New guidelines on the diagnosis of Alzheimer's disease (AD) were announced in April, 2011 by the National Institute on Aging and the Alzheimer's Association. These guidelines, the first issued in 27 years, divide Alzheimer's into three phases: (1) brain changes that can occur 10 years or more before symptoms appear; (2) mild cognitive impairment, meaning there are some memory problems but affected individuals can still live independently; and (3) Alzheimer's dementia, the final stage of disease.
The physical changes that are characteristic of the first stage of AD can be documented only with brain scans or tests of cerebrospinal fluid. These tests are not yet ready for widespread use - they're still being researched, and investigators don't yet know how reliable they are or what specific changes indicate early disease and eventual progression. For example, amyloid plaques are consistently found at autopsy in people who die of AD, but about one third of people with amyloid plaques in the brain never develop Alzheimer's in their lifetimes. Furthermore, even if an imaging or lab test for AD were possible today, all medicine can offer if the result is positive are drugs that may alleviate symptoms and slow progression. We presently have no pharmaceutical methods to arrest or reverse the disease.
The new guidelines expand the concept of Alzheimer's disease beyond memory loss and specify that the first symptoms noticed could be declines in other aspects of cognition, such as word-finding, vision/spatial issues, and reasoning or judgment.
Once we know more about the biomarkers being studied, scientists may be able to identify therapies that can treat significant brain changes early, before the disease moves on to its devastating final stage.
Meanwhile, you may be able to help prevent or slow the progression of the condition by following my Alzheimer's disease recommendations for diet, dietary supplements, exercise, and mental stimulation.
Andrew Weil, M.D.