Ask an Expert about Alzheimer's Disease

If your mother's apartment building houses many elderly residents, age may be a more important factor than location; however, there have been attempts to study geographical clustering of AD in order to understand the causes of this brain disease more fully. Many researchers have wondered whether location determines exposure to a risk factor in the environment. Other experts have wondered if the geographic clustering may represent to some degree variations in physicians' diagnostic procedures, reporting practices, and medical opinions. So far, though, there appears to be no universal explanation for the observed clustering that raises questions such as yours.

Alzheimer's disease is the most common form of dementia, but there are many other conditions that interfere with memory, reasoning, language, visual and spatial orientation, and other cognitive abilities. All the other causes, grouped together, are non-Alzheimer's dementia. Many of the patients with non-Alzheimer's dementia have vascular dementia, dementia with Lewy bodies, or one of the frontotemporal dementias. If your mother's mental capacity is indeed “fine” and halted speech is her only symptom, a vascular cause may be the explanation for her symptom. It would certainly be reasonable to seek another opinion, this time from a neurologist with expertise in strokes.

The temporal areas of the skull received their name because this is one area of the body that shows the effects of time's passage, though usually with graying and not typically with indentation. Perhaps indentations are developing because of wasting of the temporalis muscles. This can occur in a person whose health status is declining and who suffers from nutritional deficiency or increased nutritional needs that are not being fully met. Such a development is not a normal feature of Alzheimer's disease and should lead to a medical examination to look for diseases associated with muscle wasting.

The best time, if there is one, for discontinuing cognitive enhancing medications remains arguable and uncertain. Some research has found the benefits of these medications to be modest, but other studies suggest that even late in the course of Alzheimer's disease they may add value to treatment by delaying or reducing changes in behavior that would be difficult to manage.

At 48, your brother was pretty young even for early-onset of Alzheimer's disease, so the autopsy results are understandably of interest. You may want to check whether brain tissue was saved, and whether it was properly prepared in order to diagnose Alzheimer's disease. It is possible that the diagnosis can be suggested by examination of the brain tissue, though the presence of clinical symptoms remains a necessity.

“White spots” most likely represent changes in the small blood vessels that are visible on certain types of MRI images. Sometimes these occur as a normal part of aging. In other cases, they represent changes associated with disease. They are found in some types of vascular cognitive impairment but are not a diagnostic feature of Alzheimer's disease (AD). Nevertheless, some patients with AD have white spots on their MRIs because many cases that are called AD should more accurately be considered cases of “mixed dementia” in which symptoms of AD are combined with symptoms of vascular cognitive impairment.

Only a small percentage of Alzheimer's disease (AD) cases are considered strongly heritable, but research shows that there is also a limited increase in the likelihood of AD in people who have multiple affected relatives. This increase in risk is small, however.

The marriage of blood relatives reduces the opportunity to bring new and different genes into a family, and it slightly increases the likelihood that they might share a disease gene. Although your family's lineage does not seem especially risky, you may want to consult a genetic counselor, who can give you a more detailed risk assessment, if you have concerns about disease inheritance.

Although his medications may not be relevant, it's worth considering whether they are playing a role. The cholinesterase inhibitors are known for causing diarrhea. Your husband's primary care physician will also want to check him for other causes of diarrhea including impaction, infection (including parasites), and nerve problems that can be associated with diabetes.