What Is Alzheimer's Disease?
Dementia is a brain disorder that seriously affects a person's ability to carry out daily activities. Alzheimer's disease -- the most common form of dementia among older people -- initially involves the parts of the brain that control a person's thought process, memory, and language.
Alzheimer's disease bears the name of Dr. Alois Alzheimer, a German physician. In 1906, Dr. Alzheimer noticed changes in the brain tissue of a woman who had died of an unusual mental disorder. During the autopsy, he found abnormal clumps (now called amyloid
plaques) and tangled bundles of fibers (now called neurofibrillary tangles) within the brain. Today, these plaques and tangles are considered classic signs of Alzheimer's disease.
Scientists have also found other brain changes in people with Alzheimer's disease, including:
- The death of nerve cells in areas of the brain that are vital to memory and other mental abilities
- Disruptions in the connections between nerve cells
- Lower levels of some of the chemicals in the brain that carry messages back and forth between nerve cells.
All three of these changes may contribute to the impaired thinking and memory seen with Alzheimer's disease.
Age is the most important risk factor for Alzheimer's disease. In fact, the number of people with this disease doubles every 5 years after age 65.
Alzheimer's research scientists are studying the role of genetics in the development of Alzheimer's disease. Researchers have discovered three genes that cause early symptoms of (familial) Alzheimer's disease and other genetic mutations that cause excessive accumulations of amyloid protein. The buildup of these proteins is associated with age-related (sporadic) Alzheimer's disease.
Common symptoms of Alzheimer's may include:
- Memory loss
- Poor judgment
- Confusion
- Deterioration of language skills
- Impaired ability to understand visual information
- Mood swings
- Restlessness.
Eventually, the disease destroys a person's ability to think, process information, and function.
It is important to note that
early signs of Alzheimer's disease, which include forgetfulness and loss of concentration, are often missed because they closely resemble the natural signs of aging.
Statistics on Alzheimer's Disease
Scientists believe that up to 4.5 million Americans suffer from Alzheimer's disease. Alzheimer's usually begins after age 60 and the risk of developing this condition increases with age. For example, about 5 percent of men and women ages 65 to 74 have Alzheimer's disease, and nearly half of those who are over 85 years of age may have the disease. However, it is important to note that Alzheimer's disease is not a normal part of aging.
While younger people may also get Alzheimer's disease, this is much less common.
Prognosis for Alzheimer's Disease
Alzheimer's disease is a condition that progresses slowly. It starts with mild memory problems and eventually leads to severe brain damage. The course of this disease can vary widely from one person to the next. On average, patients with Alzheimer's disease continue to live for 8 to 10 years after they are diagnosed, though some people live for as many as 20 years after their diagnosis.
