Scientists developed the Walk Again Project, based in Sao Paulo, Brazil, thinking that they could enable paraplegics to move about using the exoskeleton controlled by their thoughts.
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Speaking as the findings were published in Scientific Reports, he said: “We couldn’t have predicted this surprising clinical outcome when we began the project”. But as the researchers trained the patients to manipulate either avatars in a virtual reality context or the exoskeleton for around an hour per day, twice a week, they noticed that some voluntary muscle movements and sensation returned to areas below the sites of the participants’ spinal cord lesions.
Miguel Nicolelis, at Duke University in North Carolina, and his team used a virtual reality system which connects to the brain to simulate leg control in eight people who had suffered spinal cord injuries.
Most of the people who took part in the training also said they had better bladder control and bowel function, meaning they could cut back on laxatives and catheters, reducing their risk of catching life-threatening infections.
“Until now, nobody has seen recovery of these functions in a patient so many years after being diagnosed with complete paralysis”, he told journalists in a phone briefing. “If the brain of a paralyzed person is engaged and imagining movements and controlling a device directly and then the brain gets feedback from this device and the body of the patient is moving too, the brain is reinforced”. The protocol included using a brain-controlled robotic exoskeleton, virtual-reality environments and training on non-invasive brain controlled virtual avatar bodies with visual and tactile feedback.
“We may actually have triggered a plastic reorganization in the cortex by re-inserting a representation of lower limbs and locomotion in the cortex”, Nicolelis said.
More challenging physical equipment was later introduced to further test patients’ control over their posture, balance and ability to use upper limbs. “But it turned out that six months into the training of these patients, and after the World Cup in 2014, we started realizing that the patients were experiencing an improvement in their neurological information”.
Mr Nicolelis is an expert in his field having worked for almost 20 years to build and hone systems that record hundreds of simultaneous signals from neurons in the brain, to extract motor commands and translate them into movement.
The original goal of the project, which is called the Walk Again Project and headquartered in Brazil (where a paraplegic in a brain-controlled exoskeleton kicked off the 2014 world cup in men’s soccer), was to develop one such assistive technology, a brain-controlled assistive neuroprosthetic exoskeleton.
One of them – a 32-year-old woman paralyzed for more than a decade – may have experienced the most dramatic transformation.
Within 13 months, she could walk with the help of braces and a therapist, and could produce a walking motion while suspended from a harness.
Seven of the patients in the new study have continued their rehabilitation with brain-machine interface technologies, and the researchers are continuing to document each patient’s progress.
But the report, which Nicolelis and his colleagues reported in the August 11, 2016, issue of Scientific Reports, “may upgrade this technology from just an assistive technology to a potential rehab therapy for patients with severe spinal cord injuries”, he said. Some may have survived and went quiet for many years.
A new trial is also being earmarked to include people who have suffered more recent spinal cord injuries.
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However, Nicolelis says researchers have found, to their “big surprise”, that it can lead to partial neurological recovery.
