Department of Psychology, University of Exeter, Exeter EX4 4QC, UK; Prince of Wales Clinical School, UNSW, Sydney, NSW 2052, Australia.
Prince of Wales Clinical School, UNSW, Sydney, NSW 2052, Australia; Neuroscience Research Australia, UNSW, Sydney, NSW 2052, Australia.
Neurosci Lett. 2022 Jun 11;781:136677. doi: 10.1016/j.neulet.2022.136677. Epub 2022 May 8.
We present an initial report using 5 subjects, of short and long latency collic evoked responses following a half cycle of 100 Hz vibration (5 ms) applied to the sternocleidomastoid (SCM) tendon. These were detected in EEG and extraocular and leg muscles and compared with vestibular-dependent responses from direct mastoid stimulation. The responses from the extraocular recording site are likely to be evoked myogenic potentials, thus "collic evoked myogenic potentials" (CEMPs). An n19/p24 presumed ocular CEMP (oCEMP) was followed by a P22/N28 response over the posterior fossa, referred to as a collic cerebellar evoked potential (CoCEP), with responses in leg muscles starting around 55 ms. In contrast to their vestibular analogues, the oCEMP and CoCEP were predominantly ipsilateral to the side of stimulation, consistent with a double-crossed projection. In addition, their thresholds were just above the threshold of vibrotactile sensation, implying a low threshold, oligo-synaptic projection of SCM afferents to both extraocular and cerebellar targets. Following these short latency responses, SCM tendon stimulation evoked prolonged EMG responses in postural muscles of the legs, consistent with a role in the afferent limb of a short latency, spino-bulbar-spinal postural response to sternal perturbations. These collic evoked responses are likely to be of value in understanding the functions of cervical muscle afferents and have clinical value, for example in monitoring compensation after vestibular loss.
我们呈现了一项初步研究结果，使用 5 名被试，在对胸锁乳突肌（SCM）肌腱施加半周期 100Hz 振动（5ms）后，记录到短潜伏期和长潜伏期的丘系诱发反应。这些反应在 EEG 和眼外肌及腿部肌肉中被检测到，并与直接乳突刺激引起的前庭依赖性反应进行了比较。眼外肌记录部位的反应可能是诱发的肌源性电位，因此称为“丘系诱发肌源性电位”（CEMPs）。n19/p24 假定的眼源性 CEMP（oCEMP）之后，在颅后窝出现 P22/N28 反应，称为丘系小脑诱发电位（CoCEP），腿部肌肉的反应大约在 55ms 开始。与它们的前庭类似物不同，oCEMP 和 CoCEP 主要对侧于刺激侧，符合双交叉投射。此外，它们的阈值略高于振动触觉的阈值，这意味着 SCM 传入纤维到眼外肌和小脑的投射具有低阈值、少突触的特性。在这些短潜伏期反应之后，SCM 肌腱刺激在腿部姿势肌中诱发了延长的肌电图反应，这与胸骨扰动的短潜伏期、脊髓-延髓-脊髓姿势反应的传入臂中的作用一致。这些丘系诱发反应可能有助于理解颈肌传入纤维的功能，并且具有临床价值，例如在监测前庭损失后的代偿。
