Brain Scan May Spot Early Alzheimer's
Study Shows fMRI Could Some Day Confirm Early Diagnosis of Alzheimer's Disease
Sept. 26, 2007 -- A specialized type of brain scan may spot early signs of
Alzheimer's disease and aid in treatment of the disease.
In a new study, brain scans suggest a shift in brain activity that may be an
early warning sign of Alzheimer's.
Until now, doctors have only been able to confirm an Alzheimer's diagnosis
during an autopsy. But the new study suggests that brain scans using functional
magnetic resonance imaging (fMRI) may spot Alzheimer's earlier.
Although more research is needed to confirm these preliminary results,
researchers say an fMRI scan may one day be used in conjunction with other
tests to confirm an early diagnosis of Alzheimer's disease or identify people
at risk for the disease.
There is no cure for Alzheimer's, but early diagnosis of the disease can
significantly improve treatment options and quality of life.
"As new therapies for Alzheimer's disease enter the pipeline over the
next five years, early diagnosis will become critical," says Jeffrey
Petrella, MD, professor of radiology at Duke University, in a news release.
"fMRI may play a key role in early diagnosis, when combined with clinical,
genetic and other imaging markers."
New Test for Alzheimer's?
In the study, researchers studied 13 people with mild Alzheimer's disease,
34 with mild cognitive impairment, and 28 healthy people with an average age of
73. The results appear in Radiology.
All of the participants were monitored with fMRI while they were asked to
complete a face-name memory task. The scan revealed increased activity in the
area of the brain associated with episodic memory in people with Alzheimer's
compared with the others, as suggested by previous studies.
But more surprisingly, fMRI showed there was a change in activity in the
brain's memory circuitry that deals with turning off personal memory while
performing another memory-related task. The magnitude of impairment in this
area was closely related to the degree of memory impairment in the three groups
"In other words, the brain not only loses its ability to turn on in
certain regions, but also loses its ability to turn off in other regions, and
the latter may be a more sensitive marker. These findings give us insight into
how the brain's memory networks break down, remodel and finally fail as memory
impairment ensues," says Petrella.