A motorcycle accident in 2017 left Michel Roccati lparalyzed from the waist down. Now, four years after his injury, he has regained the ability to walk thanks to electrodes implanted on his spine.
"I am free," says Roccati to CNN's Tasnim Ahmed. "I can walk wherever I want to."
Roccati is one of three men who suffered paralyzing spinal cord injuries that can now stand, walk and cycle with the help of surgically-implanted electrodes.
To perform an action like walking, the brain sends a message to our muscles in the form of electricity that tells the legs to move. But after a complete spinal cord injury, the brain’s signals can’t reach the nerves, resulting in paralysis. By using electrical stimulation from electrodes, doctors were able to send similar electical signals to the body that the brain normally would, like “sit,” “stand,” or “walk.”
The flexible electrodes, which sit between the spinal nerves and vertebrae, are controlled with the touch of a tablet screen. The patient or doctor can then control pulses that activate muscles in the trunk and legs, according to the study published in the journal Nature Medicine. Depending on the electrode stimulation pattern, the signals translate to specific muscle activities, like getting up from a chair or riding a bike.
"All three patients were able to stand, walk, pedal, swim and control their torso movements in just one day after their implants were activated," says study author Grégoire Courtine, a neuroscientist and professor at the Swiss Federal Institute of Technology Lausanne, in a statement. “Patients can select the desired activity on the tablet, and the corresponding protocols are relayed to the pacemaker in the abdomen.”
The patients were ages 29, 32, and 41, and each had been injured in motorcycle accidents several years ago. All three men had six centimeters of healthy spinal cord below their injury and had no movement or sensation in their legs before the operation. After the devices were implanted, the patients were given training on how to use the device, which took a little getting used to.
"It was not perfect at the beginning, but they could train very early to have a more fluid gait," says Jocelyne Bloch, an associate professor of neurosurgery at Lausanne University Hospital, to the Guardian’s Ian Sample.
The three study participants could take as many as 300 steps independently, with some support, within days of receiving their implants. After getting comfortable with the devices in the lab, patients progressed to using the devices in their daily lives.
Just 11 days after Roccati received his spinal implant, he was walking with support. “I was able to see my legs moving, and it was very emotional,” he tells New Scientist’s Clare Wilson. After four months, he was able to use a walker to cruise over half a mile without stopping.
Next, researchers will test the stimulation devices in a larger trial with people of different genders and patients with more recent injuries. There is some evidence in animal studies that early electrical stimulation may help the spinal cord heal after injury, which could help patients regain more sensation and motor control.
"The next step is to start earlier, just after the injury, when the potential for recovery is much larger," Bloch tells Kaitlin Sullivan of NBC News.