T is for Trepanation

I’m fixing a hole where the rain gets in
And stops my mind from wandering
Where it will go
I’m filling the cracks that ran through the door
And kept my mind from wandering
Where it will go

“Fixing a Hole,” McCartney/Lennon.

Archaeology was a pretty new discipline in the 18th and 19th century, so perhaps we can forgive the excavators who kept finding skulls with holes and tossing them aside. Oh, there’s another that’s been bashed in the head, poor bugger. Communication was a lot slower in, say, 1820, so they didn’t all talk to each other. They didn’t have a chat room where they could all post examples of what they’d found, to suddenly realize that Geez!, there were hundreds of these, and all over the world: Russia, China, Germany, France–especially France–Egypt, Greece, Peru–most especially Peru!

The key advance, if you will, came in 1867 in the Andes, when an artifact collector in South America named George Squiers wrote to an eminent French brain expert named Paul Broca. The rest is trepanation history. Because it turns out that 10,000 years ago, brain surgery was practiced, and it was practiced nearly everywhere.

In looking into the ancient invention of trepanation, let’s consider three questions:

1. Why would anybody drill holes in their head?
2. Where and when did cultures drill holes in their head in ancient history?
3. What does the incidence of ancient trepanation suggest about medical history?

How to Get It Through that Thick Head of Ours

Trepanation, also called trephinning, means drilling a hole in the skull. The word is from the Greek, referring to the boring tool, trȳ́panon. The synonymous word, trephinning, which is done using a trephine, has a completely different origin. It comes from the French trephine, after the Latin a tribus finibus, of three ends, because the tool’s handle has two ends. Hippocrates described the process, @450 BCE, and the Greeks had such a tool.

In 8000 BCE, they didn’t have metal. They had flint and obsidian knives. But remember that arrows were invented around 71,000–it was handy to start this alphabet with a very old invention–so with 60,000 years of practice, early modern humans had honed their knives, arrow points, and axes to a scalpel’s edge.

Moreover, some surgeons had also figured out the drilling principle. Surgery was not the first practical use of the drill, which dates back thousands of years earlier, to 35,000 BCE. After all, fire control was nearly a million years old, and starting fires was accomplished in part with a circular “drilling motion.” Even Neanderthals could twist sharp objects into a hole. The breakthrough, so to speak, was creating the right kind of instrument to be able to penetrate bone just enough, but not to much.

Here, from a 4000 BCE excavation site in Catalonia, is a Neolithic trepanning instrument, looking remarkably like what Hippocrates used in Greece 3500 years later and what John Woodall, a naval surgeon, used around 1620. The difference between these is that in many of the Mesolithic and Neolithic (8000-4000 BCE) sites, the survival rate from trepanation ranged from 40-80% of patients, whereas around in the 1800s, only around 10% survived.

Seriously? Holes in the Head? On Purpose?

The process of trepanning is straightforward, so much so that it is still practiced today, in medicine, in religious ,and as part of the practice of “psychosurgery.” Amanda Feilding, who heads a group that investigates the boundaries of consciousness, trepanned herself and described the process in a 2013 interview.

I was obviously very cautious and prepared myself very carefully. I used an
electrical drill with a flat bottom and a foot pedal, and tested the drill head on the membranes of my hand to see if it would damage the skin….After I’d performed the procedure, I wrapped up my head with a scarf, had a steak to replace iron from the lost blood, and went to a party. It doesn’t set you back at all, it doesn’t incapacitate you. It’s just a half-hour operation.

From Vice magazine, “An Interview With a Woman Who Drilled Holes in Her Head…” 2013.

This kind of “fad” for trepanning that emerged in recent decades could probably be grouped with LSD, sensory deprivation, and other techniques people try in order to connect with a different type of consciousness. (I’m trying to adopt a neutral tone, although, as I type, I just keep muttering this is nuts, these people are nuts. In case you found yourself muttering that, you’re not alone.)

Feilding herself said that she felt a lightening, a reduction of anxiety, and an improvement in her dreams. Frankly, we don’t know how everything in the brain works, so I’m perfectly willing to admit that someone who drilled a hole in their head in 2025 might feel a lightening of mood or a change in their dreams. I’m just thinking that oops the drill slipped, darn it, now I can’t remember any words that begin with T.

The modern term for this process is craniotomy, and it has non-higher-consciousness uses. In particular, trepanning is used to reduce pressure on the brain from subdural hematomas, These are cases where people get hit on the head, sometimes with a concussion and sometimes not, and a swelling occurs that risks creating a blockage. Various “intercranial pressures” that could occur which might be relieved by this procedure.

Without delving much farther into anatomy–because, as you know, I was not a pre-med student–your scalp covers your skull, which holds your brain inside. The brain sloshes around in a little bit of liquid and matter between it and the skull. That’s where swelling can occur if you’re in a car accident or bang your head for other reasons. But also, because there’s some room there, drilling through the skull might not actually poke into your brain. If a surgeon–even a Neolithic surgeon–had enough practice, they might get quite good at it. Apparently, several did.

