When someone suffers a concussion (mild traumatic brain injury) their incidence of future degenerative brain disease increases. When someone suffers multiple or repeat concussions, there is a strong link between the concussions and future degenerative disease.
We know this from recent studies, reports, and research. And, anyone who works with injury victims who have sustained concussions knowns this from experience. In fact, we have written extensively on the link between concussions and long-term impairment.
The research and our experience, however, does not answer the question of why: why do concussions or other traumatic brain injuries increase the risk of degenerative brain disease?
The full answer is that the brain is a complex organ that we are still trying to fully understand. The short answer is that we simply don’t know.
It was first theorized that the long-term damage cam from the initial trauma. For instance, when someone suffers a severe whiplash injury, or a trauma to the head, what is taking place inside the head is a sudden acceleration and/or deceleration of the brain. The brain is bouncing around and hitting first one side of the skull and then the other.
And despite the traumatic nature of this event, it does not explain the slow progression of the loss of function and cognition problems and eventual issues such as Alzheimer’s and dementia.
However, we do have several competing theories that attempt to explain the phenomena; the link between concussions or traumatic brain injury and degenerative brain disease. Author and researcher John Medina has written extensively on this subject in his best selling book, “Brain Rules.”
The central theory that Dr. Medina puts forth involves chronic traumatic encephalopathy (CTE). Because of the use of MRI, FMRI and CT scans we know that CTE involves the tangling or knotting of a brain protein called tau. Tau is a normal protein in the brain that supplies nutrients to brain cells and is a normal component of neurons. However, when the neurons and pathways in the brain are interrupted, brain cells begin to die from a lack of nutrients. And this, the theory goes, leads to CTE and all of the cognitive impairment symptoms that come with it.
This is, of course, only one theory that explains CTE and the link between concussions or traumatic brain injury and degenerative brain disease. There are several additional competing theories. Thus, we need more research and studies in order to better and accurately understand exactly what is taking place in the brains of injury victims when they sustain a brain injury.
The better we are able to understand the link between a brain injury and future cognitive problems and brain diseases, the better we will be able to treat injury victims and possibly prevent future impairments from taking place.
