Mayo Clinic researchers used electrical stimulation on the spinal cord and intense physical therapy to help a man intentionally move his paralysed legs, stand and make step-like motions for the first time in three years.
The case is the result of collaboration with University of California – Los Angeles (UCLA) researchers.
Researchers say these results offer further evidence that a combination of this technology and rehabilitation may help patients with spinal cord injuries regain control over previously paralysed movements, such as step-like actions, balance control and standing.
"We're really excited, because our results went beyond our expectations," says neurosurgeon Dr Kendall Lee, principal investigator and director of Mayo Clinic's Neural Engineering Laboratory. "These are initial findings, but the patient is continuing to make progress."
The 26-year-old patient injured his spinal cord at the sixth thoracic vertebrae in the middle of his back three years earlier. He was diagnosed with a motor complete spinal cord injury, meaning he could not move or feel anything below the middle of his torso.
The study started with the patient going through 22 weeks of physical therapy. He had three training sessions a week to prepare his muscles for attempting tasks during spinal cord stimulation. He was tested for changes regularly. Some results led researchers to characterise his injury further as dis-complete, suggesting dormant connections across his injury may remain.
Following physical therapy, he underwent surgery to implant an electrode in the epidural space near the spinal cord below the injured area. The electrode is connected to a computer-controlled device under the skin in the patient's abdomen. This device, for which Mayo Clinic received permission from the US Food and Drug Administration for off-label use, sends electrical current to the spinal cord, enabling the patient to create movement.
After a three-week recovery period from surgery, the patient resumed physical therapy with stimulation settings adjusted to enable movements. In the first two weeks, he intentionally was able to: control his muscles while lying on his side, resulting in leg movements; make step-like motions while lying on his side and standing with partial support; and stand independently using his arms on support bars for balance intentional, or volitional, movement means the patient's brain is sending a signal to motor neurons in his spinal cord to move his legs purposefully.
"This has really set the tone for our post-surgical rehabilitation – trying to use that function the patient recovered to drive even more return of abilities," says Dr Kristin Zhao, co-principal investigator and director of Mayo Clinic's Assistive and Restorative Technology Laboratory.
The Mayo researchers worked closely with the team of Dr V Reggie Edgerton, at UCLA on this study, which replicates earlier research done at the University of Louisville. The Mayo study marks the first time a patient intentionally controlled previously paralysed functions within the first two weeks of stimulation.
The data suggest that people with discomplete spinal cord injuries may be candidates for epidural stimulation therapy. However, more research is needed into how a discomplete injury contributes to recovering function.
Teams from Mayo Clinic's departments of neurosurgery and physical medicine and rehabilitation, and the division of engineering collaborated on this project.
"While these are early results, it speaks to how Mayo Clinic researchers relentlessly pursue discoveries and innovative solutions that address the unmet needs of patients," says Dr Gregory Gores, executive dean of research, Mayo Clinic. "These teams highlight Mayo Clinic's unique culture of collaboration, which brings together scientists and physician experts who work side by side to accelerate scientific discoveries into critical advances for patient care."
Abstract
We report a case of chronic traumatic paraplegia in which epidural electrical stimulation (EES) of the lumbosacral spinal cord enabled (1) volitional control of task-specific muscle activity, (2) volitional control of rhythmic muscle activity to produce steplike movements while side-lying, (3) independent standing, and (4) while in a vertical position with body weight partially supported, voluntary control of steplike movements and rhythmic muscle activity. This is the first time that the application of EES enabled all of these tasks in the same patient within the first 2 weeks (8 stimulation sessions total) of EES therapy.
Authors
Peter J Grahn, Igor A Lavrov, Dimitry G Sayenko, Meegan G Van Straaten, Megan L Gill, Jeffrey A Strommen, Jonathan S Calvert, Dina I Drubach, Lisa A Beck, Margaux B Linde, Andrew R Thoreson, Cesar Lopez, Aldo A Mendez, Parag N Gad, Yury P Gerasimenko, V Reggie Edgerton, Kristin D Zhao, Kendall H Lee
[link url="https://www.sciencedaily.com/releases/2017/04/170403123621.htm"]Mayo Clinic material[/link]
[link url="http://www.mayoclinicproceedings.org/article/S0025-6196(17)30162-3/abstract"]Mayo Clinic Proceedings abstract[/link]