Why Ancient People Might Have Needed Holes in their Head

The earliest skulls with holes found were by French archaeologists, @1685, but it was thought at the time that the holes were made either accidentally (I fell down) or on purpose, but not with good intentions (I bash you on the head). What surprised the researchers was when they stopped to look a little more closely and noticed that the holes were not irregular. They were square… like they’d been cut that way on purpose (a-ha!)… or pretty round. In fact, the French archaeologists also found round disks of various sizes (not just from trepanning) and called those rondelles. Sometimes those bone rondelles were part of necklaces, so they didn’t really think about them coming from the holes in people’s heads.

We don’t have any medical journals written by Neolithic surgeons, but we can make intelligent guesses about why they might have drilled holes in heads. First, the main thought is that these were a part of religious ritual. When archaeologists–and these were bioarchaeologists, specialists in human skeletal remains–figured out these holes were made on purpose with drills not clubs, they thought that perhaps the goals was to remove demons or evil spirits. Our modern understanding of mental illness suggests that trepanning could reduce the suffering of someone with acute anxiety or other mental illnesses. We don’t call it demons any more, but relief is relief.

Secondly, and this is not mentioned much in the research but seems obvious to me, some of the holes were drilled postmortem, i.e. on deceased people, so that doctors could learn anatomy. Autopsies are performed today for that purpose. I would hope that a doctor trying to figure out exactly how to drill would practice on a non-live person first. I think it’s likely these did.

Lastly, trepanation was practiced for the same reasons as craniotomies today. It relieved swelling and pressure from hematomas–bash on head. Since the prototypical cartoon of a caveman shows him with a club, rather than an axe, bow, or knife, you can easily imagine that people got clubbed on the head a lot.

Hippocrates clarified it further:

…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.

Hippocrates @450 BCE, On the Injuries of the Head.

That is, trepanning would work best when there was pressure that needed to be relieved. If the skull was already broken, then there was less pressure. Getting the skull to heal was a different problem. One analysis points out that although trepanning was practiced on woman and occasionally children, the majority of patients were men. It’s thought that hunters, more often men in this society, were more likely to risk falling down or getting hit on the head, whether they were fighting off mastodons, tigers, or rival tribes.

Where They Did and Where They Didn’t

Neolithic humans did, all over Europe, Russia, Scandinavia, and the Americas. One report suggests that some 5-10% of skulls show some evidence of drilled holes. Whether it was for evil spirits, epilepsy, head wounds, anxiety, ear aches, or some other reason, the incidence of trepanning five to thousand years ago was widespread, although not universal. More than 1500 skulls have been discovered with trepanned holes.

The Mayans didn’t. The Incas did. The Egyptians didn’t. The Mesopotamians did.

The Mesopotamians had two medical practitioners, the ashipu (sorcerer) and the asu (physician). The ashipu’s job was to get rid of demons or solve demon-caused illnesses, while the asu treated the patient for physical ailments. A depiction of a surgical knife naglabu could be created by combining the pictures of barber with knife, perhaps the first example where barbers and surgeons were thought of together.

The Egyptians did not practice trepanation much. It’s thought this may be because they believed the heart was the site of both reason and emotion and that medical practices needed to be aimed at the heart.

The Peruvians did it so often that archaeologists couldn’t help but notice. In 1867, after conferring with other South American researchers, George Squiers wrote to the most well-respected brain scientist in the world, Frenchman Paul Broca. Broca was particularly famous because he had discovered that a particular part of the frontal lobe was the source of language. This is why that region is now called Broca’s area.

Broca examined the skull that Squiers had sent and definitively concluded that it had been done for surgical purposes, and that the patient had recovered. There were salons of naturalists, archaeologists, and scientists who met and discussed their ideas in 19th century France, but they had previously concluded that skulls found in that condition were assumed to be from people who died from head wounds. After that point, hundreds of skulls were found and examined. In some places, such as Peru, the recovery rate was very high; some 70-80% of skulls showed that the patient had lived afterward, sometimes for quite a long time.

It was also long believed that the ancient Chinese did not practice trepanation because they tended to use traditional medical treatments–herbal remedies, acupuncture, and so forth–to successfully treat patients rather than cutting them open. However, more recent research has discovered at least a half dozen examples from the Chinese Neolithic Age, where trepanation was accomplished to help a patient. One theory is that the practice might have been banished at the onset of the Confucian Age because other types of surgeries were considered too intrusive. Chinese bioarchaeology is a young practice, so perhaps time will tell if more evidence is found of a wider practice.

What is certainly true is that physicians 10,000 years ago, all around the world, had discovered a cure for head wounds, even though it must have been difficult to do. Without being able to share knowledge with each other, one medicine man or healing woman after another figured out how to drill a hole in their patient’s heads.

Knowledge about this practice has intrigued people ever since. I’ve known that song that I quoted above, from Sergeant Pepper’s, since I was a kid. Apparently, it was not a coincidence. John actually asked Paul if he thought they might try a little trepanning. Because if you’re trying LSD (Lucy in the Sky with Diamonds), maybe you should try everything. Paul’s response:

Yeah, but this is the good thing about John and I – I’d say no. And he knew me well enough that if I said no, I meant no and I’m not frightened of being uncool to say no. And I wouldn’t go so far as to say, ‘You’re fucking crazy,’ because I didn’t need to say that. But, no, I’m not gonna trepan, thank you very much. It’s just not something I would like to do.

McCartney interviewed in GQ, describing a 1969 conversation with Lennon.