Clues to Alzheimer's Cure

Study Finds Memory Impairment Leads to Alzheimer's

March 15

When are memory lapses normal, and when are they a sign of
something more severe?

     For the first time, a new study published in the current Archives of Neurology finds that the more severe kind of memory loss, called mild cognitive impairment (MCI), is a likely precursor of Alzheimer's disease. But with that potentially bad news comes new hope for research that could postpone the devastating disease.

     In Good Morning America's House Calls with Dr. Tim Johnson, he took a look at the study from Washington University School of Medicine in St. Louis.

     The study is significant, because if researchers can identify people with MCI early on, doctors can potentially prevent the progression to Alzheimer's, Johnson said.

What Is MCI?

     Four million Americans suffer from Alzheimer's and 400,000 are diagnosed with it each year. And it is estimated that at least 2.5 million elderly people may have MCI.

     Mild cognitive impairment symptoms include the following: memory loss, abnormal memory for age, the ability to carry out normal activities of daily living, normal general cognitive function and no dementia.

     Those with MCI, have an abnormal memory problem, more serious than plain forgetfulness, but with the rest of the brain still working, Johnson said. They can carry on normal life, and do not show signs of dementia.

Deciphering the Study

     The Washington University researchers looked at 404 patients, breaking them down into four categories. They were either normal, had an uncertain diagnosis of MCI, suspicion of MCI, or a fairly confident diagnosis of MCI.

     The research team then followed the groups with annual memory tests, and after five years, saw that Alzheimer symptoms had developed in 6.8 percent of the normal group, 19.9 percent of the uncertain of MCI group, 35.7 percent of the suspicious of MCI group and 60.5 percent of the fairly confident of having MCI group.

     What this demonstrates is that the more obvious the memory deficit at an early age, the more likely you were to develop Alzheimer's, Johnson said. Sixty percent had developed Alzheimer's within five years. By the end of the study, after nine and-a-half-years, all the volunteers with the most severe form of MCI had developed the clinical symptoms of Alzheimer's.

     It doesn't mean that if you experience some forgetfulness you will get Alzheimer's, Johnson said. Losing some memory power is a natural product of aging.

Help for Researchers

     Many studies are underway that are looking at drugs to prevent the progression to Alzheimer's disease.

     Test subjects have just been recruited for a National Institutes of Health study that will test the usefulness of two drugs, donepezil and Vitamin E, in slowing or stopping the progression from MCI to Alzheimer's.

     Other studies look at what happens if you give drugs that are used to treat Alzheimer's much earlier, and still other studies are looking at lowering cholesterol, which some people think has a link to the disease.

     Most importantly, doctors are studying the brain to look for possible underlying causes. There is feverish work going on in the area of early detection, and improved tools and drugs for it, Johnson said.