For the first time in 27 years, the clinical criteria and guidelines for diagnosis of Alzheimer’s Disease have been revised.
The new Guidelines recognize that the development of Alzheimer’s begins 10 or more years before clear symptoms of the fully developed disease present themselves, and for the first time include diagnostic criteria for earlier stages of the disease.
More than 5 million Americans now suffer with Alzheimer’s, and nearly 15 million Americans are caring for someone with Alzheimer’s. Every 69 seconds someone in the U.S. now develops Alzheimer’s, which is the 6th leading cause of death in the U.S. The Alzheimer’s Association has termed as an epidemic the rapid spread of Alzheimer’s that is facing the U.S. as the Baby Boom generation ages.
The new Guidelines for Diagnosis of Alzheimer’s were issued by three working groups of experts convened by the National Institute on Aging (NIA), which is part of the National Institutes of Health (NIH) under the U.S. Department of Health & Human Services, and the Alzheimer’s Association, and were published today in Alzheimer’s & Dementia: The Journal of the Alzheimer’s Association.
The three expert panels that issued the Guidelines were comprised of more than 40 experts, including doctors from Johns Hopkins, the Mayo Clinic, and Harvard Medical School, among others. They have worked on the Guidelines for over two years, including periods of public comment and revision. Summaries of the new Guidelines were issued today by the National Institute on Aging and by the Alzheimer’s Association.
The new Guidelines update and broaden the 1984 Guidelines of the Alzheimer’s Association and National Institute of Neurological Disorders and Stroke, which included criteria for diagnosing only fully developed Alzheimer’s based upon the symptoms presented.
“We’re redefining Alzheimer’s disease and looking at this in a different way than had ever been done,” Creighton Phelps, director of the National Institute on Aging’s Alzheimer’s Disease Centers Program, told the New York Times. “I think we’re going to start to identify it earlier and earlier,” he said.
The new Guidelines recognize three distinct stages of the disease:
- Preclinical – The Guidelines for the Preclinical Stage apply only in a research setting, and are not yet applicable to clinical practice. This phase is the earliest stage in which brain changes, including amyloid buildup and other early nerve cell changes, may already be in process. At this early point, clinical symptoms are not yet presented. In some people, amyloid buildup can be detected with PET (positron emission tomography) scans and cerebrospinal fluid (CSF) analysis. However, science cannot yet predict to what extent these people are actually at risk for development of Alzheimer’s. Use of imaging and biomarker tests at this stage are recommended only for research. These biomarkers are still being developed and standardized and are not ready for use by doctors in clinical practice.
- Mild Cognitive Impairment (MCI) – The guidelines for the MCI stage are also largely for research, but they do clarify existing guidelines for MCI for use in clinical settings. The MCI stage is characterized by symptoms of memory problems, enough to be noticed and measured, but not compromising a person’s independence. People with MCI may or may not progress to Alzheimer’s dementia. Researchers are working to identify and standardize biomarkers for amyloid and for other possible signs of change or deterioration of the brain. Currently identified biomarkers include elevated levels of tau or decreased levels of beta-amyloid evident in the CSF analysis, reduced glucose uptake in the brain as determined by PET, and atrophy of certain areas of the brain as seen with structural magnetic resonance imaging (MRI). These tests will be used by researchers primarily, but may be applied in certain specialized clinical settings to supplement standard clinical tests to help evaluate MCI symptoms and determine their possible causes.
- Alzheimer’s Dementia – These criteria apply to the final stage of the disease, and are most relevant for doctors and patients. They outline criteria for doctors in evaluating causes and progression of cognitive decline. The guidelines also expand the concept of Alzheimer’s dementia beyond memory loss, which is its most central characteristic. Other symptoms among the first to be noticed include decline in other aspects of cognition, such as word-finding, vision/spatial issues, and impaired reasoning or judgment. Even though the validity of biomarker tests and their value for clinical practice is still under study, at this third stage, biomarker test results may be used in some cases to increase or decrease the level of certainty about a diagnosis and to distinguish Alzheimer’s dementia from other dementias.
The panels intentionally left the guidelines flexible to allow for changes as scientific understanding develops.
“Alzheimer’s research has greatly evolved over the past quarter of a century. Bringing the diagnostic guidelines up to speed with those advances is both a necessary and rewarding effort that will benefit patients and accelerate the pace of research,” the NIA quoted its Director Richard J. Hodes, M.D. as saying.
“We believe that the publication of these articles is a major milestone for the field,” said William Thies, Ph.D., chief medical and scientific officer at the Alzheimer’s Association. “Our vision is that this process will result in improved diagnosis and treatment of Alzheimer’s, and will drive research that ultimately will enable us to detect and treat the disease earlier and more effectively. This would allow more people to live full, rich lives without—or with a minimum of—Alzheimer’s symptoms.”
Some of the most interesting advances made by the new Guidelines are in the area of Mild Cognitive Impairment (MCI). This area may be of most interest to the millions of aging Baby Boomers experiencing mild signs of forgetfulness and wondering whether these are normal signs of aging, or may be early symptoms of Mild Cognitive Impairment that could lead to Alzheimer’s.
According to the Alzheimer’s Association, “The new guidelines formalize an emerging consensus that everyone who eventually develops Alzheimer’s experiences this stage of minimal but detectable impairment, even though it’s not currently diagnosed in most people. However, not everyone with with MCI eventually develops Alzheimer’s, because MCI may also occur for other reasons. The guidelines designate the condition of minimal impairment preceding Alzheimer’s as “MCI due to Alzheimer’s disease,” and define four levels of certainty for arriving at this diagnosis.”
The four criteria characterizing MCI which were identified by the expert panel on MCI, include:
- Concern regarding a change in cognition
- Impairment in one or more cognitive domains
- Preservation of independence in functional abilities
- Not demented
Read the paper of the expert panel on MCI » “The diagnosis of mild cognitive impairment due to Alzheimer’s Disease: Recommendations from the National Institute on Aging and Alzheimer’s Association Workgroup”.
For further information on Mild Cognitive Impairment, view this 21-minute video in which Ronald Petersen, M.D., Ph.D., Chairman of the Alzheimer’s Association Medical and Scientific Advisory Council, explains mild cognitive impairment (MCI) and highlights the importance of distinguishing among the various dementias that can occur with aging:
This video is part of the “THE ALZHEIMER’S PROJECT,” a presentation of HBO Documentary Films and the National Institute on Aging at the National Institutes of Health in association with the Alzheimer’s Association, The Fidelity® Charitable Gift Fund and Geoffrey Beene Gives Back® Alzheimer’s Initiative.
For more information on Alzheimer’s Disease and Dementia, see our resource pages on Alzheimer’s/ Dementia, including:
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