Einzigartiger Planet

He teaches paraplegics to walk

They have lost control over their bodies — but Grégoire Courtine, a neuroscientist, uses pioneering new technology to hand control back to his paraplegic patients. He was consequently awarded the Rolex Award for Enterprise.
Published in February 2020icon-clockTime to read: 4min 43s

The New York Times wrote that actor Christopher Reeve “was already Superman before he played Superman” — tall, strong, good-looking, sporty and ideal for his role in four Superman films that made him world-famous. In 1995, Reeve participated in a riding tournament in Culpeper, Virginia. He had a severe fall and remained paralysed from the neck down.

Reeve took up the fight against his paralysis, received treatment, trained relentlessly, started a foundation and supported research. “One must act and stand up for oneself — even when one sits in a wheelchair”, said Reeve.

A key moment for the researcher
The man who was Superman died in 2004. A few months before his death, he talked with some scientists who worked for his foundation, among them a young Frenchman. Grégoire Courtine remembers: “I will never forget his words. He told us: ‘When you leave the lab tomorrow, I want you to go to the Rehabilitation Centre. Look at the patients there. Look how they fight for every little step. How they struggle just to keep standing upright. And on your way home, think about what you can change in your research to make the life of these people easier. Think pragmatically!’”

This was a key moment for Courtine, 44, who first studied mathematics and physics and then specialised in experimental medicine. He followed the advice of Christopher Reeve. Today, Professor Courtine conducts research at the Swiss Federal Institute of Technology in Lausanne (EPFL). He teaches paraplegics who were considered hopeless cases to walk with the aid of technology. Courtine has developed an “electronic bridge” that transmits signals from the brains of paraplegics to their motor neurons in the lower spinal cord. The results of the treatment are remarkable. Courtine was therefore honoured with the Rolex Award for Enterprise.

The award for exceptional men and women
The Rolex Awards for Enterprise, which are awarded every two years, are part of the “Perpetual Planet” campaign that was initiated in 2019. For more than four decades, the Swiss luxury watch manufacturer has been supporting ongoing or visionary new projects that benefit humankind and/or our planet.

The award was established in 1976, on the occasion of the 50th anniversary of the Rolex Oyster, the world’s first waterproof wristwatch. Like the Rolex Oyster, the awards, and particularly their recipients, represent the values that have defined Rolex since its establishment by Hans Wilsdorf in 1905: Quality, innovation, determination and, in particular, entrepreneurial spirit.

The breakthrough was achieved with a new approach
150 women and men have been honoured since the prize was awarded for the first time. Winners receive support for the continuation of their projects as well as access to the Rolex network.

Courtine, the scientist, is also a mountaineer and an extreme athlete. “Movement has always been important to me.” In his early days in Zurich, he worked with a paralysed patient who was very similar to himself: “I could empathise well with him — he was approximately my age and had also done a lot of sports. It was heart-wrenching to see that he had lost an ability that is so important in my own life.”

Unlike many of his research colleagues, Courtine focused his work on paraplegic patients, not on the injured part of the spinal cord, but on an area below the injury: an area of the lumbar spine that is still active in many patients and works like a second command centre for the legs, fairly independently from the connection of the spinal cord to the brain.

The data link to the brain is interrupted
It is precisely this important data connection that is fully or partially interrupted when the spinal cord is damaged by an accident, infection or tumour. When the upper or middle cervical spine is affected, the patients are paralysed from the neck downwards. As arms and legs, i.e. all four extremities, can no longer be moved, this state is called tetraplegia (from Ancient Greek: “tetra” meaning four and “plēgḗ” meaning stroke or paralysis).

If the damage is below the seventh cervical vertebra, the legs can usually no longer be moved — and this is called paraplegia. Courtine’s patients are paraplegics who no longer have control over their legs and cannot walk independently — at least not yet.

The reason is that the neural information network in the vertebral cord no longer functions. Sensory messages from the body no longer reach the brain. Therefore the legs feel numb. The commands from the brain no longer reach the muscles. Therefore the legs can no longer be moved. Get up and go? Impossible.

