Ancient cranial surgery in Peru investigated
|Some 900 years ago, a Peruvian healer used a hand drill to make dozens|
of small holes in a patient's skull [Credit: Danielle Kurin]
Excavating burial caves in the south-central Andean province of Andahuaylas in Peru, UC Santa Barbara bioarchaeologist Danielle Kurin and her research team unearthed the remains of 32 individuals that date back to the Late Intermediate Period (ca. AD 1000-1250). Among them, 45 separate trepanation procedures were in evidence. Kurin's findings appear in the current issue of the American Journal of Physical Anthropology.
"When you get a knock on the head that causes your brain to swell dangerously, or you have some kind of neurological, spiritual or psychosomatic illness, drilling a hole in the head becomes a reasonable thing to do," said Kurin, a visiting assistant professor in the Department of Anthropology at UCSB and a specialist in forensic anthropology.
|New bone growth at the trepanation site on the side of the head indicates a successful procedure.|
However, the holes drilled at the top of the skull were as the individual was
dying or shortly after he died [Credit: Danielle Kurin]
But Kurin wanted to know how trepanation came to exist in the first place. And she looked to a failed empire to find some answers.
"For about 400 years, from 600 to 1000 AD, the area where I work -- the Andahuaylas -- was living as a prosperous province within an enigmatic empire known as the Wari," she said. "For reasons still unknown, the empire suddenly collapsed." And the collapse of civilization, she noted, brings a lot of problems.
|A cutting method was employed for this incomplete trepanation. The patient died|
before the bone plug could be removed successfully [Credit: Danielle Kurin]
Kurin's research shows various cutting practices and techniques being employed by practitioners around the same time. Some used scraping, others used cutting and still others made use of a hand drill. "It looks like they were trying different techniques, the same way we might try new medical procedures today," she said. "They're experimenting with different ways of cutting into the skull."
Sometimes they were successful and the patient recovered, and sometimes things didn't go so well. "We can tell a trepanation is healed because we see these finger-like projections of bone that are growing," Kurin explained. "We have several cases where someone suffered a head fracture and were treated with the surgery; in many cases, both the original wound and the trepanation healed." It could take several years for the bone to regrow, and in a subset of those, a trepanation hole in the patient's head might remain for the rest of his life, thereby conferring upon him a new "survivor" identity.
|Several trepanation holes were drilled over an area of mottled, inflamed bone.|
The surgery may have been done to alleviate the pain caused
by serious infection [Credit: Danielle Kurin]
"As bioarchaeologists, we can tell that they're experimenting on recently dead bodies because we can measure the location and depths of the holes they're drilling," she continued. "In one example, each hole is drilled a little deeper than the last. So you can imagine a guy in his prehistoric Peruvian medical school practicing with his hand drill to know how many times he needs to turn it to nimbly and accurately penetrate the thickness of a skull."
Some might consider drilling a hole in someone's head a form of torture, but Kurin doesn't perceive it as such. "We can see where the trepanations are. We can see that they're shaving the hair. We see the black smudge of an herbal remedy they put over the wound," she noted. "To me, those are signs that the intention was to save the life of the sick or injured individual."
|Ancient practitioners used various tools to create trepanations of|
distinct sizes and shapes [Credit: Danielle Kurin]
But thanks to Kurin's careful archaeological excavation of intact tombs and methodical analysis of the human skeletons and mummies buried therein, she knows exactly where, when and how the remains she found were buried, as well as who and what was buried with them. She used radiocarbon dating and insect casings to determine how long the bodies were left out before they skeletonized or were mummified, and multi-isotopic testing to reconstruct what they ate and where they were born. "That gives us a lot more information," she said.
"These ancient people can't speak to us directly, but they do give us information that allows us to reconstruct some aspect of their lives and their deaths and even what happened after they died," she continued. "Importantly, we shouldn't look at a state of collapse as the beginning of a 'dark age,' but rather view it as an era that breeds resilience and foments stunning innovation within the population."
Author: Andrea Estrada | Source: University of California - Santa Barbara [December 19, 2013]