Buzz
In the 1860s, a U.S. newspaper editor, author, and amateur archaeologist, E.G. Squier, journeyed to Cuzco, Peru. He visited a wealthy woman's home, known for her collection of antiquities, where he examined an ancient skull discovered in an Inca cemetery in the Yuca Valley. The skull, dating back to pre-Columbian times, had a large rectangular hole at its crown.
Squier, a well-rounded intellectual with deep knowledge of Latin American culture, was instantly captivated by the skull. He brought it to New York in 1865 and shared it with the members of the New York Academy of Medicine.
Squier was convinced that the skull provided clear proof that ancient Peruvians practiced brain surgery. The edges of the hole, marked by cross-hatching, were created by a human hand. Squier speculated that a burin, a tool used by engravers for wood and metal, had likely been used. Even more astonishing was his observation that the skull exhibited signs of healing, suggesting the person survived the operation for at least one to two weeks before their death.
Members of the medical field were doubtful that the incisions had been made while the person was still alive. To resolve the issue, Squier consulted the esteemed French surgeon and anthropologist, Paul Broca, who examined the skull and concluded that Indigenous cultures had been practicing 'advanced surgery' long before the arrival of Europeans.
It was an unexpectedly intricate form of Stone Age surgery.
Trepanation involves drilling or scraping a hole into the skull’s cranial vault to access brain tissue and treat injuries. First referenced in the Hippocratic Corpus, it ranks among the world’s oldest known surgeries (the term 'trepanation' is derived from the Greek word meaning 'auger' or 'borer'). Today, the medical community refers to it as a craniotomy.
Trepanation has been practiced across the globe throughout history. Ancient Greeks and Romans performed it, and it is still reported to be used in regions of Africa, South America, and the South Pacific. In ancient Greece, it was performed to relieve pressure, remove skull fragments following trauma, and drain fluid. From the Renaissance through the early 19th century, it was commonly used to treat head injuries, and into the 18th century, it was also employed to treat epilepsy and mental disorders.
During the era of Squier and Broca, Western physicians found it hard to believe that non-European cultures had attempted such procedures. Given the dismal survival rates of surgeries in the 19th century, primarily due to hospital-acquired infections, they were skeptical that ancient patients could have survived long after undergoing the operation.
Once Broca confirmed Squier’s discovery, researchers began uncovering trepanned skulls from various parts of the world, tracing back to the Neolithic period. Skull openings were found in Western Europe and the Americas. Over time, it became evident that numerous cultures had practiced trepanation, with evidence dating back at least 10,000 years to the late Paleolithic era.
Physicians developed specialized tools and methods for performing trepanation.
Surgical approaches to trepanation varied across cultures. Early Peruvian trepanations were carried out using a ceremonial knife called a tumi, which was employed to scrape or cut through the bone. The Hippocratic school introduced the trephine drill, which created holes in the skull. In the South Pacific, sharpened seashells were used for bone cutting, while in Europe, flint and obsidian served the purpose. By the Renaissance, surgeons regularly used specially designed instruments for performing trepanations.
Trepanation was carried out on both the young and the old, as well as males and females. Research by cognitive neuroscientist Charles Gross estimates survival rates ranging from 50 to 90 percent, with some prehistoric patients living for years following the surgery. However, in many instances, the medical condition that led to the procedure remains unclear.
John Verano, an anthropologist at Tulane University who specializes in trepanation studies in Peru, told Mytour in 2016 that he firmly believes that 'in Peru, the South Pacific, and many other parts of the world, trepanation began as a very practical treatment for head injuries. Say somebody has a head wound that’s torn up their skull. You’d clean it out, remove broken fragments, and let the brain swell a little bit, which it naturally does after injuries.'
In some cases, trepanned skulls clearly exhibit signs of trauma, suggesting there was a specific reason for the surgery. However, archaeologists have also discovered skulls with no visible fractures. For example, Squier’s famous skull showed no evidence of a head injury. Additionally, skulls with multiple holes have been found, indicating that patients may have undergone and survived multiple surgeries.
According to modern eyewitness reports from Africa and the South Pacific, trepanation is still used today to treat head injuries, headaches, or intracranial pressure, Verano noted. In other parts of the world, it is believed that trepanation may have once been used to expel evil spirits or treat mental disorders like epilepsy. Without written records, however, the exact reasons for these procedures remain unknown.
It is likely that trepanation was performed without the use of anesthesia.
Patients may have been unconscious during the procedure if they had a head injury, Verano explained. Otherwise, they likely remained awake. 'The scalp has many nerves, so cutting it would be painful,' he noted. 'It bleeds a lot, but then it stops. The skull has few nerves, and the brain itself lacks any nerves.' Additionally, ancient surgeons would not have cut through the dura mater, the protective outer membrane of the brain. If they had, patients would have developed meningitis and died.
In today’s medical practice, trepanation is no longer seen as a standalone treatment. Surgeons perform craniotomies to remove necrotic or infected tissue, relieve pressure within the skull, or conduct exploratory surgeries. It’s remarkable to think that this procedure has persisted for millennia—and that prehistoric humans understood the brain's critical role in controlling the body.
Further Reading: A Hole in the Head; Trepanation: History, Discovery, Theory
