By Merritt McKinney
NEW YORK, Nov 22 (Reuters Health) -- Scientists have moved a step closer
to developing a test that would detect Alzheimer's disease. Such a test may lead
to earlier diagnosis of the disease and perhaps improved treatment, the
researchers predict.
Currently, the only way to diagnose Alzheimer's disease definitively is to
look for protein deposits in the brain. These deposits are too small to be
detected with a common scan called magnetic resonance imaging (MRI), so they can
be detected only when the brain is examined under a microscope during an
autopsy.
But, using a more powerful version of MRI, called magnetic resonance
microscopy, researchers at Duke University Medical Center in Durham, North
Carolina, have detected the protein deposits in samples taken from human brains.
Their report is published in the Proceedings of the National Academy of Sciences
A team of researchers led by Dr. Helene Benveniste collected brain samples
from five people who had Alzheimer's disease when they died and three people who
did not have the disease. Using magnetic resonance microscopy, the investigators
were able to detect the characteristic deposits in the brain tissue of the
people who had Alzheimer's disease.
However, detecting the deposits was "...extremely challenging," they note.
In an interview with Reuters Health, Benveniste stressed that the test is
still in the preliminary stages. "We are far from being at a point where we can
do this in (living) humans," she said.
Right now, Benveniste and her colleagues are using the technology to study
live rats, although she said that it is too soon to tell whether it will work.
According to the Duke scientist, there is some controversy about whether
the protein deposits actually cause the symptoms of Alzheimer's disease. Having
a test to detect those deposits might help resolve the controversy, she said.
By following people over several decades, physicians would be able to see
if symptoms of Alzheimer's disease appeared or worsened as more of the deposits
accumulated, she explained.
