New research has found abnormal proteins or ‘plaques’ in the brains of those who have experienced head injuries which may offer insight into cognitive problems associated with TBI. The amyloid plaques seen in the study match those found in individuals with Alzheimer’s disease, but differ in their distribution in the brain.
“People, after a head injury, are more likely to develop dementia, but it isn’t clear why,” study co-author David Sharp, a neurology professor at Imperial College London in the United Kingdom, said in a statement. “Our findings suggest [that traumatic brain injury] leads to the development of the plaques which are a well-known feature of Alzheimer’s disease.”
For the study, which was published in the journal Neurology, the researchers used advanced imaging methods to scan the brains of nine people who all had a single traumatic brain injury (TBI) that was moderate or severe. The average age of the participants in the study was 40, but their head injuries occurred between 11 months to 17 years before the study began. The researchers also recruited and scanned 10 people with Alzheimer’s disease and a control group of nine healthy participants.
The results of the scans showed that both people with a history of brain injury and those with Alzheimer’s disease had plaques in a region of the brain known as the posterior cingulate cortex. The region of the brain is known to be affected in the early stages of Alzheimer’s.
However, people with a record of TBI also showed plaques in the brain’s cerebellum, while those with Alzheimer’s did not. The researchers also noted the buildup of plaque was worse in the patients who had more damage to the brain’s white matter related to their brain injury.
Their observations lead the team to believe “plaques are triggered by a different mechanism after a traumatic brain injury,” than they are in people with Alzheimer’s. Sharp also speculated, “The damage to the brain’s white matter at the time of the injury may act as a trigger for plaque production.”
The participants in the study also underwent tests to evaluate their thinking abilities. According to the report, these showed that those with brain injuries performed worse on tests of attention, information-processing speed, and cognitive flexibility, compared with the control group.
“The patients we studied here had a single, moderate-severe traumatic brain injury, for example, from motor vehicle accidents,” said lead study author Dr. Gregory Scott, a clinical research fellow who is also with Imperial College London. “Our results suggest the consequences of such an injury can be very prolonged and potentially lead to [the] development of dementia,” he told Live Science.
“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,” Sharp said.
The research could open the door to new ways of understanding the mechanisms occurring during a traumatic brain injury that lead to cognitive difficulties. However, the researchers note the most recent study was small and more research will be needed to confirm their findings.