Almost a decade ago, at a talk at the Royal College of Physicians in London, I heard Prof Geoff Raisman describe to a packed audience how he was on the verge of treating paralysed spinal cord injury patients with their own stem cells.
Today, marking the culmination of almost half a century of effort, the BBC reports how Prof Raisman’s pioneering therapy has at long last been carried out by surgeons in Poland, enabling a paralysed man to walk again.
Darek Fidyka, aged 40, was paralysed from the chest down after his spinal cord was severed in a knife attack in 2010 and had not responded to intensive physiotherapy.
Mr Fidyka told the BBC how walking again – with the support of a frame – was “an incredible feeling”, adding: “When you can’t feel almost half your body, you are helpless, but when it starts coming back it’s like you were born again.”
Prof Geoff Raisman, chair of neural regeneration at University College London, said that for a paralysed person this feat was “more impressive than man walking on the moon”.
When a nerve fibre is severed it attempts to regrow but is unable to do this is due to the disruption of the pathway along which the nerve fibres need to travel. Often that gap is blocked by cells that close off the spinal cord by forming a scar.
The new hope rests on the discovery that there is only one part of the nervous system in which nerve fibres are in a state of continuous growth throughout adult life. These nerves are at the top of the nose and are concerned with the sense of smell.
Prof Raisman spent years studying in animals how to bridge a severed spinal cord using these olfactory ensheathing cells (OECs). Depending on where the spine is severed in laboratory animals these cell transplants result in the ability to reach with a paw or to climb.
In the first of two operations on Darek Fidyka, when he was 38 years old, surgeons in Wroclaw removed one of his olfactory bulbs and grew the component cells in culture.
Two weeks later the team led by Dr Pawel Tabakow, consultant neurosurgeon at Wroclaw Medical University, transplanted around half a million of these cells above and below his spinal cord along with strips of nerve tissue taken from the patient’s ankle, providing the means for the gap to be closed once again. Being the patient’s own cells, there was no danger of rejection and thus no need for immunosuppressive drugs.
After three months, Mr Fidyka noticed that his left thigh began putting on muscle. Six months later he took steps with the help of parallel bars, leg braces and the support of a physiotherapist. After two years he can now walk using a frame. He has also recovered a degree of bladder and bowel sensation and sexual function.
Spinal cord injury is classified into five categories on the ‘ASIA Impairment Scale.’ “After OEC transplantation and the building of the nerve bridge, this patient improved from ASIA A to ASIA C,” said Dr Tabakow (“A” indicates a “complete” spinal cord injury where no motor or sensory function is preserved and “C” indicates an “incomplete” spinal cord injury).
“Prior to the transplantation we estimated that without this treatment, our patient’s recovery chances were less than one percent,” he explained. “However, we observed a gradual recovery of both sensory and motor function that began four months after the surgery.”
MRI scans suggest that the 8 mm gap in the cord has closed up following the treatment. However, Prof Raisman stresses that the success with Mr Fidyka will need to be repeated in more patients to show definitively whether it can stimulate spinal cord regeneration.
Roger Highfield is Director of External Affairs at the Science Museum.