Injuries to the spinal cord can be debilitating, as they can disrupt the signals from the brain to the lower extremities and cause partial or total paralysis. But a recent development has shown promise in helping patients regain some mobility, through epidural electrical stimulation. A small device is implanted near the spinal cord that uses electrical pulses to stimulate neurons that control leg movements.

Numerous improvements to the technique made over the last decade have shown steadily better results, helping previously completely paralyzed patients move their legs, stand and even walk with aids like crutches and frames. In a new clinical trial from a research center called NeuroRestore, nine patients regained the ability to walk, and their motor function improvements persisted even after the rehabilitation process was completed. Crucially, they could still walk even after the electrical stimulation device had been turned off, a milestone that has eluded previous studies.

This suggested that some level of reorganization had occurred in the nerve fibers used for walking, so the scientists investigated the specific mechanisms in mice and molecular models to see if and how this may be happening.