Department of Anesthesiology, University Medical Center Goettingen, Robert Koch-Strasse 40, 37075 Goettingen, Germany; Department of Neurology, University Medical Center Goettingen, Robert Koch-Strasse 40, 37075 Goettingen, Germany.
Department of Neurology, University Medical Center Goettingen, Robert Koch-Strasse 40, 37075 Goettingen, Germany.
Clin Neurophysiol. 2022 Jun;138:173-185. doi: 10.1016/j.clinph.2022.03.019. Epub 2022 Apr 6.
The influence of the TMS-parameters on the efficacy and reliability to induce diaphragmatic motor-evoked potentials (diMEPs) has not been studied so far. Therefore, the objective of the present research is to probe the role of TMS- waveform (monophasic- [Mo] vs. biphasic-pulses [Bi]) and current direction (posterior-anterior [Pa] vs. anterior-posterior [Ap]) in the activation of the diaphragm.
Four different pulse-configurations (Mo-Ap, Mo-Pa, Bi-Ap, Bi-Pa) were applied by means of neuronavigated-TMS and surface MEP-recordings at relaxed end-expiration in 19 healthy subjects. The parameters resting motor threshold (RMT), diMEP-amplitude and -latency, as well as best stimulation site (motor hotspot) and central motor conduction time were studied. Diaphragm movements were simultaneously recorded via ultrasound. To control for possible signal contamination the MEPs of muscles neighboring the diaphragm were also obtained.
The motor hotspots of the diaphragm showed similar spatial distribution for the Mo-Ap, Mo-Pa, Bi-Ap and Bi-Pa. The biphasic-pulses yielded significantly lower RMTs and higher diMEP-amplitudes as the monophasic-pulses. Anterior to posterior oriented Bi- and Mo-pulses evoked significantly shorter diMEP-latencies than the posterior-anterior oriented ones.
The present research demonstrates that biphasic- as compared to monophasic-pulses require significantly less charge and time for inducing diMEPs.
The biphasic-TMS is best suited for the demanding stimulation of the diaphragm.
目前尚未研究 TMS 参数对膈神经运动诱发电位（diMEPs）的疗效和可靠性的影响。因此，本研究的目的是探讨 TMS 波形（单相- [Mo] 与双相脉冲 [Bi]）和电流方向（后前- [Pa] 与前后- [Ap]）在膈神经激活中的作用。
通过神经导航 TMS 和在放松的呼气末进行表面 MEP 记录，在 19 名健康受试者中应用了四种不同的脉冲配置（Mo-Ap、Mo-Pa、Bi-Ap、Bi-Pa）。研究了静息运动阈值（RMT）、diMEP 幅度和潜伏期以及最佳刺激部位（运动热点）和中枢运动传导时间。同时通过超声记录膈膜运动。为了控制可能的信号污染，还获得了邻近膈肌的肌肉的 MEP。
膈神经的运动热点对于 Mo-Ap、Mo-Pa、Bi-Ap 和 Bi-Pa 具有相似的空间分布。双相脉冲比单相脉冲产生的 RMT 显著降低，diMEP 幅度更高。与后前向定向的 Mo 和 Bi 脉冲相比，前后向定向的 Bi 和 Mo 脉冲诱发的 diMEP 潜伏期显著缩短。
本研究表明，与单相脉冲相比，双相脉冲在诱发 diMEPs 时需要的电荷量和时间显著减少。
双相 TMS 最适合对膈神经进行苛刻的刺激。
