If you read the medical news lately you may have seen a headline title Skeleton May Show Ancient Brain Surgery. This article was about an 1800 year old skeleton found in Veria, Greece. The skeleton was of a woman of about 25 years of age that suffered severe head trauma and underwent cranial surgery, unfortunately evidence shows that she did not survive.

There is an interesting history of skull surgery, known as trepanation, which comes from the Greek word trypanon, meaning auger or borer. Cranial trepanation has caught the interest of surgeons and archeologist since the 1860's, when it was first realized that ancient humans had scraped or cut holes in the skulls of living persons in France and Peru.

Trepanation is serious enough surgical procedure in this day and age, could this procedure have taken place as a routine operation as long ago as 2000 BC? We do have a historical record of thousands of skulls with evidence of this surgery. Sometimes historical records suggest a reality that we find hard to accept.

Maybe the romantic in us wants to believe that our ancestors could accomplish this but logic tells us that they didn’t have the technology or medical understanding to perform this surgery. They must have done it on dying or dead patients, that would be the logical answer. Unfortunately historical evidence exists that proves beyond any doubt that patients not only were alive when they had cranial surgery but survived in most cases, and many endured several of these operations over a lifetime.

In studies of healing patterns after primitive trepanations some assumptions can be made:

If there is no sign of biological activity around the surgical site, then death was almost immediate.

If there is a discrete ring of superficial osteoporosis around the wound then it is likely that the patient has lived 1 to 4 weeks postoperatively.

When the edge of the wound reaches an equilibrium and calcium is deposited where new bone forms radial striations, and eventually the edge consolidates the patient has survived several months postoperatively. (Marino p946)
Credit: www.musees-haute-normandie.fr

Why would primitive cultures of France, nearly 4000 years ago, practice trepanation? The suggested reasons for this surgery are numerous but not substantiated. Researchers over the last century and a half have speculated that cranial surgery was done in cases of trauma from battle or accident, cranial infections, headaches, mental disease, and religious rituals. (Marino p944) Rituals involving the opening of the skull were believed to facilitate the exit of evil spirits that caused epilepsy. This seems plausible because in almost every age and culture epileptic seizures were believed to be the work of evil spirits. (Finger p915)

Some of these reasons for trepanation, though logical do not hold up under scrutiny. There is no gender difference in the distribution of the older French skulls, if combat had caused injury we would expect more males to be candidates for this procedure. Also if war were a major cause of head injury there would be more surgeries to the left side of the skull, if they were struck by a right-handed adversary.(Clower p1421)

In the study of trepanation over the last one hundred and fifty years two men stand out Dr. Paul Broca (1824-1880) and Dr.Victor Horsley (1857-1916). Dr. Broca was not the first person to find, examine or collect trepanned skull but he was the first person to understand and explain what he saw. Horsley's interest amounted to little more than a passing fancy, but his theories regarding the origins of the practice of trepanation contributed significantly to our understanding. Unfortunately neither Broca nor Horsley’s theories have withstood the test of time.

The theories of Broca and Horsley remain widely cited in the anthropological and archeological literature. (Finger p911) Scientists still compare and contrast Horsley's empirical-surgical theory of trepanation with the more anthropological-medical approach chosen by Broca, who attempted to connect seizure disorders in children to supernatural events. (Finger p916) "For Broca, the major stumbling block proved to be the lack of solid evidence to prove that young people were routinely chosen for the operation." Without the age factor, his theory is more plausible.

For Horsley, the idea that the openings were above the motor cortex proved problematic. Without this feature, his notion of traumatic injury also seems more reasonable. (Finger p916) It is interesting that Horsley was one of the first researchers to conclude that the "motor cortex" is smaller than he originally thought and probably did not extend back to include the parietal lobe. Horsley's later motor cortex mapping research helped to undermine the very trepanation theory he had proposed.(Finger p915)

Horsley's general thesis, that blows to the skull with or without epilepsy might have been the initial reason trepanation was performed, is more likely. The best empirical support for the skull fracture theory comes not from French anthropological sites, but from skulls found in Peru that he did not examine. (Finger p915) Peruvian skulls have a male-to-female ratio that is approximately 4:1, about half of the skulls have facial area damage, and they have significantly more trepanations on left side. This suggest that Peruvian physicians saw many more head injuries caused by combat among right handed warriors.(Finger p916) Notably missing from the 20th-century scientific literature is evidence that trepanation was performed for religious, magical, or cultural reasons.

