Researchers at the University of Louisville (USA) have succeeded in getting a man with a complete spinal cord injury, who had lost motor function below the level of the injury, to recover the ability to move his legs voluntarily.
The study, published in the journal Scientific Reports, describes the recovery of the motor function of the patient who had previously received training based on long-term activity along with spinal cord epidural stimulation (basically electrical signals are sent to the motor neurons in the column thanks to a device implanted in the nervous system).
After 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 human’s even years after the injury.” This should open up new opportunities for rehabilitation based on recovery as a recovery agent, not just to learn how to work with compensatory strategies, even for those with the most serious injuries “, explains 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 support training based on activities at home. After another year of independent training, he returned to the lab to train for three months in a training program based on supervised activities with two daily one-hour training sessions and included both foot and step training with the help of epidural stimulation.
After that training, Meas was able to voluntarily extend his knees and improve his hip flexion.In addition, using the upper part of his body and minimal additional assistance to reach a standing position, he was able to stand without help and even stand erect on one leg, without the use of epidural stimulation.
The authors suggest that several mechanisms may be responsible for the recovery of Meas’s mobility, including the growth of axons from the point of injury down. Another possible explanation could be that activity-based training with epidural stimulation promoted the remodeling of connections between neurons in the spinal cord.
In addition, they suggest that the patient’s effort in the voluntary movement may have been a key factor in recovery. During the supervised training, Meas was attentive and focused on the motor task, trying to actively contribute to motor performance.
“The human nervous system can recover from a serious injury to the spinal cord even years after the injury, in which case they implanted the stimulator four years after their injury, we saw the motor recovery two years later, so six years later of the injury, “said Enrico Rejc, co-author of the work. Bearing in mind that one year after an injury of this type is already classified as chronic and is likely to not improve any further, “These data are proof that the human nervous system has much greater recovery capabilities than expected.”