Sugawara Kenichi, Tanabe Shigeo, Higashi Toshio, Tsurumi Takamasa, Kasai Tatsuya
Division of Physical Therapy, Faculty of Health and Social Work, Kanagawa University of Human Services, Heisei-cho, Yokosuka, Kanagawa, Japan.
Int J Rehabil Res. 2011 Jun;34(2):100-9. doi: 10.1097/MRR.0b013e3283419496.
The aim of this study is to investigate excitability changes in the human motor cortex induced by variable therapeutic electrical stimulations (TESs) with or without voluntary drive. We recorded motor-evoked potentials (MEPs) from extensor and flexor carpi radialis (FCR) muscles at rest and during FCR muscle contraction after the application of TES on FCR. TES application conditions were changed intensities, frequencies, and trains. In addition, to evaluate the contribution of M1 inhibitory circuits to the effects of TES application, we also recorded MEPs using paired-pulse transcranial magnetic stimulation. In resting muscle states, an increase in TES intensity resulted in an increase in MEP ratio in both the muscles. In contrast, when TES was applied to FCR during contraction, MEP ratios of both the muscles decreased with increased number of pulse trains. However, under both the states, MEP ratios decreased induced by paired-pulse transcranial magnetic stimulation in extensor carpi radialis to which TES was not applied. Excitability changes in M1 induced by TES application were reversibly modulated depending on the presence or absence of voluntary drive. This study showed that the therapy and the voluntary drive of the target muscles act together, and complement the effects of each other, which may be beneficial for optimizing the rehabilitation if the therapy accompanies voluntary drive.
本研究的目的是调查在有或没有自主驱动的情况下，可变治疗性电刺激（TES）对人类运动皮层兴奋性变化的影响。我们在对桡侧腕屈肌（FCR）施加TES后，记录了休息时以及FCR肌肉收缩期间桡侧腕伸肌和FCR肌肉的运动诱发电位（MEP）。改变了TES的应用条件，包括强度、频率和串刺激。此外，为了评估M1抑制性回路对TES应用效果的贡献，我们还使用配对脉冲经颅磁刺激记录了MEP。在静息肌肉状态下，TES强度增加导致两块肌肉的MEP比率均增加。相反，当在收缩期间对FCR施加TES时，随着脉冲串数量的增加，两块肌肉的MEP比率均下降。然而，在这两种状态下，未施加TES的桡侧腕伸肌在配对脉冲经颅磁刺激下MEP比率下降。TES应用引起的M1兴奋性变化根据是否存在自主驱动而受到可逆调节。本研究表明，治疗和目标肌肉的自主驱动共同起作用，并相互补充效果，如果治疗伴有自主驱动，这可能有利于优化康复。
