Department of Anesthesiology, Nara Medical University, Nara, Japan.
J Neurosurg Anesthesiol. 2010 Jan;22(1):6-10. doi: 10.1097/ANA.0b013e3181b9dd3a.
Recently, we developed a new technique to augment myogenic motor evoked potentials (MEPs), called as posttetanic MEPs (p-MEPs), in which tetanic stimulation is applied to peripheral nerve before transcranial stimulation. However, the data on p-MEPs are limited. This study was conducted; (1) to evaluate the influences of repetitive use of p-MEPs on p-MEP amplitudes, (2) to evaluate the residual effects of use of p-MEPs on subsequent conventional MEPs (c-MEPs), and (3) to compare the variability of p-MEPs with that of c-MEPs.
Sixty patients under propofol/fentanyl anesthesia with partial neuromuscular blockade were enrolled. For p-MEP measurements, tetanic stimulation was applied to posterior tibial nerve 1 second before transcranial stimulation. In study 1, p-MEPs were repetitively recorded with intervals of 10 or 60 seconds. In study 2, the amplitudes of c-MEPs recorded 15, 30, 60, and 120 seconds after p-MEP recordings were compared with those of control. In study 3, the coefficients of variation of c-MEP and p-MEP responses were compared.
The repetitive use of p-MEP with an interval of 10 seconds, but not 60 seconds, induced a significant reduction of p-MEP amplitude. Amplitudes of c-MEP were significantly increased when applied within 60 seconds after p-MEP recordings. The coefficient of variations of p-MEPs was similar to those of c-MEPs.
The results indicated that the amplitudes of p-MEP and c-MEP might be affected when applied with a short interval after p-MEP recording.
最近，我们开发了一种增强肌源性运动诱发电位（MEPs）的新技术，称为强直后 MEPs（p-MEPs），其中在经颅刺激前对周围神经施加强直刺激。然而，关于 p-MEPs 的数据有限。本研究旨在：（1）评估重复使用 p-MEPs 对 p-MEP 幅度的影响；（2）评估使用 p-MEPs 对随后的常规 MEPs（c-MEPs）的残留影响；（3）比较 p-MEPs 的可变性与 c-MEPs 的可变性。
纳入 60 例在丙泊酚/芬太尼麻醉下接受部分神经肌肉阻滞的患者。对于 p-MEP 测量，在经颅刺激前 1 秒对腓肠神经施加强直刺激。在研究 1 中，p-MEP 以 10 秒或 60 秒的间隔重复记录。在研究 2 中，比较了记录 p-MEP 后 15、30、60 和 120 秒时 c-MEP 的振幅与对照的差异。在研究 3 中，比较了 c-MEP 和 p-MEP 反应的变异系数。
重复使用 p-MEP 的间隔为 10 秒而不是 60 秒会导致 p-MEP 幅度显著降低。当在记录 p-MEP 后 60 秒内施加 c-MEP 时，c-MEP 的振幅显著增加。p-MEPs 的变异系数与 c-MEPs 的变异系数相似。
结果表明，在记录 p-MEP 后短时间内施加 p-MEP 和 c-MEP 可能会影响其幅度。
