While watching a golf tournament, a 37-year-old man is struck on the side of the head by a golf ball. He is conscious and talkative after the injury, but several days later he is noted to be increasingly lethargic, somewhat confused, and unable to move his right side. (SELECT 1 DIAGNOSIS)

Subdural hematomas usually arise from tears in the veins bridging from the cerebral cortex to the dura or venous sinuses, often after only minor head injuries. They can become apparent several days after the initial injury. Treatment is with drainage of the hematoma through a burr hole; a formal craniotomy may be required if the fluid reaccumulates. Significant brain contusions due to blunt trauma are usually associated with at least transient loss of consciousness; similarly, epidural hematomas result in a period of unconsciousness, although a "lucid interval" may follow during which neurologic findings are minimal.Subarachnoid hemorrhage (SAH) in the absence of antecedent trauma most commonly arises from a ruptured intracranial aneurysm, which typically is found at the bifurcation of the major branches of the circle of Willis. Other less frequent causes include hypertensive hemorrhage, trauma, and bleeding from an arteriovenous malformation. Patients present with the sudden onset of an excruciating headache. Complaints of a stiff neck and photophobia are common. Loss of consciousness may be transient or evolve into frank coma. Cranial nerve palsies are seen as a consequence both of increased intracranial pressure due to hemorrhage and pressure of the aneurysm on adjacent cranial nerves. CT scans followed by cerebral arteriography help to confirm the diagnosis as well as to identify the location of the aneurysm. Treatment consists of surgical ligation of the aneurysm by placing a clip across its neck. Early surgical intervention (within 72 h of SAH) may prevent aneurysmal rebleeding and allow aggressive management of post hemorrhage vasospasm.