Neurostimulation restores feeling in paralysed hand for months after
Keith Thomas, 48, has paralysis, but brain stimulation meant he regained some feeling and movement in his hands – and this was maintained even when the stimulation was turned off
A man who became paralysed after a diving accident six years ago regained the ability to move and feel pressure in his hands thanks to brain stimulation. Now, researchers have revealed he maintained this ability for months after the stimulation was turned off. This suggests the intervention has caused a rerouting of his neuronal connections through neuroplasticity.
“We turned everything off completely, for many months, and yet he’s maintained these gains,” says Chad Bouton at Feinstein Institutes for Medical Research in New York. “That’s unheard of.”
Keith Thomas, 48, was paralysed from the chest down in July 2020. He had no sensation or control over his limbs and had significant muscle wasting, says Bouton.
Advertisement
In 2023, Bouton and his colleagues performed a double neural bypass surgery on Thomas, placing five electrodes into his brain in regions associated with arm movements and feeling. They then connected computer cables to these electrodes, so artificial intelligence could interpret his movement intentions. That information was then wired into electronic splints that stimulated his arms, hands and fingers to carry out his intended movements, enabling him to pick up coffee cups and scratch his face.
To recreate the sense of feeling, the team embedded force sensors into 3D printed wearable devices for Thomas’ hands and fingers, which sent feedback via electrical stimulations into the brain’s sensory areas.
After conducting a series of experiments – which even involved Thomas feeling objects through another person’s hand – Bouton says the team planned to stop the stimulation for about a month, to test for any lingering effects. “Then we had a fire in the building, and it actually forced us to stop stimulation for even longer than we’d planned, for about three months.”
The unexpected interruption led to surprising findings: Thomas continued to maintain strength, feeling and function in his hands. “He’s now also controlling individual fingers with even more accuracy, so that’s big,” says Bouton.
In a video interview with New Scientist, Thomas raised his elbows nearly to shoulder level and described feeling “tingling” in his wrist in response to pressure, even when he’s “unplugged from the computer”. “When I first felt it, it was amazing,” he says. “I’m used to it now.”
Sergey Stavisky at the University of California, Davis, says the work suggests that this approach promotes lasting recovery of the nervous system. “The goal is to help the nervous system partially heal so the person can move their own body better,” he says.
“If these improvements persist even when the system is turned off, then the device is doing more than temporarily restoring function,” says Daniel Lu at UCLA. “It may be helping the nervous system reorganise itself through neuroplasticity.”
This describes the brain’s ability to rewire itself by forming new neural connections, such as after an injury or even in response to a new hobby. “After an injury such as spinal cord injury, those same mechanisms may help restore function by strengthening spared pathways or recruiting alternative circuits, allowing neural signals to travel through networks that were previously too weak to support meaningful movement,” says Lu.
The researchers have observed stronger neural responses in Thomas’ sensory cortex since the intervention.
But this is just a single case report, so it’s unclear how well this approach would work on other people with paralysis from different types of injuries. Charles Greenspon at the University of Chicago, says he has spent years working on stimulation to restore touch in people with spinal cord injuries and continues to find that some respond better than others, and some not at all. “And we have no idea why,” he says. “So, the question is: can you replicate it? This is a really ambitious study, but we need to see them replicating their results in more participants before we believe the hype.”
As to Thomas’ future, “at this point now we know nothing’s impossible, or anything’s possible”, says Boulton. “I think it’s possible he will continue to to improve,” he adds.
Nature Medicine DOI: 10.1038/s41591-026-04498-0
What's Your Reaction?
