Major breakthrough in the treatment of Parkinson’s disease: a neuroprosthesis restores fluid walking

Avoiding falls and freezing

In this new study, the team developed a similar neuroprosthesis to compensate for falls and the phenomenon of freezing – when the feet remain glued to the ground during walking – that is sometimes associated with Parkinson’s disease.

Unlike conventional treatments for Parkinson’s, which target the brain regions directly affected by the loss of dopamine-producing neurons, this neuroprosthesis targets the spinal cord region responsible for activating the leg muscles during walking, which is not believed to be directly affected by the disease. However, the spinal cord is under the voluntary control of the motor cortex, whose activity is modified by the loss of dopaminergic neurons.

Drawing on their complementary expertise, the French and Swiss teams were able to develop and test the neuroprosthesis in a non-human primate model reproducing the locomotor deficits caused by Parkinson’s disease. The system not only reduced the locomotor deficits, but also restored walking capacity in this model by reducing freezing.

“Previous attempts to stimulate the spinal cord have failed because they provide blanket stimulation of the locomotor centres without taking physiology into account. In our case, the stimulation overlays the natural functioning of the spinal cord neurons to target, with spatiotemporal coordination, the different muscle groups responsible for walking,” add Courtine and Bloch, co-directors of NeuroRestore, the research centre based in French-speaking Switzerland.

These promising results paved the way for clinical development, to test the device in a patient.

Improvement Thanks to the Neuroprosthesis

A first patient, aged 62, who has been living with the disease for three decades, underwent surgery two years ago at Vaud University Hospital (CHUV) in Lausanne. During a precision neurosurgical procedure, Marc, originally from Bordeaux, was fitted with this new neuroprosthesis, consisting of a field of electrodes placed against the region of his spinal cord that controls gait, and an electrical-impulse generator implanted under the skin of his abdomen.

Thanks to the targeted programming of spinal-cord stimulations that adapt to his movements in real time, Marc has quickly seen his gait problems improve. After a few weeks of rehabilitation with the device, his walking has almost returned to normal.

This neuroprosthesis therefore opens up new prospects for treating the gait disorders suffered by many people with Parkinson’s disease. However, at this stage, this therapeutic concept has only demonstrated its efficacy in one person, with an implant that still has to be optimised for large-scale deployment.

The scientists are therefore working to develop a commercial version of the device* that incorporates all the essential features for optimal daily use. Clinical trials on more patients are also due to start early next year**.
“Our ambition is to enable widespread access to this innovative technology in order to significantly improve the quality of life of patients with Parkinson’s disease, throughout the world”, conclude the researchers.

*In partnership with ONWARD Medical, a company based in Switzerland that will develop these implants.

**Thanks to a one-million-dollar donation from the Michael J. Fox Foundation for Parkinson’s research, NeuroRestore will embark on clinical trials on six new patients early next year. These trials aim not only to validate the technology developed in collaboration with ONWARD, but also to identify the patient profiles most likely to benefit from this innovative therapy. Founded by actor Michael J. Fox (Back to the Future), who himself has Parkinson’s disease, this foundation is the leading private donor in the field of Parkinson’s disease research.

Sources : Inserm newsroom