Trepanation (also known as trepanning, trephination, or trephining) is a very old form of medical intervention performed on the skull wherein a burr hole is made to expose the dura mater to treat or address intracranial diseases and similar health problems. The procedure is believed to release pressure from the head thereby relieving symptoms or pains felt in the head area. Those who perform and/or undergo this procedure also believe that it cures epileptic seizures. Trepanation uses an instrument called trephine that cuts out a round piece of the skull.
Human remains from the Neolithic period (and later) as well as cave paintings provide indications or evidences that trepanation existed even in prehistoric times and that many believed it was a valid solution for epileptic seizures, migraines, and mental disorders.
Though widely regarded as pseudoscience at present, trepanation is still practiced for purported medical benefits. The most prominent supporting explanation comes from Bart Huges. He claims that trepanation raises brain blood volume that leads to enhanced cerebral metabolism.