Floating heads or Frankenstein: a step-by-step guide to a (maybe) successful head transplant

Have you ever wondered how long a head could be kept alive once isolated from the body? Probably not, but this was a far more common curiosity in the early 19th century, probably for the simple reason that the guillotine was in high demand. This demand tended to produce a surplus of severed heads, and, naturally, people began to ponder about post-decapitated consciousness.

 

It is this public curiosity that has since led many a scientist to explore the implications of keeping a severed head alive. Thus, in 1884, Dr Laborde successfully connected the head of a decapitated murderer to the arteries of a living dog; causing the facial muscles to contract and the jaw to snap shut (not signs of consciousness, but a good start nonetheless). The next breakthrough would not be until the 1920’s, when Dr Brukhonenko discovered that, by using a combination of anticoagulant drugs and a self devised heart-lung machine, he could keep a dog’s head alive for 3 hours. Even more impressively, he showed the head could still react to external stimuli; it’s pupils contracted in reaction to light, it flinched in reaction to loud noises, and (somewhat disturbingly) it swallowed a piece of cheese that just popped out of the other end of it’s esophageal tube.

 

As little more could be achieved with reanimated heads, attention soon turned to head transplants (probably a far more useful medical endeavor than producing conscious, floating heads). It was then in 1970 that Dr White performed the first full head transplant. The caveat, however, being that the experiment was conducted using monkeys rather than humans, but lets not quibble over 1.23% chromosomal variance. So Monkey A’s head was severed and reattached to Monkey B’s body. Monkey AB (?) awoke a few hours after surgery and could perceive external stimuli, much like the dog with the cheese, including visually tracking objects and attempting to bite the surgeon. However, as the spinal cord remained severed, the monkey could not move any part of his new body, essentially making him a quadriplegic and unfortunately died from surgical complications a few days later (I bet you’re hoping that bite was painful now).

 

Riding the wave of this obvious success, Dr White proposed attempting a human head transplants next, but, fortunately for society (and undergraduate test subjects), his ideas were deemed abhorrent and funding soon dried up. Fast forward a few decades and those ideas have been resurrected by Dr Sergio Canavero, who has stated he will perform the first human head transplant by December 2017 (and he even has a volunteer). So reality is imitating fantasy, and by next Christmas we may have a walking (unlikely), talking (probably grunting) Frankenstein.

 

There are probably many questions springing to your frontal lobe; like who would volunteer? Does Canavero look like a deranged scientist? Seriously, who would volunteer??But maybe more importantly, will it actually work? Well, theoretically, neurosurgery is advanced enough that he may be able to circumvent the spinal fusion barriers faced by his predecessors; in which case it might. However many of his colleagues are skeptical of his bold claims and somewhat dubious methodological rigour. So in order to help you assess the probability of success for yourself, here is a brief step-by-step run through of the experiment:

(Disclaimer: Do not try this on your pets or partners)

1.Firstly, the head of the volunteer and the body of the donor must be cooled to approximately 10˚C, thus increasing the length of time cells can survive without oxygen.

2.The neck tissue must then be dissected and the spinal cords of both patients cleanly severed (a clean cut is important for reattachment).

3.The head of the volunteer can then be attached to the body of the donor by beginning to fuse the spinal cords.

(This is undeniably the stage most likely to fail, as thousands of neuronal connections need to be remade across the cord ends, and if they grow past each other no pathways can be formed (meaning no movement). This is akin to precisely lining up the loose fibres of rope ends and expecting them to intertwine. However, Canavero hopes that by injecting polyethylene glycol (PEG) into the spinal cord ends, the neurons can be stimulated to grow towards each other as PEG encourages the fat in cell membranes to mesh together. In addition, a team in the US has recently improved the PEG solution by adding graphene nanoribbons – an electrically conductive material that acts as a scaffold for neurons to grow along. Failing that, stem cells could be used to help reestablish neuronal pathways.)

4.After the PEG solution is applied, the blood supply should be connected and muscle tissue sutured.

5.The patient must then be kept in a coma for 3-4 weeks to prevent movement, facilitate spinal cord fusion and allow for healing (keeping a person in an induced coma for this length of time also has severe implications for cognitive function).

6.Then, to cement the Frankenstein allusions further, Canavero suggests using regular electrical stimulation of the spinal cord to strengthen the new nerve connections.

7.Finally, if all goes to plan, Frank is born (Frankenstein seems so formal after all those hours in an operating theatre together).

 

So whether you are a skeptic or not, the world will be watching this maverick surgeon to see if he can deliver. And if he does, I would like to place an early bird order on a supermodel body (preferably something from the Hadid lineage), to be kept on ice until further notice.

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