An 19-year-old man is admitted to the emergency room following a motorcycle accident. He is ale and fully oriented, but witnesses to the accident repo an interval of unresponsiveness following the injury. Skull films show a fracture of the left temporal bone. Following x-ray, the patient suddenly loses consciousness and dilation of the left pupil is noted. This patient should be considered to have?: (A) Ruptured berry aneurysm, (B) Epidural hematoma, (C) Acute subdural hematoma, (D) Intra Abdominal hemorrhage
Answer is B. Epidural hematomas are typically caused by a tear of the middle meningeal aery or vein or a dural venous sinus. Ninety percent of epidural hematomas are associated with linear skull fractures, usually in the temporal region. The lesion appears as a hyperdense biconvex mass between the skull and brain on CT scan. The typical history is one of head trauma followed by a momentary alteration in consciousness and then a lucid interval lasting for up to a few hours. This is followed by a loss of consciousness, dilation of the pupil on the side of the epidural hematoma, and then compromise of the brainstem and death.