Hayashi Hironobu, Kawaguchi Masahiko, Yamamoto Yuri, Inoue Satoki, Koizumi Munehisa, Ueda Yurito, Takakura Yoshinori, Furuya Hitoshi
Department of Anesthsiology, Nara Medical University, 840 Shijo-cho, Kashihara, Nara 634-8522, Japan.
Anesth Analg. 2008 Jul;107(1):215-20. doi: 10.1213/ane.0b013e318177082e.
Recently, we reported a new technique to augment motor-evoked potentials (MEPs) under general anesthesia, posttetanic MEP (p-MEP), in which tetanic stimulation of the peripheral nerve before transcranial stimulation enlarged amplitudes of MEPs from the muscle innervated by the nerve subjected to tetanic stimulation. In the present study, we tested whether tetanic stimulation of the left tibial nerve can also augment amplitudes of MEPs from the muscles which are not innervated by the nerve subjected to tetanic stimulation.
Thirty patients undergoing spinal surgery under propofol-fentanyl anesthesia with partial neuromuscular blockade were examined. For conventional MEP (c-MEP) recording, transcranial stimulation with train-of-five pulses was delivered to C3-4, and the compound muscle action potentials were bilaterally recorded from the abductor pollicis brevis, abductor hallucis (AH), tibialis anterior, and soleus muscles. For p-MEP recording, tetanic stimulation (50 Hz, 50 mA of stimulus intensity) with a duration of 5 s was applied to the left tibial nerve at the ankle 1 s before transcranial stimulation. Transcranial stimulation and recording of compound muscle action potentials were performed in the same manner as c-MEP recording. Amplitudes of c-MEP and p-MEP were compared using Wilcoxon's signed rank test.
Amplitudes of p-MEPs from the left AH muscle innervated by the left tibial nerve with tetanic stimulation were significantly larger compared with those of c-MEPs. Amplitudes of p-MEPs from the bilateral abductor pollicis brevis and soleus muscles and right AH and tibialis anterior muscles, which were not innervated by the left tibial nerve with tetanic stimulation, were also significantly larger compared with those of c-MEPs.
In patients under propofol and fentanyl anesthesia with partial neuromuscular blockade, the application of tetanic stimulation to the left tibial nerve augmented the amplitudes of MEPs from the muscles without tetanic nerve stimulation and those with stimulation.
最近，我们报道了一种在全身麻醉下增强运动诱发电位（MEP）的新技术，即强直后运动诱发电位（p-MEP），其中在经颅刺激前对周围神经进行强直刺激可增大受强直刺激神经所支配肌肉的MEP幅度。在本研究中，我们测试了对左侧胫神经进行强直刺激是否也能增大未受强直刺激神经支配肌肉的MEP幅度。
对30例在丙泊酚-芬太尼麻醉下接受脊柱手术且存在部分神经肌肉阻滞的患者进行检查。对于传统MEP（c-MEP）记录，以五联刺激进行经颅刺激，刺激部位为C3-4，双侧记录拇短展肌、拇展肌（AH）、胫骨前肌和比目鱼肌的复合肌肉动作电位。对于p-MEP记录，在经颅刺激前1秒，在踝关节处对左侧胫神经施加持续5秒的强直刺激（50Hz，刺激强度50mA）。经颅刺激和复合肌肉动作电位记录方式与c-MEP记录相同。使用Wilcoxon符号秩检验比较c-MEP和p-MEP的幅度。
与c-MEP相比，对左侧胫神经进行强直刺激时，左侧AH肌肉的p-MEP幅度显著增大。与c-MEP相比，双侧拇短展肌和比目鱼肌以及右侧AH和胫骨前肌（这些肌肉未受左侧胫神经强直刺激支配）的p-MEP幅度也显著增大。
在丙泊酚和芬太尼麻醉且存在部分神经肌肉阻滞的患者中，对左侧胫神经施加强直刺激可增大未受强直神经刺激肌肉以及受刺激肌肉的MEP幅度。
