Brain injuries stemming from head trauma may lead to the buildup of amyloid plaques related to Alzheimer's disease, according to new research by scientists from the Imperial College London. Over the past 10 years, traumatic brain injury (TBI) emergency room visits increased by 70 percent and approximately three to five million Americans live with disabilities rooted in TBI.
"The study is small and the findings preliminary, however, we did find an increased buildup of amyloid plaques in people who had previously sustained a traumatic brain injury," said David Sharp, author of the study, in a press release. "The areas of the brain affected by plaques overlapped those areas affected in Alzheimer's disease, but other areas were involved. People after a head injury are more likely to develop dementia, but it isn't clear why. Our findings suggest TBI leads to the development of the plaques, which are a well-known feature of Alzheimer's disease."
The study examined nine people with an average age of 44 with moderate to severe TBI that was confirmed through positron emission tomography (PET) and magnetic resonance imaging (MRI) brain scans. PET scans were used for plaque detection, whereas MRI scans were used to detect brain cell damage associated with TBI. These injuries all took place between 11 months to 17 years prior to the beginning of the study. Each participant was compared to 10 people with Alzheimer's disease and a control group of nine healthy subjects.
The results showed that both subjects with TBI and those with Alzheimer's had plaques in their posterior cingulate cortex, common early in Alzheimer's, but only those with TBI had plaques in their cerebellum. Furthermore, the team also found that the more damage that was found in white matter of the brain, the higher the frequency of plaques.
"It suggests that plaques are triggered by a different mechanism after a traumatic brain injury," said Sharp. "The damage to the brain's white matter at the time of the injury may act as a trigger for plaque production."
"If a link between brain injury and later Alzheimer's disease is confirmed in larger studies, neurologists may be able to find prevention and treatment strategies to stave off the disease earlier," he concluded.
The findings were published in the Feb. 3 issue of Neurology.
