Primitive cranial trephining, the surgical opening of the skull performed with primitive tools and techniques, is one of the most fascinating surgical practices in human history. It probably started in the Neolithic at least 7000 years ago.

Remarkably, it is performed yet today in parts of Africa, South America, and Melanesia.

The word trepanation is derived from the Greek. It means auger or borer. The word trephination more specifically means an opening made by a circular saw of any type. In this article we will use the terms interchangeably.

Skull trepanation in early times was independently practiced in many areas of the world, with the highest concentration of activity in Peru and Bolivia. Evidence for it also is found in Europe, Asia, New Zealand, some Pacific Islands, and North America. The evidence of the practice nearest to Chicago is on the Rock River at Sterling, Illinois.

The operation consisted of removing a piece of the skull (frontal, parietal, or occipital bones) from a living patient to expose the dura mater. The dura mater is the tough fibrous membrane forming the outer envelope of the brain. If it is not breached, a patient in the pre-anaesthesia, pre-antisepsis era had a fair to good chance of surviving without brain infection.

Although the operation was performed on men, women, and children, it was most often performed on adult males. Overall, patients that underwent the operation had an impressive recovery rate. As many as two thirds of the skulls examined reveal various degrees of healing--which is the evidence for survival. Considering the danger of severe bleeding, shock, brain edema, and infection, the achievements of such postoperative results suggest considerable skill and experience.



The motives for Neolithic trephining have been the subject of speculation since the first specimens were discovered in the nineteenth century. Generally, it is surmised that, on the living, it was performed for the escape or entrance of spirits. This, of course, is conjectural. It may have been done for therapeutic reasons, such as for headaches, fractures, infections, insanity, or for convulsions. It might have been done for religious reasons. It has been suggested that the motive was to acquire rondelles (the disks of bone obtained from the cutting of circular holes in the skulls). In this event, they would have been used for charms, amulets, or talismans.

Frequently, there is evidence of skull fracture, suggesting that the procedure was done to relieve intra cranial pressure.

The following essential aspects of trephining must be accounted for in any explanation of the practice:

a. The practice was astonishingly widespread.

b. It was practiced in the presence, and absence of head trauma.

c. Only a small percentage of discovered skulls are trephined.

d. The practice was performed on the living and on the dead.

e. Men, women, and children were operated upon.

f. Some skulls show multiple operations.

g. In some skulls, the trephining was incomplete, as if the procedure was abandoned mid-operation.



From a modern perspective, the performance of such surgery is intrepid and audacious. It is all the more remarkable, since the 'surgeons' had little or no knowledge of anatomy or physiology and only rudimentary knowledge or instrumentation at their disposal. There were probably three general techniques: scraping, drilling, and cutting.

Trepanning drills have smooth wooden shafts and tips of very hard material, to cut into the bone as neatly as possible. The earliest trepanned skulls are from the Neolithic Stone Age long before the introduction of metallurgy. Their holes were cut not by a drill, but with a sharp-edged flint scraper or knife. A circular or rectangular groove was made. The practitioner would cut deeper and deeper until penetration to the dura mater was accomplished. In ancient Peru, people used knives of bronze or obsidian. They would cover the wound with a shell, a gourd, or even a piece of gold or silver.

The most common of the techniques was the bow drill. The bow was made of springy wood and had a leather thong wound around the drill several times. To perform the procedure, the operator positioned the drill tip on the head and thereby made the bore through the bone.

Drilled holes were usually roughly circular. Knife cut ones were usually more square. A few skulls have up to five holes, the longest of which measures two inches across.

It is interesting that in modern times, neurological surgery is one of the more recently developed specialties. Yet, it has this remarkable antecedent in Neolithic times. It is very unlikely, however, that Neolithic surgeons entered the brain itself. We can only conjecture as to why they did it.



The most remarkable trephination in our time is the spectacular case of a modern African who had endured a large number of these operations. He could only recall the range between five and 30 trephinations. Afterward a very large portion of his skullcap was entirely missing. Examples like these tend to overshadow another extreme--very small trephinations. These are called "symbolic trephinations" in recent literature.

Cases from Hungary, Russia, and Bulgaria are well documented. The bore holes were on the order of 2 mm in diameter. In the Bulgaria site, close to one-third of the skulls recovered had been trephined in this manner. Of the 85 skulls, healing suggests that all the persons survived the procedure. The investigators suspect that the trephining was a mass administration of the procedure for therapeutic purposes.



A good sense of humor is suggested as you read this section.

Sometime in the early '70s (he doesn't remember exactly when), a jeweler from Pennsylvania by the name of Peter Halvorson made a T-shaped incision in his scalp, secured a power drill to his bathroom ceiling and proceeded to perforate his skull. He reported that it took several drill bits. They kept getting clogged with blood and bone. Halvorson stopped when he felt the drill give way and penetrate into the cranial cavity.

His interest isn't an isolated affair. Eli Kabillio, an award-winning independent filmmaker has produced a documentary entitled "A Hole in the Head." He was reportedly making attempts to have PBS or HBO broadcast it. Orthodox medical doctors are not enthusiastic about this sort of thing. They are astonished that anyone would do trephining. The 'revival' of trephining has been dismissed as the ultimate in body piercing. Are you interested?

The International Trepanation Advocacy Group web page is www.trepan.com

It had 35,000 hits in 1998.

..... CJ '99

Sources and further reading

Alt, K. et al "Evidence for Stone Age Cranial Surgery " Nature 387: p 364 (22 May 1997).

Parker, S. Collins Eyewitness Science: Medicine. Sydney: HarperCollins Publishers, 1995.

Price, W. Nutrition and Physical Degeneration. New Canaan: Keats Publishing, Inc., 1989.

Prioreschi, P. "Trephining" Perspect Biol Med Winter, 34: 296-303, 1991.

Stone, J. and Miles, M. "Skull Trepanation Among the Early Indians of Canada and the United States" Neurosurgery 26: 1015-1020, 1990.

Valasco-Suarez, M., et al "Archaeological Origins of Cranial Surgery: Trephination in Mexico" Neurosurgery 31: 313- 319, 1992.

Vogt, A. "Hole-istic medicine: Try getting your HMO to cover this procedure. Chicago Tribune. June 11, 1998.

Yordanov, A. and Dimitrova, A. "Symbolic Trephinations in Medieval Bulgaria" Homo Vol. 41/3, pp 266-273 Gustave Fischer Verlag, Stuttgart.



Trepanning Drills


Trepanning drills have smooth wooden shafts and tips of very hard material, to cut into the bone as neatly as possible. The earliest trepanned skulls from the Stone Age are about 20,000 years old. Their holes were usually cut with a sharp edged flint scraper or knife, making a circular or rectangular groove, which became deeper and deeper until it passed right through the bone. In ancient Peru, people used knives of bronze or obsidian, a black glassy rock. They sometimes covered the wound with a shell, a gourd, or even old and silver. The bow drills are a reconstruction.


Shown at the right are reconstructions of ancient drills used for trepanning.

Trepanned Skull

This skull comes from Jericho and is over 4,000 years old. It has three trepanned holes. Drilled holes were roughly circular whereas knife-cut ones were usually more square. A few skulls have up to five holes--the largest ones measuring more than two inches across. Some people, including this individual, survived the process--this can be deduced from the fact that the bone shows signs of healing.

In Europe, the piece of bone cut away by the knife method could be worn on a necklace cord as an amulet to ward off evil. Trepanning continues today--for brain surgery in the modern operating theatre using precision electric powered drills and saws.



Parker, S. Collins Eyewitness Science: Medicine. Sydney: HarperCollins Publishers, 1995.