Tm. Roebuck et al., Neuromuscular responses to disturbance of balance in children with prenatal exposure to alcohol, ALC CLIN EX, 22(9), 1998, pp. 1992-1997
Alcohol-exposed children display delayed motor development and impaired fin
e- and gross-motor skills, including deficits in the maintenance of balance
. In a recent study, we assessed the contribution of visual, somatosensory,
and vestibular information to the ability to maintain balance. Our finding
s suggested that alcohol-exposed children were overly reliant on somatosens
ory information and were unable to compensate by using the visual and/or ve
stibular systems. To understand the nature of these observed balance defici
ts, corrective postural reactions were examined by exposing standing subjec
ts to rapid toe-up movements of the support surface. Subjects for this stud
y were alcohol-exposed (ALC) and normal control (PIC) children matched for
age and sex. Postural reactions were quantified by measuring electromyograp
hic activity of the triceps surae and anterior tibialis muscles. Analyses r
evealed no differences between the ALC and NC groups on short- and medium-l
atency electromyographic responses, which are thought to be involuntary mon
o- and polysynaptic spinal reflexes, respectively. However, when compared w
ith the NC group, the ALC group displayed increased long-latency responses,
which are thought to involve a transcortical pathway. Although we are not
able to rule out the possibility of additional peripheral (e.g,, vestibular
) disturbance as a contributing factor to postural instability, our finding
s suggest that the balance deficits seen in alcohol-exposed children are, a
t least in part, central in nature.