Yamamoto Yusuke, Shigematsu Hideki, Kawaguchi Masahiko, Hayashi Hironobu, Takatani Tsunenori, Tanaka Masato, Okuda Akinori, Kawasaki Sachiko, Masuda Keisuke, Suga Yuma, Tanaka Yasuhito
Department of Orthopaedic Surgery, Nara Medical University, Shijocho 840, Kashihara, Nara, 634-8521, Japan.
Department of Anesthesia, Nara Medical University, Nara, Japan.
J Clin Monit Comput. 2022 Feb;36(1):259-270. doi: 10.1007/s10877-020-00647-z. Epub 2021 Jan 9.
Tetanic stimulation of the peripheral nerve, immediately prior to conducting transcranial electrical stimulation motor evoked potential (TES-MEP), increases MEP amplitudes in both innervated and uninnervated muscles by the stimulated peripheral nerve; this is known as the remote augmentation of MEPs. Nevertheless, the mechanisms underlying the remote augmentation of MEPs remain unclear. Although one hypothesis was that remote augmentation of MEPs results from increased motoneuronal excitability at the spinal cord level, the effect of spinal anterior horn cells has not yet been investigated. We aimed to investigate the effect of tetanic stimulation of the peripheral nerve on spinal cord anterior horn cells by analyzing the F-wave. We included 34 patients who underwent elective spinal surgeries and compared the changes in F-waves and TES-MEPs pre- and post-tetanic stimulation of the median nerve. F-wave analyses were recorded by stimulating the median and tibial nerves. TES-MEPs and F-wave analyses were compared between baseline and post-tetanic stimulation time periods using Wilcoxon signed-rank tests. A significant augmentation of MEPs, independent of the level corresponding to the median nerve, was demonstrated. Furthermore, F-wave persistence was significantly increased not only in the median nerve but also in the tibial nerve after tetanic stimulation of the median nerve. The increased F-wave persistence indicates an increase of re-excited motor units in spinal anterior horn cells. These results confirm the hypothesis that tetanic stimulation of the peripheral nerve may cause remote augmentation of MEPs, primarily by increasing the excitability of the anterior horn cells.
在进行经颅电刺激运动诱发电位（TES-MEP）之前，对外周神经进行强直刺激，可使受刺激外周神经支配和未支配的肌肉中的MEP波幅均增加；这被称为MEP的远程增强。然而，MEP远程增强的潜在机制仍不清楚。尽管一种假说是MEP的远程增强是由于脊髓水平运动神经元兴奋性增加所致，但脊髓前角细胞的作用尚未得到研究。我们旨在通过分析F波来研究外周神经强直刺激对脊髓前角细胞的影响。我们纳入了34例行择期脊柱手术的患者，并比较了正中神经强直刺激前后F波和TES-MEP的变化。通过刺激正中神经和胫神经记录F波分析。使用Wilcoxon符号秩检验比较基线期和强直刺激后时间段的TES-MEP和F波分析。结果显示，MEP有显著增强，且与正中神经对应的水平无关。此外，在正中神经强直刺激后，不仅正中神经的F波持续时间显著增加，胫神经的F波持续时间也显著增加。F波持续时间增加表明脊髓前角细胞中重新兴奋的运动单位增加。这些结果证实了外周神经强直刺激可能主要通过增加前角细胞的兴奋性导致MEP远程增强的假说。
