From Rats to Humans: Project NEUWalk Closer to Clinical Trials
A completely paralyzed rat can be made to walk over obstacles and up stairs by electrically stimulating the severed part of the spinal cord. The EPFL scientists discovered how to control in real-time how the rat moves forward and how high it lifts its limbs. A new lab at the CHUV will extend this technology to human patients as early as next summer using an innovative Gait Platform, bringing the European Project NEUWalk closer to clinical trials.
Lausanne, Switzerland. EPFL scientists have discovered how to control the limbs of a completely paralyzed rat in real time to help it walk again. Their results are published today in Science Translational Medicine.
Building on earlier work in rats, this new breakthrough is part of a more general therapy that could one day be implemented in rehabilitation programs for people with spinal cord injury, currently being developed in a European project called NEUWalk. Clinical trials could start as early as next summer using the new Gait Platform now assembled at the CHUV (Lausanne University Hospital).
How it works
The human body needs electricity to function. The electrical output of the human brain, for instance, is about 30 watts. When the circuitry of the nervous system is damaged, the transmission of electrical signals is impaired, often leading to devastating neurological disorders like paralysis.
Electrical stimulation of the nervous system is known to help relieve these neurological disorders at many levels. Deep brain stimulation is used to treat tremors related to Parkinson’s disease, for example. Electrical signals can be engineered to stimulate nerves to restore a sense of touch in the missing limb of amputees. And electrical stimulation of the spinal cord can restore movement control in spinal cord injury.
But can electrical signals be engineered to help a paraplegic walk naturally? The answer is yes, for rats at least.
“We have complete control of the rat’s hind legs,” says EPFL neuroscientist Grégoire Courtine. “The rat has no voluntary control of its limbs, but the severed spinal cord can be reactivated and stimulated to perform natural walking. We can control in real-time how the rat moves forward and how high it lifts its legs.”
The scientists studied rats whose spinal cords were completely severed in the middle-back, so signals from the brain were unable to reach the lower spinal cord. That’s where flexible electrodes were surgically implanted. Sending electric current through the electrodes stimulated the spinal cord.
They realized that there was a direct relationship between how high the rat lifted its limbs and the frequency of the electrical stimulation. Based on this and careful monitoring of the rat’s walking patterns – its gait – the researchers specially designed the electrical stimulation to adapt the rat’s stride in anticipation of upcoming obstacles, like barriers or stairs.
“Simple scientific discoveries about how the nervous system works can be exploited to develop more effective neuroprosthetic technologies,” says co-author and neuroengineer Silvestro Micera. “We believe that this technology could one day significantly improve the quality of life of people confronted with neurological disorders.”
Taking this idea a step further, Courtine and Micera together with colleagues from EPFL’s Center for Neuroprosthetics are also exploring the possibility of decoding signals directly from the brain about leg movement and using this information to stimulate the spinal cord.
Towards clinical trials using the Gait Platform at the CHUV
The electrical stimulation reported in this study will be tested in patients with incomplete spinal cord injury in a clinical study that may start as early as next summer, using a new Gait Platform that brings together innovative monitoring and rehabilitation technology.
Designed by Courtine’s team, the Gait Platform consists of custom-made equipment like a treadmill and an overground support system, as well as 14 infrared cameras that detect reflective markers on the patient’s body and two video cameras, all of which generate extensive amounts of information about leg and body movement. This information can be fully synchronized for complete monitoring and fine-tuning of the equipment in order to achieve intelligent assistance and adaptive electrical spinal cord stimulation of the patient.
The Gait Platform is housed in a 100 square meter room provided by the CHUV. The hospital already has a rehabilitation center dedicated to translational research, notably for orthopedic and neurological pathologies.
“The Gait Platform is not a rehabilitation center,” says Courtine. “It is a research laboratory where we will be able to study and develop new therapies using very specialized technology in close collaboration with medical experts here at the CHUV, like physiotherapists and doctors.”
This project / NEUWalk received funding from the European Union’s Seventh Framework Programme for research, technological development and demonstration under grant agreement no CP-IP 258654.
For more information, please check:
Youtube epflnews: http://youtu.be/fxNRfxeFnjk
European Project NEUWalk: http://www.neuwalk.eu/
CHUV Adjoint du service & Relations avec les medias
M: +41 79 556 6000
Project Officer – European Commission
T: +32 229 56684
EPFL International Media Relations
M: +41 79 703 4809
Grégoire Courtine (French, English, Italian)
T: +41 21 693 8343
Silvestro Micera (Italian, English)
T: +41 21 693 1047
M: +39 348 071 8936
About the Gait Platform
For technical details about the Gait Platform, please contact:
Joachim von Zitzewitz (French, English)
T: +41 21 693 7280
For questions about patient selection for clinical trials, please contact:
Kim-Yen NGUYEN (English, French)
Executive Assistant for Courtine’s lab
T: +41 21 693 0762