Postural instability and falls in the elderly patient constitute a maj
or health care problem. The etiology is often multifactorial, involvin
g abnormal sensory input (visual, vestibular, and somatosensory), poor
central processing, and suboptimal musculoskeletal biomechanics. Estr
ogen replacement therapy has been shown to prevent Alzheimer's disease
and to improve cognitive performance in women with dementia. It was,
therefore, postulated that estrogen replacement may improve central pr
ocessing speed, which would result in improved postural stability. In
this prospective, randomized, double-blinded study, 87 elderly female
subjects (age > 69) were examined by repeated dynamic platform posturo
graphy, to measure the effect of estrogen therapy versus placebo upon
postural stability. Results indicate that those receiving estrogen had
no significant improvement in postural stability at 2 and 8 months of
treatment relative to those receiving placebo. Trail Making B test wa
s used as the psychometric test of central processing speed. There was
no significant effect of estrogen on this measure over the 8 months o
f observations. It is concluded that 8 months of estrogen replacement
therapy has no significant effect on central processing speed or postu
ral stability in a healthy older female population.