Zhang Wanhong, Yamaguchi Tomofumi, Fujiwara Toshiyuki
Juntendo Iji Zasshi. 2024 Jun 15;70(4):283-288. doi: 10.14789/jmj.JMJ23-0039-OA. eCollection 2024.
This study aimed to assess the effect of the spinal circuit of repetitive magnetic stimulation (rPMS) on the soleus muscle among healthy subjects.
Nineteen healthy adults were included in this study. Intermittent rPMS was applied to the left soleus muscle for 20 minutes. We applied different intensity rPMS (high-intensity, low-intensity, and non-stimulation) in different three days. RI (reciprocal inhibition) from the tibialis anterior to the soleus muscle with an inter-stimulus interval (ISI) of 2ms and 20ms was assessed before, immediately after and 30 minutes at each session.
Two factor repeated measure ANOVA test showed a significant interaction (F = 9.688, p < 0.001) between tasks and time in the RI ratio 2ms. Post-hoc analysis showed that RI ratio 2ms significantly differed from those immediately after, and 30 min after high-intensity rPMS (p = 0.001 and p = 0.003, respectively). A significant difference was observed between high-intensity rPMS and non-stimulation immediately after the stimulation (p = 0.003). However, no significant difference was found in the RI ratio 20ms between all the intensities (p > 0.05).
This study demonstrates that high-intensity rPMS can effectively modulate spinal circuits, as evidenced by the decreased RI in healthy individuals. This suggests the potential use of rPMS as a therapeutic intervention for patients with muscle weakness. Disinhibition of the RI may lead to a more effective contraction of the target muscle. This effect could be expected to strengthen the muscles and alleviate paralysis, making it a promising avenue for future research and clinical applications in the field of rehabilitation. Further investigation is warranted to explore the precise mechanisms underlying the observed effects and to optimize the parameters of rPMS for specific clinical populations.
本研究旨在评估重复性磁刺激（rPMS）的脊髓回路对健康受试者比目鱼肌的影响。
19名健康成年人纳入本研究。对左侧比目鱼肌进行间歇性rPMS治疗20分钟。在不同的三天内施加不同强度的rPMS（高强度、低强度和无刺激）。在每次治疗前、治疗后即刻以及治疗后30分钟，评估刺激间隔（ISI）为2毫秒和20毫秒时，从胫骨前肌到比目鱼肌的RI（交互抑制）。
两因素重复测量方差分析显示，在RI比率2毫秒时，任务和时间之间存在显著交互作用（F = 9.688，p < 0.001）。事后分析显示，高强度rPMS后即刻和30分钟时，RI比率2毫秒与其他时间点有显著差异（分别为p = 0.001和p = 0.003）。刺激后即刻，高强度rPMS与无刺激之间存在显著差异（p = 0.003）。然而，所有强度下的RI比率20毫秒均无显著差异（p > 0.05）。
本研究表明，高强度rPMS可有效调节脊髓回路，健康个体中RI降低证明了这一点。这表明rPMS有可能作为肌肉无力患者的治疗干预手段。RI的去抑制可能导致目标肌肉更有效的收缩。这种效应有望增强肌肉并缓解瘫痪，使其成为康复领域未来研究和临床应用的有前景途径。有必要进一步研究以探索观察到的效应背后的精确机制，并针对特定临床人群优化rPMS参数。
