A man with paralysis in both legs due to spinal cord injury was enabled to walk using his own brain power, according to results recently published in the Journal of NeuroEngineering and Rehabilitation.
According to results from the preliminary proof-of-concept study, this is the first time that a person with paraplegia due to spinal cord injury was able to walk without relying on manually controlled robotic limbs. The participant, who had been paralyzed for 5 years, used an electroencephalogram (EEG) based system — which sends signals from the participant’s brain to electrodes placed near the knees — to walk along a 3.66 m long course.
“Even after years of paralysis the brain can still generate robust brain waves that can be harnessed to enable basic walking,” An H. Do, MD, a lead researcher on the study and faculty in the Department of Neurology at University of California, Irvine, said in a press release. “We showed that you can restore intuitive, brain-controlled walking after a complete spinal cord injury. This noninvasive system for leg muscle stimulation is a promising method and is an advance of our current brain-controlled systems that use virtual reality or a robotic exoskeleton.”
The researchers used mental training over 19 weeks of testing to reactivate the participant’s walking abilities in the brain. The participant worked to control an avatar in a virtual reality environment while sitting and wearing an EEG cap to read brainwaves. He also underwent physical training to recondition and strengthen his leg muscles. Later, the participant practiced “walking” while suspended 5 cm above the ground, which enabled him to move his legs without having to support his weight. On the participant’s 20th visit, he was able to walk on the ground while wearing a body weight support system to prevent falls.
Further studies are needed to show whether the results of a single patient can be translated to a larger population.
“Once we have confirmed the usability of this noninvasive system, we can look into invasive means, such as brain implants,” Zoran Nenadic, DSc, senior lead researcher of the study and associate professor of Biomedical Engineering at University of California, Irvine, said in the release. “We hope that an implant could achieve an even greater level of prosthesis control because brain waves are recorded with higher quality. In addition, such an implant could deliver sensation back to the brain, enabling the user to feel their legs.”
Reference: Do et al. J Neuroeng Rehabil. 2015; doi:10.1186/s12984-015-0068-7.
Disclosure: The researchers report the study was funded by a grant from the National Science Foundation for which Nenadic is the principal investigator and Do is the co-principal investigator, as well as a private foundation — the Spinal Cord Injury Fund — for which Nenadic is the sole investigator.