Divisions of Physical Therapy and Rehabilitation Science, Department of Rehabilitation Medicine, School of Medicine, University of Minnesota, Minneapolis, MN, USA.
MicroTransponder Inc., Austin, TX, USA.
Exp Brain Res. 2022 Feb;240(2):561-574. doi: 10.1007/s00221-021-06277-4. Epub 2021 Dec 2.
The effects of neuromodulation are virtually unexplored in adductor laryngeal dystonia (AdLD), a disorder characterized by involuntary contraction of intrinsic laryngeal muscles. Recent findings indicated that intracortical inhibition is reduced in people with AdLD. Low-frequency repetitive transcranial magnetic stimulation (rTMS) induces prolonged intracortical inhibition, but the effects in AdLD are unexplored. This pilot and feasibility study aimed to examine the safety, feasibility, and effects of a single session 1 Hz rTMS over the laryngeal motor cortex (LMC) in people with AdLD and healthy individuals.
The stimulation location was individualized and determined through TMS-evoked responses in the thyroarytenoid muscles using fine-wire electrodes. 1200 pulses of 1 Hz rTMS were delivered to the left LMC in two groups: Control (n = 6) and AdLD (n = 7). Tolerance, adverse effects, intracortical inhibition, and voice recordings were collected immediately before and after rTMS. Voice quality was assessed with acoustic-based and auditory-perceptual measures.
All participants tolerated the procedures, with no unexpected adverse events or worsening of symptoms. No significant effects on intracortical inhibition were observed. In the AdLD group, there was a large-effect size after rTMS in vocal perturbation measures and a small-effect size in decreased phonatory breaks.
One rTMS session over the LMC is safe and feasible, and demonstrated trends of beneficial effects on voice quality and phonatory function in AdLD. These preliminary findings support further investigation to assess clinical benefits in a future randomized sham-controlled trial. CLINICALTRIALS.GOV: NCT02957942, registered on November 8, 2016.
喉内收肌痉挛（AdLD）是一种以内收喉肌不自主收缩为特征的疾病，其神经调节作用尚不清楚。最近的研究结果表明，AdLD 患者皮质内抑制降低。低频重复经颅磁刺激（rTMS）可诱导皮质内抑制延长，但在 AdLD 中的作用尚不清楚。本研究旨在探讨 1Hz rTMS 单次刺激喉运动皮质（LMC）在 AdLD 患者和健康个体中的安全性、可行性和效果。
使用细电极的甲状杓肌 TMS 诱发电位来个体化和确定刺激位置。两组患者（对照组 n=6，AdLD 组 n=7）接受左 LMC 1Hz rTMS 1200 个脉冲。在 rTMS 前后立即收集耐受性、不良反应、皮质内抑制和语音记录。使用基于声学和听觉感知的测量方法评估语音质量。
所有参与者均耐受了这些程序，无意外不良事件或症状恶化。皮质内抑制无明显变化。AdLD 组 rTMS 后嗓音扰动能级测量有较大效应量，发声中断减少有较小效应量。
LMC 单次 rTMS 安全可行，对 AdLD 患者的语音质量和发声功能有改善趋势。这些初步发现支持进一步研究，以在未来的随机假刺激对照试验中评估临床获益。CLINICALTRIALS.GOV：NCT02957942，于 2016 年 11 月 8 日注册。
