Trepanation. 14th century artwork of a doctor using a hammer and scalpel to perform a surgical operation known as trepanation. This is a form of treatment in which a hole is drilled into the patient's skull. It was used to treat many conditions in the Middle Ages, including headaches, migraines, epilepsy and mental illness. Artwork from Anathomia (1345), by the Italian anatomist Guido da Vigevano.