Removing Ovaries Before Menopause Leads to Memory, Movement Troubles

Mar. 23 -- WEDNESDAY, Aug. 29 (HealthDay News) -- Removing one or both ovaries before a woman reaches natural menopause increases the risk of both dementia and movement disorders such as Parkinson's disease.

But giving hormone-replacement therapy at least until the age of 50 blunts that risk, according to a study by Mayo Clinic researchers.

"It's the first study that shows that taking out the major source of endogenous estrogen, which is ovaries, will have this impact on movement disorders and one of the first with dementia," said Farida Sohrabji, an associate professor of neuroscience and experimental therapeutics at Texas A&M Health Science Center College of Medicine.

The study findings were published in the Aug. 29 online issue of Neurology.

A woman's ovaries are her main source of endogenous (produced by the body) estrogen.

There has been some evidence that estrogen can protect against cognitive decline, although the landmark Women's Health Initiative (WHI) study actually showed the opposite for women aged 65 and older.

The authors of the new study used the Rochester Epidemiology Project, a database of records dating from 1935 housed at the Mayo Clinic in Rochester, Minn, to identify all women in Olmsted County, Minn., who had had one or both ovaries removed between 1950 and 1987. These women were then compared to a control group. Each group consisted of about 1,500 women.

The researchers then interviewed women in both groups (or their relatives) to assess any degree of cognitive impairment or dementia, and compared the two groups. Women who were still alive also underwent a cognitive test over the phone.

Those women who had had one or both ovaries removed before menopause were almost twice as likely to develop cognitive problems or dementia, compared with women who did not have this surgery, known as oophorectomy.

Women who were younger when they underwent oophorectomy were more likely to develop dementia than women who were older at the time of the surgery. The removal of ovaries is often done to protect women at high risk of breast or ovarian cancer.