Redefining Alzheimer’s disease

 In Alzheimer's Disease

Alzheimer’s has no cure. That’s what many of the 6.2 million Americans living with the disease have come to accept, but it’s only one side of the story.

Alzheimer’s has a pre-clinical stage of one to two decades. Suppose neurologists like myself could diagnose healthy, young, and cognitively normal individuals without symptoms in that pre-clinical stage. In that case, we could stop the disease before it caused irreversible changes to the brain.

Conventional, symptoms-based diagnostic tools like the 1984 Clinical Diagnostic Criteria for PROBABLE Alzheimer’s Disease and Montreal Cognitive Assessment(MoCA) don’t allow for pre-clinical diagnoses. Instead, the future of Alzheimer’s diagnoses and treatment depends on a new, biology-based definition.

A new definition of Alzheimer’s disease

The 1984 Clinical Diagnostic Criteria for PROBABLE Alzheimer’s Disease focuses on clinical symptoms like dementia and the progressive worsening of memory. However, these symptoms don’t affect every person living with the disease. Those in their early stages are often symptom-free ticking timebombs. Eventually, the condition will take hold and augment their cognitive abilities, but there is an opportunity for intervention beforehand.

Suffice to say, the outdated, symptoms-based definition is inadequate. Luckily, we have a new one:

“The term “Alzheimer’s disease” refers to an aggregate of neuropathologic changes and thus is defined in vivo by biomarkers and by postmortem examination, not by clinical symptoms.” – NIA-AA Research Framework: Toward a biological definition of Alzheimer’s disease

Under this explanation, Alzheimer’s is defined by biomarkers. This new definition gives other neurologists and me a broader scope for diagnosis, meaning we can catch pre-clinical patients and provide treatment that redirects the trajectory of their health journey.

Biology-based diagnostic tools

There are several biology-based diagnostic tools available today – many of which I use in my clinic. Let’s scratch the surface and investigate three ways we can examine biomarkers.

Magnetic resonance imaging (MRI)

Structural MRI scans are a non-invasive way to analyze the pathology and anatomy of the brain. These scans are distinct from fMRIs, which examine activity in the brain.

In the diagnosis of Alzheimer’s disease, we are interested in 3D volumetric scan sequences. These measure different brain structures and determine the volume of tissue.

Until recently, structural MRI scans were predominantly used to exclude non-Alzheimer’s causes of dementia. However, we can also use the severity of frontotemporal atrophy to support a diagnosis in the pre-dementia stages of Alzheimer’s.

Cerebrospinal fluid examinations

A spinal fluid examination also called a lumbar puncture, is a routine procedure that I carry out frequently at my clinic. It’s a test that evaluates cerebrospinal fluid (CSF), a biologically active tissue formed in the brain’s center. CSF moves around the brain and brainstem through aqueducts and channels and spreads throughout the central nervous system.

Similar to a blood test, a spinal fluid examination can investigate a range of biomarkers. When it comes to testing for Alzheimer’s disease, I look for amyloid protein, beta-amyloid 42, total tau protein, and phosphorylated tau.

I can also test for the APOE ε4 gene. If present, this gene increases the individual’s likelihood of developing Alzheimer’s. It’s also linked to an earlier onset of the disease. About one in four people have one copy of the APOE ε4 gene, with two to three percent carrying two copies.

PET scan technology

In 2016, research out of the University of California Berkeley found that PET scans can trace the progression of Alzheimer’s disease in adults that are cognitively normal by examining cellular-level changes in the brain’s tissue.

The study suggests that the imaging of tau – one of the biomarkers I look for in spinal fluid examinations – will likely play a role in the development of early-stage therapeutic approaches to treatment.

As we move into the new age of diagnostics, we might start performing routine “cognoscopies” beginning at age 60 to predict the onset of disease and prevent it from occurring in the first place.

Biology-based diagnoses and emerging pharmaceutical treatments

My ability to diagnose patients early in the progression of Alzheimer’s using biology-based systems will be critical to realizing the promise of emerging drugs targeting the disease. There are several treatments in the development pipeline, several of which should become commercially available in the next few years – even months.

They are not going to be magic bullet fix-alls, but here are two of the most promising treatments on the horizon:

  • Biogen’s Aducanumab, a monoclonal antibody, is currently under review by the FDA, with a decision expected on or before June 7, 2021. Its journey to this point has been a rocky one, with an FDA advisory committee voting unanimously against the drug in November 2020.
  • Eli Lilly’s Donanemab is expected to deliver its study results in 2023.

I am happy to report that the Sharlin Health Neuroscience Research Center is a study site for the donanemab Trailblazer phase 3 trial and a candidate participant in a real-world experience aducanumab trial. If you would like to learn more about the neuroscience research at Sharlin Health and Neurology, also including studies on multiple sclerosis, traumatic brain injury, amyotrophic lateral sclerosis, and pediatric migraine, please do not hesitate to call my office and ask for Shawna or Mikhayla. 

Access the future of medicine today

The future of Alzheimer’s disease diagnoses and treatment looks bright, but there are people – maybe you, or perhaps a loved one – living with the condition today.

You do not have to wait for some miracle cure or brand-new technology to experience real improvements in your life. Together with my multi-dimensional team of healthcare professionals, I help you map an effective, highly personalized pathway to well-being using a functional medicine approach.

If you are sick of being told there’s nothing anyone can do if you don’t want to rely on drugs, and if you are ready to put in the hard work to live the life you know you deserve, reach out today. Schedule your initial consultation, and let’s work toward your health goals together.

 

 

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