In new results from a clinical trial, researchers show that electrical stimulation of the spinal cord can restore the muscle control and sensory feedback required for coordinated walking movements.
PROVIDENCE, R.I. [Brown University] - The effects of spinal cord injuries are complex and multifaceted. People lose not only the ability to control the movement of their limbs, but also the ability to receive sensory feedback from them. Both are critical to generate the coordinated movement involved in walking.
Now, a team of researchers from Brown University, Rhode Island Hospital, and VA Providence Healthcare has shown progress in restoring two-way communication across a damaged site of the spinal cord. In a study in Nature Biomedical Engineering, the researchers report results from a clinical trial involving three people who had lost the use of their legs following complete spinal cord injuries.
The participants received electrical stimulation of the spinal cord from electrode arrays implanted both above and below their injury sites. The study found that stimulation below the injury could partially restore muscle control in lower extremities, while stimulation above the injury enabled participants to understand where their legs were located in space as they walked, with the assistance of physical therapists, on a treadmill.
"This is the first time that simultaneous motor stimulation and sensory feedback have been demonstrated in people with complete spinal cord injuries," said David Borton, an associate professor of engineering at Brown and a biomedical engineer at the VA Center for Neurorestoration and Neurotechnology. "This is an important step toward the goal of fully bridging the gap created by a spinal lesion. By providing both motor activation and simultaneous sensory feedback, we are making progress toward restoring coordinated movements and functional independence."
The federally supported research is a collaboration between scientists and clinicians from Brown's Institute for Biology, Engineering and Medicine and Carney Institute for Brain Science, Rhode Island Hospital's neurosurgery department, the VA Center for Neurorestoration and Neurotechnology, and other institutions.
"We are incredibly grateful to the participants who volunteered for this study without expectation of long-term benefit to themselves," said Borton, the study's corresponding author. "Their generosity paves the way for future research aimed at fully restoring functions lost to devastating spinal cord injuries."
Dr. Jared Fridley, chief of spinal neurosurgery at the University of Texas at Austin, who contributed to the research while he was a neurosurgeon at Rhode Island Hospital, said the research demonstrates what is possible when engineering innovation is integrated with clinical neuroscience.
"By simultaneously restoring motor activation and meaningful sensory feedback, we're moving beyond isolated function toward coordinated, purposeful movement," Fridley said. "That's a critical step if neurotechnology is going to translate into real-world independence for people living with severe spinal cord injury."
"This work highlights the power of collaboration between the Center for Innovative Neurotechnology for Neural Repair (CINNR) and neurosurgery at the Norman Prince Spine Institute to advance neuromodulation and neurotechnology aimed at improving outcomes for patients with serious spinal cord injuries," said Theresa Williamson, MD, Director of the Center for Minimally Invasive and Endoscopic Spinal Surgery at the Norman Prince Spine Institute and Director of CINNR. "I'm excited to continue this work with Dave Borton and our partners in neurosurgery and at the Carney Institute for Brain Science at Brown University."
Stimulation above and below the injury site
For the study, the team recruited three volunteers who were paralyzed from the waist down after spinal cord injuries. Surgeons placed small electrode arrays above and below the injury site along the participants' spinal cords at the beginning of the two-week, in-hospital study. Both arrays delivered patterned electrical stimulation to the spinal cord that can mimic the natural electrical pulses that travel through a healthy spinal cord.
