The Tangled Neuron

New Alzheimer's Diagnostic Techniques: Not Ready for Widespread Use?

Summary:  A recent study questions the accuracy of proposed biomarkers for diagnosing Alzheimer’s. 

Doctors currently make a diagnosis of Alzheimer’s based on symptoms and by ruling out other medical causes for those symptoms.  Two groups of researchers have proposed new diagnostic criteria that add certain "biomarkers" -- physical or biochemical characteristics that are signs of disease.  One set of criteria was developed by panels convened by the Alzheimer’s Association and the U.S. National Institute on Aging.  A similar set, the "Dubois Criteria," was developed by the International Working Group for New Research Criteria for the Diagnosis of AD.

The goal of these new criteria is more accurate diagnosis, which hopefully will lead to earlier and better treatment.  More accurate diagnosis would have been enormously valuable for my family, eliminating the long diagnostic roller coaster that my father endured. 

But at least initially, these new criteria may cause more confusion than clarity. Researchers at the Karolinska Institute in Stockholm recently compared the diagnoses of memory clinic patients via the current methods with diagnoses of the same patients using the Dubois criteria.  Use of the new criteria drastically decreased the number of people diagnosed with Alzheimer’s.

Television coverage of Alzheimer's

Summary:  Television coverage of Alzheimer’s has increased dramatically, but tends to emphasize treatments and personal and celebrity stories over less sensational facts. However, increased use of celebrities, along with expanding coverage in entertainment programs, may help publicize fact-based awareness and prevention campaigns.

Researchers at the University of Texas at San Antonio have published an interesting analysis of television coverage of Alzheimer’s news in the United States.  Television is still the major source of news for Americans, they say, and shapes how we view Alzheimer’s.

       Seok Kang, Ph.D.

Looking at 1371 television news transcripts from 1984 to 2008, the researchers found that coverage has increased dramatically.  News pieces during this period emphasized treatments, personal stories, celebrities and policies.  Facts, causes, signs and diagnosis received much less coverage.  Fact-based awareness and risk reduction efforts by the Centers for Disease Control (CDC) and National Institutes of Health (NIH) were not covered much at all.

Why so little emphasis on facts?  “It is related to the survival of the news media in this competitive media market environment,” says Seok Kang, Assistant Professor of New Media at the University of Texas at San Antonio and co-author of the analysis.

Education and Employment: Nondrug Ways to Prevent Alzheimer's and Dementia?

Summary:  The prevalence of dementia in older Americans seems to be decreasing.   Whether or not researchers find new medicines to prevent dementia, higher levels of education and late-life activity might reduce dementia rates.

       Ken Langa, MD, Ph.D.

Much has been written about the coming “silver tsunami” and the expected “epidemic” of Alzheimer’s and other dementias.   My conversations with eldercare professionals here on the west coast of Florida seem to confirm these predictions.   But in the U.S. overall, the numbers suggest the situation might not be so dire.

Researchers at the University of Michigan recently analyzed data on cognitive impairment from the Health and Retirement Study, a large survey of older Americans.  Along with his colleagues, Ken Langa, an Internist and Professor at the university, surveyed more than 7000 people over the age of 70 in 1993. They found 12.2 percent had cognitive impairment “consistent with dementia.”  In their similar 2002 survey, that percentage decreased to 8.7, a relative decrease of almost 30 percent.

Dr. Langa, whose work focuses on the epidemiology and costs of Alzheimer’s and other dementias, is the lead author on another recent study suggesting the use of Medicare claims to calculate dementia prevalence and costs of related care results in overstatement of both.

Alzheimer's and Dementia Screening

Summary:  As part of the new health care reform law in the U.S., Medicare will begin covering dementia screening next year.  Researchers who developed a new screening questionnaire called AD8 at Washington University in St. Louis believe it is the right tool for screening.  No matter which tool is best, screening all older adults for dementia may not be practical or useful. 

Along with more than 100 other participants, I listened to Tuesday’s Alzheimer Research Forum webinar about a new paper and pencil test to screen for dementia.  The new screening tool, called AD8, was developed by researchers at Washington University in St. Louis.  It consists of eight questions about changes in behavior that could be caused by problems with memory and thinking, and is meant to be answered by a family member or close relative or friend.  It can also be filled out by the person being screened.

A good portion of the webinar was a presentation by one of the tool’s developers, Dr. James Galvin (now at New York University).  He presented research showing AD8 is better at detecting early dementia than some other tools.  But the panel discussion and questions towards the end of the hour got at the more fundamental question:  is screening all older adults for dementia a good idea?