Concussions may accelerate Alzheimer's disease: Study

Concussions may accelerate cognitive decline related to Alzheimer's disease, especially in people who are at genetic risk for the disorder, a new study has found.

Moderate-to-severe traumatic brain injury is one of the strongest environmental risk factors for developing neurodegenerative diseases such as late-onset Alzheimer's disease, although it is unclear whether mild traumatic brain injury or concussion also increases this risk.

Researchers from Boston University School of Medicine in the US studied 160 Iraq and Afghanistan war veterans, some who had suffered one or more concussions and some who had never had a concussion.

Using MRI imaging, the thickness of their cerebral cortex was measured in seven regions that are the first to show atrophy in Alzheimer's disease, as well as seven control regions.

"We found that having a concussion was associated with a lower cortical thickness in brain regions that are the first to be affected by Alzheimer's disease," said Jasmeet Hayes, assistant professor at Boston University.

"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," said Hayes.

Of particular note was that these brain abnormalities were found in a relatively young group, with the average age being 32 years old.

"These findings show promise for detecting the influence of concussion on neurodegeneration early in one's lifetime," said Hayes.

"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," Hayes added.

"Treatments may then one day be developed to target those mechanisms and delay the onset of neurodegenerative pathology," she added.

The study appears in the journal Brain.