脊柱手术中经颅电刺激运动诱发电位监护的应用探讨

目的探讨脊柱手术中经颅电刺激运动诱发电位（transcranial electrical stimulation motor evoked potential,TES-MEP）监护的可行性和应用价值。方法2006年7月至2008年10月，在241例胸椎手术中对双侧胫前肌、足踇短屈肌、大鱼际肌或小鱼际肌（颈椎病变时）实施TES-MEP监护。术中全静脉麻醉58例，静脉麻醉＋七氟烷吸入麻醉（浓度〈1％）67例，静脉麻醉＋小剂量肌松剂116例。结果TES-MEP的检出率为89．2％，虽然3种麻醉方式的检出率无显著性差异，但各年龄组、不同靶肌肌力的检出率有显著性差异。术中TES-MEP阳性26例，其中不明原因的假阳性6例，真阳性20例，且均与手术操作有直接相关性。TES-MEP对脊髓运动功能监护的灵敏度为100％，特异度为97．9％，约登指数为0．979；对脊髓感觉功能监护的灵敏度为74．1％，特异度为97．9％，约登指数为0．72。结论异丙芬静脉麻醉＋七氟烷吸入麻醉（浓度〈1％）为首选方案，异丙芬静脉麻醉＋小剂量肌松剂为次选方案。TES-MEP不但能瞬间、直接、准确地监护脊髓的运动传导功能，而且能间接反映脊髓的感觉传导功能，是安全监护脊柱手术的新方法。

Application of transcranial electrical stimulation motor evoked potential monitoring during spinal surgery

Objective To investigate the application of transcranial electrical stimulation motor evoked potential （TES-MEP） monitoring during the spinal surgery. Methods From July 2006 to October 2008, 241 patients were simultaneously recorded for the TES - MEP response on bilateral anterior tibial muscle and flexor hallucal brevis during the spinal surgery. In addition, we also applied TES-MEP monitoring on the muscle of thenar or the muscle of hypothenar when the patients underwent the cervical surgery. Of the 241 patients, 58 patients were anesthetized by total intravenous anesthesia, 67 by propofol and sevoflurane （ inhalant concentration 〈 1% ）, and 116 by propofol and a small dose of muscle relaxation drugs. Results The success rates of TES - MEP recording was 89. 2%. There was no statistic difference of the success rate of TES - MEP among the three different anesthetic groups; however, the difference was significant within different age groups and different targeting muscle strength groups. Evoked potentials changes occurred in 26 cases, in which 20 cases were the true positive in relation to an incorrect operative maneuver directly while 6 cases were the false positive with unknown causes. The sensitivity, specificity and Youden index were 100%, 97. 9% and 0. 979 with TES - MEP monitoring for locomotor function of spinal cord, and were 74. 1%, 97. 9% and 0. 72 with TES-MEP monitoring for sensory function of spinal cord, respectively. Coneluslon Anesthesia by intravenous propofol, and its complementary sevoflurane （inhalant concentration 〈 1% ） or muscle relaxation drugs of small dosage are feasible for the recording of spinal cord function. TES-MEP is a novel and safe monitoring method during the spinal surgery.