A paper recently published in the The Journal of the Alzheimer’s Association advocates for sweeping changes in the way researchers define Alzheimer’s disease. Current guidelines – established in 2011 by another group of National Institute of Health researchers – breaks the disease into three stages. They include:
- Preclinical: Signs of Alzheimer’s (such as abnormal MRI readings) but no physical symptoms, or poor memory or cognition.
- Mild Cognitive Impairment: A condition which often, but not always, leads to Alzheimer’s disease.
- Alzheimer’s Disease: Doctors are often unable to definitively diagnose Alzheimer’s disease while the patient is alive, because brain tissue can only be examined after death.
Unfortunately the current framework is imprecise. And because the current framework only uses dementia symptoms to mark progression, Alzheimer’s disease has become a catch-all definition for dementia diseases. This new research seeks to remedy this problem by recognizing and defining Alzheimer’s disease based on its unique biomarkers.
There are many afflictions like stroke, Parkinson’s disease, Lewy Body, and more that can cause the memory and cognition problems we commonly call dementia. But only Alzheimer’s disease patients have the beta-amyloid and tau protein build ups in their brains. Research advances now allow doctors to identify these biomarkers in a patient’s brain and spinal fluid. The proposed new guidelines want to take advantage of that. Their proposed new framework would look like this:
- Alzheimer’s pathologic change: Signs of beta-amyloid buildup but no tau.
- Non-Alzheimer’s pathologic change: Too much tau but not beta-amyloid.
- Alzheimer’s Disease: The new definition only includes patients with both beta-amyloid and tau buildup.
- Visible nuerodegeneration: This closely correlates with physical symptoms and could be used to further differentiate patients, but isn’t a necessary for a diagnosis.
The authors believe this new framework is a better reflection of how our brains become diseased. For example, someone with mild cognitive impairment might not have Alzheimer’s disease. If biomarker testing shows no beta-amyloid buildup, their impairment could be the result of some other kind of brain injury.
Hope for More Accurate Research
The authors hope that by identifying beta-amyloid as a key biomarker of Alzheimer’s disease, researchers will be better able to test if it ultimately causes the diseases’ devastating changes or merely coincides with its progress. In addition, researchers will be able to ensure that studies include only patients with Alzheimer’s disease and not one of the other dementia-causing disease that are often mistakenly lumped under the Alzheimer’s banner. Hopefully a more accurate common language of diagnosis will help doctors and researchers work more efficiently towards a cure.
Patient’s Won’t See Much Change
The paper’s authors admit this proposed new framework is still very much a work in progress. And they’re not advocating for a change in the way doctors currently diagnose and treat the disease. But until now, there’s been little progress in finding a cause for Alzheimer’s and there are no effective treatments. Hopefully this new framework will be a step in the right direction.