Most patients with more severe traumatic brain injury have of a combination of intracranial injuries, which can include diffuse axonal injury, cerebral contusions, and intracranial bleeding, including subarachnoid hemorrhage, subdural hematoma, epidural hematoma, and intraparenchymal hemorrhage. The recovery of brain function following a traumatic accident is highly variable and depends upon the specific intracranial injuries that occur, however there is significant correlation between the severity of the initial insult as well as the level of neurologic function during the initial assessment and the level of lasting neurologic deficits. Initial treatment may be targeted at reducing the intracranial pressure if there is concern for swelling or bleeding within this skull, which may require surgery such as a hemicraniectomy, in which part of the skull is removed.