In 2014, an experiment with four paralyzed patients began at the University of Louisville (USA). It was based on the methodology of Dr. Susanne Harkim from the Center for Spinal Cord Injury Research in Kentucky, who was going to "re-educate" the spinal cord and teach it to act separately from the brain. Today we can state that the idea was correct.
When the spinal cord is injured, it often remains functional, but loses its connection with the brain. In this state, he can conduct nerve signals to the limbs and muscles, but does not receive commands - Dr. Harkima decided to use the Medtronic pain stimulator to create an imitation of them. In parallel with this, the legs of the patients were forcibly moved from the outside in order to provoke the appearance of a new reflex, which the spinal cord could master and remember.
The orderlies put the patient on a walker and bent his legs in a pattern to imitate walking. The stimulator synchronously sent impulses to the spinal cord according to the same pattern - this was how a connection was created. Three types of exercise were involved: maintaining balance while standing, walking, and jogging on a treadmill. After the reflex was formed, the walkers were replaced with a cane or crutches, the required mode was switched on on the pain stimulator, and the patients' legs began to move in time with the signal. Without direct control on their part, but quite confidently.
In all four experimental subjects, the time of reflex formation, its effectiveness and other parameters are very different, plus the data from the Mayo Clinic, where similar studies were carried out, only brought chaos - each case is individual and difficult to analyze. Dr. Harkima has proven herself right - the thesis that the spinal cord is much stronger and more reliable than we thought. Therefore, it can work without a link with the brain, on its own or under external control.
But the need to carry an external stimulator just to walk is not much better than a wheelchair - the person is still radically dependent on the equipment. Therefore, it would be premature to talk about success, but as a basis for further research, this experiment is very encouraging and inspiring. And at the same time, it makes science fiction closer, when in the literal sense we will be able to connect the most complex equipment directly to ourselves and not be afraid of inadvertently losing our vulnerable head.