Abstinent chronic alcoholics investigated by dynamic posturography, ocular smooth pursuit and visual suppression

Eleven male chronic alcoholic volunteers aged 44-65 years (mean 57 years) were investigated by dynamic posturography, ocular smooth pursuit and visual suppression of the vestibulo-ocular reflex (VOR). Their drinking time ranged from 8-30 years (mean 20 years) and they had been abstinent for the last 1-20 years (mean 7 years). Ocular smooth pursuit showed abnormalities in 8/11. Abnormalities were found in 5/11 in the visual suppression of the VOR. The results of dynamic posturography tests were compared to an age-matched reference material. Dynamic posturography (EquiTest) comprises a sensory organization (SO) part in which the support surface and visual surround are either stable or referenced to the patient's sway, with eyes open or closed. In the SO part the chronic alcoholics had lower equilibrium scores in all test conditions, and the differences were significant in 4 tests out of 6. In a movement coordination part the platform makes active movements, the latencies to which were significantly prolonged in the 2 larger of the 3 translational amplitudes. Adaptation to repeated tilting of the platform was estimated to be pathological in 4/10, compared to none of the controls. The abnormal pattern found in dynamic posturography correlates well with the pathology in ocular smooth pursuit and visual suppression tests, suggested to be due to alcohol induced cerebellar lesions. It is concluded that dynamic posturography is a valuable test for assessing dysequilibrium in chronic alcoholics, even abstinent.