背景:基于不断发展的患病率见解,肌张力障碍越来越受到关注。先前的研究发现,在宫颈肌张力障碍中,应用于数字神经的高频重复体感刺激(RSS;HF-RSS)矛盾地减少了感觉运动抑制机制,而低频RSS(LF-RSS)增加它们。然而,没有对受影响的身体部位进行直接测试。
目的:本研究旨在探讨RSS直接应用于与局灶性手部肌张力障碍有关的前臂肌肉是否可以调节皮质抑制机制和临床症状。
方法:我们应用了HF-RSS和LF-RSS,后者同步或异步,涉及肌张力障碍的前臂肌肉。结果测量包括配对脉冲体感诱发电位,通过双脉冲体感诱发电位测量的空间侧向抑制,经颅磁刺激测试短皮质内抑制,肌张力障碍肌的肌电图活动,和手功能的行为测量。
结果:同步和异步低频体感刺激均改善了皮质抑制性相互作用,短皮质内抑制和侧向空间抑制增加,以及成对脉冲体感诱发电位的幅度降低。用高频刺激观察到相反的效果。电生理标志物的变化与行为结果平行:尽管低频刺激改善了手功能测试并减少了肌张力障碍的激活,在相反方向操作的高频刺激。
结论:我们的发现证实了肌张力障碍患者感觉运动系统对RSS的反应存在异常的稳态可塑性,特别是在抑制回路中。重要的是,通过直接在肌张力障碍肌上施加低频电刺激,可以将这种异常反应用于治疗目的。©2024作者(S)。由WileyPeriodicalsLLC代表国际帕金森症和运动障碍协会出版的运动障碍。
BACKGROUND: Dystonia presents a growing concern based on evolving prevalence insights. Previous research found that, in cervical
dystonia, high-frequency repetitive somatosensory stimulation (RSS; HF-RSS) applied on digital nerves paradoxically diminishes sensorimotor inhibitory mechanisms, whereas low-frequency RSS (LF-RSS) increases them. However, direct testing on affected body parts was not conducted.
OBJECTIVE: This study aims to investigate whether RSS applied directly to forearm muscles involved in focal hand
dystonia can modulate cortical inhibitory mechanisms and clinical symptoms.
METHODS: We applied HF-RSS and LF-RSS, the latter either synchronously or asynchronously, on forearm muscles involved in
dystonia. Outcome measures included paired-pulse somatosensory evoked potentials, spatial lateral inhibition measured by double-pulse somatosensory evoked potentials, short intracortical inhibition tested with transcranial magnetic stimulation, electromyographic activity from dystonic muscles, and behavioral measures of hand function.
RESULTS: Both synchronous and asynchronous low-frequency somatosensory stimulation improved cortical inhibitory interactions, indicated by increased short intracortical inhibition and lateral spatial inhibition, as well as decreased amplitude of paired-pulse somatosensory evoked potentials. Opposite effects were observed with high-frequency stimulation. Changes in electrophysiological markers were paralleled by behavioral outcomes: although low-frequency stimulations improved hand function tests and reduced activation of dystonic muscles, high-frequency stimulation operated in an opposite direction.
CONCLUSIONS: Our findings confirm the presence of abnormal homeostatic plasticity in response to RSS in the sensorimotor system of patients with
dystonia, specifically in inhibitory circuits. Importantly, this aberrant response can be harnessed for therapeutic purposes through the application of low-frequency electrical stimulation directly over dystonic muscles. © 2024 The Author(s). Movement Disorders published by Wiley Periodicals LLC on behalf of International Parkinson and Movement Disorder Society.