Zuma E Maia F C, Cal Renato, D'Albora Ricardo, Carmona Sergio, Schubert Michael C
Clínica Maia, Canoas, Brazil.
Federal University of Pará, Belém, PA, Brazil.
J Neurol. 2017 Jun;264(6):1264-1270. doi: 10.1007/s00415-017-8524-x. Epub 2017 May 23.
Tilt suppression refers to both tilting the head away from an Earth vertical axis and a reduction of an induced horizontal nystagmus. This phenomenon of reducing an induced horizontal nystagmus involves a circuitry of neurons within the vestibular nuclei and the cerebellum (collectively referred to as velocity storage) and signals from the otolith end organs. Lesions involving this circuitry can disrupt tilt suppression of induced horizontal nystagmus. We investigated the clinical value of combining the horizontal head-shaking nystagmus test with tilt suppression in 28 patients with unilateral peripheral vestibular hypofunction and 11 patients with lesions affecting the central nervous system. Each of the subjects with peripheral vestibular lesions generated an appropriately directed horizontal nystagmus after head shaking that then suppressed the induced angular slow phase velocity on average 52 ± 17.6% following tilt down of the head. In contrast, patients with central lesions had very little ability to suppress post-head-shaking nystagmus (mean 3.4 ± 56%). We recommend tilting the head after head shaking as a useful clinical test to assist in the differential diagnosis of vertiginous patients. In the case of unilateral peripheral vestibular hypofunction, head tilt suppresses the induced nystagmus via influence of the otolith organ. In the case of central pathology, the inability to suppress the nystagmus is from lesions impairing the otolith mediation on the velocity storage circuitry.
倾斜抑制是指头部偏离地球垂直轴以及诱导性水平眼震的减弱。这种减弱诱导性水平眼震的现象涉及前庭核和小脑内的神经元回路（统称为速度存储）以及来自耳石终器的信号。涉及该回路的病变可破坏诱导性水平眼震的倾斜抑制。我们研究了在28例单侧外周前庭功能减退患者和11例影响中枢神经系统的病变患者中，将水平摇头眼震试验与倾斜抑制相结合的临床价值。每例外周前庭病变患者在摇头后均产生了方向适当的水平眼震，随后在头部向下倾斜后，诱导性角慢相速度平均抑制了52±17.6%。相比之下，中枢病变患者抑制摇头后眼震的能力非常弱（平均3.4±56%）。我们建议在摇头后倾斜头部作为一项有用的临床检查，以协助对眩晕患者进行鉴别诊断。在单侧外周前庭功能减退的情况下，头部倾斜通过耳石器官的影响抑制诱导性眼震。在中枢病变的情况下，无法抑制眼震是由于病变损害了速度存储回路上的耳石介导作用。