Why did these patients survive cranial surgery? In the documented cases of cranial surgery recorded by French anthropologist, that took place over 4,000 years, I have not read of a solid defendable hypothesis. Of the cases documented from Peru until 500 years ago I have some ideas. Survival of surgery is a quality-of-life issue. The citizens of pre-Columbian Peru had a substantially higher quality-of-life than their counterparts in Medieval and Renaissance Europe.

Examination of Peruvian skulls, by today’s physicians, reveals that these cranial surgeries rarely became infected, and most survived. Even more impressive are the skulls exhibiting successful cranio-plasties (plates inserted into the trephination holes) made of silver and gold, which were placed with such skill that the bone healed around them. (Marino p942 this reference has pictures of sculls with gold cranio-plasties that is well worth the trip to a medical library to see) In contrast, during the 18th century, trephination of the cranium in Europe reached a nearly 100% fatality rate.(Marino p945) Comparing the two cultures may give a clue to why the Peruvian patient’s quality-of-life was better and therefor he/she was more likely to survive.

If you are reading this from a North American point-of-view you probably don’t have a preconceived view of life in South America one thousand years ago, this is a good situation. To better understand the relative timelines and pre-Columbian empires a short review is appropriate so as not to confuse the different cultures. Reviewing the map from north to south the Aztecs settled in what is now central Mexico on small islands in Lake Texcoco where they founded the city of Tenochtitlan (circa 1300 ad) that is now Mexico City. They created a cultural and political empire during the 15th century. Looking farther south the Maya controlled southern Mexico from about 50 BC until the Spanish conquest in the 16th century. The Maya empire reached its cultural and political zenith about 550-900 AD. They controlled the area of southern Mexico and Honduras

The Inca empire, which we are interest in, was by far the largest pre-Columbian state, extending from Peru to Chile including western and central South America. This area was developed by the Chavin-Sechin (900 to 200 BC), the Huari-Tiahuanaco (750 BC to AD 1000), and the Moche-Chimfi cultures (200 BC to AD 1400).(Marino p941) During each of these periods the population reached higher levels of culture under paternal monarchs and each of these cultures were based on agricultural socialism. (Marino p942) Historically the Incas came late on the scene. The expansion of the Inca empire was achieved in some part by military conquests. Not all groups were brought into the realm by direct military action, many joined in alliances with the Incas as the result of peaceful overtures from the expanding state. Others joined out of fear that military intervention would result if an invitation to peaceful alliance were rejected. During this time the population detribalized and culture soared. (Marino p942) Quality of life was improving because of "wise and benevolent rulers."

Before Francisco Pizarro’s conquest of the Inca’s, their empire was equivalent in area to France, Belgium, Holland, Italy, and Switzerland combined, measuring approximately 980,000 km2. (Marino p941) At its height the Inca empire had an estimated 12 million people in much of what is now Peru and Ecuador and large parts of Chile, Bolivia, and Argentina. At the beginning of the Renaissance (circa 1500 AD) there were about 73 million people living in Europe. (Manchester p47)

It may be harder for you to understand Europe of 1000 to 1500 AD, you have to abandon your High School and Hollywood version of Medieval Europe and dig deep to develop a realistic world view. With the fall of the Roman Empire social structure and public works infrastructure collapsed as barbarian hordes overran Europe. As Europe emerged from the Dark Ages, life was not good even in the best of times for the average person.

European political institutions evolved over the centuries. Medievalism was born in the decaying ruins after the barbarian tribes had overwhelmed the Roman Empire. A new aristocracy of nomadic tribal leaders eventually became the ruling nobles of Europe. These militant lords, enriched by plunder and conquest were not "paternal" leaders.

