Paralyzed man's hand gains outlast brain stimulation
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- Keith Thomas, 48, who was paralysed from the chest down after a July 2020 diving accident, regained arm movement and pressure sensation through a brain-stimulation system and has kept those gains for months with the device powered down.
- Chad Bouton at the Feinstein Institutes for Medical Research led a 2023 double neural bypass, placing five electrodes in Thomas's motor and sensory cortex; AI reads his movement intent and routes commands to electronic splints that move his hands and fingers.
- 3D-printed wearables with force sensors on Thomas's hands convert pressure into electrical signals fed back to his brain's sensory areas, recreating a sense of touch.
- A building fire forced researchers to extend a planned ~1-month stimulation pause to roughly three months, after which Thomas's strength, sensation, and individual-finger control were still intact — and, per Bouton, even more precise than before.
- Researchers have recorded stronger neural responses in Thomas's sensory cortex since the intervention, which Bouton and Daniel Lu at UCLA attribute to neuroplasticity strengthening spared or alternative neural pathways.
- Charles Greenspon at the University of Chicago and other experts called the result 'ambitious' but cautioned it is a single case report, noting that some spinal-cord patients respond to stimulation and others do not, and replication in more participants is needed before the approach is taken to scale (Nature Medicine, DOI: 10.1038/s41591-026-04498-0).
Why it matters: If the gains truly outlast active stimulation, brain implants could help the injured nervous system partially heal itself rather than act as a permanent external crutch — a qualitatively different therapeutic target. Bouton's team and outside reviewers agree the single-case evidence is striking but unproven, and Charles Greenspon noted that unexplained variability in patient response means the approach must be replicated before it is treated as a generalisable treatment.
