What Causes Alzheimer’s Disease?

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Dr. Harvey Gilbert, MD

Medical and Policies Director
Harvey Gilbert, MD, is a radiation oncologist with over thirty-five years of professional experience...read more

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Senior Health—The Medical View

What Causes Alzheimer’s Disease?

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Alzheimer’s disease is a brain dysfunction. It is just one of several types of progressive memory loss that falls under the label of dementia. The occurrence of Alzheimer’s disease is increasing at a very rapid rate. Generalized memory loss, which is so commonly seen in older patients, was once considered a natural phenomenon of aging. But is Alzheimer’s a natural part of the aging process or is it related to lifelong adverse lifestyle issues that can be altered?

Lifestyle May Play a Part

Many wellness and medical professionals believe that Alzheimer’s is, at least in part, due to unhealthy lifestyle choices; in particular, a combination of nutritional inadequacies, a sedentary lifestyle and a high stress level. These factors can result in a condition called metabolic syndrome. Metabolic syndrome is related to body-wide inflammation, insulin resistance and its resultant disease states: visceral obesity, diabetes, hypertension and cardiovascular disease, among others. Many experts believe that the inflammation is associated with solid plaques of a substance called amyloid in the brain tissue, and research shows that there is a link between Alzheimer’s disease and these amyloid plaques. Alzheimer’s manifests itself in the brain much later in life than the other metabolic syndrome-related diseases. The causes of Alzheimer’s are much more complex than what is being described here, but much of the difficulty lies in treating problems that took a lifetime to develop. Regardless of whether the link between lifestyle and Alzheimer’s can be proven, the disease is appearing in a very large percentage of our aging population, and there is currently no other explanation of its origin.

How Early Can it Be Detected?

The disease state is present in the body for many years prior to becoming a recognizable disease. Thus, if the condition can be detected early, and prevented, it is a significant accomplishment. However, research has not shown that Alzheimer’s can be prevented. This is partly due to not having a reliable method of objectively identifying the abnormality in the brains of these patients early on, and therefore being unable to study these patients prior to the disease developing years later. Consequently, we are left with putting band-aids on the problem after it is too late.

We know that from the first sign of mental deterioration, there can be years of slow and steadily progressive (sometimes intermittent) dysfunction or, in some cases, a very rapidly progressive form. The period from symptom onset can be several years, and can be very destructive to patients and their families if the person does not meet the criteria for a diagnosis of dementia by mental status exams alone. Without objective evidence such as scans and blood tests to confirm the diagnosis, there can be a great deal of emotional pain during this waiting process. Without a definitive diagnosis, treatment will be delayed. And even when there is a diagnosis, the type of dementia present isn’t clear.

Because of the magnitude of the problem, the government and the insurance world have been less than enthusiastic about paying for diagnostic testing. Part of this reluctance is due to the prior lack of effective treatment for the disease; this in turn is partly due to physicians’ waiting until the disease is advanced before diagnosing a patient with Alzheimer’s.

How PET Scans Work

What are our options, and what do we know about the diagnostic accuracy of our clinical observations with or without brain imaging? We know that in the patient who has fairly advanced symptoms, PET scanning (a nuclear scan of brain function) can increase the accuracy of the diagnosis from 75% to 90%. It is optimal to scan the patient before he or she develops a more advanced form of dementia, because a doctor cannot make a diagnosis by mental status checking alone at that very early point in time. Ninety percent accuracy in this preclinical setting can be extremely helpful, both in making and ruling out a diagnosis as well as finding additional signs related to other dementia or non-dementia causes.

The other advantage of PET scanning is that it allows the physician to differentiate Alzheimer’s from fronto-temporal dementia and vascular dementia. The approach to treating these forms of dementia is quite different from the treatment of Alzheimer’s, so making an accurate diagnosis early on is very beneficial. Experts recommend PET scanning at the earliest possible time in the mental aging process. The downside of this procedure is that it must be paid for out of pocket, as it is not typically covered by insurance.

Posted in Alzheimer's & Dementia, Alzheimer's & Dementia Care at Home, Alzheimer's Care, Alzheimers & Dementia Care, Anti-inflammation Diet, Senior Health—The Medical View: Dr. Harvey Gilber, Terminal Illness