Washington, Mar 6 : Researchers have been able to classify different types of dementia with the help of positron emission tomography (PET) imaging with the radiotracer fluorodeoxyglucose (FDG), raising hopes that it may one day be possible to catch the disease in its earlier stage.
Dementia is a general term for a progressive brain dysfunction that results in the loss of memory and other intellectual abilities serious enough to interfere with daily life.
"Previously, scientists have been able to look only at the surface of the brain to differentiate various types of dementia," said Lisa Mosconi, Ph.D., assistant professor of psychiatry at the New York University School of Medicine.
"With FDG PET, we were able to develop standardized disease-specific patterns from which we could correctly classify dementia more than 94 percent of the time," she added.
The study which 548 subjects measured the cerebral metabolic rate of glucose (CMRglc), the amount of sugar the brain uses to fuel its activities, in various areas of the organ.
A decrease in this rate is indicative of a loss of nerve cells and of dysfunction associated with dementia. Because FDG behaves like glucose when injected into the body, its location in the PET scans pinpointed the specific area where glucose utilization had fallen below normal levels as compared to an age-appropriate control group.
"Each type of dementia examined-Alzheimer's disease (AD), frontotemporal dementia (FTD), and dementia with Lewy bodies (DLB)-affects a different area of the brain. Based on where in the brain this decrease occurred, we were able to determine which type of dementia a patient had," Mosconi said.
According to the researchers, the results suggest that the ability to detect differentiated uptake of glucose may result in earlier and more accurate diagnoses of MCI, an early stage of dementia known as mild cognitive impairment, and better disease management.
The study is published in the Journal of Nuclear Medicine.