Drilling a hole in the skull of a living person is a serious tactic that is only used out of medical necessity. At least, that's case today. While surgery can be dangerous, it was much more dangerous in the 19th century, when archaeologist Ephraim George Squier was presented an ancient skull in Peru. It showed not only a hole deliberately cut into it, but evidence that the previous owner had survived the surgery! For some time, that prehistoric case was considered unique.
When the skull was presented to a meeting of the New York Academy of Medicine, the audience refused to believe that anyone could have survived a trephining operation carried out by a Peruvian Indian. Aside from the racism characteristic of the time, the skepticism was fueled by the fact that in the very best hospitals of the day, the survival rate from trephining (and many other operations) rarely reached 10 percent, and thus the operation was viewed as one of the most perilous surgical procedures. The main reason for the low survival rate was the deadly infections then rampant in hospitals. Another was that the operation was only attempted in very severe cases of head injury.
While modern medicine has improved since then, archaeologists have found plenty of evidence that trepanation has been practiced in all parts of the world going back at least to the Paleolithic era, with surprising survival rates. Literature on the practice goes back to the fifth century BC. The prevalence and longevity of the technique suggests it must have worked, at least some of the time, for some ailments. Read an overview of what we know about the history of trepanation at the MIT Press Reader. -via Digg