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 of participants.
"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.