Combined neuromuscular electrical stimulation and transcutaneous spinal direct current stimulation increases motor cortical plasticity in healthy humans

Frontiers in Neuroscience

Neuroscience

Mitsuhiro Nito¹  Toshiaki Sato²  Tomofumi Yamaguchi³  Hiroshi Katoh⁴  Shigeo Tanabe⁵  Masafumi Jin⁶  Kaito Yoshida⁶  Keita Takano⁶  Tadaki Koseki⁶  Daisuke Kudo⁷ 

[1] Department of Anatomy and Structural Science, Yamagata University School of Medicine, Yamagata, Japan;Department of Occupational Therapy, Yamagata Prefectural University of Health Sciences, Yamagata, Japan;Department of Physical Therapy, Faculty of Health Science, Juntendo University, Tokyo, Japan;Department of Physical Therapy, Yamagata Prefectural University of Health Sciences, Yamagata, Japan;Faculty of Rehabilitation, School of Health Sciences, Fujita Health University, Toyoake, Japan;Graduate School of Health Sciences, Yamagata Prefectural University of Health Sciences, Yamagata, Japan;Graduate School of Health Sciences, Yamagata Prefectural University of Health Sciences, Yamagata, Japan;Department of Physical Therapy, Yamagata Prefectural University of Health Sciences, Yamagata, Japan;

关键词: afferent input;    corticospinal projection;    neural plasticity;    motor cortical excitability;    spinal excitability;   

DOI  :  10.3389/fnins.2022.1034451

 received in 2022-09-01, accepted in 2022-12-28,  发布年份 2023

来源: Frontiers

【 摘 要 】

IntroductionNeuromuscular electrical stimulation (NMES) induces neural plasticity of the central nervous system (CNS) and improves motor function in patients with CNS lesions. However, the extended stimulus duration of NMES reduces its clinical applicability. Transcutaneous spinal direct current stimulation (tsDCS), which increases afferent input, may enhance the effects and reduce the stimulus duration of NMES. This study investigated the excitability of the motor cortex, somatosensory cortex, and spinal motor neurons after the combined stimulation of NMES and tsDCS.MethodsAmong the 55 participants in this study, 24 were allocated to experiment 1, 15 to experiment 2, and 16 to experiment 3. They received intervention for 20 min on different days: (1) NMES combined with tsDCS (NMES + tsDCS), (2) NMES combined with sham tsDCS (NMES + sham tsDCS), and (3) sham NMES combined with tsDCS (sham NMES + tsDCS). NMES was delivered to the right common peroneal nerve at 25 Hz with the intensity at 120% of the motor threshold. For tsDCS, the cathodal electrode was positioned on the thoracic 10th–12th vertebral levels, and the anodal electrode was located on the right shoulder. The stimulus intensity was 2.5 mA. In experiment 1, motor evoked potentials (MEPs) and short-latency intracortical inhibition (SICI) were measured by transcranial magnetic stimulation up to 60 min after stimulation. The spinal motor neurons’ excitability was assessed by recording the posterior root muscle reflex (PRMR) induced via transcutaneous spinal cord stimulation in experiment 2, and the primary somatosensory cortex excitability was evaluated by recording the somatosensory evoked potentials (SEPs) in experiment 3 up to 15 min after stimulation.ResultsCompared to before the stimulation, NMES + tsDCS significantly increased MEP for 60 min or more, and significantly decreased SICI immediately after. Conversely contrast, the PRMR significantly decreased immediately after, and SEPs were unchanged.DiscussionThese results suggest that simultaneous afferent inputs from different stimulus positions critically induce primary motor cortex plasticity. The combined stimulation of NMES with tsDCS may facilitate the development of a new neurorehabilitation technique.

【 授权许可】

Unknown   
Copyright © 2023 Koseki, Kudo, Yoshida, Nito, Takano, Jin, Tanabe, Sato, Katoh and Yamaguchi.