An epidural hemorrhage (EDH) is an accumulation of blood between the skull and the dura mater, the membrane that surrounds the brain. Also called a hematoma, it is a common consequence of head injuries. If left untreated, blood may fill the intracranial space and cause life-threatening swelling. Treatment relieves the pressure on the brain, using neurosurgical decompression to drain fluid from under the skull. There is another type of epidural hemorrhage that occurs in the spinal column, when injured veins bleed out into the surrounding space and increase fluid pressure between the bone and spinal cord.
Epidural hemorrhage is usually caused by traumatic brain injury, commonly concussion on the side of the head. This leads to arterial bleeding into the epidural space. Hemorrhage in the tissue around the brain will result in hematoma if blood continues to pool outside the arteries. If sufficient volume of blood pools, the expansion can pressure the brain, seriously affecting consciousness, motor skills, and basic neural responses regulating breathing and pupillary response. It can prove fatal in a matter of hours.
Depending on the scale of the head trauma and the extent of bleeding, some patients with epidural hemorrhage remain fully alert, while others either briefly lose consciousness or lapse immediately into a coma. Many patients, after recovering from the initial shock, experience what is called a lucid interval where they are alert and function normally for one or a few hours. During this time, the area of the EDH will keep growing until the pressure on the brain increases to the point that the patient becomes unconscious. At this point, surgery is needed to prevent rapid deterioration.
Treatment of epidural hemorrhage requires immediate surgical decompression to relieve the pressure. Surgery involves opening the skull and draining the accumulated blood. For small to medium sized hematomas, a small hole is bored, but for major hemorrhages, surgeons perform a craniotomy to evacuate fluid and to control for clots. Epidural hemorrhages can trigger seizures, so anticonvulsant medications may be prescribed along with drugs to contain the risk of neurological infection.
Epidural hemorrhage can also occur in the spinal column. There, bleeding into the epidural space is more likely to come from damaged veins than arteries. Pressure on the spinal cord at any level is painful, and can cause bladder and intestinal problems and paralysis below the point of bleeding. An MRI is used to establish a diagnosis of epidural hemorrhage because there are many possible causes of spinal pain. Spinal epidural hematoma is usually treated with surgical decompression through drainage in a procedure that resembles a spinal tap.