A man paralysed in a snowmobile accident has been able to stand and walk with help after a device was implanted near his damaged spinal cord.
Jered Chinnock, paralysed from the waist down five years ago, has become the first person to receive the electrical stimulation device.
It is not a cure – he can only walk with assistance and has not regained sensation in his legs – but during one session the 29-year-old walked far enough to cover the length of a football pitch.
The device sends electricity to the spinal cord and enables neurons to receive the signal being given by Mr Chinnock’s brain to stand or move his legs.
It was implanted in the epidural space – the outermost part of the spinal canal – below the injured area.
The electrode connects to a pulse generator device under the skin of the man’s abdomen and communicates wirelessly with an external controller.
It was implanted after Mr Chinnock had completed 22 weeks of physical therapy in 2016.
Dr Kendall Lee, from the Mayo Clinic, implanted the device.
“What this is teaching us is that those networks of neurons below a spinal cord injury can still function after paralysis,” said Dr Lee.
After the surgery, Mr Chinnock, from the US state of Wisconsin, had 113 rehabilitation sessions while he learned to stand and walk again.
The first breakthrough was being able to move his toe, something he said left him feeling “in awe” and “very excited”.
He said: “To be able to move my legs and to walk and even to stand, it means a lot – that there’s hope not only for me but other people.”
Johns Hopkins University rehabilitation expert Dr Cristina Sadowsky, who was not involved in the research, said she was “really excited” about the development.
But she cautioned that “not everybody who has a similar injury will respond the same”.
In a similar study, by the University of Louisville, four paralysed patients tested the approach and two were able to walk with assistance.
One of them was Jeff Marquis, 35, who said: “One day we were walking and they were helping me as usual and then they stopped helping me and I took maybe three or four steps in sequence.”
Scientists are still investigating why the stimulator helps some patients but not others.
Dr Lee said: “We still have a long way to go before we can optimise this therapy and make it relevant to other patients.”
Kristin Zhao, director of the Mayo Clinic’s Assistive and Restorative Technology Laboratory, was also cautious.
She said: “Now I think the real challenge starts, and that’s understanding how this happened, why it happened, and which patients will respond.”
But Mr Chinnock is prepared to see how far his body can go with the help of the technology.
He said: “The hopeful side (is) that maybe I’ll get where I can leave the wheelchair behind – even if it is to walk to the refrigerator and back, you know, not very far.”
The research is published in the journal Nature Medicine.