常，2例转变为自发性肌电活动；椎弓根螺钉置入错位刺激神经根9例，移除并改变置钉轨道及角度，其中8例肌电活动逐渐恢复正常，1例右侧L5神经根支配肌肉仍有连续性肌电活动，术后右侧足背伸肌力减弱；4例患者探查未见刺激或损伤因素，肌电活动持续至手术结束，其中1例右侧S1神经根功能受损，术后右侧足底麻木；其余47例患者术后未出现神经功能受损。所有患者中197例未报警，术后1例左侧L5神经根功能受损，左侧胫前肌和 背伸肌肌力0级。在阳性患者中，真阳性46例，其中2例术后神经功能受损；假阳性3例，阳性预测值为93.88%。在阴性患者中，真阴性196例，假阴性1例且术后神经功能受损，阴性预测值为99.49%。自由描记肌电图监测的敏感性为97.87%，特异性为98.49%。结论：应用自由描记肌电图监测L2~S1水平的手术可以减少神经根相关损伤，因其有较好的敏感性和特异性，可以对神经根功能的瞬间改变做出及时反馈，可作为腰椎手术中较为有效的神经监测方法。

英文摘要:

  【Abstract】 Objectives: To study the use of free-run electromyogram(F-EMG) for nerve root monitoring during lumbar surgery. Methods: From October 2014 to October 2015, 246 patients(129 males, 117 females) who underwent lumbar surgery (L2-S1) and F-EMG for nerve root monitoring during operation were enrolled in this study. The mean age was 50.3±16.4 years(16-75 years). Intraoperative EMG activity, duration, the corresponding operation or event, treatment and outcome of EMG activity were recorded in all patients. The function of nerve roots were compared between preoperation and postoperation. True positive, false positive, true negative and false negative cases were collected from all patients. Sensitivity, specificity, positive predictive value and negative predictive value were calculated, and the value of F-EMG was analyzed. Results: The mean intraoperative monitoring time was 115.0±17.7min(80-140min). 49/246 cases were F-EMG positive alterations, among them, burst EMG activity, train EMG activity and spontaneous EMG activity were recorded in 19, 27 and 3 cases, respectively. Among them, 28/49 cases were excess pulled the nerve root, the EMG activity returned to normal when operator stopped the operation or release the nerve; 8/49 cases were recorded oppressed nerve root during cage or bone graft implantation, when operator removed and changed the angle, 6/8 cases returned to normal EMG activity, 2/8 cases were still spontaneous EMG activity; 9/49 cases were recorded stimulated nerve root during pedicle screw placement, when operator removed and changed the insertion angle, 8/9 cases returned to normal EMG activity, 1/9 case were still train EMG activity and showed muscle weakness of the right foot dorsiflexion postoperatively; 4/49 cases did not find stimulus or damage factors, abnormal EMG activity continued until the end of surgery, 1/4 case was found the right S1 nerve root function deficit and planter numb; 47/49 cases had no neurologic deficit postoperatively. 197/246 cases were F-EMG negative alterations, 1 case had the left foot drop. Among all the positive cases, 46 cases were the true positive, 2 cases had neurological deficit; 3 cases were the false positive, and the positive predictive value was 93.88%. Among all the negative cases, 196 cases were the true negative, 1 case was the false negative and had neurological deficit. The negative predictive value was 99.49%. The sensitivity and specificity of F-EMG were 97.87% and 98.49%, respectively. Conclusions: Free-run electromyogram for nerve root monitoring during lumbar surgery(L2-S1) can reflect the irritation and injury of nerve root. Free-run electromyogram decreases the incidence of the neurological deficit, which is a effective method.