How a Dutch paralysed man was able to walk again

Author: Danique Versluis 

A Dutch paralysed man regained his ability to walk after participating in a trial. But how was this achieved? Swiss researchers used a ‘digital bridge’ to restore the communication between his brain and spinal cord. The study was published in the world’s leading science journal Nature in May 2023.

In 2011, Gert-Jan Oskam from Tilburg became paralysed in a cycling accident in China. Normally, your brain sends signals to the part of your spinal cord that is involved in the movement of your hips and legs to ensure motion. In Gert-Jan’s case, the cycling accident ensured that part of the signals from his brain are prevented from arriving in the spinal cord, making it impossible to walk.

‘Digital bridge’

Swiss researchers managed to restore the communication between Gert-Jan’s brain and spinal cord with a so-called ‘digital bridge’. This construct consists of two brain implants above the area involved in locomotion and one implant at the spinal cord level that provides movement of the lower limbs.

The brain implants were trained to recognise brain signals that are linked to hip, knee, and ankle movements by measuring Gert-Jan’s brain activity while he attempted to make these movements. After the signal is recognised by the brain implants, a stimulation programme is activated. This programme can send information to the implant in the spinal cord on what muscles to control. Once arrived, the signal is forwarded to nerve cells that pass on the signal to the correct muscles, causing the intended movement. 

So, with the help of this digital bridge, Gert-Jan is able to make his desired movements simply by thinking about them.

Natural control

Five years before he was involved in this study, he took part in another trial. In these experiments, signals were sent from a computer to his spinal cord to simulate leg movement. This system allowed him to take some steps, but the movement was robotic and Gert-Jan reported having no natural control.

Unlike this earlier trial, the Dutchman does have natural control over his movements with the brain implants. Within two minutes of the system being connected, he mentioned having control over his hips. He is now able to climb stairs, stand at a bar to drink a beer, and walk on irregular terrains.

Improvements without digital bridge

Surprisingly, Gert-Jan also gained more control over his movements when the system is off. He is now capable to walk around the house and get in or out of the car without stimulation.

The reason for this improvement is not known. The researchers suspect that new nerve connections have been formed that lead to a better connection between the brain and spinal cord. 

Wide-scale use in the future? 

Although Gert-Jan is the first and only person on whom the system has been tested, the researchers are optimistic for the future. They are hopeful that this digital bridge can be used for different types of paralysis. However, to enable large-scale use, the system will have to be reduced in size and the communication properties will need to be made even faster.