epidural hematoma
May be intracranial (in the skull) or in the spine.
  1. In this type of hematoma, a blood vessel outside the brain bursts. Blood begins to rapidly accumulate between the inside of the skull and the strong outer covering of the brain (called dura mater). The pressure of the blood clot strips the dura mater away from its normal firm attachment to the inside of the skull. The blood clot then can press on the brain, causing injury, and if not diagnosed and treated promptly, may be fatal.
  2. In spinal epidural hematoma, the blood fills the space between the spinal column and the outer lining of the spinal cord. It may be a result of trauma, bleeding disorders, or may occur spontaneously.