Trephining

Trephining, also known as trepanning, is an ancient medical practice that involves cutting a hole in the skull of a person. Known from archaeological digs, the how and why of this type of operation is not totally understood but is believed to have been used as a means of releasing the "evil spirits" that ancient people believed were responsible for mental and physical illness. This practice was apparently performed by highly skilled individuals because a great many examples of this procedure show definite signs of healing. Modern surgeons also use this type of procedure to deal with head injuries to release pressure on the brain as a result of hematomas of the brain or other conditions that result in brain swelling.