Faculty of Rehabilitation, Shijonawate Gakuen University, Daitou City, Osaka, Japan.
Neurorehabilitation Research Center of Kio University, Koryo-cho, Kitakatsuragi-gun, Nara, Japan.
PLoS One. 2024 Nov 1;19(11):e0310173. doi: 10.1371/journal.pone.0310173. eCollection 2024.
This study aimed to investigate whether the cerebellum contributes to contraction-induced facilitation (CIF) of contralateral corticospinal excitability. To this end, repetitive cerebellar transcranial magnetic stimulation (TMS) was used to test whether it modulates CIF. Overall, 20 healthy young individuals participated in the study. Single-pulse TMS was applied to the left primary motor cortex to induce motor-evoked potentials (MEP) on electromyography of the right first dorsal interosseous (FDI) muscle to test corticospinal excitability. This measurement was conducted during contraction (10% maximum voluntary contraction [MVC]) and rest (0% MVC) of the FDI muscle. CIF, cerebellar brain inhibition (CBI), cortical silent period (cSP), and resting motor threshold (rMT) were measured before and after low-frequency repetitive TMS (crTMS) of the right cerebellum to downregulate cerebellar output. The CIF (contraction/rest of the MEP), CBI (conditioned/unconditioned MEP) during contraction, cSP, and rMT were not affected by crTMS. At rest, CBI was decreased. These findings indicated that the primary motor cortex function for the increase in corticospinal excitability was not affected by crTMS. This study contributes to our understanding of the role of the cerebellum in motor control. Additionally, it may inform decision-making for the site of cerebellar ataxia treatment using non-invasive brain stimulation.
本研究旨在探讨小脑是否参与了对侧皮质脊髓兴奋性的收缩诱导易化(CIF)。为此,采用重复经颅磁刺激(TMS)来检验小脑刺激是否会对 CIF 产生影响。共有 20 名健康的年轻个体参与了该研究。采用单脉冲 TMS 刺激左侧初级运动皮层,在肌电图上诱发右侧第一背侧骨间肌的运动诱发电位(MEP),以测试皮质脊髓兴奋性。该测量在 FDI 肌肉收缩(10%最大自主收缩 [MVC])和休息(0% MVC)时进行。在右小脑低频重复 TMS(crTMS)下调小脑输出之前和之后,测量 CIF、小脑脑抑制(CBI)、皮质静息期(cSP)和静息运动阈值(rMT)。CIF(收缩/MEP 休息)、收缩时的 CBI(条件/非条件 MEP)、cSP 和 rMT 不受 crTMS 的影响。在休息时,CBI 降低。这些发现表明,crTMS 不会影响皮质脊髓兴奋性增加的初级运动皮层功能。本研究有助于我们理解小脑在运动控制中的作用。此外,它可能为使用非侵入性脑刺激治疗小脑性共济失调的部位提供决策依据。