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18th century French illustration of trepanation

Trepanation (also known a trepanning, trephination, trephining or burr hole) is a form of surgery in which a hole is drilled or scraped into the skull, thus exposing the dura mater in order to treat health problems related to intracranial diseases, though in the modern era it is used only to treat epidural and subdural hematomas, and for surgical access for certain other neurosurgical procedures (e.g. intracranial pressure monitoring).

Trepanation was carried out for both medical reasons and mystical practices for a long time: Evidence of trepanation has been found in prehistoric human remains from Neolithic times onwards, per cave paintings indicating that people believed the practice would cure epileptic seizures, migraines, and mental disorders. Furthermore, Hippocrates gave specific directions on the procedure from its evolution through the Greek age.

Trepanation in pre-Columbian Mesoamerica

Main article: Trepanation in Mesoamerica

In pre-Columbian Mesoamerica, evidence for the practice of trepanation and an assortment of other cranial deformation techniques comes from a variety of sources, including physical cranial remains of pre-Columbian burials, allusions in iconographic artworks and reports from the post-colonial period.

Among New World societies, trephinning is most commonly found in the Andean civilizations such as the Inca.[1] Its prevalence among Mesoamerican civilizations is much lower, at least judging from the comparatively few trepanated crania which have been uncovered.[2]

The archaeological record in Mesoamerica is further complicated by the practice of skull mutilation and modification which was carried out after the death of the subject, in order to fashion "trophy skulls" and the like of captives and enemies. This was a reasonably widespread tradition, illustrated in pre-Columbian art which on occasion depicts rulers adorned with or carrying the modified skulls of their defeated enemies, or of the ritualistic display of sacrificial victims. Several Mesoamerican cultures used a skull-rack (known by its Classical Nahuatl language term, tzompantli ) on which skulls were impaled in rows or columns of wooden stakes.

Even so, some evidence of genuine trepanation in Mesoamerica (i.e., where the subject was living) has been recovered.

The earliest archaeological survey[3] published of trepanated crania was a late 19th-century study of several specimens recovered from the Tarahumara mountains by the Norwegian ethnographer Carl Lumholtz.[4] Later studies documented cases identified from a range of sites in Oaxaca and central Mexico, such as Tilantongo, Oaxaca and the major Zapotec site of Monte Albán. Two specimens from the Tlatilco civilization's homelands (which flourished around 1400 BCE) indicate the practice has a lengthy tradition.[5]

A study of ten low-status burials from the Late Classic period at Monte Albán concluded that the trepanation had been applied non-therapeutically, and, since multiple techniques had been used and since some people had received more than one trepanation, concluded it had been done experimentally. Inferring the events to represent experiments on people until they died, the study interpreted that use of trepanation as an indicator of the stressful sociopolitical climate that not long thereafter resulted in the abandonment of Monte Alban as the primary regional administrative center in the Oaxacan highlands.[How to reference and link to summary or text]

Specimens identified from the Maya civilization region of southern Mexico, Guatemala and the Yucatán peninsula show no evidence of the drilling or cutting techniques found in central and highland Mexico. Instead, the pre-Columbian Maya seemed to have utilised an abrasive technique which ground away at the back of the skull, thinning the bone and sometimes perforating it, similar to the examples from Cholula. Many of the skulls from the Maya region date from the Postclassic period (ca. 950–1400), and include specimens found at Palenque in Chiapas, and recovered from the sacred cenote at the prominent Postclassic site of Chichen Itza in northern Yucatán.[6]

Trepanation as a Pseudoscience

The use of trepanation in the modern era is considered a pseudoscience. For trepanation to be considered a genuine science it would have to follow these guidelines set forth by Stephen S. Carey author of A Beginner’s Guide to Scientific Method:

  • Genuine science tends to be self correcting; pseudoscience is not (Carey 120).

Today trepanations are performed by people who aren’t real medical doctors. Real medical doctors won’t perform trepanations because they are illegal and they could lose their license if they perform one. Since real doctors and real scientists aren’t involved with the practice of trepanation; real scientific journals edited and checked by other scientists aren’t written about trepanation. Since trepanation doesn’t follow this practice the actual benefits of trepanation can’t be proven or documented correctly.

  • Genuine science embraces skepticism; pseudoscience tends to view skepticism as a sign of narrow-mindedness (Carey 123).

Trepanation tends to view skepticism as a sign of narrow-mindedness. A benefit of a trepanation is believed to be increased brainbloodvolumn which makes you expand your consciousness ( Since there is no way to scientifically prove that someone feels better after a trepanation it can’t be considered a science. ITAG (International Trepanation Advocacy Group) set up a pilot study in 2000 in which people went to Monterrey, Mexico to be trepanned. The pilot study, The ITAG Protocol, is being performed to show the possible effects of changes of cerebral brainbloodvolumn due to trepanation. Before the 15 people who have taken part in the study, so far, are able to participate they have to sign a waiver that says that they will participate knowing that there are no established benefits to the procedure and that they participate taking full and sole responsibility for the outcome and hold no individual or institution responsible ( This shows the narrow-mindedness of the pseudoscience because participants are risking their lives knowing that there are no established benefits to the procedure of trepanation; but they are still participating in the procedure.

  • As a scientific discipline develops it will gradually produce a maturing body of explanatory or theoretical findings; pseudoscience produces very little theory (Carey 122).

Very little theory can be produced from trepanation. Pete Halvorson the senior director of ITAG claims this after he had a trepanation, “I find myself busy long after others are asleep. I'm ready to start again early in the A.M. The truth is I can't get enough of life” ( This is a spectacular claim about the benefits of a trepanation, but there is very little theory or merit behind this explanation because his behavior can’t be directly linked to his trepanation. On his website,, he lists no scientific studies that we’re performed on him to show signs of advanced brain functioning since his trepanation was performed. A claim like this is what makes trepanation a pseudoscience rather than an actual genuine science.

See also


  1. Tiesler (2003a)
  2. Ibid.
  3. According to Tiesler (2003a).
  4. Lumholtz's study was published in the journal American Anthropologist (Lumholtz 1897).
  5. Romero (1970).
  6. Tiesler (1999).


  • Lumholtz, Carl (1897). Trephining in Mexico. American Anthropologist 10 (12): pp.389–396.
  • Romero Molina, Javier (1970). "Dental Mutilation, Trephination, and Cranial Deformation" Wauchope, et. al. (Eds.) Handbook of Middle American Indians, Vol. 9, 2nd. edition (revised), Austin: University of Texas.
  • Tiesler Blos, Vera (1999). "Rasgos Bioculturales Entre los Antiguos Mayas: Aspectos Culturales y Sociales". Doctoral thesis in Anthropology, UNAM. (Spanish)

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