Hippocrates, Galen, and the uses of trepanation in the ancient classical world.

Trepanation is the process by which a hole is drilled into the skull, exposing the intracranial contents for either medical or mystical purposes. It represents one of the oldest surgical procedures, and its practice was widespread in many ancient cultures and several parts of the world. Trepanation was used in ancient Greece and Rome, as described in several ancient texts. Hippocrates and Galen are two of the most prominent ancient Greek medical writers, and their works have influenced the evolution of medicine and neurosurgery across the centuries. The purpose of this paper is to examine Hippocrates' and Galen's written accounts of the technique and use of trepanation in the ancient Greek and Roman world. Examination of those records reveals the ancient knowledge of neurological anatomy, physiology, and therapeutics, and illustrates the state and evolution of neurosurgery in the classical world.