New rehabilitation platform combines virtual reality and nerve stimulation for stroke recovery

Researchers at the Medical University of Vienna and ETH Zurich have developed a rehabilitation platform for people suffering from the long-term effects of a stroke, which combines virtual reality with targeted sensory nerve stimulation. In a randomized feasibility clinical study with stroke patients, recently published in "Nature Medicine", the new technology contributed to improvements in arm and hand function, as well as in tactile and body awareness. These results open up the prospect of personalized and more accessible rehabilitation that can support patients' recovery beyond the limits of conventional therapy.

Stroke is one of the leading causes of long-term disability worldwide. Even after intensive early physiotherapy, many stroke survivors continue to live with reduced arm and hand function, impaired sensation and altered body awareness long after the initial event. While conventional rehabilitation can improve motor functions, it often focuses primarily on movement training, instead sensory deficits and body awareness are frequently given insufficient attention. There is therefore a need for more comprehensive rehabilitation strategies.

Personalized training in a virtual environment

To address this need, a research team led by Stanisa Raspopovic (Center for Medical Physics and Biomedical Engineering, MedUni Vienna) has developed "MultiSensy", a rehabilitation platform for patients with arm and hand impairments following a stroke, which combines immersive virtual reality with transcutaneous electrical nerve stimulation. The system turns rehabilitation exercises into interactive virtual tasks designed to train specific arm and hand functions, including reaching, grasping, pinching, and forearm rotation.

At the same time, electrodes attached to their skin stimulate the nerves in real time, allowing participants to feel virtual objects as if they were physically touching them. Inspired by occupational therapy principles, the games can be adapted to each participant's impairment level, allowing training to be both targeted and engaging.

Our aim was to go beyond mere movement training. After a stroke, patients often have difficulty not only moving the affected limb, but also feeling it and perceiving it correctly. MultiSensy was developed to reconnect movement, sensation and body awareness during rehabilitation."

Stanisa Raspopovic, study leader

The system was tested on 34 patients who had suffered a stroke more than three months before the study. Some participants trained using MultiSensy: they wore VR goggles and performed arm and hand exercises in a digital training environment designed to simulate everyday tasks. The control group received conventional rehabilitation, including physiotherapy and occupational therapy. Both groups completed a three-week rehabilitation protocol consisting of twelve training sessions. The clinical examinations were supported by a team from the Faculty of Medicine in Belgrade.

Improvements in function and body perception

The study showed greater improvements in arm and hand recovery in participants treated with MultiSensy than in those receiving conventional rehabilitation. In the Fugl-Meyer Assessment for the upper limb, a standard measure of motor impairment after stroke, the MultiSensy group showed nearly twice the improvement observed in the control group. Similar benefits were also seen in the Action Research Arm Test, which evaluates how well patients can use their arm and hand in everyday functional tasks. But motor disability is just a part of the problem. "After a stroke, some patients struggle to feel touch in their affected hand and may even perceive the arm as distorted in size, shape, or position. Participants treated with the new system showed improvements in their sense of touch and in perception of their affected arm," adds lead author Valerio Aurucci (ETH Zurich). Furthermore, the platform collects movement data during training, providing objective indicators of rehabilitation progress. This allows patients' performance and recovery to be monitored over time, helping clinicians to assess progress more precisely and adapt therapy for each individual.

"The results provide early clinical evidence that immersive virtual reality combined with sensory nerve stimulation can support recovery after stroke, even after months from the event", says Stanisa Raspopovic. "The technology is still at the research stage, and larger clinical trials are needed to confirm its benefits. However, the study opens a promising perspective for future personalized and potentially home-based stroke rehabilitation."