Ethanol consumption impairs vestibulo-ocular reflex function measured by the video head impulse test and dynamic visual acuity

• Published in: Journal of vestibular research Vol. 24; no. 4; pp. 289 - 295
• Main Authors: Roth, Thomas N, Weber, Konrad P, Wettstein, Vincent G, Marks, Guy B, Rosengren, Sally M, Hegemann, Stefan C A
• Format: Journal Article
• Language: English
• Published: Netherlands 01.01.2014
• Subjects: Adult; Alcohol Drinking - physiopathology; Breath Tests; Dose-Response Relationship, Drug; Ethanol - pharmacology; Female; Head Impulse Test - methods; Head Movements - drug effects; Head Movements - physiology; Humans; Male; Reflex, Vestibulo-Ocular - drug effects; Reflex, Vestibulo-Ocular - physiology; Space life sciences; Visual Acuity - drug effects; Saccade; vestibulo-ocular reflex (VOR); dynamic visual acuity; Ethanol; vestibular; video head impulse test
• DOI: 10.3233/VES-140520
• ISSN: 0957-4271

Ethanol affects many parts of the nervous system, from the periphery to higher cognitive functions. Due to the established effects of ethanol on vestibular and oculomotor function, we wished to examine its effect on two new tests of the vestibulo-ocular reflex (VOR): the video head impulse test (vHIT) and dynamic visual acuity (DVA). We tested eight healthy subjects with no history of vestibular disease after consumption of standardized drinks of 40% ethanol. We used a repeated measures design to track vestibular function over multiple rounds of ethanol consumption up to a maximum breath alcohol concentration (BrAC) of 1.38 per mil. All tests were normal at baseline. VOR gain measured by vHIT decreased by 25% at the highest BrAC level tested in each subject. Catch-up saccades were negligible at baseline and increased in number and size with increasing ethanol consumption (from 0.13° to 1.43° cumulative amplitude per trial). DVA scores increased by 86% indicating a deterioration of acuity, while static visual acuity (SVA) remained unchanged. Ethanol consumption systematically impaired the VOR evoked by high-acceleration head impulses and led to a functional loss of visual acuity during head movement.