Three people who were paralyzed from the waist down owing to spinal cord injuries can now walk with the assistance of wheeled walking frames or crutches, thanks to implants that electrically stimulate nerves in their back and legs.
The device provides electrical pulses to his muscles, simulating brain activity, and may one day allow people with severe spinal injuries to stand, walk, and exercise.
It draws on a long history of research into the use of electrical pulses to improve quality of life for persons with spinal cord injuries, including a 2018 study by the same team that allowed people with partial lower-body paralysis to walk again.
"It was a very emotional experience," Michel Roccati said.
He was one of three patients in the study, which was published in the journal Nature Medicine on Monday, who were all unable to move their lower bodies following accidents.
Several research groups have looked into utilizing implants to stimulate spinal cord nerves in patients who have been injured, although most have concentrated on those who have less severe lesions and more intact nerves. Although it takes months of training, the idea is that the stimulation makes the residual nerves more excitable, amplifying the feeble impulses from the brain to the legs.
The three men in the latest study suffered total paralysis from the waist down after being injured for more than a year. The use of specially designed electrodes is critical for obtaining immediate effects.
Roccati, who was paralyzed in a motorcycle accident in 2017, currently utilizes the implanted gadget for 1 to 2 hours per day, including going for solo walks. By selecting different stimulation programs, he can also stand for 2 hours, cycle, and even swim. He discovers that walking or standing relieves the agony caused by sitting in a wheelchair all day.
A tablet computer allows users to select the type of movement patterns they require. This wirelessly connects to a neurostimulator implanted in their abdomen, which connects to electrodes on their spine. The neurostimulator will need to be changed after roughly nine years, but the electrodes should last the recipient's entire life.
Because six centimeters of healthy spinal cord is required, the implants are only acceptable for patients with injuries above the lower thoracic spinal cord, which runs from the base of the neck to the belly.
The researchers noted that there is still a lot of work to be done before the implant can be used outside of clinical trials.
