This new device could help people with spinal cord injuries restore function in their hands and arms

Patient on trial manipulating a Rubik's cube during stimulation

A new device may help patients who have lost movement in their hands and arms gain that function again.

Other trials aiming to help spinal cord injury patients using electrical stimulation required devices implanted into the patient's body.

The new ARC-EX device invented by researchers at the Ecole Polytechnique Fédérale de Lausanne (EPFL) and the University of Washington, can be worn externally and was part of a trial involving 65 patients in the US and one in Scotland.

With electrodes placed near the cervical spinal cord on the neck, the device is designed to send a powerful electrical current to the spinal cord to restore arm and hand function.

Melanie Reid, a journalist in the UK who took part in a clinical trial of the device, was paralysed after falling from a horse 14 years ago.

She says regaining mobility and strength in hands is “all you really want” for a person with spinal cord injuries.

After using the ARC-EX device for several months, she reports more strength and mobility in her left hand.

The electrical current given to the patients was five times stronger than would normally be given in treatment.

"Stimulation used in this study used a very high-frequency waveform, and that let us pass about five times more current through the skin to activate the spinal cord," said Chet Moritz, a neural engineer and physiologist at the University of Washington.

“The high-frequency stimulation numbed the skin under the electrodes so that people could easily tolerate that five-fold higher stimulation current,” he added.

Rehabilitation tests

Before being given the electrical stimulation treatment over 12 weeks, patients went through weeks of intensive rehabilitating exercise.

Moritz says the improvements in movement were very clear when the stimulator was switched on and off so there could be no confusion about how much the device contributed to improved movements in the patient.

During the trials, patients were constantly tested and the trial tracked how they were able to complete tasks.

"We used a battery of strength tests, so pinching an object between the fingertips, grasping an object, testing the muscles, ten muscles in each arm and grading those as they do in the clinical settings," said Moritz.

“Then we also use two different functional tests that challenged people to do things like inserting a key into a lock or a coin into a slot, moving pegs in a board. And both of those together showed us that over 72 per cent of the people responded to both a strength and a function outcome measure”.

‘Not a miracle’

Sherown Campbell, a US resident who became a quadriplegic in 2014 while wrestling with a friend, says the non-invasive electrical therapy has significantly increased his movement.

"I had to sell my home because I had stairs and no way to get a power chair in and out of it. You lose the ability to work, the ability to drive, the ability to take care of yourself at home it was a very big adjustment," said Campbell.

He says people should understand that it's not a miracle device but getting independence day by day is a huge change for him.

Campbell says the treatment meant he could prepare for his daughter’s birthday party.

"Being able to do that, being able to give her the birthday party she wanted. It's always nice for parents to get to satisfy a kid's needs. I've been living on my own, like with my kids and stuff for quite a few years, so being able to help them and support them and do things like that, like provide that for myself, is a really huge accomplishment," he added.

Researchers hope that patients will be able to use the device at home on a continuous basis to maintain and improve movement in their limbs.

The trial ran through the summer of 2021. Some patients who continue rehabilitation exercises still benefit from the stimulation they've received to a degree, according to the research team.

The device only works for patients who have maintained some neural activity, which is true for many, researchers say.

A report on the trials has been published in Nature Medicine. Researchers involved in the trials have set up a company to develop and market the stimulation device.

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