INFLUENCE OF LOW-DOSE ALCOHOL ON FIXATION SUPPRESSION

The decrease of fixation suppression after small doses of alcohol was studied in 40 healthy volunteers (20 male, 20 female) using rotatory s timulation. 0.5 g alcohol per kg body weight were given within 20 min. The maximum fixation suppression and blood alcohol concentrations (BA G) were measured before and al 15, 30, 45, 60, 120, 180 and 240 min af ter ingestion. We determined the maximum angular acceleration during w hich total suppression of the vestibulo-ocular-reflex (VOR) was still possible. Fixation suppression was successful up to mean values of 43. 6 degrees/s(2) before ingestion of alcohol (reference level). A first significant deterioration of fixation suppression was observed at BAC of 20 mg/100 ml decreasing constantly with increasing BAG. Al the medi an maximum BAC of 65 mg/100 ml. fixation suppression was possible up t o acceleration values of 20% compared with reference levels. Measuring of the maximum fixation suppression in rotational rests is a reproduc ible easy method to describe the central nervous system control of ves tibular functions. This method shows impressingly the enormous effects of low doses of alcohol on equilibrium. It is concluded that at BAC o f more than 50 mg/100 ml a remaining vestibular nystagmus might be obs erved when driving a bend.