Traumatic brain injury (TBI) – A traumatic brain injury is any damage to the brain or the brain’s ability to function correctly that’s the result of an external force. Traumatic brain injuries can be closed, meaning nothing breaks through the skull to damage brain tissues, or open, meaning the skull is fractured, and the brain is exposed.
Concussion – A concussion is a bruise on the brain that occurs when the brain crashes into the skull due to a sudden change in momentum. They’re common in motor vehicle accidents as well as sports.
Stroke - Strokes occur when there’s a disruption in the brain’s blood supply. Strokes usually result from a clot that cuts off flow to the brain or by leaking blood into the brain as the result of a burst blood vessel.
Aneurysm - If the wall of an artery or blood vessel in the brain weakens, it may swell and form a blister-like bulge called an aneurysm. If an aneurysm continues to grow, it can pressure surrounding tissue, leading to a range of harmful side effects. Strokes can also occur if the aneurysm breaks.
Hemorrhage/hematoma - A hematoma or hemorrhage injury is the medical term for when blood vessels break inside the brain, leading to blood accumulating in brain tissue or within the brain’s empty spaces. Blood clots in the brain usually cause hematomas. A hard blow to the head most often causes hemorrhages.
Edema - An edema injury occurs when something causes brain tissues to swell, putting pressure on the brain as its presses against the inside of the skull. If the injury is not treated correctly, this intense pressure can cause damage to brain tissues and other harmful effects.
Skull fracture- Skull fractures, in which part of the skull breaks or cracks, are caused by hard blows to the head. Depending on the strength of the impact and where exactly it occurs, the skull may break outright and fragment, or it may simply crack. If the skull fragments, pieces of bone can penetrate the brain and cause extensive damage to tissues and blood vessels. Even if the skull merely fractures, it can put pressure on the brain, leading to further harmful effects. A fracture to the skull at the base of the brain, known as a basilar skull fracture, can cause cerebral spinal fluid to leak from the brain.
Penetration injuries - Penetration injuries happen when some external object becomes lodged in the brain after breaking through the skull, such as a bullet. This can cause severe damage to brain tissue and impact the flow of blood to the brain.
Shear injuries - These injuries occur when the brain is shaken or experiences a sharp, severe rotation (such as the head twisting suddenly after the impact from a car accident). They’re also known as diffuse axonal injuries.
Coup-contrecoup injuries - This is the term for injuries that occur when the brain is shifted from side to side within the skull after a hard impact. The multiple impacts with the inside of the head can severely damage blood vessels and brain tissue.