Electronic implant aids spinal cord injuries

Injuries to the spinal cord usually result in permanent disabilities, including paralysis. This is because the spinal cord is effectively a giant bundle of nerve pathways that connect the brain with the motorneurones that make muscles move. Cutting the cord disconnects the two, so signals to move can’t make it through. But now scientists in Switzerland have published results on a system they’ve developed to bypass the block. They use electrical implants in the spinal cord controlled by external computer systems to activate the motor nerves directly and restore movement. Julia Ravey spoke to Grégoire Courtine from the Swiss Federal Institute of Technology Lausanne whose team designed the technology, and neurosurgeon Jocelyne Bloch…

Grégoire - The spinal cord is disconnected from the brain. So it's anatomically intact, but it's in a silent state. We are inserting electrode arrays, which use electricity and re-awaken the spinal cord, in order to reestablish the motor function.

Julia - You've performed this procedure on several patients. What have been the results?

Jocelyne - We've implanted nine patients. The first six had an incomplete spinal cord injury, meaning that they still had a little bit of neurological function. And the last three had a complete spinal cord injury - this means that they had no movement, no sensations. All nine could immediately step after the surgical procedure, but they all needed a few months of training in order to be better and better.

Julia - Is there a line, do you think these individuals can get better and better with their motor function? Or do you think there's going to be a stop point of where they can improve?

Jocelyne - Surprisingly, the first patient we implanted with an incomplete spinal cord injury - that was in 2016 - and he was with that for six months and we still see him every six months, coming from some tests and examinations, and we still see progress. So as long as they keep training, even if it's a slow curve, they keep progressing. So it's hard for us to tell exactly where it's going to stop.

Julia - One of the recipients of these implants is David M'zee, who joins us now,. David, how has this procedure changed your life day to day?

David - I have an incomplete injury. So now that I have more strength in my right leg and a little bit of something in my left one, it makes it easier to get into my wheelchair when I'm on the floor. So if I go to the lake in summer to take a swim, when I get back, it's much easier to get back in my chair. So it's many things that have changed, but it's not like I'm walking at home in an everyday life setting.

Julia - How do you operate the implant itself?

David - The implant is controlled by a tablet. It's a little bit cumbersome because the tablet is connected to a device that communicates with another device that communicates with even another device that in the end communicates with the internal pulse generator. But in the end, once the connection is established, I can control the stimulation from the tablet. And then I can increase, for example, the amplitude of the signals down to the legs and I can play with timings and stuff. So once it's all set up it's a really cool thing.

Julia - So far, this technology's been used for people who still have a certain length of spinal cord intact. Is there any hope for people who have a different type of paralysis to benefit from this type of technology?

Grégoire - What we are conducting as a research trial is to link the brain to the stimulation. So electrodes in the brain decode the intention and link it wirelessly to the stimulation: a wireless bridge between the brain and the spinal cord.

Julia - And when do you think the technology that has been used in these clinical trial patients will be more widely available?

Jocelyne - It's still hard to say. There are still a few ongoing clinical trials, but I hope that within a few, let's say two to three years, there will be a product available.

Grégoire - To get the right expectation, our patients still live in a wheelchair. So they can stand, take a few steps, but it is not a cure for spinal cord injury. Our goal is to maximize recovery, improve quality of life, but this is not enough to cure spinal cord injury.

Julia - David, what would be the next step that you'd love to reach with your training?

David - The next really big step would be to walk hands free. But I think with only this technology, at least in my case, it would be really hard to achieve that. But other things were called impossible before, so we'll see how it goes.