A new study, published in the journal Neurology suggests people with traumatic brain injury
(TBI) may have buildup of plaques similar to those found in the brains of
Alzheimer’s patients. Although these amyloid plaques match, their spatial
distribution differs.
A corresponding editorial says that over the past decade the
rate of emergency department visits related to traumatic brain injury (TBI) has
increased by 70% in the United States. The editorial also says an estimated
three to five million Americans live with a TBI-related disability.
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TBI occurs when the brain experiences damage due to a sudden
trauma.
Study author Prof. David Sharp, MD, of Imperial College
London said:
"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.”
"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 aremore 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."
People who suffer from TBI can have a slew of medical
issues. While some TBI patients may experience cognitive impairments or
difficulty with sensory information, others might have display mental health
issues such as anxiety or depression. Yet, another long-term risk factor TBI patients
is dementia. Scientists do not know the exact mechanism behind this
relationship, but recent studies have made some progress into understanding it.
For the study, researchers recruited 9 people with an
average age of 44 who had a single moderate to severe TBI. Their brain injuries
had occurred between 11 months and 17 years previously. The research team took
an in-depth look at their brains by taking PET and MRI scans. The PET scans
detected amyloid plaques in the brain and the MRI scans searched out evidence
of cellular damage resulting from the trauma.
The scan results were compared with 10 people with
Alzheimer's disease and nine healthy participants (control group).
Both the people with brain injuries and the people with
Alzheimer's disease had plaques in the posterior cingulate cortex, which is
affected early in Alzheimer's. The researchers also found that plaques were
increased in patients with more damage to the brain's white matter.
Interestingly, the TBI group, but not the Alzheimer's group,
also showed plaques in the cerebellum.
Prof. Sharp said:
"It suggests that plaques are triggered by a different
mechanism after a traumatic brain injury."
"The areas of the brain affected by plaques overlapped
those areas affected in Alzheimer's disease, but other areas were involved.
“It suggests that plaques are triggered by a different
mechanism after a traumatic brain injury. The damage to the brain's white
matter at the time of the injury may act as a trigger for plaque
production."
The current study is a relatively small-scale trial,
however, Prof. Sharp believes that if a substantial link can be found between
brain injury and the onset of Alzheimer's disease, it might help neurologists
uncover treatment and prevention strategies to reduce the progression of
Alzheimer's at an earlier stage.
