Amyloid distribution different in Alzheimer’s memory and language dementias

Researchers are getting a better look at the brains of people with a rare kind of dementia—and in real time.

Using a special imaging technique, researchers at the Northwestern University Feinberg School of Medicine were able to study the brains of people living with primary progressive aphasia (PPA), a rare type of language dementia that causes people to lose their ability to express themselves and understand language. Their findings were published in the March issue of the "Annals of Neurology."

"By understanding where these proteins accumulate first and over time, we can better understand the course of the disease and where to target treatment," says Emily Rogalski, lead study investigator and research associate professor at Northwestern’s Cognitive Neurology and Alzheimer’s Disease Center, in a university issued news release.

Researchers compared beta-amyloid buildup in the brains of people with PPA and with Alzheimer’s memory dementia, the more common disease that causes memory problems. Both memory and language dementia can be caused by an accumulation of beta-amyloid.

Researchers scanned the brains of 32 people with PPA, 19 of whom had high amounts of amyloid and were likely to have the Alzheimer’s pathology. They compared them to 22 people who had the Alzheimer’s memory dementia.

People with PPA have more amyloid protein build-up on the left side of the brain, where language is processed. People with memory dementia had the same amount of amyloid on the left and right side of the brain.

"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," says Adam Martersteck, first author and graduate student in Northwestern’s neuroscience program.

In the past, amyloid accumulation could only be studied after an individual with Alzheimer’s disease had died, after the amyloid had spread throughout the entire brain. 

Topics: Alzheimer's/Dementia