Revised Alzheimer’s Guidelines Help Us Catch It In Time

Will revised guidelines for Alzheimer’s disease diagnosis help physicians identify the illness sooner than was previously possible?  For the first time in 30 years, scientists have created guidelines to advance the diagnosis of Alzheimer’s disease and help doctors identify the earliest signs of the degenerative condition, even before memory loss begins with the goal of helping patients prepare early, and eventually treat, the disease.

The National Institute on Aging/Alzheimer’s Association Diagnostic Guidelines for Alzheimer’s Disease outline new approaches and give scientists more advanced instructions for moving forward with research on diagnosis and treatments.  The revised guidelines also have the potential to more than double the number of people being diagnosed with Alzheimer’s in a given year.  “The new guidelines reflect today’s understanding on how key changes in the brain lead to Alzheimer’s disease, said Creighton Phelps of the National Institute of Health’s (NIH) National Institute on Aging.

Writing in Time, Alice Park says that “Currently, Alzheimer’s disease can be definitively diagnosed only at autopsy, when pathologists can confirm the presence of protein plaques and tangles in the brain of a patient who has shown signs of memory loss and cognitive deficits.  The new guidelines tease apart three different stages of the disease that are meant to help doctors better identify affected patients while they are alive.  The phases also reflect the latest research, which suggests that Alzheimer’s develops in the brain over a long period of time — perhaps years or even decades before the first cognitive deficits are noticeable.”

Approximately 5.4 million Americans have Alzheimer’s, which dims memory and other cognitive abilities.  People with Alzheimer’s can undergo dramatic personality changes and ultimately are confused, unable to take care of themselves or recognize family members.  An aging population equals more Alzheimer’s cases.  This has made it more important for scientists to develop early diagnosis and treatment tools, as well means to distinguish Alzheimer’s from other types of dementia.  “At this time, we don’t know enough to be able to advise patients properly about what their risk for later dementia might be,” said John C. Morris of the Washington University School of Medicine.  “Even if we do determine what that risk might be, we don’t have treatment to reduce that risk.”

In 1984, Alzheimer’s was diagnosed based on a single symptom – dementia. The updated guidelines reflect a more advanced understanding of the disease: Alzheimer’s can begin as many as 10 years before signs of dementia.  For clinicians, the guidelines reflect how many doctors already diagnose the disease.  For example, memory isn’t always the initial casualty; vision, literary skills and speech can decline while memory remains intact.  Although Alzheimer’s is unusual in people younger than 40, the disease progresses in the same way as a 90-year-old.  Testing for mutations in three genes can determine whether a patient has early onset of Alzheimer’s (though 10 related genes are known).

According to the new guidelines, Alzheimer’s is recognized as a continuum of stages: Alzheimer’s itself with clear symptoms; mild cognitive impairment (MCI) with mild symptoms; and also the “preclinical” stage, when there are no symptoms but when recognizable brain changes may already be occurring.  Additionally, the revised guidelines use what are known as biomarkers – as an example, the levels of certain proteins in blood or spinal fluid — to diagnose the disease and measure its progress.  “It will not change practice,” said Dr. Guy M. McKhann, one of the guideline authors.

Older adults with this impairment progress to dementia at a higher rate than those with no impairment, but progression is not inevitable,” according to the Alzheimer’s Association. “Not everyone diagnosed with MCI goes on to develop Alzheimer’s,” the association noted.

According to William Thies, chief medical and scientific officer of the Alzheimer’s Association, the new guidelines “will result in little change in current clinical practice of medicine as applied to Alzheimer’s disease.  The new criteria are really extending the range of our ability to investigate this disease and eventually to find treatments that will be so necessary to avoid the epidemic of Alzheimer’s that we see facing us.”

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