Mr Spiridinov, from Russia, suffers from Werdnig Hoffman disease, a muscle wasting condition that seriously diminishes his physical capabilities and left him dependent on a wheelchair.

Now he has announced his intention to become the world’s first subject of a full head transplant, so that his brain can be attached to a healthy body.

Italian neuroscientist Dr Sergio Canavero claims he can complete the unprecedented procedure in less than a day.

The whole process, Dr Canavero says, is “90 per cent” guaranteed to succeed, though he admitted: “Of course there is a marginal risk. I cannot deny that."

Other doctors have expressed serious doubts, and, in particular, the likelihood that Mr Spiridinov’s brain will still be functional by the time the surgery is complete.