The National Institute on Aging and the Alzheimer's Association
has published new guidelines for the diagnosis of Alzheimer's
disease. This is the first update since the original guidelines
were created in 1984.
The guidelines include several significant changes. First, they
describe three disease stages: asymptomatic (preclinical),
thinking difficulties (mild cognitive impairment), and dementia
(Alzheimer's). This is the first formal recognition of what
research has suggested for several years now — that Alzheimer's
disease evolves gradually over many years and that physiological
changes in the brain occur a decade or more before noticeable
symptoms such as memory loss or behavioral changes.
Second, the guidelines propose — for research purposes only —
using biomarker tests in conjunction with clinical assessments to
determine whether someone might be at an early stage of
Alzheimer's. The biomarkers are still being tested, however, and
are not meant for routine use in a clinical setting.
Finally, the guidelines emphasize that although Alzheimer's
usually involves memory loss, in some cases it will cause other
symptoms first — such as difficulty in finding the right words
for something or problems seeing the "big picture" in a
Investigators, clinicians, and policy makers are hoping the
guidelines will help accelerate research on ways to prevent or at
least slow the progression of Alzheimer's.
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