Don't Chalk Forgetfulness Up to Normal Aging
March 14, 2001 -- It may be a myth that forgetfulness is part of the normal aging process. A new study suggests that older people who have repeated memory lapses may actually have an early form of Alzheimer's disease, even if they do not have the dementia characteristic of the disease.
Researchers concluded that patients diagnosed with a syndrome known as mild cognitive impairment, which has been considered a state somewhere between normal aging and Alzheimer's, actually have early stage Alzheimer's disease. The findings, if accepted, could profoundly affect the diagnosis of the disease and suggest that the true prevalence of Alzheimer's is much greater than widely believed.
About 10% of people over the age of 65 develop Alzheimer's disease -- that's about 1% each year. But in patients found to have mild cognitive impairment, the progression to Alzheimer's has been estimated to be closer to 15% per year.
"There is currently a lot of discussion about whether mild cognitive impairment is Alzheimer's or a risk factor for the disease, and this is by no means the final word on the subject," Neil Buckholtz, PhD, tells WebMD. "It may come down to what clinicians feel comfortable saying to patients. The diagnosis of Alzheimer's sets in motion a flood of emotional, legal, and planning issues, and it is not something that a patient needs to hear if we aren't sure." Buckholtz is chief of the Dementias of Aging branch of the National Institute on Aging, which funded the study.
Researchers from Washington University Medical Center in St. Louis followed 404 mostly elderly patients with either mild memory loss or no memory problems for just under a decade in an effort to determine if memory difficulties are directly linked to Alzheimer's disease. They reported their findings in the March issue of Archives of Neurology.
At the end of the observational period, all of the participants who were judged to have the most severe memory problems had developed clinical symptoms of Alzheimer's. Subsequent postmortem examination of 25 patients who were initially diagnosed with mild cognitive impairment confirmed that 21 had Alzheimer's disease. Postmortem analysis is the only way to diagnose Alzheimer's disease with 100% accuracy.
"Everybody loses their keys sometime or forgets where they put something, no matter what age," study author Martha Storandt, PhD, tells WebMD. "But the message here is that if older people experience troubling memory loss or a change in [thought] function, it should be checked out. Early diagnosis is becoming more important, because interventions are on the horizon that may slow the process of the disease."
Alzheimer's cases could skyrocket to 14 million within the next 30-40 years, as baby boomers reach old age. Though there is currently no intervention proven to either prevent the disease or slow its progression, research efforts appear promising. At the forefront of that research are vaccines and drugs designed to prevent or reduce plaque buildup in the brain caused by beta amyloid protein. It is believed that the injury to nerve cells caused by this plaque buildup is responsible for the dementia associated with Alzheimer's disease.