In some of Peru's museums, such as at the Gold Museum in Lima, there is evidence of brain surgery having been practiced thousands of years ago with a variety of skulls bearings holes, some of which had been covered up with gold. This is called trephination, an operation to cut out a disk of bone. Healed bone around the operation shows that the patient survived the treatment. Some historians believe it was used by primitive peoples to release devils or cure headaches, but we felt the high degree of skill that was needed to perform this operation seems out of place with these superstitions.
Furthurmore it's interesting to note that this type of brain surgery is not even practiced in Peru's hospitals today.
