The Birth of Functional Neurosurgery

Located at 2,000 meters above sea level, in the southern Mexican state of Oaxaca, Monte Albán is relatively easy to find. Road signs indicate the way to the archaeological site. It takes about three hours of uphill walking from the Zócalo, the main square of Oaxaca (Zócalo is the common name for the main square in every city in Mexico). But, like any sensible traveler, I spared myself from the midday sun and decided to take a ride on a small local bus. In less than 40 minutes — during which I often felt I was risking my life in the traffic — I set foot on the very place where pre-Columbian neurological functional surgery had its center of excellence.

The trephined skulls of Monte Albán

The partially excavated civic-ceremonial center of Monte Albán sits atop an artificially leveled ridge. There are fewer tourists than I expected, especially after visiting the crowded site of Teotihuacán just a few weeks earlier. Founded around 500 BCE, Monte Albán reached a population of nearly 20,000 at its peak, making it one of the largest cities in Mesoamerica at the time.

The city was a political, military, and religious center. But what is most relevant to this story is a remarkable discovery made by modern archaeologists: the trephined skulls of Monte Albán.

"Trephined" refers to a surgical procedure where a hole is deliberately made in the skull. In ancient times, this was done using scraping, cutting, or drilling techniques, often to treat head injuries, relieve pressure, or for ritual purposes. Some researchers also suggest it may have been used to address functional diseases like epilepsy, chronic headaches, or mental disorders, as seen in modern neurosurgery.

From scalpels to high-precision brain surgery

Archaeologists have found more than 1,500 trephined skulls throughout the world, from Europe and Scandinavia to North America, and from Russia and China to South America. The oldest known trephined skulls date back to the Neolithic period (5000 BCE). By the Bronze Age, this practice had become widespread across the globe. Researchers still debate whether trepanation originated from a common ancestral practice or if it developed independently in different cultures.

What makes the trephined skulls of Monte Albán unique is the use of drilled trepanation, a rare technique in the ancient world. Unlike the more common scraping and cutting methods found in the Andes or Europe, Monte Albán skulls show evidence of circular perforations made with a tubular drill, possibly adapted from dental or jewellery-making techniques.

I imagine that in those ancient times, Monte Albán may have witnessed the rise of a pre-Columbian version of Professor Lars Leksell: the innovation of performing trepanation with a tubular drill was, in its era, comparable to what stereotactic radiosurgery represented thousands of years later in modern medicine. If you look at the precision of the drilled holes, it is actually impressive.

In fact, the skulls of Monte Albán suggest that Zapotec surgeons actively experimented with different surgical methods, making the city one of the few known centers of pre-Columbian neurosurgical innovation in Mesoamerica.

Ritual practice or therapeutic purpose?

But how do we actually know if trepanation was just a ritual practice, or if it had a therapeutic purpose — especially for functional neurological conditions?

As with all fascinating historical debates (fascinating for me, at least!), scientists have different opinions, and the discussion is far from settled. One particularly interesting take on the subject comes from a relatively recent review published in World Neurosurgery (Volume 122, February 2019, Pages 549-558) by Jesús Q. Beltrán & José D. Carrillo-Ruiz. The title itself is pretty cool:

"Neurological Functional Surgery in Mexico: From Pre-Columbian Cranial Surgery to Functional Neurosurgery in the 21st Century."

So, could ancient Mesoamerican surgeons really have been early pioneers of functional neurosurgery? Here are the key points that suggest Monte Albán was more than just a ritual site — it may have been a center of neurological innovation:

1. Evidence of healing: they didn’t just drill for fun

Many trephined skulls from Monte Albán show signs of healing, meaning that patients survived the procedure. This suggests that trepanation was not just a ritual sacrifice — it was likely intended to treat something. If people were surviving, it wasn’t just a reckless hole-in-the-head experiment.

2. Monte Albán: the ancient Brain Surgery Lab?

Monte Albán is one of the very few sites in the world where multiple trephination techniques were used — including the rare drilling method, which is almost unheard of in pre-modern neurosurgery. This suggests that Zapotec surgeons were experimenting with different surgical methods, much like early neurosurgeons refining their techniques in the 19th and 20th centuries.

3. Borrowing techniques from dentistry and jewellery making

One hypothesis is that the Zapotecs adapted their skull-drilling technique from their advanced dental work and jewelry-making methods. That’s a big deal because it shows they were thinking about precision and control — key factors in modern functional neurosurgery.

4. Understanding neurological disorders before they had a name

According to the papers reviewed in this study, mesoamerican cultures had a surprisingly advanced understanding of neurological conditions. They identified different types of seizures, recognized the link between head trauma and behavioural changes, and even had words for specific neurological disorders. This suggests they may have performed trephination to relieve epilepsy, migraines, or mental illnesses — just as functional neurosurgery does today.

5. Monte Albán as a precursor to modern neurosurgery

If trephination was just a ritual or a symbolic act, why do we see evidence of different techniques and survival rates? The fact that they were experimenting with methods and improving them over time suggests that they were engaged in a serious attempt to treat brain-related conditions—something that echoes early modern neurosurgery centuries later.

Read more

• Neurological Functional Surgery in Mexico: From Pre-Columbian Cranial Surgery to Functional Neurosurgery in the 21st Century - ScienceDirect
• Neolithic trepanation decoded- A unifying hypothesis: Has the mystery as to why primitive surgeons performed cranial surgery been solved? Surgical Neurology International
• Tomb 7, Monte Alban | Dr. Geoffrey McCafferty

About me

I’m passionate about radiation and radiation safety, and I lead these efforts at a top MedTech company. My experience includes working with the European Commission and international physics laboratories, where I developed my expertise in nuclear physics (without causing any explosions!). With a PhD in applied nuclear physics, I’ve published research in peer-reviewed journals and enjoy crafting content that makes complex topics in science, safety, and security accessible and engaging—because everyone loves a good science story!

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