Occurs when the head accelerates and then rapidly decelerates or collides with another object (e.g. wall, or dashboard of a car) and brain tissue is damage, but there is no opening to the skull or dura.
OPEN BRAIN INJURY
Occurs when an object penetrates the skull, enters the brain and damages the soft brain tissue in its path (penetrating injury).
Cerebral contusion , latin contusio cerebri , a form of traumatic brain injury , is a bruise of the brain tissue. Like bruises in other tissues , cerebral contusion can be caused by multiple microhemorrhages , small blood vessel leaks into brain tissue. Head CT scans of unconscious patients reveal that 20% have hemorrhagic contusion.
Contusions, which are frequently associated with [[edema]], are especially likely to cause increases in [[intracranial pressure]] (ICP) and concomitant crushing of delicate brain tissue. Contusions are also more likely to result in hemorrhage than is [[diffuse axonal injury]] because they occur more often in the cortex, an area with more [[blood vessel]]s.
Contusions typically form in a wedge-shape with the widest part in the outermost part of the brain.
Epidural Hematoma: a blood clot that forms between the skull and the top lining of the brain (dura). This blood clot can cause fast changes in the pressure inside the brain. Emergency surgery may be needed. The size of the clot will determine if surgery is needed.
Subdural Hematoma: a blood clot that forms between the dura and the brain tissue. If this bleeding occurs quickly it is called an acute subdural hematoma. If it occurs slowly over several weeks, it is called a chronic subdural hematoma. The clot may cause increased pressure and may need to be removed surgically .