Ever hope to walk again was too strong. In the year 2016, numerous clinical trials worldwide, involving new techniques are being developed. And high-tech equipment are entering rehabilitation centers for paraplegic patients recover upright.
Exoskeletons, brain-machine interface, stimulation of the spinal cord …, many promising avenues seem to open, not to mention the spectacular, cell therapy that has already begun to prove itself. A Polish firefighter 40 years was able to walk again a few months ago thanks to a revolutionary treatment based on olfactory cells … (read S. and A. No. 815, January 2015). Today, the patient “feels good and continues to recover functionally,” says her surgeon Pawel Tabakov, associate professor at the Medical University of Wroclaw (Poland). “We are in intense preparation for the next step. “Geoffrey Raisman, researcher at the Institute of Neurology at University College London (UCL) and co-author of this essay promises:” Further clinical trials will be conducted this year. ”
Walking again is possible
With new patients, but always the same ingenious procedure. Walking again is possible. This is already the case in mutual center of functional rehabilitation Kerpape in Ploemeur (Morbihan). This seaside center which deals, among others, the trauma of the spinal cord, invested two years ago in “exoskeletons”. This term originally booked the hard shell of arthropods, now refers to the external robotic devices that attach to the patient’s body to support them and enable them to move forward. The legs are inserted in two grooves provided engines ankles and knees, powered by batteries carried in a backpack. The paraplegic rises relying on crutches and advance the basin. This single pulse then instructs the robotic legs to make a step forward, then another. Two models are in operation in the center of Kerpape, one developed by the Israeli company ReWalk, the other by the American company Ekso Bionics. “We are not magicians, though tempers Philippe Labarthe, director of rehabilitation care. Do not give false hopes. Nonetheless, this mobility aid could develop in five to ten years out of rehabilitation centers. “The major obstacle is the cost (about € 80,000), unaffordable for most patients.” For now, the work of verticality offered by these exoskeletons used to re train the patient to the effort, work and improve his cardiac, respiratory and muscle strength, “added Philippe Labarthe.
The benefit of such an exercise e? As to remuscler and e? Avoid the conse? Quences of a permanent sitting position in a wheelchair (ULCE? Res, troubles me? Taboliques, oste? Oporose …). Still, the exoskeletons of assistance are not has? their infancy. The idea? S would indeed can happen to be? Skittles to gain freedom? movement, pro- ject which has attele? e the socie? you? franc? Wandercraft comfortable. But the date of the first test does not cease for the time e? Be rejected? Seen before 2017.
A new route bypassing the spinal cord
The idea pursued by lighthouse researchers would also give back to reach the “voluntary” walking paraplegic. Indeed, victims of spinal cord no longer have control of their lower limbs because the transmission between the brain and the lower body is interrupted. Recall that the role of the spinal cord is to route the information to the brain of the various parts of the body through the nerves, which carry actuators but also sensory information from the body. When the leads that form the spinal cord is severed or crushed, the nerve fibers in the spinal cord do not grow back, preventing electrical controls the brain to play their role and paralyzing a number of functions.
At the University of California at Irvine (USA), the team of Dr. Christine King and has just reached a crucial stage. She found a way to restore that link brain-legs’ round the problem “in some way. And reconnecting the commands of the brain directly to the muscles, bypassing the spinal cord through a brain-computer interface. To do this it was first necessary to check a key point: “People with spinal cord injury-they retain the neurological signal the walk? And if so, can they still use it to control their locomotion? “Was first interviewed Christine King. To answer, the team turned to virtual reality, this digital universe that replaces the physical reality in which to submerge. She asked Paraplegic subjects to control an avatar (virtual character) via electrical signals from the brain, recorded by an electrode headset (electroencephalogram, EEG). And the device worked! “Patients whose spinal cord was injured therefore retain this neurological signal,” says the researcher.
Algorithms for processing brain signals
The next step was for patients to take control, always through these brain signals, an exoskeleton. Supported by a harness suspended – for security reasons – a paraplegic equipped with an EEG headset to focus his mind on the controls “on” or “idle”. Algorithms have immediately treated the brain signals recorded before transmitting, by the computer, the robotic legs of the system. “This is the first demonstration to the world that a person whose spinal cord is injured can recover a guided stroll through the brain and again perform a directed walking task, “are then excited researchers.
An additional step was taken in 2015. Finished the exoskeleton! This time, the patient’s legs have been equipped with an electrical stimulation system placed on the femoral and peroneal nerves. Still hanging on his harness, the patient can again adjust his thinking brain signals controlling “on” or “idle”. But the order was this time directly transmitted by the computer, to the electrodes of electrical stimulation of the muscles. Thirty workouts and nineteen weeks later, the patient was able to travel a distance of three meters. Never seen ! Now, “we are trying to miniaturize the system and reduce the number of electrodes needed to record brain signals,” said Christine King. The system does not suit all patients. “They must have retained the use of their arms and trunk movements. Those with a weakness or paralysis in the arms, as quadriplegics, are not able to maintain an upright posture during electrical stimulation. ”
Walk again is not a priority elsewhere quadriplegics according to experts. Regaining control of arm and hand grip is especially more important. “This would greatly improve their quality of life because it is probably more important to be able to eat alone than walking,” comments Christine King. For the future, the dream researcher systems controlled by sensors implanted directly into the brain. The University of Melbourne (Australia) is in the process of grant. The first test of an exoskeleton control by an electrode inserted into a brain artery, called “stentrode” is indeed announced for 2017. Elsewhere at the Federal Polytechnic School of Lausanne (Switzerland), we are preparing for a another first: repair spinal cord, rather than overcome its deficiencies. The team of French researcher Gregoire Courtine has already caused a sensation in 2014 by showing that it was possible to walk again paralyzed rats by stimulating electrically and chemically part of the severed spinal cord. The “Courtine” method showed that the neural circuits that control the operation can thus be reactivated. The results of an experiment conducted in monkeys should be published shortly. And already looming the first trial in humans. Expected results in 2017 … impatiently.