Concussions can be a dangerous injury for anyone, but they can be extra risky for those who carry the genes associated with Alzheimer’s. The findings of a new study published in the journal Brain suggest concussions can cause more memory problems and atrophy in areas of the brain if they possess the high-risk genes for the disorder.
The relationship between concussions and Alzheimer’s has long been established, but it is also very murky. We know moderate to severe traumatic brain injury is considered a strong risk factor for diseases like Alzheimer’s. However, whether less serious brain injuries also raise the risk or how the two are linked is poorly understood.
To investigate the link further, a team of researchers from Boston University School of Medicine (BUSM) evaluated 160 Iraq and Afghanistan war veterans – some of whom had experienced one or more concussions during their time in the service. Of those who had a history of brain injury, most had lost consciousness and reported memory issues. A number also had post-traumatic stress disorder.
The veterans underwent MRI imaging to measure the thickness of their cerebral cortex in seven regions that are known to be the first to show signs of atrophy in Alzheimer’s disease, as well as seven control regions.
“We found that having a concussion was associated with lower cortical thickness in brain regions that are the first to be affected in Alzheimer’s disease,” explained corresponding author Jasmeet Hayes, PhD, assistant professor of psychiatry at BUSM and research psychologist at the National Center for PTSD, VA Boston Healthcare System.
“Our results suggest that when combined with genetic factors, concussions may be associated with accelerated cortical thickness and memory decline in Alzheimer’s disease relevant areas.”
The researchers note that the brain abnormalities were observed in a relatively young group. The average age of the veterans was 32 years old.
“These findings show promise for detecting the influence of concussion on neurodegeneration early in one’s lifetime, thus it is important to document the occurrence and subsequent symptoms of a concussion, even if the person reports only having their “bell rung” and is able to shake it off fairly quickly, given that when combined with factors such as genetics, the concussion may produce negative long-term health consequences,” said Hayes.
While the link between mild concussions and Alzheimer’s is a concern, Hayes is quick to emphasize that the abnormalities were not seen in all veterans with concussions.
“This is good news for all those out there who have suffered from concussion,” she says. “You have to have a concussion and genetic risk.”