Zapping spinal cord injuries helps restore hand strength and movement?

A treatment for spinal cord injuries has helped more than two-thirds of those who tried it improve their hand and arm function.

The therapy consists of electrode pads placed on the skin above and below the injury site. They deliver electrical stimulation to the spinal cord while the user does rehabilitation exercises.

This improves function during the stimulation by boosting the excitability of the remaining nerves. Over time, people gain lasting improvements even when they aren’t using the device. It seems to work by causing nerves in the spine to regrow and make new connections, says Grégoire Courtine at the Swiss Federal Institute of Technology in Geneva.

“Everyone thinks that with spinal injury, all you want is to be able to walk again,” says Melanie Reid, a participant in the trial. “What matters most is working hands. Tiny gains can be life-changing.”

The approach is only suitable for people whose spine hasn’t been completely crushed or severed, as there need to be intact parts of the spinal cord remaining to let new nerves grow, although this applies to more than two-thirds of people with spine injuries.

The device, called ARC Therapy, is being developed by Swiss firm Onward Medical. Apart from rehab, there are no treatments for spinal cord injuries, which may leave people unable to walk or, if the injury is higher up the spine, move their arms.

Courtine’s team is also developing electrical implants for spinal cord injuries that have helped a few people to regain some walking ability, but these require surgery.

The new approach of placing electrode pads on the skin was tested in 60 people who had a spinal injury in their neck and varying degrees of function of their hands.

The participants had two months of intensive hand and arm rehab, three times a week, followed by another two months of the same exercises while the stimulators were applied. The trial’s primary goal was for participants to improve the function and strength of their hands and arms to the extent that it would make a noticeable difference to their lives. When tested at the end of the trial, without stimulators, 43 people reached this threshold

Reid, who broke her neck when she was thrown by a horse 14 years ago, initially had good function in her right hand, but almost none in her left hand. Now, “my left hand is much stronger, I’ve got some grip back in it,” she says. “Suddenly to find you have more power and function in your fingers and thumb that were completely useless beforehand was extraordinary.”

Previous studies testing the approach in rats showed that the stimulation makes nerves regrow, although this can’t be proved to happen in people. Courtine says the stimulators may bring greater gains in function if they are offered soon after an injury. The participants in this trial had their accidents several years ago.

Rob Brownstone at University College London says that is a reasonable assumption. “This trial had a small number of patients, but hopefully we will see great things to come.”