SECTION: News; Pg. A16

LENGTH: 437 words

HEADLINE: Scans chart ravages of Alzheimer's: Tests could help doctors evaluate treatments

SOURCE: Reuters

BYLINE: Maggie Fox

DATELINE: WASHINGTON

BODY:
WASHINGTON -- Dramatic new scans show brain cells quickly and steadily disappearing in patients with Alzheimer's disease, an international team of researchers said yesterday.

They used magnetic resonance imaging, also known as MRI, to chart a five-per-cent annual loss of brain cells in Alzheimer's patients -- up to 10 per cent in key memory areas. By contrast, healthy volunteers monitored in the study lost less than one per cent of their brain cells a year. "For the first time, you can see Alzheimer's disease progressing in living patients," said Paul Thompson, an assistant professor of neurology at the University of California Los Angeles school of medicine, who led the study.

"We were stunned to see a spreading wave of tissue loss.

"Initially confined to memory areas, this loss moved across the brain like a lava flow, destroying more and more tissue as the disease progressed."

Writing in the Journal of Neuroscience, the researchers said their findings would help doctors check to see if treatments are helping and perhaps help chart the course of the disease.

Alzheimer's is assessed using standard tests of a patient's behaviour and performance, rather than any physical evidence.

This will probably continue to be the case, said Dr. Sid Gilman, director of the Alzheimer's centre at the University of Michigan.

"The diagnosis of Alzheimer's disease really depends upon demonstration of cognitive dysfunction," Dr. Gilman said.

"No amount of PET scanning or MRI scanning will make the diagnosis. There are anecdotal stories of people dying who had scored normal on tests of cognitive function a few weeks before and upon death the brain can show definitive signs of Alzheimer's."

"Currently, all we have is symptomatic treatment," he said. "We have no treatment that stops the progression."

But researchers are working on ways to stop the now-incurable disease, such as vaccinations that might stop the buildup of toxic proteins in the brain.

For their study, Mr. Thompson and colleagues at UCLA, in Britain and Australia scanned the brains of 12 Alzheimer's patients and 14 healthy volunteers every three months.

They were able to put together images that can be seen on the Internet at www.loni.ucla.edu/thompson/AD-4D/dynamic.html .

The Alzheimer's patients lost 5.3 per cent of their brain cells each year. In memory regions, they lost up to 10 per cent.

Mr. Thompson hopes the method could not only be used to compare treatments for Alzheimer's, but perhaps to see if exercise and mental exercise could prevent or delay Alzheimer's in people at a high risk of the disease.

LOAD-DATE: February 7, 2003