Scientists at the University of Louisville (USA) have succeeded in helping a man with a complete spinal cord injury, who had lost motor function below the level of the injury, to regain the ability to move his legs voluntarily.
The study, published in the journal Scientific Reports, describes the recovery of motor function in patients who had previously received long-term activity-based training in conjunction with spinal cord epidural stimulation (electrical signals are basically sent to motor neurons in the spine thanks to a device implanted in the nervous system).
34.5 months after the original training, patient Andrew Meas , regained substantial voluntary motor control of the lower extremities and the ability to stand independently without the use of spinal cord stimulation devices.
“ Activity-dependent plasticity can restore voluntary control of movement and position after complete paralysis in humans even years after injury. This should open up new opportunities for recovery-based rehabilitation as a recovery agent, not just to learn to function with compensatory strategies, even for those with the most serious injuries “, clarifies Susan Harkema, leader of the work.
The original training protocol included daily one-hour training sessions with the help of epidural stimulation. After 9 months, Meas continued with activity-based support training at home. After another year of independent training, he returned to the laboratory to train for three months in a supervised activity-based training program with two daily one-hour training sessions that included both foot and step training with the help of epidural stimulation.
After that workout, Meas was able to voluntarily extend his knees and improve his hip flexion. Additionally, using his upper body and minimal additional assistance to get into a standing position, he was able to stand unaided and even stand upright on one leg, without the use of epidural stimulation.
The authors suggest that several mechanisms may be responsible for the recovery of the mobility of Meas, including the growth of axons from the point of injury downwards. Another possible explanation could be that activity-based training with epidural stimulation promoted the remodeling of the connections between neurons in the spinal cord.
Furthermore, they suggest that the patient’s effort in voluntary movement may have been a key factor in recovery. During supervised training, Meas was attentive and focused on the motor task, actively trying to contribute to motor performance.
“The human nervous system can recover from a severe spinal cord injury even years after the injury. In this case, he had the stimulator implanted four years after his injury. We saw motor recovery two years later, so six years later. of the injury, “said Enrico Rejc, co-author of the work. Taking into account that one year after an injury of this type it is already classified as chronic and it is likely that it will not improve further, “these data are proof that the human nervous system has much greater recovery capacities than expected.”
Reference: Enrico Rejc et al, Motor recovery after activity-based training with spinal cord epidural stimulation in a chronic motor complete paraplegic, Scientific Reports (2017). DOI: 10.1038 / s41598-017-14003-w
