This is the VOA Special English Health Report.

Alzheimer's disease usuallyappears late in life. In the United States alone, experts say aboutfour million people have this brain disorder. Over time, it robspeople of their memory and ability to think. There are no cures.

Until now, Alzheimer's could be confirmed only by examining braintissue after death or by taking brain tissue from a living patient.Now, a new test offers hope that Alzheimer's may be found earlier.

Experts currently give written and spoken tests to help decide ifa person has the disease. They also use a process called magneticresonance imaging to see the brain changes that may meanAlzheimer's.

Many patients already have been seriously affected by the timethe disease shows up on these M-R-I's. Most of the materialsbelieved linked to the disease are present on the image. They arecalled protein clumps.

But the new test makes it possible to see the protein clumpsbefore they could be found by M-R-I. The new test might identify thedisease before a person shows signs of Alzheimer's. Treatment couldbegin earlier. Doctors could see if the treatment is helping. New orimproved drugs may be developed.

William Klunk of the University of Pittsburgh School of Medicinein Pennsylvania helped invent the test. It calls for patients toreceive a small amount of a radioactive molecule called PittsburghCompound B. It is administered through the blood.

Doctor Klunk says it connects itself to proteins called amyloidplaques. These plaques exist in the brains of Alzheimer's patients.Doctors can see them with an examination called a PET scan. Proteinsaffected by Alzheimer's show as yellow and red.

For years, Doctor Klunk and his team searched for a substancethat could connect with the amyloid. Finally they found a materialthat can reach the brain through the blood. This Pittsburgh CompoundB can color the amyloid.

The finding led to a test of sixteen suspected Alzheimer'spatients. The researchers say the test found amyloid in thosepatients. It also found small amounts in one of nine healthy peopletested for comparison. Testing on more people is needed. The UnitedStates Food and Drug Administration currently is consideringapproval of the process.

This VOA Special English Health Report was written by JerilynWatson.