New Recommendations for Alzheimer's Diagnosis
Experts Propose 3 Stages Aimed at Earlier Detection
New Criteria for Diagnosis of Alzheimer's: A Closer Look continued...
Experts in Alzheimer's disease were tapped to work on the updated criteria.
Among the advances important to consider in setting up the proposed diagnostic criteria, according to the Alzheimer's Association, is:
- Changes in the brain triggered by Alzheimer's develop slowly over many years, reflecting the importance of catching the disease earlier.
- Genes can help predict a form of the disease known as early-onset Alzheimer's; these genetic observations indicate that the initial brain event that leads to symptoms and the brain changes begin with disordered beta-amyloid metabolism.
- An alternative form of the ApoE gene is now known as a major genetic risk factor for the more common late-onset disease.
- Much is known about biomarkers and ongoing research is validating these biomarkers.
For each of the stages, the workgroups have suggestions, Morris says.
- The first workgroup, on pre-clinical disease , suggests thinking about Alzheimer's disease not just as dementia, but a brain disorder that begins years before symptoms occur. "This pre-clinical stage may be important for future research," Morris says, hopefully leading to intervention strategies and eventually prevention.
- The second, on mild cognitive impairment, also suggests incorporating biomarkers to better differentiate the stages of the disease.
- The third, on Alzheimer’s dementia, suggests that the inclusion of biomarkers will increase the confidence of the diagnosis.
The Alzheimer's Association and the National Institute on Aging are launching a web site at www.alz.org/research/diagnostic criteria to solicit input from additional experts.
"The criteria are open for comment until September 2010," Thies says. Then the criteria will be published in a peer-reviewed medical journal.
As to the effect on patients, Thies expects very little effect short term. "Long term, people will be layered into three groups," he says, depending on their symptoms and diagnosis. Those with mild cognitive impairment, now underrepresented in research studies, will be included in larger numbers, he says.