Cities in Europe and Peru are not related in structure or function. In Europe people lived in walled towns for protection. In Peru the detribalized population was united, cities were cultural and religious centers, people lived in surrounding countryside. The wall around a town in Europe was its first line of defense. Therefore the land within was very valuable, and not an inch of could be wasted. The twisting streets were extremely narrow and were not paved Doors opened directly onto streets which were filthy, urine and solid waste were simply dumped out windows. Sunlight rarely reached the ground level, because the second story of each building always extended out over the first story, and the third story extended over the second, nearly meeting the building on the other side of the street. (Manchester p48)

The walled town was not typical of Europe though. Between 80 and 90 percent of the population lived in villages of fewer than a hundred people. These villages were fifteen or twenty miles apart surrounded by endless forest. (Manchester p53) Unless a person was a noble or priest his/her mental geography limited their world to what they knew. If war took a man even a short distance form his nameless village, the chances of his returning were slight, and finding his way back alone was virtually impossible. "Each hamlet was inbred, isolated, unaware of the world beyond the most familiar local landmark."(Manchester p21)

Cities in Peru did not have the cramped population and unsanitary conditions of Europe. Nor did they have the pollution-producing industries emerging in Europe. These people were engaged the cooperative efforts of agriculture, mining, herding, and fishing. They had a rural lifestyle in small villages over the high plateaus and coastal lowlands. Their cities appeared to be cultural centers where people would travel to, they lived in the outlying country side. Because even the remote mountain villages were tied to the rest of the empire with an intricate road system of approximately 20,000 km for rapid messenger service to communicate across the empire the pre-Columbian people had a much broader mental geography.

In Europe at the end of the Dark Ages agriculture and transportation of foodstuffs were inefficient, the population was never fed adequately from year to year. Famines, Black Death and recurring pandemics repeatedly thinned the population of Europe at least once a generation after 1347(Manchester p5). The Peruvians demonstrated knowledge of the contagion mechanisms of typhus (which would be understood in Europe only at the beginning of the twentieth century). They fought it with isolation measures and recognized the role of body lice in its spread. It is also evident that they understood the means by which malaria, endemic on the Peruvian coast, was spread. Houses were routinely built in the high and sandy part of the valleys, outside of the access radius of the mosquito vectors. (Marino p942 ) Tuberculosis, whose cause and spread depends essentially on poor social conditions was not endemic in their culture, Europe was not so lucky.

There are numerous reports in historical chronicles that refer to the pharmacological wealth of South America that was used by the pre-Columbian cultures. Many of these drugs could help the patient survive trepadation. The most obvious would be drugs that could be used for anesthesia. This could have been accomplished with drugs known to be used by the Incas such as, coca, datura, or yuca. It is know that alcoholic beverages such as chicha, made of fermented corn, was given to patients, causing a relaxed or sedated state. The next most obvious drug choice would seem to be an antiseptics to prevent infection, such as, Peru balsam, tannin, saponins, and cinnamic acid. These were available and used for embalming the dead, they may have been used in surgery. It would be prudent to have a good drug to control bleeding, this could have been done with herbal extracts of Indean ratania root, pumachuca shrub, and preparations high in tannic acid. (Marino p947) Beyond surgery a drug used then as well as today to control Malaria is quinine. It is well known that they used the bark of the cincona tree as a source of quinine to treat malaria. (Marino p943) The tragedy of the pre-Columbian historical period is the lack of written records (Marino p942) this would have provided remarkable insights into early surgeons and their medical practices.

Jim Myres, R.Ph.


Clower, William & Finger, Stanley, Discovering Trepanation: the contribution of Paul Broca, Neurosurgery Vol. 49 No. 6, p.1417-1425, December 2001

Finger, stanley & Clower, William T., Victor Horsley on "Trephining in Pre-historic Times," Neurosurgery, vol. 48, Number 4, p. 911- 918, April 2001

Manchester, William, A World Lit Only By Fire, Litle, Brown and Company, Boston, 1993.

Marino, Raul & Gonzales-Portillo, Marco, Preconquest Peruvian Neurosurgeons: A study of Inca and Pre-Columbian Trephination and the Art of Medicine in Ancient Peru, Neurology, vol. 47, No 4, p. 940 – 955, October 2000,