Traumatic brain injury describes any injury to the head that causes dysfunction. These injuries may or may not penetrate the skull and brain tissue and may or may not cause bleeding within the brain. Traumatic Brain Injuries range from mild to severe, and can sometimes be fatal. When the skull fractures, bleeding or hydrocephalus occurs, and neurosurgical treatment may be indicated. The goal of surgery is to relieve any pressure placed on the brain by fluid or blood. A patient's prognosis is related to the extent of the original injury. Patients usually require long term rehabilitation and can have lasting neurological deficits or even subtle changes in personality or behavior.