Alzheimer's disease experts are revamping the way doctors diagnose patients with the progressive brain disorder - the most common type of dementia - by devising a seven-point rating scale based on cognitive and biological changes in the patient.
The proposed guidelines, unveiled by experts on Sunday in a report issued at an Alzheimer's Association conference in Amsterdam, embrace a numerical staging system assessing disease progression similar to the one used in cancer diagnoses. They also eliminate the use of terms like mild, moderate and severe.
The revamp - replacing guidelines issued in 2018 - was prompted by the increased availability of tests detecting key Alzheimer's-related proteins such as beta amyloid in the blood and new treatments that require confirmation of disease pathology prior to use.
The new system is designed to be more accurate and better reflect a person's underlying disease, according to Dr. Clifford Jack of the Mayo Clinic in Rochester, Minnesota, lead author of the report sponsored by the Alzheimer's Association and the National Institute of Aging, a part of the U.S. government's National Institutes of Health.
The change comes at a time when doctors are preparing to identify and treat patients with Eisai and Biogen's drug Leqembi, which won Food and Drug Administration approval this month, and Eli Lilly's experimental drug donanemab, which is now under FDA review.
"We really are getting into an era of much more personalized medicine, where we're starting to understand that there are certain biomarkers that are elevated to certain degrees in people in different stages," said Dr. Maria Carrillo, chief scientific officer for the Alzheimer's Association.
Under the new diagnostic approach, patients would receive a score of 1 to 7 based on the presence of abnormal disease biomarkers and the extent of cognitive changes. The system also includes four biological stages ranked a, b, c and d. For example, Stage 1a is when a person is completely asymptomatic but has abnormal biomarkers.
"Stage 1a is really the beginning of evidence that someone has the disease," Jack said.
In Stage 2, an individual may have abnormal biomarkers and very subtle changes in cognition or behavior. Stage 3 is roughly equivalent to the current presymptomatic stage known as mild cognitive impairment, while stages 4, 5, and 6 are equivalent to mild, moderate and severe dementia.
The new scale also includes a Stage 0 for people who carry genes that guarantee they will develop Alzheimer's. This category includes people with Down Syndrome, 75% of whom develop Alzheimer's as adults.
Noting the new system's similarity to cancer stages, Jack said, "There's no such thing as mild breast cancer. They're numeric stages." Jack also noted that many other conditions can cause dementia but not all dementia is Alzheimer's disease.
The proposed guidelines are intended for doctors to use in clinical practice as many face the prospect for the first time of offering patients treatments that can slow the course of the disease, rather than just treat symptoms.
The draft guidelines are open for expert review and comment and will be revised later to reflect that input, according to a spokesperson for the Alzheimer's Association.
Alzheimer's, which gradually destroys memory and thinking skills, is characterized by changes in the brain including amyloid beta plaques and neurofibrillary, or tau, tangles that result in loss of neurons and their connections.
The 2018 guidelines, which were intended for research use, incorporated existing technologies for detecting Alzheimer's proteins based on PET scans of the brain and tests of cerebrospinal fluid, which were only accessible via a lumbar puncture. Such tests were costly and not typically used in standard medical practice.
© Thomson Reuters 2023.
7 Comments
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virusrex
Very nice description of the new scale and why it is important. Alzheimer's patients are finally getting some hope. The scale is the product of two different advancements, first the much better understanding of the disease that made it possible to classify it in stages with actual meaning, the second is the slow but progressive development of treatments that makes it relevant for patients to be classified so the progression of the disease much more closely followed.
Elvis is here
Excellent news.
gcFd1
The new system is designed to be more accurate and better reflect a person's underlying disease, according to Dr. Clifford Jack of the Mayo Clinic in Rochester, Minnesota, lead author of the report sponsored by the Alzheimer's Association and the National Institute of Aging, a part of the U.S. government's National Institutes of Health.
Have to give credit to the US medical experts who are leading the way and the global health institutions like the NIH, CDC, FDA, who are backing these medications.
virusrex
None of the agencies mentioned are global institutions, they can't even issue recommendations to other countries, nor the yare backing medications, at much they are not irrationally rejecting their approval after they have been already developed and tested completely.
Roy Sophveason
What a weird hill to die on.
gcFd1
The change comes at a time when doctors are preparing to identify and treat patients with Eisai and Biogen's drug Leqembi, which won Food and Drug Administration approval this month, and Eli Lilly's experimental drug donanemab, which is now under FDA review.
Global health authorities such as the FDA, CDC (which has multiple international locations) are at the forefront of medicine these day with their backing of these highly needed medicines.
virusrex
Having locations in other countries is not an argument that supports the claim of being an authority on those places, that would at least require for the institution to routinely give recommendations, or according to your own argument it would be needed for the institution to have legal powers in those locations, which obviously is not the case for any of the institutions you mention.