Paralysed man walks again after scientists implant 'digital bridge' in brain

Gert-Jan Oskam can stand, walk, navigate ramps and even climb stairs

Gert-Jan Oskam has regained the ability to stand and walk naturally, using technology developed by researchers in Switzerland. EPFL/PA

A man paralysed by a spinal cord injury has walked again after scientists created a “digital bridge” restoring communication between his brain and spine.

Using crutches, Dutchman Gert-Jan Oskam, 40, can stand, walk, navigate ramps and even climb stairs, science journal Nature reported on Thursday.

Mr Oskam said he is able to walk at least 100m or more on some days.

He is also able to walk on crutches when the implant is switched off, raising hope that technologies such as these could restore lost nerve function.

“I feel like a toddler, learning to walk again,” Mr Oskam told the BBC.

“It has been a long journey, but now I can stand up and have a beer with my friend. It's a pleasure that many people don't realise.”

Mr Oskam was paralysed in a biking accident 11 years ago that caused an incomplete spinal cord injury.

Five years later, a clinical trial involving a spinal cord implant restored Mr Oskam’s ability to take steps when aided with a walker.

He could walk but only over flat surfaces, and had difficulty starting and stopping.

The aim of the study, by a team including Gregoire Courtine, a neuroscientist at the Swiss Federal Institute of Technology in Lausanne, was to hand control to Mr Oskam’s brain.

“Despite using the [spinal cord implant] stimulation for three years, he hit a plateau in his recovery, and became interested in using the new brain-controlled stimulation,” Dr Courtine said.

“So, he became our first test pilot.”

'Encouraging' results

To walk, the brain delivers executive commands to the neurons in the lumbosacral spinal cord.

Damage to these neurons can interrupt brain commands that are necessary to walk. The result is permanent paralysis.

But scientists created the bridge between the brain and spinal cord to enable control over the timing and volume of muscle activity, restoring control of standing and walking in people paralysed by a spinal cord injury.

Once the patient’s brain activity was decoded, the brain-spine interface took a few minutes to calibrate. Soon the man reported natural-feeling control over movements.

A study published in Nature in 2022 showed that stimulating spinal cord nerves could produce some movement.

But the latest study is the first time that a patient’s own brain activity has been used to restore voluntary control of leg movements.

Dr Courtine and colleagues analysed Mr Oskam’s brain activity while he attempted leg movements. They found patterns of activity were different when he attempted hip, knee and ankle movements.

The team reproduced a walking motion using stimulation patterns aimed at muscles that control putting weight down, pushing forward and leg swings.

An artificial intelligence algorithm translates incoming brain signals into appropriate command signals for the spinal implant.

Mr Oskam underwent two operations to implant electrodes in the brain and the spinal cord to make the digital bridge.

The technology uses artificial intelligence to convert movement thoughts into actions, establishing a direct link between the brain and spinal cord regions involved in walking.

Dr Courtine said: “For the first time this digital bridge bypasses an injury, restoring the communication between two regions of the central nervous system that are disconnected.

"What we observed is a digital repair of the spine, a recovery of neurological function that he has lost for many years."

Physiologist V Reggie Edgerton of California’s Rancho Los Amigos National Rehabilitation Centre, told Science News: "The results are consistent with what I’d hope would happen, which is encouraging.”

Mr Edgerton, who was not involved in the study, said in terms of treating spinal cord paralysis, “we’re at the stage of the Wright brothers and flight”.