- "A simple evacuation of the expanding epidural hematoma will relieve the pressure!"
An epidural hematoma was a type of brain injury that could occur in Humans, in particular after massive head trauma such as that associated with a steep or long fall. It is somewhat similar to a subdural hematoma. (VOY: "Gravity")
An expanding epidural hematoma, a hematoma bleeding directly on the brain, was a very serious medical condition which could result in death. In the 20th century, the treatment for an expanding epidural hematoma was to drill a hole through the skull, thus allowing the blood to drain and relieve pressure on the brain.
By the 23rd century, doctors knew that "drilling holes in people's heads wasn't the answer" and the treatment for an epidural hematoma was to repair the middle meningeal artery, usually with the use of a small device fitted over the patient's forehead. (Star Trek IV: The Voyage Home)