FRIDAY, March 22, 2002 (HealthDayNews) -- Mild but persistent memory impairment, like always forgetting appointments you used to remember, could mean you're at increased risk of developing Alzheimer's disease.
However, it doesn't mean you'll automatically get the debilitating disease, according to scientists at the University of Kentucky.
Their study of 130 nuns, aged 75 to 102, found those who had mild memory or other cognitive impairment were more likely to have higher levels of abnormal protein deposits in their brains, a physiological condition associated with Alzheimer's disease. However, not all the nuns who had high levels of the protein went on to develop Alzheimer's.
"Just because you have mild cognitive impairment doesn't mean you're going to have dementia," says Kathryn P. Riley, a psychologist at the university's Sanders-Brown Center on Aging and lead author of the study. It appears in the May 2002 Annals of Neurology, but is already available online.
Riley's study is one of several that have used data from a long-term study of 678 School Sisters of Notre Dame to find evidence of physiological changes in the brain that could be associated with Alzheimer's. The nuns she studied were tested for cognitive abilities four times over six years. Following their deaths, brain autopsies revealed a close correlation between the degree of cognitive impairment and levels of the protein, called "neurofibrillary tangles."
However, a little less than half of the nuns who had mild cognitive dysfunction and whose brains showed the presence of the neurofibrillary tangles never went on to develop Alzheimer's.
"At this point, researchers are still trying to learn what predicts this outcome," Riley says.
The impairment Riley and her colleagues charted weren't the occasional lapses that plague people as they get older, but repeated memory problems that affect daily living.
"This is not people who just lose their car keys, but those with significant and enduring impairment, like a person who consistently loses track of appointments or someone who has made the same recipe for years, and starts to leave out ingredients again and again," she says.
While the findings that mild cognitive impairment could be an indication of impending Alzheimer's is hardly reassuring, Riley finds several bits of good news in her study.
The first is that mild cognitive impairment does not automatically lead to Alzheimer's, and that people can take some action on their own if they're worried.
"People shouldn't sit at home and worry," she says. "They need to get a baseline assessment, like women do for osteoporosis."
If the doctor finds that you do, indeed, have a mild impairment, he or she will ask you to come back in six months to differentiate temporary lapses from more enduring problems, Riley says.
Second, the drugs now in use for Alzheimer's patients might be effective in preventing cognitive problems from worsening in those with milder impairments.
"Currently, drugs are not being prescribed for people with mild impairment, but we are looking to see if those medications can stop the progress of impairment," Riley says. "We are not there yet, but there is hope."
Bill Thies, vice president of medical and scientific affairs for the Alzheimer's Association, says, "it's correct that there is a rough correlation between neural pathology and the development of dementia." However, he adds, other studies of data taken from the nun study have shown that "vascular pathology" could also predict Alzheimer's' onset.
Riley agrees, adding her study purposely excluded those nuns with vascular disease to concentrate on the neurofibrillary tangles.
Unfortunately, the only way now to get data on the brain changes that may presage Alzheimer's is through autopsies, Thies says.
"We have great hopes of imaging techniques that will allow us to track the disease," he says. That could be invaluable in the earlier detection and possible prevention of Alzheimer's, he adds.
What to Do: The Alzheimer's Association provides a glossary of terms about the disease. Further information about the disease is available by visiting The Alzheimer's Association of Los Angeles.
