Head Transplant

*Note: This is more formal than how this website 
typically works because I originally wrote this for a 
school magazine.

Recently there has been news of the world’s first head transplant, announced to be fully complete by 2017 on a Russian man who believes this can possibly save him from his case of spinal atrophy, better known as Werdnig-Hoffman disease. When the spine atrophies, the nerve cells that control voluntary movement degenerates and the victim loses most motor control. In the case of the Werdnig-Hoffman disease, severe weakness appears before the age of 6 months and most will die before they reach 2 years old. Symptoms include having difficulty breathing and being unable to sit up unaided. The survival of the victim with this disease depends on how well the victim can still breathe.

In other words, this man is slowly losing control of his body. But is such a thing really feasible? To take the head of one and attach it to the body of another would require severing the spinal cord, which is widely known to be the cause of paralysis in the limbs. Dr. Sergio Canavero from the University of Turin has risen up to the challenge, with an elite international team of surgeons behind him of course.

In the summary of Sergio Canavero’s report, Surgical Neurology International, he cites how head transplants have previously been done on dogs and rats by previous scientists. (The first two headed dog that could control its own motions resulted from one of these head transplants in the 1950s, so the idea of head transplants has been floating around for a while. It has also resulted in experiments involving normal dogs with an additional 20 puppy heads attached to each.) The two key factors to this theory on head transplants includes that: 1. To create the sharp severance necessary, approximately 26000N would be needed to be applied to the spinal cord with either a sharp instrument or a projectile. 2. The gray matter (basically the gray tissue around the brain and spinal cord area that contains a considerable quantity of nerve cells) is more dominantly necessary for human motor control than the pyramidal tract (either of the two bundles of nerves that connect both hemispheres of the brain to all of the voluntary muscles in the human body). In other words, the surgeons must ensure that the gray matter will be reconnected to keep the goal of this transplant in mind, which is to give the patient back his motor control.

The protocol for this human head transplant is to first cool down both the body and the head in question to hypothermic conditions (hyperthermia is around 35 ℃) in order to slow down the blood circulation and prevent death by blood loss. Next, both the head and body is severed from each person with either a specially fashioned diamond microtomic snare-blade or a nanoknife made from a thin layer of silicon nitride (due to silicon being mechanically stronger than steel). Then, the spinal cords will be attached together with polyethylene glycol (a chemical that encourages the fat in cell membranes to mesh together). The outer rim of the pyramidal tracts will require mini-sutures (even smaller than normal stitching). The gray matter is expected to be restored by keeping each body’s respective gray matter very close together at the point where the spinal cords will be connected. Next, the veins and muscles will be sewn together and electrically stimulated, which according to previous research, will shorten the recovery period from 8-10 weeks to approximately 4 weeks.

This is only the physical part of the head transplant though. What about the mental part? Will the patient still be himself afterwards? The success rate is horribly low due to possible problems with the procedure, as pointed out by a neurological surgery professor from University of California, Davis, such as trying to keep the patient healthy for 4 weeks in a coma. And assuming the patient survives all of that against the odds, is it even possible for him to make enough of a recovery to live a normal life afterwards? In the experiment with the two headed dog, it is noted that the two heads were in conflict with each other at times. For example, one head was known to have bitten the other head’s ear. On the subject of those experiments, oftentimes the animal died within a week. For example, the dogs with the additional 20 puppy heads attached usually lived from 2-6 days. So with our human patient, would he be able to survive long enough to make any kind of recovery? And after all of that, can this procedure be considered morally acceptable? Even now, Dr. Sergio Canavero and Harbin Medical University’s Xiao-Ping Ren are experimenting on rats and monkeys in order to comprehend just what this surgery will entail, but would society be able to except the result?

-Xiumin

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