Ubags L H, Kalkman C J, Been H D, Koelman J H, Ongerboer de Visser B W
Department of Anesthesiology, Academic Medical Center, University of Amsterdam, The Netherlands.
Anesth Analg. 1999 Mar;88(3):568-72. doi: 10.1097/00000539-199903000-00019.
Transcranial motor evoked potentials (tc-MEPs) are used to monitor spinal cord integrity intraoperatively. We compared myogenic motor evoked responses with electrical and magnetic transcranial stimuli during nitrous oxide/opioid anesthesia. In 11 patients undergoing spinal surgery, anesthesia was induced with i.v. etomidate 0.3 mg/kg and sufentanil 1.5 microg/kg and was maintained with sufentanil 0.5 microg x kg(-1) x h(-1) and N2O 50% in oxygen. Muscle relaxation was kept at 25% of control with i.v. vecuronium. Electrical stimulation was accomplished with a transcranial stimulator set at maximal output (1200 V). Magnetic transcranial stimulation was accomplished with a transcranial stimulator set at maximal output (2 T). Just before skin incision, triplicate responses to single stimuli with both modes of cortical stimulation were randomly recorded from the tibialis anterior muscles. Amplitudes and latencies were compared using the Wilcoxon signed rank test. Bilateral tc-MEP responses were obtained in every patient with electrical stimulation. Magnetic stimulation evoked only unilateral responses in two patients. With electrical stimulation, the median tc-MEP amplitude was 401 microV (range 145-1145 microV), and latency was 32.8 +/- 2.3 ms. With magnetic stimulation, the tc-MEP amplitude was 287 microV (range 64-506 microV) (P < 0.05), and the latency was 34.7 +/- 2.1 ms (P < 0.05). We conclude that myogenic responses to magnetic transcranial stimulation are more sensitive to anesthetic-induced motoneural depression compared with those elicited by electrical transcranial stimulation.
Transcranial motor evoked potentials are used to monitor spinal cord integrity intraoperatively. We compared the relative efficacy of electrical and magnetic transcranial stimuli in anesthetized patients. It seems that myogenic responses to magnetic transcranial stimulation are more sensitive to anesthetic-induced motoneural depression compared with electrical transcranial stimulation.
经颅运动诱发电位（tc-MEP）用于术中监测脊髓完整性。我们比较了在氧化亚氮/阿片类麻醉期间，电刺激和磁刺激诱发的肌源性运动诱发电位反应。11例接受脊柱手术的患者，静脉注射依托咪酯0.3mg/kg和舒芬太尼1.5μg/kg诱导麻醉，并用舒芬太尼0.5μg·kg⁻¹·h⁻¹和50%氧化亚氮-氧气维持麻醉。静脉注射维库溴铵使肌肉松弛维持在对照值的25%。使用设置为最大输出（1200V）的经颅刺激器进行电刺激。使用设置为最大输出（2T）的经颅刺激器进行磁刺激。就在皮肤切开前，从双侧胫前肌随机记录对两种皮层刺激模式下单个刺激的三联反应。使用Wilcoxon符号秩检验比较波幅和潜伏期。电刺激时，所有患者均获得双侧tc-MEP反应。磁刺激仅在2例患者中诱发单侧反应。电刺激时，tc-MEP的中位波幅为401μV（范围145 - 1145μV），潜伏期为32.8±2.3ms。磁刺激时，tc-MEP波幅为287μV（范围64 - 506μV）（P<0.05），潜伏期为34.7±2.1ms（P<0.05）。我们得出结论，与电刺激相比，磁刺激诱发的肌源性反应对麻醉诱导的运动神经抑制更敏感。
经颅运动诱发电位用于术中监测脊髓完整性。我们比较了电刺激和磁刺激在麻醉患者中的相对效果。与电刺激相比，磁刺激诱发的肌源性反应似乎对麻醉诱导的运动神经抑制更敏感。
