Three men who have suffered spinal cord injuries are able to walk again thanks to technology developed at the Swiss Federal Institute of Technology, Lausanne.
The men, who suffered sustained cervical spinal cord injuries, can now walk with the aid of crutches or a walking stick. This is thanks to new rehabilitation protocols that combine targeted electrical stimulation of the lumbar spinal cord and weight-assisted therapy. An electrical device inserted around the spine helps boost signals from their brain to their legs, and helps damaged nerves in the spinal cord to regrow.
The study, called STIMO (STimulation Movement Overground) – led by the Ecole Polytechnique Fédérale de Lausanne (EPFL) and the Lausanne University Hospital (CHUV) and scientists Grégoire Courtine and Jocelyne Bloch – saw the patients involved recover voluntary control of leg muscles with neurological function shown to continue beyond training sessions, even after electrical stimulation was turned off.
Jocelyne Bloch said: “The targeted stimulation must be as precise as a Swiss watch. In our method, we implant an array of electrodes over the spinal cord which allows us to target individual muscle groups in the legs. Selected configurations of electrodes are activating specific regions of the spinal cord, mimicking the signals that the brain would deliver to produce walking.”
GTX medical, co-founded by Courtine and Bloch, will use the findings to develop neurotechnology with the aim of turning it into a treatment at hospitals and clinics.
Professor Courtine said: “Our findings are based on a deep understanding of the underlying mechanisms which we gained through years of research on animal models. We were thus able to mimic in real time how the brain naturally activates the spinal cord.”
Professor Courtine, along with Professor Stéphanie Lacour, developed an e-Dura implant designed specifically for implementation on the surface of the brain or spinal cord – imitating the mechanical properties of living tissue. It can simultaneously deliver electrical impulses and pharmacological substances – whilst risks of rejection and/or damage to the spinal cord have been reduced.
The implant is placed beneath the dura mater, directly onto the spinal cord. Its elasticity and its potential for deformation are almost identical to the living tissue surrounding it. When implanted into rats, the e-Dura prototype caused neither damage nor rejection, even after two months.The researchers tested the device prototype by applying their rehabilitation protocol – which combines electrical and chemical stimulation – to paralysed rats. Not only did the implant prove its biocompatibility, but it also did its job perfectly, allowing the rats to regain the ability to walk on their own again after a few weeks of training.
Professor Lacour said: “Our e-Dura implant can remain for a long period of time on the spinal cord or the cortex, precisely because it has the same mechanical properties as the dura mater itself. This opens up new therapeutic possibilities for patients suffering from neurological trauma or disorders, particularly individuals who have become paralysed following spinal cord injury."