Alzheimer’s 101

I very frequently get asked by patients if they might be developing Alzheimer’s. While many doctors seem to think this is a pretty simple question, as a neuropsychiatrist I know that the answer is far more complex. My hope with this post is to give patients and their families a very brief overview of Alzheimer’s, both to help them understand the changes in the diagnosis over time, and why the very rare pure Alzheimer’s disease isn’t as likely as they might think. 

Unfortunately, it must start with a history lesson. I don’t do this to bore you, but just to clarify why the diagnosis is both easy and difficult to make. Dr. Alzheimer identified his one and only “Alzheimer” patient about 110 years ago. He found Auguste Deter on a psychiatric asylum when she was in her late 40s, and she was bizarre. Apart from her memory loss, she looked like many of the other schizophrenic patients there with delusions, hallucinations, agitation, and strange behavior. She was mostly unique to him because she developed psychosis late in life, not because she became forgetful early in life. When she died, he looked at her brain tissue and found changes that later became synonymous with the disease, namely “amyloid plaques” outside the neurons and “Tau tangles” inside the neurons. For the next 80 years, there were very few publications on Alzheimer’s disease and it was mostly considered a rare academic interest. 

Throughout the 1900s, older folks getting confused was considered a variation of normal decline, but in the research they found that when people made it to 80 years old, a pretty big percentage of them began having those same Plaques and Tangles, and sometimes this seemed to be associated with cognitive decline. The smart folks in boston decided that these older folks (and some very rare young folks) had the same disease that Dr. Alzheimer discussed. But how to tell the difference between Senility and Alzheimer’s disease? 

After about a decade of arguing, in 1984 they came up with the first criteria for Alzheimer’s disease (as opposed to senility and other forms of forgetfulness), and the main symptoms of it haven’t changed since. Senility and cognitive decline due to medical issues usually had symptoms of “subcortical” dysfunction where the otherwise healthy Alzheimer’s patient had slowly progressive “cortical” deficits. The cortex is where most of the brain cells live and the “subcortical” tissue is where the longer wires connect one area of the brain to another. Now, they wouldn’t have been neurologists if they gave these cortical deficits normal english names, so they chose to call them “Apraxia, Aphasia, and Agnosia”. I will write a separate post about what those words mean, but suffice it to say, very few patients have that category of problem as their primary complaint. Subcortical brain problems are SUPER common. That is the stuff where you can’t find your keys for an hour and you are so frustrated that you can’t think of that word. Its also a subcortical problem when you can technically do everything you used to (or most of it) but it is just so much harder than it should be. 

So there are these very specific clinical features with Alzheimer’s that most doctors don’t even consider. Then how do we diagnose Alzheimer’s disease? The biggest problem is that loads of people are diagnosed with Alzheimer’s when they really have 10 medical problems causing forgetfulness. Those doctors ignore the part of the diagnosis requiring that there is no “Evidence for another concurrent, active neurological disease, or a non-neurological medical comorbidity or use of medication that could have a substantial effect on cognition.” 

This is a huge problem in the research for Alzheimer’s disease. One group of researchers is doing an amazing job of only including otherwise healthy people to study for progression and treatment. A separate group of researchers will call someone an Alzheimer’s disease patient when their brain is riddled with strokes, their diabetes and hypothyroidism is completely out of control, and their depression is so severe that it alone could make them look demented (what medical students are taught to call Pseudodementia). So, when the second group looks for risk factors for Alzheimer’s, they inevitably find that hypertension, diabetes, and depression are huge risk factors since they aren’t actually studying Alzheimer’s, but cognitive decline due to hypertension, diabetes, and depression. 

But what about the Plaques and Tangles? This is where it gets really tough. A third group of researchers wants to get rid of the clinical diagnosis entirely. They want evidence of Plaques and Tangles (found with very expensive scans or a lumbar puncture) to be the main way we diagnose Alzheimer’s. They call it “Biologically Defined Alzheimer’s” and you can just be a little forgetful but have no other symptoms and these folks will diagnose you with Alzheimer’s disease. What is worse, about 30% of perfectly healthy older folks (over 80 years old) have those changes on scans and lumbar punctures. 

So to summarize, one group (mostly very specialized neurologists) will only diagnose Alzheimer’s in rare cases of otherwise perfectly healthy people who have “apraxia, aphasia, and/or agnosia”. Another group (mostly primary care docs) determines that nearly everyone who can’t take care of themselves as having Alzheimer’s. A third group would diagnose alzheimer’s disease in 30% of perfectly healthy older adults that have little or no cognitive decline. 

What is a patient to do? I feel like the best option is probably to put the Alzheimer’s question on the back burner. As a society we have become obsessed with the term, and the whole question of Alzheimers vs Dementia vs Normal Aging would have been confusing for patients and their families even without all of this disagreement in the research. In essence though, for most people a Alzheimers diagnosis isn’t all that relevant. Currently, there is no obvious treatment specifically for Alzheimer’s disease that really makes an impact on functioning. The CDC guidance (likely based on the second group of patients we discussed with other medical contributors) says you can prevent Alzheimer’s with diet, exercise, and better sleep. In the end, while that second group of patients is least likely to be suffering from Alzheimer’s disease, the advice for them is probably the most useful. Attempts to improve overall health with diet and exercise, treating known medical problems, and focusing on the treatment of specific symptoms is likely to give the most help to the most people. 

In future articles, I will discuss some of the main habit changes that can reduce “dementia” overall as well as some of the medications that can improve specific “dementia symptoms”. These are probably the best Bang for your Buck when it comes to improving quality of life and staying independent as long as possible. For a consultation to better understand how this affects your personal situation, contact us today!