Effect of ethanol on dynamic visual acuity during vertical body oscillation in healthy volunteers

Abstract

Visual orientation is the most important sensory input during locomotion (e.g. walking, driving a car, riding a bicycle). We investigated dynamic visual acuity (DVA) during vertical body-oscillations (amplitude 5 cm; frequency 1.5 Hz) in 12 healthy subjects before and twice after ethanol consumption. During oscillation, vertical eye movements were recorded under two test conditions: with eyes closed (EC) and during DVA testing. A significant increase in vertical eye-amplitude after ethanol ingestion occurred only during EC tests, as a possible sign of vestibular hyperreaction. During vestibular stimulation alone (EC), ethanol did not affect the phase shift between stimulus and eye movements. However, when the subjects were given an additional visual stimulus (DVA), the post-alcohol phase shift rose significantly. Surprisingly, the post-alcohol phase shift values for the two test conditions showed no significant differences. After ethanol ingestion we found no changes in static visual acuity but a significant loss of DVA. Volunteers with a change of DVA threshold (DVAT) showed significantly (P = 0.004) higher post-alcoholic changes in the phase shift. In summary, low doses of ethanol disturbed the visually guided oculomotor response during fixation of an earth-fixed target while the observer was subject to linear vertical acceleration. This effect led to an increasing delay between the beginning of body and eye movements. The consequence was an increasing phase shift and thus a decrease in DVA during whole-body oscillation which was comparable to movements during human locomotion.

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

“…Compared to visual acuity recorded with the head still (static visual acuity, SVA), acuity recorded during head movement (dynamic visual acuity, DVA) is reduced due to the failure of the VOR to stabilise gaze. Previous research has shown that ethanol reduces DVA during vertical linear sinusoidal acceleration [21,22]. Subjects showed a raised acuity threshold and an increase in errors following a single dose of ethanol and blood ethanol levels ranging from 0.09 to 0.94 per mil [21].…”

“…Previous research has shown that ethanol reduces DVA during vertical linear sinusoidal acceleration [21,22]. Subjects showed a raised acuity threshold and an increase in errors following a single dose of ethanol and blood ethanol levels ranging from 0.09 to 0.94 per mil [21]. We aimed to extend these findings by investigating the effects of ethanol on DVA recorded during unpredictable, high acceleration head impulses.…”

The effect of alcohol on cervical and ocular vestibular evoked myogenic potentials in healthy volunteers

“…Markham and Diamond (2006) reported a decrease in ocular counterrolling after alcohol consumption, suggesting reduced sensitivity of the utricle to dynamic tilt. In contrast, a possible effect of alcohol on the sacculo-ocular reflex might be suggested by the finding that dynamic visual acuity was reduced during vertical translations after alcohol consumption (Schmäl et al, 2000(Schmäl et al, , 2003. However in both cases the effects were thought to be caused by changes in central VOR pathways and not by a direct effect of alcohol on the otolith organs.…”

“…Alcohol has been shown to significantly diminish the nystagmus evoked by both caloric irrigation and horizontal angular rotation (Berthoz et al, 1977;Bochenek and Ormerod, 1962;Chiang and Young, 2007;Post et al, 1994;Tianwu et al, 1995). Similarly, alcohol decreases dynamic visual acuity during vertical translations, though the gain of the translational VOR does not appear to be affected (Schmäl et al, 2000(Schmäl et al, , 2003. Studies of ocular counterrolling have shown a small decrease in torsion after alcohol consumption (Diamond and Markham, 2008;Markham and Diamond, 2006).…”

Episodisch auftretendes Schwindelgef�hl

“…B. beim Gehen nicht unerhebliche lineare Beschleunigungen auftreten, die zu einer Stimulation des Sakkulus führen. Immer dann, wenn es bei diesen Patienten durch bestimmte Kopf-oder Körperbe-wegungen zu einer Störung der Blickfeldstabilisierung kommt, tritt für Millisekunden ein Schwindelgefühl auf,da in dieser Situation die Orientierung des Patienten im Raum kurzfristig gestört ist.Auch bei gesunden Personen lässt sich z.B.durch Konsum von Ethanol bereits in geringer Dosierung eine Störung dieses Mechanismus herbeiführen[58].…”