Changes considered in how Alzheimer’s disease is diagnosed

It’s time to update the way Alzheimer’s disease and early stages of the illness are diagnosed, according to experts on the disease. Diagnostic criteria for the disease have not been updated since 1984.

Preliminary information on new diagnostic criteria was released Tuesday at a meeting of the Alzheimer’s Assn. International Conference on Alzheimer’s Disease in Honolulu. The proposed new criteria, which are still under study, would rely on advances in detecting biomarkers for the disease, such as substances found in spinal fluid or appearing on sophisticated brain imaging scans conducted with PET or MRI. Effort is expected to be placed on diagnosing early stages of the disease as soon as possible so that patients can participate in studies to slow the progression or prevent further damage.

Three working groups convened by the Alzheimer’s Assn. and the National Institute on Aging are involved in the process of updating the criteria. One will recommend a research agenda to identify ways to help predict risk for developing the disease and the use of biomarkers and other tools to diagnose early cognitive decline before the appearance of symptoms.

Another group will redefine the term “mild cognitive impairment” to better differentiate it from Alzheimer’s. Research is underway to look at what biomarkers might help define this particular stage of the disease and methods that best indicate which people are likely to progress to Alzheimer’s dementia.

The third group is revising the existing criteria for diagnosing Alzheimer’s disease to incorporate biomarkers and other assessments. A website has been established to seek input for the process. Eventually the proposals will be published in medical journals and tested in clinal trials.

After more than 25 years, it certainly seems time to try to better define the disease and its various stages. And, to be sure, diagnosing someone early in the disease or even before symptoms are apparent could make a huge difference in the success of treatments. However, it will be interesting to see whether people will be reluctant to obtain a very early diagnosis, and whether doctors will want to issue one, given the potential stigma of such a diagnosis in the workplace and other arenas.