Vestibular Dysfunction in Acute Cerebellar Ataxia / 대한평형의학회지

Acute cerebellar ataxia is described as a clinical syndrome of acute onset of cerebellar dysfunction with a good long-term prognosis. The pathogenesis of acute cerebellar ataxia remains unclear. A 55-year-old woman presented with acute onset of gait ataxia and dysarthria. The videonystagmography showed saccadic pursuit and saccadic abnormalities including slightly prolonged latency and hypometria. Rotational chair test revealed increased vestibuloocular reflex (VOR) gains and a failure of VOR suppression by visual fixation. Brain magnetic resonance imaging and cerebrospinal fluid examination were normal. The patient was treated with steroids and made nearly complete recovery over a period of 3 months.

Numerically simulating the biomechanical response to membranous labyrinth in the vestibular system / 医用生物力学

Objective To study the biomechanical response to cupulae partition of statoreceptor in the rotational chair test and to provide a quantitive platform for vestibular system assessment. Method Based on the histological slides from the right temporal bones from a healthy volunteer, a three dimensional geometry of membranous labyrinth in the vestibular system was reconstructed. The biomechanical response of the volunteer to sinusoidal rotation chair test (0.8 Hz, ±40°) with the head pitch 30° was numerically simulated by the Lagrangian method. ResultsThe maximum displacement of cupula partition in the right horizontal semicircular canal is 54.2 μm, and 15.9 μm in the posterior semicircular canal as well as 43.7 μm in the anterior semicircular canal. However, the displacement response in the anterior semicircular canal is identical on both ears, and it would counteract the eye movement. Secondly, the normal displacement in the right semicircular canal deflect from the side of canal to the side of utricle, while in the left semicircular canal, it deflect from the side of utricle to the side of canal when the chair rotated to the right, and it is opposite when the chair rotate to the left. Conclusions The biomechanical response to cupulae partition by this numerical simulation is in accordance with Flourens law and Ewald laws.