Prenatal exposure to alcohol affects the ability to maintain postural balance

Abstract

Prenatal exposure to alcohol is known to affect gross motor functioning. Animal studies have shown that balance is particularly affected, and there is some evidence that similar deficits exist in alcohol-exposed children. In the current study, postural balance, or the ability to maintain equilibrium, was assessed in a group of alcohol-exposed children (ALC group; n = 11) and controls (NC group; n = 11) individually matched for age and sex. Balance was measured across six conditions designed to systematically manipulate or eliminate visual or somatosensory information. Equilibrium and strategy scores for each condition and a derived composite balance score were analyzed. Although the ALC group had a lower mean composite balance score, their performance was similar to that of the NC group on all conditions where somatosensory input was reliable. However, when somatosensory input was manipulated, and when both somatosensory and visual input were inaccurate, the ALC group performed more poorly than controls. Interestingly, there were no differences between the ALC group and NC group in the type of control strategy used to maintain balance. These results suggest that alcohol-exposed children are overly reliant on somatosensory input. When this input is atypical, alcohol-exposed children display significantly greater anterior-posterior body sway and are unable to compensate using available visual or vestibular information. These deficits may be related to cerebellar anomalies previously reported in fetal alcohol syndrome children.