Effects of alcohol on body-sway patterns in human subjects

Abstract

The vestibulospinal aspects of vestibular function are commonly neglected in the evaluation of alcohol-induced intoxication. Thus, in the present study the effect of an acute intoxication with a low or moderate quantity of alcohol was examined with respect to the equilibrium in 30 healthy subjects. The blood alcohol concentration (BAC) was measured 30 min after the ingestion of the last alcohol, ranging between 0.22 and 1.59 per thousand. Stability of stance was quantified by static platform posturography in Romberg-test conditions with eyes open and eyes closed. Among other parameters, the average body sway path (SP) and area of body sway (SA) were assessed. Posturography revealed a significant increase in body sway. There was a positive correlation between SA (or SP) and BAC both with eyes open and eyes closed. Multiple group comparisons revealed that the large-alcohol-dose group (BAC > or = 1.0 per thousand) could be clearly differentiated from test cases with BAC lower than 0.8 per thousand. Sway area was the most sensitive parameter for detecting increased body sway after alcohol ingestion. The area increase, present not only with eyes closed but with eyes open, revealed an inadequate compensation of the ethanol-induced ataxia by visual stabilization. The Romberg's quotient, which denotes eyes closed relative to eyes open, remained constant. The increase in sway path with eyes closed showed an omnidirectional sway. A comparison of the sway pattern of subjects after acute ethanol ingestion with the data of patients with permanent cerebellar lesions suggested that the acute effect of alcohol resembles that of a lesion of the spinocerebellum. This finding contrasts with earlier studies, which postulated an acute effect of ethanol resembling that in patients with an atrophy of the anterior lobe of the cerebellum due to chronic alcohol abuse. In seven cases of the lower dose group (BAC < or = 0.8 per thousand), a reduction in body sway after alcohol ingestion was observed. This finding may be consistent with a dose-related biphasic action of alcohol, which - besides its well-known depressant effects with high doses - also shows stimulatory action with small doses.

Blood alcohol concentration at 0.06 and 0.10% causes a complex multifaceted deterioration of body movement control

“…During unperturbed standing, the stability was only marginally affected at 0.06% BAC, whereas under balance perturbations the body movement increases were almost linearly related to the increase in BAC and the stability was substantially deteriorated already at 0.06% BAC. In accordance with our findings, previous studies have revealed that the unperturbed standing is only marginally impaired by alcohol intoxication below 0.08% BAC (Nieschalk et al, 1999). Hence, while a subject with 0.06% BAC may find the quiet stance stability almost unaffected, the subject may find a balance perturbation unexpectedly already difficult to handle at 0.06% BAC.…”

“…These have revealed that BAC above 0.07% -0.08% impairs postural control in unperturbed standing (Dick et al, 1989;Nieschalk et al, 1999;Thyssen et al, 1981), whereas perturbed standing can be affected from about 0.06% BAC (Woollacott, 1983). However, most studies performed on human postural control and alcohol intoxication were done over 20 years ago.…”

“…One problem with this approach is illustrated in the study by Nieschalk and colleagues (Nieschalk et al, 1999) showing that the BAC in the 30 subjects assessed ranged from 0.022% to 1.59%, 30 minutes after consumption. This finding highlights the importance in the study design to consider the large individual difference in absorption of alcohol, anthropometrical influences and the risk of assessing the alcohol intoxication effects in different Mellanby states.…”

Alcohol Badly Affects Eye Movements Linked to Steering, Providing for Automatic in-Car Detection of Drink Driving

“…Acute alcohol intoxication temporarily affects cerebellar function (Chu, 1983), producing symptoms that resemble mild or moderate cerebellar ataxia (Diener et al, 1983;Nieschalk et al, 1999), including loss of coordination between eye movements and other visually guided actions (Crowdy and Marple-Horvat, 2004).…”

The Effects of Alcohol on Static Balance in University Students

“…This output implies that alcohol has a particular influence on control over static posture, which is closely related to instability of the ankle, and this seems to result from a decrease in reaction velocity of nerve roots 12) . A study by Nieschalk found that measuring postural stability by using Romberg's test after applying a small and middle amount of alcohol showed that the tests with the eyes open and closed revealed a relation between the blood alcohol content and postural sway 13) . Another study measured the velocity and range of postural sway after injecting alcohol by 0.5 mL/kg of alcohol 14) .…”