We do not fully recover from brain injuries if we have abnormal inflammation.
Inflammation is a natural process within our immune system that is activated by the body to repair damaged tissue or to fight infection. Our body is constantly under stress and requiring repair from normal inflammation. Our body repairs the routine bumps in life, the gravitational stress on our joints and muscles, and the mechanical stress it experiences each day. One example of mechanical stress and repair is the work done by our heart valves who must open and close 30 million times per year. Our heart valves require continual repair in order for us to stay alive.
When a healthy individual suffers a brain injury there is cellular damage in the brain and an inflammatory response targeted at repairing the damage is activated. This response in many ways is no different than the inflammatory response required to repair a strained tendon or a bruised muscle.
Normal Inflammation Response
Our normal inflammation response within the brain involves the activation of a specialized type of white blood cell called a microglial cell. Microglia activate and repair the injured brain tissue and once the repair is complete the microglial cells shift back to a quite, non- inflammatory resting state.
When inflammation works properly and the microglia turn off when their job has been completed, and the damage from a brain injury should completely recover. The normal inflammatory response is like the damage that is suffered when tendons are strained or when muscles are bruised.
Imbalance of Inflammation Response
But in a growing number people the repair process does not work properly because their inflammation regulatory system is damaged. Multiple factors allow their inflammatory system to activate too easily, while other factors impede their ability to shut their inflammatory response off.
Abnormal functioning microglia cells are a major reason why brain injuries are not repaired. Instead of repairing the damage and returning to an idle state, the dysfunctional microglia never shut off. This continued state of microglia activity compounds the brain damage and prevents their recovery. The abnormally functioning microglia, who are our heroes when they behave correctly as part of our natural inflammatory repair process, have now become our problem.
The dysfunctional microglia never stop producing the inflammatory chemicals that contribute to the brain injury. These inflammatory chemicals, called cytokines, have a direct damaging effect on tissue and they lead to a state of chronic inflammation within the brain referred to as neuroinflammation.
Neuroinflammation from chronic microglial cell activation is the single most important feature that prevents recovery in individuals with a brain injury. Individual who do not have neuroinflammation typically recover several weeks or several months after their injury, but individuals with chronic neuroinflammation will never recover without medical assistance.
What is not fully understood nor appreciated in the field of concussion management today is that if an athlete’s inflammatory repair process is not operating correctly, the multitude of common minor head traumas that most athletes will sustain (i.e., minor traumatic brain injury, mild sub-concussive brain injury and non-traumatic brain injury) will never be fully repaired and the athlete’s brain damage will silently accumulate. Given enough occurrences, with each minor trauma adding to the overall problem, these minor yet unresolved brain damage events will eventually have the cumulative effect of a single significant brain injury for the athlete.
The reversal of neuroinflammation and the underlying chronic brain damage is possible when the multiple underlying causes of the abnormal inflammation regulation are reversed. Once the neuroinflammation is normalized, the bodies’ natural repair mechanisms become active, and the brain damage can be reversed months, years, or even decades after the injury.