February 12, 2003
(The Los Angeles Daily News) -- UCLA researchers have mapped the progression
of cell death in Alzheimer's disease using computer-generated time-lapse
video, a technology that may help in the development of new drug therapies
and serve as an evaluative tool in the treatment of patients.
The
team of neuroscientists from UCLA and the University of Queensland in Australia
took magnetic resonance imaging scans every three months of 12 patients diagnosed
with Alzheimer's and compared them to 14 healthy elderly volunteers. Able
to detect fine changes in the MRI scans, the imaging technique displayed
the sequence of destruction over a two-year span.
"Though the pictures
are depressing, there's tremendous hope for evaluating drugs now that you
can see this elapsing over time in a brain image," said Paul Thompson, assistant
professor of neurology at UCLA and lead investigator. "It's a powerful approach."
Researchers found that Alzheimer's first attacked brain areas controlling
memory. Then the disease hit areas affecting self-control and inhibition,
followed by emotion. Toward the end, Alzheimer's destroyed sensation. Like
lava flowing around rocks, the disease left islands of brain tissue intact,
including those controlling vision and breathing. After two years, the entire
brain was engulfed, Thompson said.
Though the sequence has been
observed in cognitive tests of memory and language, the imaging technique
provides a precise delineation of events, said Dr. Jeffrey Cummings, director
of the UCLA Alzheimer's Disease Center and president of the Los Angeles chapter
of the Alzheimer's Association. Until now, the physical degeneration had
only been examined in autopsy studies, he said.
"The autopsy shows
us what the battlefield looks like, but then you have to reconstruct the
battle," Cummings said. With the imaging technique, "you watch the event
unfold. This is a more secure way of knowing how the brain is affected."
Cummings recommended some patients for the study but was not involved in the research.
Bill Thies, vice president for medical and scientific affairs for the national
Alzheimer's Association in Chicago, said the UCLA study is part of a larger
effort to track the biology of the disease using competing technologies.
What's needed is a much longer-term study that tracks the progression before
the onset and through the entire course of the disease, he said.
"I've not seen anyone use this particular technique, which is very interesting,"
Thies said. "And it will be interesting to see if other people pick this
up as a worthwhile technique."
On average, Alzheimer's patients
in the study lost 5.3 percent of brain tissue a year. But in the memory regions,
brain cell death occurred at higher rates, up to 10 percent. The healthy
volunteers lost only 0.9 percent of brain tissue a year.
Thompson
plans to use the imaging technique to evaluate people considered at risk
for Alzheimer's. By the time of diagnosis, patients in the study had already
lost 10 percent of their gray matter, making early detection a priority,
he said.
An estimated 4 million Americans suffer from the disease,
according to the Alzheimer's Association. About 10 percent of those are over
65 years of age, rising to 50 percent for those age 85 and older. Though
current drug therapies may slow Alzheimer's, scientists have not yet found
a cure.
Copyright 2003 The Los Angeles Daily News. All rights reserved.