Unlike other parts of the human body, the brain never truly heals from an injury. This does not mean that a patient can never recover from any type of brain injury. For all but the most severe brain injuries, a patient will regain some level of consciousness and may approach a point of stability. If the patient is lucky, he may even be able to resume normal life.
However, unlike muscles and bones, the brain never re-develops the nerve cells that were damaged in connection with the victim's head trauma. As a result, those areas of the brain that suffered damage may never again be able to perform as expected.
It should be noted in this respect that the damage caused to the brain after a trauma event can be quite extensive, and not just localized to the area of the brain that took the brunt of a blow. For example, with a sudden force to the head, some of a person's network of nerve cells can get seriously stretched or damaged, making it impossible for the body to send electrical impulses from one part of the body to the other. While hard to see this type of damage, it can still affect a variety of a person's abilities since communication gets effectively cut off from one part of the brain to the rest of the body.
Another problem associated with a brain injury is that, after significant damage, chemicals that are ordinarily within the confines of one's brain cells tend to leak. Outside of their individual cells, these chemicals can be toxic to the tissues nearby.
On a practical level, the victim of a brain injury may learn to cope, but he or she will never truly heal from her injury. Recovery from any brain injury takes time and expense. If another person's negligence caused the injury, then the victim may be able to recover compensation for her loss which can help alleviate the financial burden associated with this type of injury. It may also help an individual achieve a sense of justice and closure