A new method of PET scan is allowing researchers to gain a better understanding of dementia disorders while patients are alive, including a finding that those with language dementia -- primary progressive aphasia -- have a buildup of amyloid plaques on the left side of the brain. This differs from Alzheimer's disease patients, who have the buildups on both sides of their brain. Photo by sfam_photo/Shutterstock
CHICAGO, March 8 (UPI) -- Amyloid plaques build up on one side of the brain, responsible for language and communication, in patients with primary progressive aphasia, or PPA, a finding researchers said will help in diagnosing and treating the condition.
Researchers at Northwestern University found the plaques build up primarily on the left side of the brain using a new type of positron emission topography, or PET, scans that detect amyloids.
A combination of computed tomography, or CT, scans and cognitive memory or language tests have typically been used to diagnose Alzheimer's and other dementia-type conditions. The method has been somewhat effective in diagnosing patients, though the only way to confirm the disease is examination of the brain after death.
The new method of PET scans, demonstrated in studies at Lund University last year and at the University of California Berkeley this year, suggests doctors may soon have a more reliable method of diagnosing and monitoring progression of dementia in patients while they are alive.
PPA is a rare form of dementia that affects the ability to understand and use language, which progressively forms in the brain similarly to Alzheimer's.
"This new technology is very exciting for Alzheimer's research," Adam Martersteck, a researcher at Northwestern University, said in a press release. "Not only can we tell if a person is likely or unlikely to have Alzheimer's disease causing their PPA, but we can see where it is in the brain. By understanding what the brain looks like in the beginning stages of Alzheimer's, we hope to be able to diagnose people earlier and with better accuracy."
For the study, published in the Annals of Neurology, researchers scanned 32 patients with PPA, finding that 19 had high amounts of amyloid.
The PPA patient scans were then compared to 22 people with Alzheimer's memory dementia. PPA patients had higher buildups of amyloid plaques on the left side of the brain, where language and communication function is located, and memory dementia patients had amyloids evenly distributed on both sides of their brains.
"By understanding where these proteins accumulate first and over time, we can better understand the course of the disease and where to target treatment," said Emily Rogalski, research associate professor at Northwestern University's Cognitive Neurology and Alzheimer's Disease Center. "It is important to determine what Alzheimer's looks like in PPA, because if it's caused by something else."