Making Holes in the Skull:
Ancient Psychosurgery?

Neolithic trepanned skulls

Just imagine: a hole of 2.5 to 5 cm of diameter, drilled by hand into the skull of a living man, without any anesthesia or asepsis, during 30 to 60 long minutes. This is maybe the most ancient form of brain surgery known to man: it is called trepanning (from Greek trupanon, borer) or trephining. And one of the reasons for performing this bone-chilling procedure was perhaps the same that motivated modern surgeons, such as Dr. Egas Moniz, to perform psychosurgery, in order to alleviate mental symptoms.

Skulls with signs of trepanning were found practically in all parts of the world where man has lived. Trepanning is probably the oldest surgical operation known to man: evidence for it goes back as far as in 40,000 year-old Cro-Magnon sites.

Trepanning was "fashionable" on and off along the ages, probably with different reasons. It was practiced in the Stone Age, in Ancient Egypt, in the Greek and Roman pre-historic and classic times, in the Far and Middle East, among the Celtic tribes, in China (ancient and recent), India, among the Mayans, Aztecs and Incas, among Brazilian indians (karaya and eugano), in the South Seas, and in North and Equatorial Africa (where they are still in use, incredibly as it may seem).

The first historical and medical accounts of trepanning in Antiquity were made in 1867, by E.G. Squier, in North America, and by Paul Broca, in Europe.

Aztec trephining knife made of bronze
and gold (1200-1400 AC)

"Crown" trephines from the 17th century

We will never know how and when primitive man came to the discovery of trepanning, and we can only speculate on the reasons for which they were carried out. The specialists think that, according to culture and time, these reasons could be:

  • Magical and religious rituals, to bring luck and to offer sacrifice, etc. In many cultures (mainly those which were known as head-worshippers, because they attributed special significance to the head and brain in their religion), trepanning was very common, and the round slab of bone taken out of a skull is used as an amulet. There is the possibility that the large number of trepanned skulls found in military posts were from enemies, who were used as suppliers of these amulets.
  • Shamanistic therapies, mainly due to the conviction that opening the skull would liberate "bad spirits" or demons that inhabited the patient's body. These trepanations could then be considered "psychosurgeries", in the sense that probably the most common indications were mental diseases, epilepsy, blindness, etc.
  • For the treatment of legitimate medical conditions, such as strong headaches, skull fractures and wounds, osteomyelitis, encephalitis, elevated intracranial pressure due to hematomas, hydrocephalus and brain tumors, etc. In fact, for some of these conditions, trepanning shows a true therapeutic effect, and it is still used by neurosurgeons. In the South Seas and in North African tribes (rifkabyla and hausa) and Kenya (kisi), trepanning is carried out particularly for relieving war wounds inflicted to the head. The Father of Medicine, Hippocrates, wrote detailed instructions on how to perform skull trepanning for a variety of medical conditions,
  • From the Middle Ages well into the 18th century in Europe, trepanning was common as a medical procedure very much like bloodletting, i.e.; it had no medical usefulness per se. Repeated trepanning was common; for instance it is related that Prince Philip of Orange was trepanned 17 times by his physician. De La Touche, a French physician trepanned 52 times one of his patient, within a two-month period! Many physicians, from the Roman times on, also believed that the bone slabs (called rondelles) taken from trepanned skulls had therapeutic value when pulverized and mixed with other beverages given to the patients for several diseases.

Ancient Greek metal trephines

Trepanning was performed either by bone abrasion (by using a sharp-edged stone or volcanic glass knifes) or by cutting (using semicircular trephines, which cut by means of a swinging motion, such as those found in the Central and South America civilizations). The Egyptians invented the circular trephine, made by a tube with serrated borders, which cuts much easier by means of rotation, and which was then extensively used in Greece and Rome, and gave origin to the "crown" trephine, used in Europe from the first to the 19th century. One of the major inventions in trephine technology was the central spike, which was used to center the rotational movement, so that a better precision was achieved.

How long took a surgical trepanning?

When it is made in a single session (yes, in some cultures the trepanning is made in several sessions, which can take up to 12 days!), it takes from 30 to 60 minutes of continuous sawing or drilling. Paul Broca, the ubiquitous French neurosurgeon and anthropologist, determined this experimentally in animals and cadavers, in 1867.

19th century trephine saw
Did patients survive such a drastic operation, without antibiotics, asepsis or anesthetics?

It is hard to believe, but judging from the number of skulls which showed healing and bone regeneration at the borders, the proportion of "patients' who survived the ordeal of a trepanning was quite high, from 65 to 70 %. Out of 400 skulls examined by one researcher, 250 indicated recovery. In modern times (14th to 18th centuries) this proportion was much lower, sometimes approaching zero.
Birner (1996) cites that a professional "trepanator" named Mery, lost all his patients in 60 years of activity. The most common cause of death was infection of the meninges or of the brain, or hemorrhage. If these factors are carefully controlled (for example, by interrupting the action of the trephine before it touches the brain meninges), it is quite a safe operation. In 1962, a Peruvian neurosurgeon performed a trepanning on a head-trauma patient, using the surgical instruments of ancient Peru. The patient survived.

To Know More

From: The History of Psychosurgery
Author: Renato M.E. Sabbatini, PhD
Source: Brain & Mind Magazine, June 1997

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