An epidural hematoma:

A. Is usually arterial in origin.

B. Is usually accompanied by a skull fracture

DISCUSSION: An epidural hematoma is a blood clot situated between the skull and the dura. Epidural hematomas are usually arterial in origin and most often are secondary to hemorrhage from the middle meningeal artery. Approximately 90% of adult patients with an epidural hematoma have a concomitant skull fracture. Such skull fractures are much less common in children under the age of 2 years. The epidural hematoma is best diagnosed before transtentorial herniation and the development of third cranial nerve palsy (“blown pupil”). The outcome of therapy is directly related to the patient's level of consciousness before surgery. The clinical diagnosis of an epidural hematoma is rarely confirmed by brain CT.