Inflammation is the body’s response to injury and stress. This is well known as the swelling and redness that follows an injury or infection. However, inflammation that occurs in the brain, known as neuroinflammation, has been recognized and linked to many disorders which now includes Alzheimer’s disease.
The new study, published in the journal Brain, consisted of a team of researchers from the University of Cambridge who set out to examine whether neuroinflammation occurs in forms of dementia. This would then imply that it is common to many neurodegenerative diseases.
Frontotemporal Dementia
Researchers analyzed 31 patients with three different types of frontotemporal dementia (FTD). FTD is a group of various conditions resulting from the build-up of several abnormal ‘junk’ proteins in the brain. Two positron emission tomography (PET) brain scans were used to detect inflammation and junk proteins. Each scan used an injection with a chemical ‘dye’ that can light up special molecules that reveal either the brain’s inflammatory cells or the junk proteins.
For the first scan, researchers lit up the cells causing neuroinflammation. These cells indicate current damage to the brain cells and their connections. In the second scan, the dye binds to the different types of ‘junk’ proteins found in FTD.
Researchers found that the more inflammation in each part of the brain, the more harmful the build-up of the junk proteins. To further investigate that the dyes were indeed picking up the inflammation and harmful proteins, researchers went on to analyze under the microscope 12 brains donated after death to the Cambridge Brain Bank.
“We predicted the link between inflammation in the brain and the build-up of damaging proteins, but even we were surprised by how tightly these two problems mapped on to each other,” said Dr. Thomas Cope from the Department of Clinical Neurosciences at Cambridge.
Dr. Richard Bevan Jones added, “There may be a vicious circle where cell damage triggers inflammation, which in turn leads to further cell damage.”
Researchers say this study offers hope for potential new treatments for dementia. They do, however, stress that further research is needed to clarify this new knowledge of inflammation in dementia into testable treatments.
“It is an important discovery that all three types of frontotemporal dementia have inflammation, linked to the build-up of harmful abnormal proteins in different parts of the brain. The illnesses are in other ways very different from each other, but we have found a role for inflammation in all of them,” says Professor James Rowe from the Cambridge Centre for Frontotemporal Dementia.
“This, together with the fact that it is known to play a role in Alzheimer’s, suggests that inflammation is part of many other neurodegenerative diseases, including Parkinson’s disease and Huntington’s disease. This offers hope that immune-based treatments might help slow or prevent these conditions.”