For the first time in 27 years, new criteria and guidelines for the diagnosis of Alzheimer’s disease have been published by three expert workgroups spearheaded by the Alzheimer’s Association and the National Institute on Aging (NIA) of the National Institutes of Health (NIH).
The new guidelines update, refine and broaden widely used guidelines published in 1984 by the Alzheimer’s Association and the National Institute of Neurological Disorders and Stroke.
The workgroups published four articles including ready-to-use clinical diagnostic criteria for
Alzheimer’s disease dementia and mild cognitive impairment (MCI) due to Alzheimer’s. The articles expand the definition of Alzheimer’s to include two new phases of the disease: (1) presymptomatic and (2) mildly symptomatic but pre-dementia, along with (3) dementia caused by Alzheimer’s. This reflects current thinking that Alzheimer’s begins creating distinct and measurable changes in the brains of affected people years, perhaps decades, before memory and thinking symptoms are noticeable.
“It is our hope that incorporating scientific knowledge gained and technological advances made over the past quarter century will improve current diagnosis, bring the field closer to earlier detection and treatment, and ultimately lead to effective disease-modifying therapies,” said William Thies, Ph.D., Chief Medical and Scientific Officer at the Alzheimer’s Association.
“Development and publication of these articles is a major landmark in the field. That said, publication of these articles is not yet the end of the process of developing new diagnostic criteria for Alzheimer’s, but is another major step in the process.”
Three Stages of Alzheimer’s Disease
The new articles refer to three phases of Alzheimer’s disease progression over time:
Preclinical Alzheimer’s Disease – Measurable changes in biomarkers (such as brain imaging and spinal fluid chemistry) that indicate the very earliest signs of disease, before outward symptoms are visible. Currently, there are no clinical diagnostic criteria for this phase, but the group provides a scientific framework to help researchers better define this stage of Alzheimer’s.
Mild cognitive impairment (MCI) due to Alzheimer’s Disease – Mild changes in memory and thinking abilities, enough to be noticed and measured, but not impairment that compromises everyday activities and functioning.
Dementia due to Alzheimer’s Disease – Memory, thinking and behavioral symptoms that impair a person’s ability to function in daily life.
According to the authors, in order to facilitate the possibility of future presymptomatic treatment of Alzheimer’s, it was important to define the disease from the earliest changes in the brain, not only the observable, symptomatic stages of the disease. The authors propose that Alzheimer’s begins with a long asymptomatic period during which detrimental changes are progressing in the brain, and individuals with biomarker evidence of these changes are at increased risk for developing cognitive and behavioral impairment and progression to Alzheimer’s dementia.
More information:
Click here to learn the answers to Frequently asked questions about the new guidelines:
PDFs about the new guidelines can be accessed below:
National Institute on Aging/Alzheimer’s Association Diagnostic Guidelines for Alzheimer’s Disease from Alzheimer’s and Dementia: The Journal of the Alzheimer’s Association
Clifford R. Jack Jr., et al. “Introduction to the Recommendations from the National Institute on Aging and the Alzheimer’s Association Workgroups on Diagnostic Guidelines for Alzheimer’s Disease.“
Guy M. McKhann and David S. Knopman, et al. “The Diagnosis of Dementia Due to Alzheimer’s Disease: Recommendations from the National Institute on Aging and the Alzheimer’s Association Workgroup.”
Marilyn S. Albert, et al. “The Diagnosis of Mild Cognitive Impairment Due to Alzheimer’s Disease: Recommendations from the National Institute on Aging and Alzheimer’s Association Workgroup.”
Reisa A. Sperling, et al. “Toward Defining the Preclinical Stages of Alzheimer’s Disease: Recommendations from the National Institute on Aging and the Alzheimer’s Association Workgroup.”
