Gregoire Courtine: Neuroprosthetic Technologies to improve motor recovery after spinal cord injury

I want to talk to you about activity-based therapy combined with neuroprosthetics.

He’s giving a little history of how we got to epidural stimulation. Harrington, Grillner, Serge Rossignol, Reggie Edgerton . . . in 1984 they did an experiment with a transected cat that could learn what it was trained to learn. Train to step? It could step. Train to stand? It could stand. But it couldn’t do what wasn’t trained.

Gregoire began by working with astronauts to help them learn how to walk again after being in space, and then he went to Reggie’s lab at UCLA. They started with rats, chronic, complete injuries and trained them with a suspended gait system.

And got nada. Zip. Nothing. But it had worked in cats! At about that time Yuri Gerasimenko came to the lab with his epidural stimulators, developed in Russia.

After that was the first time he got to know people with spinal cord injury, starting with Christopher Reeve himself — and since that day hasn’t worked on anything else.

He published the successful rat work in Nature Neuroscience in 2009. With just a 2-electrode stimulator, the rats could walk. He went to Zurich and began his own lab. They developed a robot that allowed them to very precisely train and support the rats.

“At the beginning it was a complete failure.”

“We had forgotten something critical . . . motivation.” (image of chocolates on the screen, laughter). “We were focusing on the leg, but not the animal.” He’s showing a video now of a rat with a double-hemisected cord walking along in its little treadmill, basically chasing chocolate being dangled in front of its nose.

And then they take away the chocolate and that little critter quickly collapses. The spinal cord is part of the brain, not its servant. 

In Zurich they’ve working a sort of matrix: chemical, electrical, robotic, training across the top and mouse, rat, primate, human down the side. I can’t make the image with this technology, but picture the grid that’s formed. Four models of animals, four types of interventions. Each square needs to be understood and the last ones on this particular bingo card will be Human/Chemical, Human/Electrical, Human/Robotic, Human, Training.

Giving the cord below the injury a jolt of energy is the Model T (Model T is Reggie’s phrase for the Louisville epidural stimulators) way. Giving it the exact amount of energy needed under dynamic conditions is a super difficult challenge. They built a stretchy electrode array to solve that and it took them six years to do it. So how do you figure out how much energy to deliver and where exactly to put it? They built computer simulations to answer that question. And now they can deliver what they call “spatiotemporal” electricity — exactly how much is needed and exactly where it’s needed and exactly when it’s needed.

The next step would need to be primate research — not possible in Switzerland, very difficult in the USA. So, he moved to China (murmurs of appreciation).

He convinced Medtronic, after years of working on them, to allow him into the “vault” — the mothership. By August of 2014, they had a product ready to test on a monkey in China. And there is a video on the screen right now of a monkey walking along with that thing embedded. And he’s responding with specific movements to specific instructions that they’re giving him. Step higher, slow down, that sort of thing.

They’re developing a wireless platform right now that takes advantage of a brain implant. They can decode the animal’s intent. LET ME SAY THAT AGAIN. They can use their software/hardware to decode the animal’s intent and use the information to deliver that intent wirelessly to the animal’s muscles.

They can read the motor cortex activity in the brain. 7 years of technology development. Incredible.

An injured monkey (lateral hemisection) after 5 days post with this technology can walk. I’m looking at it. Gregoire says that when he saw this he wept.

He’s talking about a patient named Maria . . . at first she needed 70% body weight support plus stimulation. After 34 weeks, she’s walking across the room behind a walker with no support and no stimulation. They’re looking to work with ASIA C patients.

Beautiful black and white images of dozens of young scientists in his lab, all of whom, he assures us, are dedicated to making this work in humans as fast as they can.

Q: Did your primates get the same drugs as the rodents? And can humans get them, too?

A: We haven’t even started the drugs with our primates yet.

Q: This feels like you’re using a scalpel compared to the thing that was delivered in Louisville . . . why isn’t the lab in Louisville doing what you’re doing?

A: (pause) There are people here from the NIH and from Neilsen Foundation who funded that first work . . . I agree that at this point this is bigger than ego and countries and we should be collaborating.

Q: (couldn’t hear, it was about pharmacology)

Q: Please expand about the nature of the stimulator experimentation, especially about motor intent and how that drove your parameters

A: (A long, involved answer that boils down to using the brain’s natural plasticity to fix itself).

Q: You told me in an email that only ASIA C patients will be eligible for your trials. When will others be included?

A: We’ve got to do this step by step.

Man. I was pretty excited about the prospect of hearing Courtine speak, and I wasn’t wrong.

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