Alzheimer's Disease

What Is It?

Alzheimer's disease impairs the brain's intellectual functions (memory, orientation, calculation), but at first, largely spares those parts of the brain that control sensation and movement. The memory often is affected early, and gradually deteriorates, causing impaired judgment and other problems that may affect a person's ability to perform normal daily activities. Although Alzheimer's usually begins later in life, generally after age 60, it rarely may affect people as young as age 30.

In Alzheimer's disease, deposits of proteins called amyloid and TAU distort communication between brain cells. Also levels of a chemical called acetylcholine that helps transmit messages between brain cells begin to drop, causing more communication problems. Eventually, brain cells themselves are affected. They begin to shrivel and die, causing certain areas of the brain to shrink.

Alzheimer's disease is the most common cause of dementia, accounting for 50 percent to 67 percent of all cases in people age 65 and older. Approximately 4 million people in the United States currently have the disease.

Everyone is born with the potential to develop Alzheimer's disease. Your lifetime risk of developing the disease is about 10 percent to 15 percent. However, several factors may increase your risk:

• Age — The older you get, the greater your chance of developing Alzheimer's disease.
• Family history — If members of your family, especially parents or siblings, have Alzheimer's or have died from it, your risk of developing the disease increases to 23 percent to 48 percent. Your personal risk depends on a range of factors, including how many family members are affected with Alzheimer's.
• Genetic factors — Some inherited factors may increase your lifetime risk of getting Alzheimer's disease.

Symptoms

In the earliest stages of Alzheimer's disease, new or recent memories are difficult to recall. The person finds it hard to learn and retain new information. Eventually, older or more distant memories are gradually lost. It becomes difficult to remember people and events from childhood, youth or middle age. Next, other symptoms may appear, including difficulty expressing thoughts as spoken words (aphasia), difficulty carrying out simple, directed acts (apraxia) and difficulty interpreting familiar faces or other well-known objects (agnosia).

A person with early Alzheimer's disease may not be able to plan meals, manage money, remember to keep doors locked or take medicines. The person also may lose his or her sense of direction and get lost while driving or walking, even in a familiar neighborhood.

Despite all these problems, a person with early Alzheimer's disease usually is able to feed, bathe, dress and groom without help. Psychiatric symptoms (personality changes, irritability, anxiety, depression) occur in up to two-thirds of people early in the illness. These may cause serious problems in relationships with family and friends.