But scientists stress this doesn't mean seniors should rush to get the scans, more study needed
WebMD News from HealthDay
By Amy Norton
HealthDay Reporter
TUESDAY, Oct. 7, 2014 (HealthDay News) -- An MRI scan that measures blood flow in the brain may help predict which older adults are at risk for future memory loss, a preliminary study suggests.
The researchers found that, in some apparently healthy older adults, the MRI technique was able to pick up reductions in blood flow to a brain region linked to memory. And those people were more likely than their peers to show subtle memory loss 18 months later.
The results, reported online Oct. 7 in the journal Radiology, do not mean older adults should rush out to get brain scans, the researchers stressed.
But with more study, the MRI technique might prove useful for catching mental decline early. "That's the aim in the long term," said study leader Dr. Sven Haller, a senior physician at the University Hospitals of Geneva, in Switzerland.
For now, Haller said, the technology could be used in research -- specifically, to select patients for clinical trials testing new drugs to stave off Alzheimer's disease.
So far, Alzheimer's drug trials have produced disappointing results, Haller pointed out.
"The problem is that one has to include patients at an early stage, because it is unlikely that a medication will recover already existing cognitive [mental] decline," he said. "Yet it might -- hopefully -- decrease the speed of progression of cognitive decline," he suggested.
Debra Fleischman, an Alzheimer's researcher who was not involved in the study, agreed. "Early detection is critical to developing and optimizing treatments," she said.
"These findings are important in regard to early detection because they focus on persons with normal cognition, but segregate that [group] into those who stay stable and those who decline within the normal range over 18 months," said Fleischman, a professor of neurological sciences at Rush University Medical Center in Chicago.
That means the MRI technique "does have promise" for spotting mental decline before symptoms are apparent, according to Fleischman. But she stressed that much more research is needed before any brain imaging techniques can be used that way.
Right now, another type of brain scan -- called positron emission tomography (PET) -- is sometimes used to help diagnose people with symptoms of dementia, Fleischman pointed out.
That type of imaging, which requires an injection of a radioactive substance, picks up protein deposits called beta-amyloid, which can be an indicator of Alzheimer's disease.
However, Fleischman said, "there is controversy about using [PET] scans to identify risk in people without symptoms."
That's because a person with those beta-amyloid clumps is not necessarily going to develop dementia symptoms, Fleischman explained. So researchers are still hunting for tests, or test combinations, that can best zero in on people who are on the path to Alzheimer's.
source : MRI May Spot Early Signs of Mental Decline, Study Finds
