Is it Alzheimer’s?

It’s very common for people who are middle age or older person who have some lapses in memory to wonder if they might be developing Alzheimer’s. Encountering someone with Alzheimer’s dementia is becoming more common as the proportion of elderly individuals in our society increases. Forgetfulness is a normal part of aging and usually does not indicate impending dementia.

The word dementia stems from the Latin root de- “apart or away” and mentis “mind.” It is characterized by a progressive decline in cognitive and behavioral function due to damage or disease in the brain beyond what is expected in normal aging. Alzheimer’s dementia or AD is the most common form of dementia.

Approximately 5.5 million people in the U.S. suffer from clinically significant AD. There are many more who have mild disease (mild cognitive impairment) and remain functional in their day-to-day affairs. Most cases of AD are sporadic while about seven percent of cases are genetic in origin.

About 14 percent of individuals over age 65 and 40 percent of those over 80 have AD. The good news is that 86 percent over 65 and 60 percent over 80 don’t have it. It is estimated that by the year 2030 there will be 7.7 million Americans over age 65 with AD. Caring for Americans with various forms of dementia cost $321 billion in 2022. The cost of caring for a patient with AD who requires nursing home care can reach up to $100,000 a year.

Alzheimer’s is a type of dementia resulting from specific anatomic changes in the brain. The two hallmark findings in brain tissue examined under the microscope are neurofibrillary tangles (NFT) and senile plaques (SP). German psychiatrist Alois Alzheimer first described these abnormalities in 1907.

Although NFTs and SPs are found in Alzheimer’s, they can also be seen in other neurodegenerative diseases such as Chronic Traumatic Encephalopathy (CTE), the degenerative brain disorder caused by concussions in athletes like NFL football players. NFTs and SPs must be found in sufficient numbers and in a specific anatomic pattern in the brain to make the diagnosis of Alzheimer’s.

Normally, nerve cells (neurons) are very organized and follow specific pathways that allow them to communicate with other neurons. These connections allow us to think clearly. The appearance of normal nerve cells would be analogous to straight strands of hair. The nerve cells in AD look like badly tangled hair and the senile plaques that form are like mixing bubble gum in the tangles. The resulting mess of nerve cells drastically reduces their ability to communicate effectively.

The diagnosis of AD is very complex and there are numerous criteria that have to be met that are too detailed to enumerate here. Diagnosis usually requires the involvement of a team of medical experts. Physicians start by doing a history and physical exam along with some basic blood work to look for other conditions that can mimic AD. These may include (among others): infections, vitamin deficiencies, depression, and thyroid disease.

Additional testing usually involves brain-imaging using a CT and/or MRI scanner. A brain wave test or EEG may be performed and genetic testing may also be done if there is a family history of AD. Specialized neuropsychological testing may be performed by a clinical psychologist to identify exactly which parts of the brain are affected.

The earliest finding in AD is that of slowly progressive memory loss. Forgetfulness is what causes most people to worry they may be developing AD. Occasionally forgetting things such as where you placed your keys or why you came into a room is usually not a cause for concern. It’s more worrisome when memory problems start to consistently disrupt daily functioning. There is a list of ten warning signs found on the Alzheimer’s Association website at bit.ly/3ajnKKV. This site also contains a wealth of information about the disease.

The underlying cause(s) of AD has been very elusive. Research has focused primarily on tau protein, a normal protein found in nerve cells. However, when tau protein folds incorrectly, it can cause the formation of neurofibrillary tangles found in AD. Researchers are working on treatments that reduce the formation of neurofibrillary tangles, alter the abnormal folding of tau protein, or increase the destruction of abnormal tau protein. Results have been very mixed, bringing the hypothesis of abnormal tau protein being the only cause of AD into question. Hopefully Alzheimer’s will be a treatable or preventable disease in the not-to-distant future.

Dr. John Roberts is a retired member of the Franciscan Physician Network specializing in Family Medicine.