Chen Mo, Summers Rebekah L S, Goding George S, Samargia Sharyl, Ludlow Christy L, Prudente Cecília N, Kimberley Teresa J
Divisions of Physical Therapy and Rehabilitation Science, Department of Rehabilitation Medicine, School of Medicine, University of Minnesota Minneapolis, MN, USA.
Department of Otolaryngology-Head and Neck Surgery, University of Minnesota Minneapolis, MN, USA.
Front Neurosci. 2017 Mar 7;11:88. doi: 10.3389/fnins.2017.00088. eCollection 2017.
This work aimed to evaluate the cortical silent period (cSP) of the laryngeal motor cortex (LMC) using the bilateral thyroarytenoid (TA) muscles with transcranial magnetic stimulation (TMS). In 11 healthy participants, fine-wire electromyography (EMG) was used to record bilateral TA muscle responses to single pulse TMS delivered to the LMC in both hemispheres. Peripheral responses to stimulation over the mastoid, where the vagus nerve exits the skull, were collected to verify the central origin of the cortical stimulation responses by comparing the latencies. The cSP duration ranged from 41.7 to 66.4 ms. The peripherally evoked motor-evoked potential (MEP) peak occurred 5-9 ms earlier than the cortical responses (for both sides of TAs: < 0.0001) with no silent period. The right TA MEP latencies were earlier than the left TA responses for both peripheral and cortical measures ( ≤ 0.0001). These findings demonstrate the feasibility of measuring cSP of LMC based on intrinsic laryngeal muscles responses during vocalization in healthy volunteers. The technique could be used to study the pathophysiology of neurological disorders that affect TA muscles, such as spasmodic dysphonia. Further, the methodology has application to other muscles of the head and neck not accessible using surface electrodes.
这项研究旨在通过经颅磁刺激（TMS），利用双侧甲杓肌（TA）来评估喉运动皮层（LMC）的皮质静息期（cSP）。在11名健康参与者中，使用细针肌电图（EMG）记录双侧TA肌肉对在两个半球的LMC施加单脉冲TMS的反应。收集乳突（迷走神经穿出颅骨的部位）刺激的外周反应，通过比较潜伏期来验证皮质刺激反应的中枢起源。cSP持续时间在41.7至66.4毫秒之间。外周诱发的运动诱发电位（MEP）峰值比皮质反应早5 - 9毫秒出现（双侧TA：< 0.0001），且没有静息期。在外周和皮质测量中，右侧TA的MEP潜伏期均早于左侧TA的反应（≤ 0.0001）。这些发现证明了在健康志愿者发声期间基于喉内肌反应测量LMC的cSP的可行性。该技术可用于研究影响TA肌肉的神经疾病的病理生理学，如痉挛性发声障碍。此外，该方法适用于使用表面电极无法触及的头颈部其他肌肉。
