For some people with spinal cord injuries, hope of walking thanks to brain stimulation

A hope for certain people with spinal cord injuries: deep stimulation of certain areas of the brain with electrodes could help them walk more easily, according to a study and testimony released at the beginning of December.

“Now, when I see a staircase with only a few steps, I know that I can climb it alone,” says Wolfgang Jäger, one of the two patients who took part in a first test, in a video.

“It’s nice not to have to rely on others all the time,” emphasizes this 54-year-old Swiss, for whom going up and down a few steps during the holidays “was no problem” once the equipment was switched on.

Electrodes were placed in a particular region of his brain and are connected to a device implanted in his chest. When turned on, these devices send electrical impulses to the brain.

The experimental technique is intended for people suffering from incomplete spinal cord injuries – when the connection between the brain and spinal cord has not been completely severed – and capable of partial movements.

The Swiss team that led the study, published by Nature Medicine, distinguished itself by recent advances using implants in the brain or spinal cord to allow paralytics to walk again.

This time, these researchers wanted to determine the region of the brain most involved in the healing of people with spinal cord injuries.

Using 3D imaging techniques to map the brain activity of mice with these lesions, they created a form of “brain atlas.” The region sought was found to be located in the lateral hypothalamus, known to regulate arousal, eating or motivation.

A group of neurons in this area “appears to be involved in the recovery of walking after spinal cord injury,” said Grégoire Courtine, professor of neuroscience at the École Polytechnique Fédérale de Lausanne (Switzerland).

The researchers then sought to amplify the signal from the lateral hypothalamus by deep brain stimulation, a technique frequently used in Parkinson’s disease.

Tests on rats and mice showed that electrical stimulation “immediately” improved walking, according to the study.

The desire to walk

“I feel my legs,” exclaimed the first person to participate in the trial conducted in 2022 – a woman – when her device was turned on for the first time, reported neurosurgeon Jocelyne Bloch. “I feel the urge to walk,” she said once the current was increased, according to the scientist.

Patients included in the trial, who could turn on their stimulator when needed, also benefited from months of rehabilitation and strength training.

For the woman, the goal was to walk without a walker; for Wolfgang Jäger, to climb the stairs alone. “Both achieved their objective,” underlined Jocelyne Bloch.

Further research remains necessary, and this technique would not be effective for all patients, warned Grégoire Courtine.

As everything depends on the stimulation of the brain signal to the spinal cord, the amount of initial signal plays a role. And while deep brain stimulation is now more widespread, some people are not “comfortable” with such intervention on their brain, he added.

In the future, according to these researchers, the best option for recovering from this type of injury could be through stimulation of the lateral hypothalamus and the spinal cord.

Daniel LAWLER/AFP