There have been plenty of headlines recently about head transplants becoming a reality. In fact, the first one could be performed as early as 2017, the reports said. Dr. Sergio Canavero, head of the Turin Advanced Neuromodulation Group, discussed how the surgery would work in a paper and recently presented his ideas at TedxVerona. Valery Spiridonov, a Russian computer programmer with Werdnig-Hoffmann disease, has volunteered to be the first patient. If this seems too much like science fiction there are many critics who feel the same way.

Canavero has been discussing his vision for how a human head transplant could work since 2013. The biggest obstacle regarding a human head transplants involves the reattachment of the spinal cord. In 1970, Dr. Robert White successfully performed a head transplant involving monkeys. White did not attach the spinal cord and the monkey's immune system rejected the transplanted head, leading to its death. Canavero believes the key to solving this problem involves a clean, or "sharp severance," of the spinal cord. A team of researchers led by Xiaoping Ren, from Loyola University Chicago, transplanted the heads of 18 mice. Once again, the experiment lasted three hours and the success was short-lived. The mice could blink and move their whiskers, but were paralyzed.

So, the idea that a head transplant is feasible isn't too far from reality, but there are many problems that Canavero would need to solve before such a procedure would be successful. Popular Science has a good breakdown of the surgeon's plan and the potential problems he could face during a head transplant. Fusing the spinal cord using polyethylene glycol is untested and a patient would be in a medically induced coma for around four weeks while the spinal cord healed. Electrical stimulation during the healing phase would help the spinal cord fuse and the patient would be able to walk after a year of physical therapy, New Scientist reported. Because there has never been a spinal cord attachment, it's unclear if the donated head and spinal cord could communicate.

Aside from the practical matters, the ethics of such a surgery is also in question. A head transplant would have to pass clinical trials in the U.S. and that would not happen before 2017. "This is such an overwhelming project, the possibility of it happening is very unlikely," Harry Goldsmith, a clinical professor of neurological surgery at the University of California, Davis, said in an interview with New Scientist.

A head transplant is more likely to happen in 2117, not 2017, Dr. Chad Gordon, professor of plastic and reconstructive surgery and neurological surgery at Johns Hopkins University, told BuzzFeed News. "If he’s saying two [years], and he’s promising a living, breathing, talking, moving human being? He’s lying," Gordon said. The head transplant could cost around $13 million and require a team of 150 doctors and nurses.

Spiridonov, 29, has spinal muscular atrophy and has been unable to walk since he was 1 year old. He sent Canavero an email and knew there would be plenty of questions about his decision. "We must understand it’s something like being the first man in space, the first man on the moon and things like this. It’s a breakthrough in science, technology, and biology," Spiridonov said in an interview with Motherboard. Canavero will present his research in June at the annual meeting of the American Academy of Neurological and Orthopaedic Surgeons.