Some abilities may be retained if the response after injury is fast enough. The treatment normally includes a comprehensive rehabilitation programme that starts once the patient has recovered sufficiently. Medications, surgery, training and physiotherapy can recover some of the lost connections under some circumstances.

However, experience also shows that: what has not returned after six months will never come back. The patients affected must therefore face the severe challenge of coping with their condition. A life on crutches or in a wheelchair. With extremely reduced freedom.

To date, little has changed. There are numerous research projects that focus primarily on the growth of new neural connections in the interrupted region of the spinal cord. There were minor successes, e.g. by using stem cells. But there were no big advances in this direction.

Not until Grégoire Courtine developed a new way. He focused his work on an area of the spinal cord that is approximately five centimetres long, coordinates about 60 percent of the muscle activity in the legs and operates largely autonomously — i.e. without the connection along the spinal cord that has been severed in paraplegic patients.

Mobility is in a deep-sleep state — and is now awakened
The head merely sets this control network in motion and adjusts the movements — for example when we approach an obstacle. “In many of the affected patients, this area is fully operational. It is only in a post-traumatic deep-sleep phase because it has been cut off from the command chain,” said Grégoire Courtine. “We simply wake it up again.”

For this purpose, electrodes that fit snugly onto the spinal cord are implanted into the paralysed patients. Using a wireless connection from his laboratory computer, Courtine can trigger focused impulses that activate individual muscle groups. After a training phase, paralysed test subjects in a support harness can stand up again and make small steps on a treadmill.

“It is a very special moment,” said Courtine, “when somebody who was told they could never use their legs again is able to stand up on them after ten years.” Like Courtine’s patient David Mzee: This athletic man severely injured himself during a sports accident in 2010 and has been a paraplegic since then. As a participant in Courtine’s research programme, he can now use a walking aid to move on his own legs. Even outside the laboratory.

Patients can walk again after years
Particularly test subjects who retained a minimum of feeling in the legs were able to make considerable progress through additional, hard training. As they have retained some of their neural connections, commands from the brain are at least received as whispers by the command centre. However, they are too soft to wake the system from its deep sleep.

Grégoire Courtine’s neural implant wakes up the spinal cord and puts it on call. One could say: it pricks up the ears. During stimulation, the soft commands are again heard and the patient can consciously control his movements, in spite of paraplegia.

“Today, several previously paralysed test subjects can also walk outside the laboratory using a walking aid. Sometimes even when the stimulation is switched off,” said Courtine. This means that the damaged nerve connection has been regenerated by stimulation and hard training. This is a breakthrough success, most of all for the persons affected. Courtine remarks: “They have regained part of their lost freedom.”

They regain a part of their lost freedom.GRÉGOIRE COURTINE, neural scientist and winner of the Rolex Award for Enterprise

Things are different for patients whose nerve connections in the spinal cord are almost completely interrupted. They can also stand up and take steps in the laboratory, but have hardly any or no control over their legs — they are mainly remote-controlled from the outside. Grégoire Courtine is currently working on a solution to help even such severe cases.

He is developing a system that detects which movement the patient wants to perform by analysing the brain activity of the patient. Certain patterns correspond to certain movements. As the connection to the legs is no longer operational, the spinal cord injury must be bridged.

The new system detects what patients want
The system that is being developed by Courtine and his team is intended to do exactly that. It monitors movement requests and sends them to the implant in the spinal cord. This stimulates the spinal cord with the appropriate impulse pattern and thus triggers the appropriate movement. This electronic bridge ensures that the commands from the brain are reaching their destination via a detour. Patients can control the stimulation and thus also their movements in this way.

The initial results are promising. However, in spite of all these positive experiences, Grégoire Courtine remains realistic and emphasises that his method does not cure paraplegia. Courtine’s approach is a pragmatic way to make the life of sufferers easier. In spite of considerable progress, it seems unlikely that his test subjects will fully regain their mobility. However, Courtine has nevertheless managed to extend the limits of what is possible. He does not intend to leave it at that. The next goal is: “A treatment for all patients in the world,” said Courtine. This is not just his personal goal, but a message to all paraplegics, “Full of hope for them and their future”.

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