BackgroundDystonia 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.ObjectiveThis study aims to investigate whether RSS applied directly to forearm muscles involved in focal hand dystonia can modulate cortical inhibitory mechanisms and clinical symptoms.MethodsWe 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.ResultsBoth 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.ConclusionsOur 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.

中文翻译：

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通过低频重复躯体感觉刺激改善局灶性手肌张力障碍


背景肌张力障碍 基于不断发展的患病率见解，提出了越来越多的担忧。以前的研究发现，在颈部肌张力障碍中，高频重复体感刺激 （RSS;HF-RSS） 自相矛盾地减少了感觉运动抑制机制，而低频 RSS （LF-RSS） 增加了它们。然而，没有对受影响的身体部位进行直接检测。目的探讨 RSS 直接应用于局灶性手肌张力障碍的前臂肌肉是否能调节皮质抑制机制和临床症状。方法我们将 HF-RSS 和 LF-RSS，后者同步或异步应用于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横向抑制、经颅磁刺激测试的短皮质内抑制、肌张力障碍肌肉的肌电图活动以及手功能的行为测量。结果同步和异步低频体感刺激都改善了皮质抑制相互作用，表现为短皮层内抑制和横向空间抑制增加，以及成对脉冲体感诱发电位的振幅降低。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部功能测试并减少了肌张力障碍肌肉的激活，但高频刺激的运作方向相反。结论我们的研究结果证实，肌张力障碍患者的感觉运动系统中存在响应 RSS 的异常稳态可塑性，特别是在抑制回路中。重要的是，这种异常反应可以通过直接在肌张力障碍肌肉上施加低频电刺激来用于治疗目的。© 2024 作者。由 Wiley Periodicals LLC 代表国际帕金森和运动障碍协会出版的《运动障碍》。