Stimulating the spinal cord with an implanted electrode has enabled a man, paralyzed since 2013 in a snowmobile accident, to regain his ability to stand and walk with assistance, according to a study from Mayo Clinic and UCLA.
The study was published recently in Nature Medicine.
When the implanted stimulator is turned on, the man is able to step with a front-wheeled walker with assistance.
In his 113 rehabilitation visits to Mayo Clinic over a year, the man achieved the following milestones, according to a release from Mayo Clinic:
- Total distance: 111 yards (102 meters) — about the length of a football field
- Total number of steps: 331
- Total minutes walking with assistance:16 minutes
- Step speed: 13 yards per minute (0.20 meters per second)
“What this is teaching us is that those networks of neurons below a spinal cord injury still can function after paralysis,” says Kendall Lee, MD, PhD, co-principal investigator, neurosurgeon and director of Mayo Clinic’s Neural Engineering Laboratories, in the release.
In the study, the man’s spinal cord was stimulated by an implanted electrode, enabling neurons to receive the signal that he wanted to stand or step.
“Now I think the real challenge starts, and that’s understanding how this happened, why it happened, and which patients will respond, adds Kristin Zhao, PhD, co-principal investigator and director of Mayo Clinic’s Assistive and Restorative Technology Laboratory.
The study began in 2016, when the man participated in 22 weeks of physical therapy and then had an electrode surgically implanted by Dr Lee and his Mayo Clinic neurosurgery team.
During 113 rehabilitation sessions, the researchers adjusted stimulation settings, trainer assistance, harness support, and speed of the treadmill to allow the man maximum independence.
The research demonstrated that the man was able to walk over ground using a front-wheeled walker and step on a treadmill placing his arms on support bars to help with balance. However, when the stimulation was turned off, the man remained paralyzed.
In the first week, the participant used a harness to lower his risk of falling and to provide upper body balance. Trainers were positioned at his knees and hips to help him stand, swing his legs, and shift his weight. Because the man did not regain sensation, he initially used mirrors to view his legs, and trainers described leg position, movement and balance.
By week 25, he did not need a harness, and trainers offered only occasional help. By the end of the study period, the man learned to use his entire body to transfer weight, maintain balance, and propel forward, requiring minimal verbal cues and periodic glances at his legs, the release explains.
[Source(s): Mayo Clinic, Science Daily]