(MUSIC)
JUNE SIMMS: Alzheimer’s disease normally affects people more than sixty-five years old. But rare cases have been discovered in people younger than fifty.
Alzheimer’s is identified in only about two percent of people who are sixty-five. But the risk increases to about twenty percent by age eighty. By eighty-five or ninety, half of all people are found to have some signs of the disease.
SHIRLEY GRIFFITH: About five million people in the United States have Alzheimer’s. That number is expected to more than double by the year twenty fifty as the number of older Americans increases. The Alzheimer’s Association says medicines approved for use are effective in half the patients who take them. Among those fifty percent, the drugs are effective for six to twelve months.
JUNE SIMMS: For years, scientists have been attempting to learn who may develop Alzheimer’s. If the condition could be identified before its worst signs appear, people might get at least temporary medical help.
The most widely-held belief about the cause of Alzheimer’s is that a protein - called beta-amyloid - builds up in patients’ brains. It has also been found in the spinal fluid of Alzheimer’s patients. Large amounts of this protein may destroy a person’s ability to think.
But some scientists question whether beta-amyloid causes the disease. They think that the protein build-up may result from it. Still, most researchers say thick tangles or plaques of the protein are responsible for the condition. Plaques are unusual clusters, or groups, of proteins. The researchers say beta-amyloid destroys communication links in the brain.
最新
2013-11-25
2013-11-25
2013-11-25
2013-11-25
2013-11-25
2013-11-25