A spinal cord implant that uses electrical stimulation helped three paralyzed patients stand, walk, swim, and even pedal.
Dr. Jocelyne Bloch from Lausanne University Hospital and Grégoire Courtine of the Swiss Federal Institute of Technology have developed a spinal cord stimulation implant for patients with complete paralysis. The researchers recently tested the breakthrough neuro-technology in three men with complete sensorimotor paralysis. Results of the study are available in the journal Nature Medicine.
The participants ranged in ages from 29 to 41. All three had suffered a motorbike accident leading to a complete loss of voluntary movement below their injuries. As part of the trial, researchers implanted 16-electrode devices within the epidural space of the participants’ spinal cords. Within a day of the surgery, the participants regained motor function in their legs. Not only were they able to stand and walk, but also partake in activities such as swimming and cycling.
All three patients were able to stand, walk, pedal, swim and control their torso movements in just one day, after their implants were activated!
Grégoire Courtine, study author
Moreover, after months of neurorehabilitation training, the patients regained further control over their voluntary muscle movements. One participant could stand for two hours at a time while another reported walking 500 meters independently.
How Does it Work?
Stimulation of the spinal nerves in the dorsal column has previously shown success in spinal cord injuries. Therefore, the Swiss researchers developed the implant to directly target the dorsal root via epidural electrical stimulation (ESS). Using a strategic electrode placement, the researchers directly stimulated the patients’ legs and trunk muscles. Moreover, they connected the electrodes’ wires to a neurostimulator implanted under the skin in the abdomen.
Our new, soft implanted leads are designed to be placed underneath the vertebrae, directly on the spinal cord. They can modulate the neurons regulating specific muscle groups.
Grégoire Courtine, study author
Furthermore, the researchers developed software that enables patients to choose activity-specific stimulation and target the necessary nerves for that movement. Thus, allowing them to control these implants similar to the brain giving out signals for different activities.
That’s thanks to the specific stimulation programs we wrote for each type of activity. Patients can select the desired activity on the tablet, and the corresponding protocols are relayed to the pacemaker in the abdomen.
Grégoire Courtine, study author
However, the voluntary movement only works till a person receives stimulation. Once the device is off, the person cannot carry out the activities. Moreover, not all paralyzed individuals are eligible for the implant. According to study authors, one must have at least 6cm of healthy spinal cord below the lesion for electrodes’ placement.
The team is currently conducting a clinical trial for their neuro-technology.
Reference:
Rowald, A., Komi, S., Demesmaeker, R. et al. Activity-dependent spinal cord neuromodulation rapidly restores trunk and leg motor functions after complete paralysis. Nat Med (2022). https://doi.org/10.1038/s41591-021-01663-5
Wonder , I learned that atleat 6 cm should be there below the LESSION .
Yes, 6cm of the healthy spinal cord (below the lesion) is one of the inclusion criteria for the implant.