RALEIGH, N.C. – Eight paralyzed patients regained some sensation and muscle control in their legs after a year of training on brain-controlled robotics, according to a study published by a Duke University neuroscientist and his colleagues around the world.
The finding is the first of its kind that shows that brain-machine interfaces, including virtual reality, can stimulate partial recovery in paraplegics. Published in the online journal Scientific Reports, the research offers a measure of hope to people who have suffered paralysis from spinal cord injuries and strokes.
The study was conducted in Brazil as part of the Walk Again Project, a consortium of 100 researchers from 25 countries. Work began with the patients in late 2013 in a neurological rehabilitation lab using the sophisticated equipment, and within months scientists began to notice something remarkable, Duke's Dr. Miguel Nicolelis said.
Working at least two hours a week with the machines, paraplegics began to feel sensations and show movement in lower extremities, "something that nobody expected, and that was a tremendous shock," said Nicolelis, who is director of Duke's Center for Neuroengineering.
The brain-machine equipment promotes direct communication between the brain and computers or prosthetics, such as robotic limbs. The systems record signals in the brain and translate motor commands from those signals into movement.
The scientists saw that slowly, the brain was acquiring ability to modulate when the patients thought about moving. In the second stage, patients used a robotic device to move legs in the air. Ultimately the patients used an exoskeleton suit with robotic systems and gyroscopes to stand and walk for 20 to 50 steps. All along, the patients received stimulation on their arms.
By the end of a year with the training, half of the patients had been reclassified from complete paralysis to partial paralysis. One patient left the study because of a move. Now, more than two years after the work started, the seven remaining patients have been reclassified in their level of paralysis.
That doesn't mean the patients can hold themselves up or walk without help. But some can move their legs in walking motion unassisted if their weight is otherwise supported. One of them, dubbed "Patient 1," was a 32-year-old woman who was able to stand in braces or walk using a walker. By the end of 13 months, she could move her legs voluntarily if her body weight was supported in a harness. She had been paralyzed for 13 years.
