In a hospital in Switzerland, permanently paralyzed people are now learning to walk again with the help of stimulating electrodes implanted in their spines. For Grégoire Courtine, professor of neuroprosthetics at the Swiss Federal Institute of Technology Lausanne (EPFL), this day has been a long time coming. “It took us 15 years to get from paralyzed rats to the first steps in humans,” he says. “Maybe in 10 more years, our technology will be ready for the clinic.”
Courtine has made it his mission to reverse paralysis. He started 15 years ago with those paralyzed rats, putting tiny electrical implants into their spines to stimulate nerve fibers below the site of their spinal cord injuries.
Spinal cord repair and rehabilitation is a difficult but important topic to research, can you please give a brief overview of research in this field?
There are many grades of spinal cord injuries, in terms of range of movement, from small disabilities to becoming wheelchair bound for the rest of your life, the range is very broad.
There are many different approaches to try to overcome these disabilities, with key areas of research being focussed on developing stem cell therapies and using growth factors to promote regrowth of the nerve tissue after the injury.
A thin and flexible implant that can be applied directly to the surface of the spinal cord to administer electrical and chemical stimulation has been developed by scientists in Switzerland. The e-Dura implant, made from a silicon substrate embedded with electrodes, replicates the properties of the soft living tissue around the spinal cord; meaning it can remain in situ without discomfort.
In 2012 the researchers showed how electrical-chemical stimulation could restore lower body movement in rats with spinal cord injuries.
Scientists at EPFL in Switzerland have designed a spinal implant which can join severed ends of the spinal cord together allowing paralysed rats to walk again once more. The implant has been named “e-Dura”, short for “Electronic Dura Mater” because the device electronically mimics the function of the dura mater, a protective layer of tissue surrounding the spinal cord. Its function is to prevent foreign substances from entering and damaging the spinal cord.
The spinal cord itself bridges the gap between the brain (where most of the decision making process takes place) and the rest of the body.