When the brain suffers an injury, the natural response is different to that in any other part of the body.
Unlike damage to most other areas, brain tissue cannot be repaired, meaning the impact of a trauma can often be permanent.
For example, statistics show that only 25 to 33 per cent of severe brain injury patients endure positive outcomes or make a full recovery.
Around the same number of cases will be fatal, with 33 per cent ending in death.
Of course the severity of the injury dictates this, as the number drops to between seven and 10 per cent when the head trauma is moderate.
Furthermore, the cause and type of injury changes how the brain reacts and how it begins to attempt to recover.
How the brain reacts to a traumatic brain injury (TBI)
A TBI is defined as any injury to the brain that occurs from an external factor, which includes any trauma obtained by an impact to the head.
The skull plays a huge part in the outcomes of such injuries, as it essentially acts as a protective box filled with fluid that looks after the soft brain tissue.
Because the brain is floating in this fluid, any impact can cause it to not only move around, but collide with the skull which can lead to both bruising and bleeding.
This movement can also cause axons in the brain to snap.
Immediately after any damage to brain cells, fluids that were previously inside these can spill out and leak into the brain. This can cause the surrounding cells to also die.
Depending on if the head injury is an open or closed one can dictate different outcomes.
Closed head injuries are where the skull is not penetrated and the spillage of fluids or bleeding can increase the pressure on the brain causing further damage.
Open head injuries are things like skull fractures and can also be extremely harmful.
Primary and secondary injuries
A primary injury to the brain is one which occurs at the time of the injury.
Bruising and bleeding from an impact to the head are examples of primary injuries. These mainly come from head traumas as a result of things like road traffic accidents, falls or assaults.
Other examples of primary injuries are skull fractures or hemorrhages (bleeding in or around the brain).
A Diffuse Axonal Injury (DAI) also falls into this category. This is where the neurotransmitters in the brain bend or break because of the brain moving around in the skull.
Effectively these are injuries which healthcare professionals can do nothing about as they have already happened.
Their job now is to prevent any further damage through what are called secondary injuries.
Swelling is a very common secondary injury which can have strong consequences if it is not dealt with.
If the brain begins to swell and this is not controlled, it can begin to push down on the spinal cord and interrupt it. This sometimes causes a loss of motor functions in brain injury patients.
Blood and other fluids can also leak into the gaps between the brain and the skull, forcing them to press against each other.
Clinicians can attempt to reduce this pressure through medication or by putting a small hole in the skull to drain these fluids.
Recovery from a head trauma
In the hours, days or weeks after a head trauma, the brain will attempt to return to some form of stability. The severity of the injury will dictate how long this takes.
Despite the fact the brain can help recover and repair damage all over the body, the loss of its own cells is usually permanent.
Brain cells do not duplicate or renew themselves, which is why limiting the loss of these cells after any injury is vital if a person is to have a positive outcome.
Some research has shown that certains cells return to an embryonic state where – under specific conditions – they are able to form new connections.
