The historic view is that once brain cells are damaged or killed, they do not regenerate. Yet, research over the last 20 years is showing substantial evidence of cell regeneration, particularly in those under 40 year of age. Even without regeneration, the recovery process continues as a result of brain plasticity. With this being said the question of “will brain heal itself” is debatable.
Plasticity describes the process where other parts of the brain compensate for damaged or destroyed brain matter. Thru plasticity, the brain forms new synaptic connections to reroute information around the damaged areas. What this means is if a certain set of cells are there to do one action, and those cells are damaged, other sets of cells may have to take over that action which is part of will brain heal itself.
While the more extensive the damage to the brain, the less likelihood of a full recovery, remaining brain tissue can assume many of the functions of the damaged areas. Regardless of the actual organic recovery, the patient must learn how to compensate for the damage through adaptations to the environment or in his/her own way of doing things. Basically, the brain will have to teach undamaged parts to take over and relearn how to do things such as walking, talking, etc. In many of our case studies you will hear about traumatic brain injury survivors having to relearn to walk. Some may have to relearn how to drive. This may be because the parts (cells) of the brain that told the nervous system how to do these things were damaged and other parts had to take over.(tbilaw.com)