More than 1500 trephined skulls have been uncovered throughout the world, from Europe and Scandinavia to North America, from Russia and China to South America (particularly in Peru). Most reported series show that from 5% to 10% of all skulls found from the Neolithic period have been trephined with single or multiple skull openings of various sizes. Many of the skulls show evidence of fractures. In some cases the operations were incomplete, as if the patients suddenly woke up and terminated the procedure. Some skull openings showed evidence of healing, meaning the patients survived the operations; others did not. In these latter cases it is impossible to determine if the patients were already (or recently) dead or whether the patients died soon after the procedure. Trepanations were performed in children as well as adults and in both males and females. The majority of trephinations, though, have been found in adult males…

Neolithic man was a hunter and his life experience revolved around this activity. Cave dwelling paintings also testify to this phenomenon. Consequently, he was very aware of hunting and war injuries. Neolithic man noticed, for example, that penetrating injuries to the chest and abdomen were usually fatal to man and animal. Likewise, massive blunt head injuries were invariably lethal. Nevertheless, blunt injuries to the head, if not massive, were not invariably fatal. With mild blows to the head, man or animal could be knocked down briefly and then get up and run. At other times, a man could be left for “dead” in the back of the cave, but after a period of time, he could “miraculously” recover and become “undead.” It was only with head injuries that primitive man noted that this phenomenon took place — namely suddenly becoming “dead” after an injury and then “undead.” Or, as we would describe it, that a head injury caused a momentary loss of consciousness (LOC), as in a concussion, or a more prolonged LOC, as in a cerebral or brainstem contusion — and then recover as the cerebral edema subsided and neural circuits were reestablished.

Of course, primitive man did not understand the pathophysiology involved. For the Stone Age man, there was also no awareness of the inevitability of death and no recognized mortality as part and parcel of the human condition. Diseases, pain and suffering, and death took place as a result of sorcery, evil spirits, or some other supernaturalistic intervention. People could become gradually “dead” from an illness or injury and then become “undead” because of some phenomenon. In the case of injuries, these conditions were caused by observed specific events, such as penetrating injuries or serious blows. These… did not occur randomly. Such was also the case with becoming “dead” and “undead,” and the primitive surgeon of Neolithic times understandably reasoned that he could also do something to bring back to life those individuals essential to the survival of the group.

Observing that small injuries to the head, more frequently than other injuries, resulted in “dying” and “undying” (ie, spontaneous recovery), they must, according to Prioreschi, come to believe that “something in the head had to do with undying.” More blows would not accomplish the ritual, but an opening in the head, trephination, could be “the activating element,” the act that could allow the demon to leave the body or the good spirit to enter it, for the necessary “undying” process to take place. If deities had to enter or leave the head, the opening had to be sufficiently large.

Prioreschi writes: “It would appear that he was trying to recall to life people who had died (or were dying) without wounds (or with minor ones), in other words, people affected with diseases and people whose small wounds were not so serious as to prevent ‘undying’…” Incomplete trepanations, as mentioned previously, are explained, not because the patients died during the procedure, but because of patients waking up and interrupting the procedure by suddenly becoming “undead.”

–Miguel A Faria
Neolithic Trepanation Decoded — A Unifying Hypothesis