A penetrating brain injury is one that is possible in car accidents and many other types of accidents. This type of injury involves something going through the skin and the skull into the area around the brain or the brain itself. These injuries are very dangerous and require immediate medical care.
A gunshot wound to the head is one type of penetrating brain injury. Another occurs when an object, such as a metal rod or stick, impales the head. A penetrating brain injury can even occur if the skin isn't broken. If something hits the head and a piece of the skull chips off and moves into the area of the brain, it would be considered a penetrating brain injury.
There are many different risks associated with penetrating brain injuries. The risk of brain damage is one that is notable. The penetrating brain injury can lead to a small area of brain damage or a larger area, depending on the location and type of penetration.
Another risk is that of infection. Foreign objects entering the skull carry germs and bacteria. This can be deadly if the infection isn't found quickly. Antibiotics through pills, intravenous fluids or shots might be necessary to help kill the infection.
Surgery might be necessary when you suffer a penetrating brain injury. This would likely lead to considerable time in the hospital while you recover.
If the penetrating brain injury was the result of an accident, you might choose to seek compensation for the injury. Negligence or recklessness on the part of another party would have to be a factor in the accident if you choose to exercise this option.
Source: Winchester Hospital, "Penetrating Brain Injury," accessed March 30, 2017