For first time here, researchers capture 'live'
images of the protein linked to dementia
Doctors
have long known that people with Alzheimer's disease develop clumps of a
protein called amyloid in their brains - the problem was identifying this
condition while they were still alive.
But in a
first for Singapore, researchers at the Clinical Imaging Research Centre (CIRC)
have managed to capture "live" images of these protein deposits in
people's brains.
This
paves the way for better diagnosis and treatment of Alzheimer's disease, which
is the main cause of dementia in up to seven in 10 patients.
Associate
Professor Christopher Chen, who was part of the team that took the first living
brain scans here, said amyloid is deposited in the brain long before people
start showing symptoms. These microscopic proteins are thought to stop brain
cells from sending signals to each other or to be even directly toxic to the
brain, although scientists do not know for sure.
"If
we were to base our entire concept of dementia and Alzheimer's disease on just
cognitive symptoms, we may be missing opportunities to intervene at early
stages," said Prof Chen, who is from the departments of pharmacology and
medicine at the National University Health System.
"That
is why research capabilities to track these changes in the brain are so
important."
Previously,
scans allowed doctors to pick up changes in brain structure or activity, but
not conclusively say if someone has Alzheimer's.
Being
able to do so could change the way people are diagnosed and treated, said Prof
Chen. For instance, it could help research teams get a better idea of who to
pick for anti-amyloid clinical trials.
"This
kind of imaging is also useful to monitor whether treatment is effective, for
us to see if the amyloid load is actually reducing," Prof Chen said.
It could
also help doctors understand why some people who have mild cognitive impairment
- where symptoms are not bad enough to interfere with their daily activities -
go on to get dementia, while others do not.
Dementia
affects an estimated one in 10 people aged over 60 in Singapore, where the
population of seniors is expected to double to 900,000 by 2030.
Prof
Chen's team at the centre, which was jointly established by the Agency for
Science, Technology and Research (A*Star) and the National University of
Singapore, is recruiting 110 people with cognitive impairments for a study to
detect the presence of amyloid in their brains.
Ten of
these would have already been diagnosed with Alzheimer's disease, while the
other 100 would have mild cognitive impairment.
Twenty
people have been recruited as of the end of last month.
They will
be injected with a radiopharmaceutical, which travels to the patient's brain
and binds to amyloid deposits. Then, they will undergo a positron emission
tomography (PET) scan on which these deposits show up.
Scans
using the same technology are already being carried out in the United States
and Europe.
"With
our radiopharmacy capability, we can radiolabel important molecules that reach
targets for many applications in neuroscience, oncology, infectious diseases
and cardiology," said Professor David Townsend, who is the centre's
director.
Prof Chen
said the new capabilities will help his team study other molecular features in
the brain, saying: "Amyloid is not the end of the story - it's only the
beginning."
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