What Causes Alzheimer's Disease? (video)

Can Alzheimer's disease be prevented?

Can Alzheimer's disease be prevented?


Abraham Chyung, MD, a neurologist at Scripps Clinic, explains how Alzheimer's disease develops in the brain, the warning signs and why doing mentally stimulating activities, such as reading books, is good for your brain health.

Video transcript

What causes Alzheimer's disease?

What causes Alzheimer's disease?

It is not clear what causes Alzheimer's disease, but when someone is afflicted with that condition, their brain tissue shows accumulation of characteristic pathology. We refer to them as plaques and tangles. Our understanding is whatever is causing the accumulation of that pathology is the reason why people get Alzheimer's disease. We're still trying to figure out what that cause may be.

What are the early signs of Alzheimer's?

Predominantly, Alzheimer's disease causes memory loss, so the early signs typically involve forgetfulness. It's a bit challenging, because everyone develops some degree of forgetfulness as we get older, but it's all a question of degree.


Beyond forgetfulness, if there are other neurological symptoms, such as balance impairment, language difficulty, trouble with making good judgment, those provide additional clues that maybe there's Alzheimer's disease underlying the memory loss.

What is the difference between Alzheimer's disease and dementia?

Dementia is a general term meaning that there is a brain disease causing memory loss. Alzheimer's disease is the most common condition that causes dementia. However, Alzheimer's disease is not the only condition that can do this. There are other diseases, like Lewy body dementia, frontotemporal dementia, and so on.


When the diagnosis is not entirely clear, we'll use the general term dementia, but statistically, most people who have dementia actually have Alzheimer's disease.

Is there a test to diagnose Alzheimer's disease?

There is no test that is available for an accurate diagnosis of Alzheimer's disease, short of taking a sample of the brain and looking at it under a microscope. At autopsy, we can say with certainty whether someone had Alzheimer's disease.


For living patients, we use the diagnostic tests that are available, including brain imaging and detailed cognitive assessment and a variety of blood tests. Unfortunately, we don't have accurate tests available right now to confirm a diagnosis of Alzheimer's disease, but effort is being made to make such testing available in the future.

Are there ways to reduce the risk of getting Alzheimer's?

There is no proven way to reduce the risk for Alzheimer's disease or dementia. However, we have a general understanding that our brain is part of our body, so keeping ourselves physically healthy is an excellent way to protect yourself.


Eating a well-balanced diet and [following] an exercise routine can be very helpful. Additionally, we believe doing mentally stimulating activity is very helpful for the brain. Doing puzzles, reading books, whatever activity that one enjoys, they should continue to do them. 

If there is no cure, why is early diagnosis a good idea?

Early diagnosis of Alzheimer's disease is a good idea, because even in the absence of a cure, it gives the patient an opportunity to prepare for the future knowing that their condition will continue to worsen over time.


Additionally, diagnosing people with Alzheimer's disease early will give the researchers an opportunity to try different treatment options with the hope that we will someday identify a cure for Alzheimer's disease.

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