A new 3-D time-lapse video technique is helping
neuroscientists see the progression of Alzheimer’s
disease in patients’ brains for the first
time.
As this ScienCentral News video reports, it
will help in early diagnosis and intervention.
Brain Map
Until now, doctors could only measure the
physical spread of Alzheimer’s disease by
examining the brains of deceased patients after it
was too late to help them. But with a new brain
scanning technique, now they can see the disease
progressing in living patients, which will allow
them to pinpoint where and how fast the disease is
spreading, and reveal whether drugs and vaccines
combat the brain damage that Alzheimer’s
causes.
Neuroscientists from the University of
California Los Angeles (UCLA) and the University
of Queensland in Australia used a new imaging
analysis technique to track the spread of
Alzheimer’s-related cell death in living patients.
They detected changes in brain scans created using
magnetic resonance imaging (MRI), and created the
first 3-D, time-lapse
video map showing the spread of Alzheimer’s
disease.
“This is the first technique to actually watch
the physical spread of Alzheimer’s in the [living]
brain,” says Paul Thompson, assistant
professor of neurology at the David Geffen School of Medicine at
UCLA, the study’s chief investigator. “You can
use this to look at drug effects, whether they are
helping a patient. You can use it for early
diagnosis, to see if a person actually has
Alzheimer’s. You can also use it to tell if a
patient is aging healthily.”
Researchers scanned twelve Alzheimer’s patients
and fourteen healthy elderly volunteers every
three months for two years. They found that the
Alzheimer’s patients lost an average of 5.3
percent of their gray matter per year, whereas the
healthy volunteers lost only 0.9 percent of their
brain tissue annually.
The time-lapse videos revealed that the
destruction of brain cells in patients with
Alzheimer’s follows a specific sequence: the areas
affected first are those that control memory
function; then, those that control emotion and
inhibition; and finally, those that control
sensation. “You see this forest fire of tissue
loss in the brain,” says Thompson. “It’s almost as
though early changes happen in a very small area
of the brain, but then there is this sort of
terrific spreading of cell loss into other areas.
With imaging, we can actually track the
progression of this. Now, we all know that if you
can see something spreading, there might actually
be a way of stepping in and telling if the ways of
preventing it are being helpful.”
These scans will allow doctors to evaluate
whether a medication is actually working in a
patient, which, until now, they could only do by
assessing whether the patient’s memory was
improving. “Just seeing if the memory loss has
slowed down isn’t the most effective way to see if
the drug is working,” explains Thompson. “But with
brain scans you can actually see if the physical
spread of the disease is being slowed by the
medication, and which medications are best. Right
now, there are a number of medications for
Alzheimer’s. We are very excited to apply scanning
to see whether one medication is better at saving
one area, but another drug might be more effective
in different ways.”
