Jenks Vestibular Physiology Laboratory, Massachusetts Eye and Ear Infirmary, Boston, MA, USA.
Department of Otolaryngology, Harvard Medical School, Boston, MA, USA.
Sci Rep. 2019 Oct 4;9(1):14323. doi: 10.1038/s41598-019-50803-y.
Vestibular migraine (VM) is the most common cause of spontaneous vertigo but remains poorly understood. We investigated the hypothesis that central vestibular pathways are sensitized in VM by measuring self-motion perceptual thresholds in patients and control subjects and by characterizing the vestibulo-ocular reflex (VOR) and vestibular and headache symptom severity. VM patients were abnormally sensitive to roll tilt, which co-modulates semicircular canal and otolith organ activity, but not to motions that activate the canals or otolith organs in isolation, implying sensitization of canal-otolith integration. When tilt thresholds were considered together with vestibular symptom severity or VOR dynamics, VM patients segregated into two clusters. Thresholds in one cluster correlated positively with symptoms and with the VOR time constant; thresholds in the second cluster were uniformly low and independent of symptoms and the time constant. The VM threshold abnormality showed a frequency-dependence that paralleled the brain stem velocity storage mechanism. These results support a pathogenic model where vestibular symptoms emanate from the vestibular nuclei, which are sensitized by migraine-related brainstem regions and simultaneously suppressed by inhibitory feedback from the cerebellar nodulus and uvula, the site of canal-otolith integration. This conceptual framework elucidates VM pathophysiology and could potentially facilitate its diagnosis and treatment.
前庭性偏头痛（VM）是自发性眩晕最常见的原因，但仍知之甚少。我们通过测量患者和对照者的自身运动感知阈值，以及描述前庭眼反射（VOR）和前庭及头痛症状严重程度，来研究前庭中枢通路在 VM 中致敏的假说。VM 患者对滚转倾斜过度敏感，滚转倾斜会共同调节半规管和耳石器官的活动，但对单独激活这些管道或耳石器官的运动不敏感，这表明对管石整合的敏感性。当倾斜阈值与前庭症状严重程度或 VOR 动力学一起考虑时，VM 患者分为两个聚类。一个聚类的阈值与症状和 VOR 时间常数呈正相关；第二个聚类的阈值普遍较低，与症状和时间常数无关。VM 阈值异常显示出与脑干速度存储机制平行的频率依赖性。这些结果支持一种发病机制模型，即前庭症状源于前庭核，这些核被与偏头痛相关的脑干区域致敏，同时被来自小脑小结和绒球的抑制性反馈抑制，而小脑小结和绒球是管石整合的部位。这个概念框架阐明了 VM 的病理生理学，可能有助于其诊断和治疗。
