Camp Aaron J, Gu Chao, Cushing Sharon L, Gordon Karen A, Corneil Brian D
Sydney Medical School, Bosch Institute, University of Sydney, Medical Foundation Building, Parramatta Rd, Sydney, NSW, 2006, Australia.
Department of Psychology, Brain and Mind Institute, University of Western Ontario, Toronto, ON, Canada.
Eur J Neurosci. 2017 May;45(9):1212-1223. doi: 10.1111/ejn.13536. Epub 2017 Mar 1.
The cervical vestibular evoked myogenic potential (cVEMP) is a common and simple test of vestibulospinal reflex patency. In the clinic, cVEMPs are measured in response to loud sounds from the sternocleidomastoid (SCM) on the ventral neck, as subjects maintain an uncomfortable head posture needed to recruit SCM. Here we characterize the cVEMP in a dorsal neck turner (splenius capitis; SPL), and compare it with the SCM cVEMP. cVEMPs were recorded simultaneously via surface electromyography from SCM and SPL from 17 healthy subjects in a variety of postures, including head-turned postures adopted while either seated or standing, and the clinical posture. Like the SCM cVEMP recorded ipsilateral to the side of sound stimulation, the cVEMP on the contralateral SPL (synergistic with ipsilateral SCM) was characterized by a biphasic wave of muscle activity that began at ~ 13 ms. cVEMP reliability was higher on SPL vs. SCM in standing postures (chi-squared; P < 0.05), and equivalent results were obtained from SPL in a standing or seated posture. In 9 of the 17 subjects, we also obtained bilateral intramuscular (IM) recordings from SPL at the same time as the surface recordings. In these subjects, the initial surface response in SPL was associated with a consistent decrease in multi-unit IM SPL activity. Overall, these results demonstrate that SPL recordings offer a complimentary target for cVEMP assessments. The expression of SPL cVEMPs in simple head-turned postures may also improve the utility of cVEMP testing for vestibular assessment in children, the elderly, or non-compliant.
颈前庭诱发肌源性电位（cVEMP）是一种常见且简单的前庭脊髓反射通畅性测试。在临床上，当受试者保持一种不适的头部姿势以激活胸锁乳突肌（SCM）时，通过测量来自颈部腹侧胸锁乳突肌对大声响的反应来检测cVEMP。在此，我们描述了在颈部背侧肌肉（头夹肌；SPL）中的cVEMP，并将其与胸锁乳突肌的cVEMP进行比较。通过表面肌电图同时记录了17名健康受试者在各种姿势下，包括坐位或站立时转头姿势以及临床姿势下，胸锁乳突肌和头夹肌的cVEMP。与声音刺激侧同侧记录的胸锁乳突肌cVEMP一样，对侧头夹肌（与同侧胸锁乳突肌协同）的cVEMP表现为肌肉活动的双相波，起始于约13毫秒。在站立姿势下，头夹肌的cVEMP可靠性高于胸锁乳突肌（卡方检验；P < 0.05），并且站立或坐位时头夹肌获得的结果相当。在17名受试者中的9名中，我们还在进行表面记录的同时，从双侧头夹肌获得了肌内（IM）记录。在这些受试者中，头夹肌的初始表面反应与多单位肌内头夹肌活动的持续减少相关。总体而言，这些结果表明头夹肌记录为cVEMP评估提供了一个补充靶点。在简单转头姿势下头夹肌cVEMPs的表现也可能提高cVEMP测试在前庭评估儿童、老年人或不配合者中的实用性。
