Q. Alzheimer’s Test?

Dear Dr. Bhark,Dementia/Alzheimer’s

Are there valid tests for Alzheimer’s for people over 70? How do you distinguish between dementia and Alzheimer’s?


A. Hello Al, you have just ruled out any dementia on your part with your good questions!

Dementia is a very broad umbrella term for chronic (greater than six months) cognitive dysfunction (memory, attention, language and problem solving). Dementia isn’t a single disease but a syndrome, a set of signs and symptoms. The most common cause of dementia happens to be Alzheimer Disease (AD).

Unfortunately, AD is ubiquitous. It is estimated that 14% of the population over the age of 65; 28% of those over 70 and greater than 40% of the population over 80 years of age have AD. The incidence is expected to grow as the world’s population ages and longevity increases.

It is not clearly established what causes AD. It is known that pathologic brain changes predates the clinical manifestation by a decade or two, usually starting in the memory center of the brain and thus impaired memory being a relatively common feature of AD. (Forgetting where you placed your car key is a common feature as we age and therefore nothing to be concerned over. But if you look at your car keys and don’t know what they are for, you may be in trouble.) Once clinically apparent, AD often becomes a progressive disease, ultimately causing ones demise.

Now to answer your question more specifically, the diagnosis of AD is most often made on clinical grounds with or without corroborating evidence by psychological testing or neurologic imaging such as CT scan or MRI. It is often the person with early AD or a family member who seeks an opinion from a physician as a result of noticing some amount of cognitive impairment. How to diagnosis AD during the preclinical stage (that is, how to discover brain changes before one notices cognitive dysfunction) is currently a hot topic. This is where genetic testing, exotic lab work including spinal tap analysis, high tech brain scans such as PET where metabolic function of the brain can be analyzed are being scrutinized but primarily for research purposes.

There are several rules of thumb in making a clinical diagnosis of mild dementia due to AD. One, there is a concern by the person or someone close to him/her, that a change in cognition has occurred or is occurring. Two, a noticeable impairment in one or more of the cognitive domains where a lower than expected performance is noticed given the persons age and education. Three, there is a preservation of independence in the functional abilities of the person. He/she may be slower but is able to chug along. Four, no obvious social or occupational impairment is present. The diagnosis of advanced AD is obvious and often tragic.

Where testing becomes crucial is to rule out other causes of dementia. For example, Parkinson’s disease, brain tumors, alcohol related brain changes, infection such as syphilis, vitamin deficiencies, thyroid disease, multiple small strokes from poorly managed hypertension, bleeds, and multiple traumas may cause symptoms of dementia.

While the causes for AD are many and speculative (inflammation, aging process, cardiac risk factors such as cigarette use, hypertension, diabetes, abnormal cholesterol count), toxins, genetics, and vitamin deficiencies, it is important to note that we need to consider taking good care of our brain much as we would for the rest of the body. There is an axiom in medicine which states “what is good for the heart is also good for the brain”. Thus, physical exercise, reasonable nutrition, brain exercises, rest, and treating or preventing cardiac risk factors may be the proactive steps to take. Please note that there is no definitive treatment for AD, but only symptomatic remedies. Finally, AD is sporadic and very infrequently familial.

Wishing you joy and health,

Dr. Philip Bhark M.D., FACC

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