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Nov. 17, 2006 -- Memory complaints are common among women going through menopause. Now research finds that the most widely used treatment for hot flashes and other menopausal symptoms may improve memory as well.
The new brain imaging study confirms that hormone therapy has a direct and immediate effect on the part of the brain that controls a critical component of memory.
More activity was seen in that region of the brain -- known as the prefrontal cortex -- in postmenopausal women taking hormone therapy than in similarly-aged women who were not taking hormones.
"Our findings suggest that even relatively short periods of hormone therapy have effects on the memory systems that may be of benefit to some women during the perimenopausal transition or early postmenopause," says researcher Yolanda Smith, MD, MS, of the University of Michigan Health System.
Hormone Therapy and Alzheimer's
Just a few years ago, many experts believed hormone therapy had a beneficial long-term impact on the brain by lowering a woman's risk of Alzheimer's diseaseAlzheimer's disease.
However, several recent studies suggest the opposite may be true, including the Women's Health Initiative Memory Study (WHIMS), published in the spring of 2003.
WHIMS researchers concluded that combined estrogen-progestin therapy was associated with a doubling of Alzheimer's risk in women 65 and older.
Studies examining the short-term impact of hormone therapy on memory and other brain functions have been inconclusive.
Testing Brain Activity
In a study designed to literally see this impact, Smith and colleagues measured brain activity in 10 postmenopausal women between the ages of 50 and 60, using functional magnetic resonance imaging (fMRI).
The women were treated with either combined estrogen-progestin or placebo for a month, followed by a month with no medication.
Those receiving hormones and placebo were then switched for four additional weeks.
Brain activity was measured as the women performed standardized tests designed to assess visual memory.
Compared to women on placebo, those on hormone therapy showed more focused use of the prefrontal cortex, suggesting more efficient brain function, Smith tells WebMD.
The findings are published in the Nov. 16 issue of the Journal of Clinical Endocrinology and Metabolism.
"Our findings suggest that even short-term use of hormone therapy for symptoms like hot flashes may be altering brain function in a positive way," Smith says.
Clinical Significance Not Clear
Although memory complaints are common during perimenopauseperimenopause and beyond, there is little direct evidence that the hormonal changes that occur during the transition to menopause have a direct impact on brain function, says Victor W. Henderson, MD, MS.
Henderson is a professor of health research and neurology at Stanford University, where he studies the effects of agingaging on the brain.
"That doesn't mean that women don't experience symptoms related to memory loss during this point in their lives," he tells WebMD. "Many do. But it is still not clear if these symptoms are directly related to menopause or to other things going on in their busy, complicated lives at this age."
Documenting hormone therapy's direct impact on a key area of the brain is important, Henderson says. But he adds that the clinical significance of the findings remain unknown.
Rather than proving a positive benefit for hormone therapy, the brain changes seen in this and other imaging studies could be indicative of a negative impact, he says.
Until more is known, Henderson believes memory should not be part of the equation when women are deciding whether or not to take hormones as they transition to menopause.
"There just isn't enough known about the cognitive effect of hormone therapy in this age group to consider it an indication for its use."
SOURCES: Smith, Y. Journal of Clinical Endocrinology and Metabolism, Nov. 16, 2006; vol 91: pp 4476-4481. Yolanda R. Smith, MD, MS, department of obstetrics and gynecology, University of Michigan School of Public Health, Ann Arbor. Victor Henderson, MD, MS, professor of health research and policy, neurology, neurological sciences, Stanford University, Stanford, Calif.