trepanation for no particular reason

From Mo blogs at http://scienceblogs.com/neurophilosophy/2008/01/an_illustrated_history_of_trep.php
Trepanation, or trephination (both derived from the Greek word trypanon, meaning "to bore") is perhaps the oldest form of neurosurgery. The procedure, which is called a craniotomy in medical terminology, involves the removal of a piece of bone from the skull, and it has been performed since prehistoric times. The oldest trepanned skull, found at a neolithic burial site of Ensisheim in France, is more than 7,000 years old, and trepanation was practised by the Ancient Egyptians, Chinese, Indians, Romans, Greeks and the early Mesoamerican civilizations. The procedure is still performed today, for both medical and non-medical reasons.
And Hippocrates take on it:
...the contusion, whether the bone be laid bare or not; and the fissure, whether apparent or not. And if, when an indentation by a weapon takes place in a bone it be attended with fracture and contusion, and even if contusion alone, without fracture, be combined with the indentation, it requires trepanning...those [bones] which are most pressed and broken require trepanning the least
and a picture from Mo;