Neurorehabilitation

Recovering after stroke, brain injury and spinal cord injury: how rehabilitation harnesses plasticity, constraint-induced therapy, mirror therapy, speech therapy, robotics, vagus nerve stimulation and spinal stimulation that helped paralysed people walk.

Plasticity as the engine

After a stroke or brain injury, surviving brain regions can take over some lost functions, and connections can sprout and strengthen. Rehabilitation aims to guide this neuroplasticity. Key principles from research: intensity and repetition (hundreds of repetitions of meaningful movements), task specificity (practising the actual skill you want back), timing (a window of heightened plasticity in the first weeks to months after stroke), and motivation and engagement.

Movement recovery

Constraint-induced movement therapy, developed by the psychologist Edward Taub, restrains the stronger arm (for example with a mitt) for much of the day so people must use the weaker arm intensively; trials showed meaningful gains. Taub's work started from controversial research in monkeys and the concept of "learned non-use" — people stop trying to use a weak limb, which further weakens its representation. Mirror therapy, where a mirror makes the moving healthy limb appear to be the affected one, can help movement and phantom limb pain. Robotic devices and exoskeletons provide high numbers of repetitions; virtual reality and games add motivation.

Speech and cognition

Speech and language therapy helps people with aphasia and swallowing problems; intensive therapy appears more effective than spread-out low doses. Cognitive rehabilitation teaches strategies for attention, memory and executive difficulties after brain injury.

Stimulation boosts

Vagus nerve stimulation paired with rehabilitation exercises (each repetition triggering a brief pulse) was approved in the US in 2021 for chronic arm weakness after stroke, after a trial showed added benefit — the pulse is thought to release neuromodulators that enhance plasticity at the right moment.

Walking again after spinal cord injury

Teams led by Grégoire Courtine and Jocelyne Bloch in Switzerland showed that epidural electrical stimulation of the lower spinal cord, timed to intended movements and combined with rehabilitation, enabled several people with chronic paralysis to step and later walk with aids (2018, with further results in 2022). In 2023 they reported a brain–spine interface: a BCI recording intended movements from the cortex wirelessly drove the spinal stimulation, allowing a man, Gert-Jan Oskam, to walk more naturally, with some recovery persisting even when the device was off. These remain research treatments for specific injuries.