A paralysed man can walk again after receiving revolutionary treatment that one of the British scientists responsible hailed as a breakthrough "more impressive than a man walking on the Moon" - although others urged caution. Darek Fidyka was paralysed from the chest down, but can now walk using a frame after nerve cells from his nose were transplanted into his severed spinal column in Poland, according to research published yesterday in the journal Cell Transplantation . "When there's nothing, you can't feel almost half of your body. You're helpless, lost," the Polish patient, who is now recovering at the Akron Neuro-Rehabilitation Centre in Wroclaw, told the BBC's Panorama programme, which filmed his remarkable recovery. "When [the feeling] begins to come back, you feel you've started your life all over again, as if you are reborn," said the 40-year-old in Poland, whose injuries were caused by a knife attack in 2010. "It's an incredible feeling, difficult to describe," he added. Olfactory ensheathing cells (OECs), which form part of the sense of smell, were used in the treatment as they are pathway cells that enable nearby nerve fibres to be regenerated. Pawel Tabakow, consultant neurosurgeon at Wroclaw University, led a team of surgeons in removing one of the patient's olfactory bulbs before transplanting cultured cells into the spinal cord in the treatment's two crucial operations. He said the patient was "exhausted" by the documentary filming schedule, which lasted a year. The scientists involved think that the cells, implanted above and below the injury, enabled damaged fibres to reconnect, although other researchers have reacted more sceptically. "What we've done is establish a principle - nerve fibres can grow back and restore function, provided we give them a bridge," said Geoff Raisman, chair of neural regeneration at University College London's Institute of Neurology, who led the British research team working on the joint project. "To me, this is more impressive than a man walking on the Moon. I believe this is the moment when paralysis can be reversed." But other scientists were far more cautious, saying it was important to await the results of clinical testing with more cases. "We have to be very prudent," said Alain Privat from France's health and medical research institute Inserm. Dusko Ilic, senior lecturer in stem cell science at King's College London, said: "Although the achievement is indeed revolutionary, this approach worked only in one patient so far." For two years after his injury, Fidyka showed no sign of recovery despite intensive five-hour physiotherapy sessions. The first signs of improvement came three months after the surgery, when his left thigh began putting on muscle. Three months later, Fidyka was able to take his first steps with the aid of parallel bars and leg braces. "I think it's realistic that one day I will become independent," he said.