TUESDAY, Jan. 18 (HealthDay News) -- Researchers report
promising results for a scanning test that aims to reveal the
presence of Alzheimer's disease, potentially allowing doctors to
try to treat the illness in its early stages. Another study finds
that blood tests could indicate higher risks of dementia later in
But there's a catch: Alzheimer's disease is not curable, and
existing treatments only have limited effects.
Even so, the ability to precisely diagnose Alzheimer's disease
during life, which is now impossible, could lead to improved
research, said memory specialist Dr. Anton P. Porsteinsson, a
psychiatry professor at the University of Rochester School of
Medicine, who was not involved with the studies.
The findings, published Jan. 19 in the
Journal of the American Medical Association, "may have much more relevance" in the future, Porsteinsson said. "Basically, this is a step in the process."
Currently, doctors correctly diagnose Alzheimer's disease about
85 percent of the time, Porsteinsson said. The illness can be
confirmed only through brain analysis after death. Even with
existing scanning technology, "we can't see individual cells or
what's going on," he said. "We can't see the functional impairment
that happens," he added.
In one of the new studies, researchers led by a team from Avid
Radiopharmaceuticals reported that they were able to find signs of
Alzheimer's disease by using PET scanning technology. They had
scanned 35 people who appeared to have the disease before their
deaths and looked for signs of beta amyloid, a kind of gunk that
clogs the brain in people with the illness.
The other study attempted to measure levels of beta amyloid in
the blood. It linked lower levels -- a sign that the gunk is
getting tied up in the brain -- to higher cognitive problems in 997
elderly people over a nine-year period.
The researchers also found that people with higher levels of
"cognitive reserve" -- such as those with higher levels of
education and literacy -- seemed to be buffered against dementia,
said the study's lead author, Dr. Kristine Yaffe, a psychiatrist
and professor at the University of California, San Francisco.
"The fascinating implication is that if you identify those at risk, maybe you could do something like cognitive stimulation to mitigate the risk," she said.
For now, though, "the markers reported here are far too
unspecific to distinguish between people who will and will not get
the disease," said Dr. Monique M.B. Breteler, an epidemiologist
with University Medical Center Rotterdam in the Netherlands who
wrote an accompanying commentary. "The importance of this paper is
that it shows that there are detectable signals in blood that are
related to the later development of the disease."
As for cost, Porsteinsson said the expense of the blood tests
may go down. As to the other study, "the cost for the PET scans
will always be pretty high because you've got to have such
The U.S. National Institute on Aging has more on