On April 3, the Mayo Clinic published the results of a new trial that further validates the effectiveness of epidural stimulation for functional improvement in spinal cord injury subjects. In this trial, a 26-year-old, three years out from a motor-complete SCI at T6, regained volitional motor function below his level of injury while using an implanted epidural stimulation device. The study sought to replicate the results of a previous epidural stimulation trial conducted at the University of Louisville, in collaboration with the research team of V. Reggie Edgerton at UCLA.
The Mayo Clinic trial began with the subject, Jered Chinnock, undergoing 22 weeks of three times per week locomotor and task-specific strength training. Following the initial period of motor training, surgeons implanted an epidural stimulation device made by Medtronics and FDA approved for pain (with off-label approval for functional rehabilitation purposes) and connected it to an electrode array positioned on the dorsal epidural surface of the lumbosacral spine. After three weeks of post-surgical recovery, the team began epidural stimulation — with Chinnock attempting volitional leg movements while researchers tuned the settings of the stimulation device.
In the first two weeks of epidural stimulation, with the device turned on, Chinnock 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
• Stand independently using his arms on support bars for balance
Previous trials had produced standing and some volitional movement of lower limbs while reclining, but only after 17 weeks of stimulation and motor rehabilitation. The Mayo Clinic trial marks the first time a subject has been able to voluntarily make step-like movements while standing with partial support, and is the quickest turnaround for functional improvement with epidural stimulation.
“We’re really excited, because our results went beyond our expectations,” says neurosurgeon Kendall Lee, M.D., Ph.D., principal investigator and director of Mayo Clinic’s Neural Engineering Laboratory. “These are initial findings, but the patient is continuing to make progress.”
The preliminary results in this trial show functional return only while the epidural stimulation device is turned on. Previous studies have shown that after prolonged therapy, some volitional control of previously paralyzed muscles remains even when the stimulator is turned off.
It remains to be seen if Chinnock will regain even more function with continued therapy and adjustment of the stimulation settings, but even the initial findings are enough to show that functional return with epidural stimulation continues to move forward, one step at a time.
For more about Chinnock’s journey, see the below video.