Three patients took part in clinical research - neuromodulators were implanted in their bodies below the level of injury. The work is a continuation of a research published in Nature Medicine in 2018.
A first male patient, who was injured in 2013, had tried various rehabilitation methods before the procedure, but hadn't succeeded. Generally, people with similar injuries cannot restore sensorimotor activity below the injury level, and the patient had used a wheelchair. After the surgery, however, he restored independent movement in his lower limbs.
A second male patient also showed independent movement during the very first rehabilitation procedures.
A female patient commented, "Before this procedure, I went through two surgeries and was in an induced coma for a month. Here, the surgery took seven minutes. On a second day, I could turn in bed, sit down and move myself to the wheelchair. That's a sensation to me!"
Research Associate Elvira Mukhametova, Kazan Federal University, has undergone an internship at the Mayo Clinic. She explained that the method implies that the stimulator sends signals with a 20 - 40 Hz frequency to the electrodes implanted into the spinal cord and thus activates neural networks below the injury area. Thanks to this, the stimulated networks restore their capacity to receive signals from the brain.
Igor Lavrov, member of Spinal Cord Injury Research Program at Mayo and Head of Motor Neurorehabilitation Lab at Kazan University, said:
Our team's work has shown the effectiveness of epidural stimulation of the spinal cord to restore movement patterns in animals and humans. In patients with the most serious injuries and little rehabilitation potential, it's the spinal cord stimulation which can allow volitional movement and opens prospects for movement rehabilitation when other methods don't work. Stimulation parameters don't repeat signal from the brain, they activate neural networks below the injury, which helps the latter interpret and execute brain signals. With that in mind, we can say that spinal cord is not just a signal conductor, it's also a part of arranging movements - its segments operate the muscles which determine our spatial positioning and movement; spinal neurons also help us in perception. This unique property was used to restore motor functions in our patients."
According to Artur Biktimirov, neurosurgeon at the Far Easter Federal University Medical Center, the humankind has reached the cusp of a revolution in neurology, "We study the principles of brain functioning and learn to operate our brain. Using invasive neuromodulation on the spinal cord is a next important step to provide verticalization and movement rehabilitation in patients with spinal injuries and give a paraplegic individual some hope for a full recovery."
Research Associate Alyona Militskova, Kazan Federal University, adds:
At this stage, apart from implanting electrodes, we also evaluate stimulation effects depending on stimulation parameters. We study muscle response to individually attune a program for each patient. New data can help understand and optimize the rehabilitation process and give chances to patients with complete spinal cord injuries."
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