The stimulation won’t work in the small percentage of people who have no remaining connection between the brain and spine below their injury. But for people who still have a connection, the stimulation appears to make voluntary movements easier by making the nerves more likely to transmit a signal. Studies over the past couple of decades in animals suggest that the stimulation activates remaining nerve fibers and, over time, helps new nerves grow. That’s why the benefits persist even when the stimulator is turned off.
The big advantage of an external stimulation system over an implant is that it doesn’t require surgery, which makes using the device less of a commitment. “There are many, many people who are not interested in invasive technologies,” said Edelle Field-Fote, director of research on spinal cord injury at the Shepherd Center, at the press conference. An external device is also likely to be cheaper than any surgical options, although the company hasn’t yet set a price on ARCex.
“What we’re looking at here is a device that integrates really seamlessly with the physical therapy and occupational therapy that’s already offered in the clinic,” said Chet Moritz, an engineer and neuroscientist at the University of Washington in Seattle, at the press conference. The rehab that happens soon after the injury is crucial, because that’s when the opportunity for recovery is greatest. “Being able to bring that function back without requiring a surgery could be life-changing for the majority of people with spinal cord injury,” he adds.
Reid wishes she could have used the device soon after her injury, but she is astonished by the amount of function she was able to regain after all this time. “After 14 years, you think, well, I am where I am and nothing’s going change,” she says. So to suddenly find she had strength and power in her left hand—“It was extraordinary,” she says.
Onward is also developing implantable devices, which can deliver stronger, more targeted stimulation and thus could be effective even in people with complete paralysis. The company hopes to launch a trial of those next year.