Dementia

Dementia is a broad class of diseases into which Alzheimer’s disease falls. In other words, all cases of Alzheimer’s disease can be called dementia but not all dementias are Alzheimer’s disease. The terms are sometimes confused because the majority of dementia cases are Alzheimer’s disease (around 65%). Other types of dementia may include Parkinson’s disease, Lewy Body Dementia and Vascular Dementia, among others.

Alzheimer's Disease

Alzheimer’s disease is a chronic, degenerative disease, which means that it progresses slowly and gets worse as time goes on. About six million Americans have Alzheimer’s disease, and the number is expected to reach 14 million by the year 2050. Americans incorrectly assume that Alzheimer’s patients reside in nursing homes. Not true! Almost half of the Alzheimer’s patients in the United States reside at home.

It seems that the incidence of Alzheimer’s disease has increased in recent years to near epidemic proportions. While improvement in diagnosis has contributed to the rise, the real answer lies in the average length of life for human beings. At the end of the 18th Century, the average lifespan of individuals was 35 to 40 years. The average lifespan for someone living in the United States today is about 77 years. Studies show that about 10% of those over age 65 have Alzheimer’s Disease, 20% of those over 77, and up to half of those over 85. Alzheimer’s is more prevalent now because more people are living long enough to develop the disease.

We normally associate the word plaque with an award or something that our dentist warns us about when we go in for a check-up. Plaque is a major part of the Alzheimer’s Disease process. This particular type of plaque forms between nerve cells in the brain, causing nerve signals in the brain to be interrupted. Imagine that your nerve cells are like electric lines that transmit signals back and forth. Now imagine that a piece of insulation blocking the electricity is put in a line. All of a sudden, the signal cannot get through anymore. That is how plaque affects your brain. It prevents brain signals from getting from one place to another. Plaque is made up of a protein that your body produces normally. In a normal brain, that protein would be eliminated. In the Alzheimer’s brain, that protein clumps together with other pieces and forms a plaque.

Another hallmark of Alzheimer’s disease is the formation of tangles. Imagine that the nerve cells in your brain are like railroad tracks. You have two side pieces and a ladder-like structure in the middle holding everything in place. These ladder-like structures are made up of a protein that becomes abnormal in the Alzheimer’s brain and causes the ladder to weaken and collapse. If enough of these proteins become abnormal, the whole nerve cell may collapse on itself and prevent nerve signals from being transmitted.

Alzheimer’s disease begins its destruction in an area of the brain called the hippocampus. The hippocampus is responsible for taking in new information and processing it through your memory. As the disease spreads, it works its way up through the outer layers of your brain, affecting judgment, emotions and language. Eventually enough of the brain is overrun by plaques and tangles that even the most basic functions are impaired, such as the ability to toilet, communicate and walk. Alzheimer’s disease completely destroys the ability of an individual to be independent. His or her state of dependency may last for years. The average length of time from diagnosis of Alzheimer’s disease to death is three to ten years, though disease progression may take as long as 20 years.

Diagnosis

The only way to make a certain diagnosis of Alzheimer’s disease is by autopsying the brain after death. However, medical science has progressed such that a 95% certain diagnosis by using mental tests and ruling out other illnesses. Early diagnosis is important so that prescription drug therapy can be started. Though there is no cure for Alzheimer’s disease, medications may help control the symptoms and slow the disease progression.

Testing and diagnosis by a trained health professional is very important because other conditions may resemble Alzheimer’s disease. These other conditions may be treatable or completely reversible. Testing may include lab work, imaging (such as an MRI or PET scan) and cognitive function tests. The main thing to remember about testing and diagnosis is that they require many components. There is no single test that determines Alzheimer's Disease.

Tips for Caregivers

If you care for a family member with Alzheimer's disease, remember these recommendations:

1. Keep expectations realistic.
2. Maintain a calm environment.
3. Keep tasks simple.
4. Use memory aids.
5. Reassure and praise.
6. Treat the person as an adult.
7. Maintain safety.

For more information

• University of Georgia Family & Consumer Sciences, Senior Sense newsletter article, Declines in Mental Ability
• For a slideshow on Alzheimer's disease from the National Institute on Aging: http://nihseniorhealth.gov/alzheimersdisease/toc.html
• For an interactive presentation on the brain from the Alzheimer's Association: http://www.alz.org/brain/overview.asp

If you are an educator seeking program materials related to Alzheimer's disease, visit the National Institute on Aging for the Speaker's Kit: Unraveling the Mystery http://www.nia.nih.gov/Alzheimers/Publications/speakerskit.htm