I don't know if this information will be of any use to you, but, just in case it might, here goes; Many years ago I had a friend that had to undergo back surgery, unfortunately things did not go well for her; she was unable to walk her feet were so numb, with no feeling at all in them. She was obstinate though and every day she would be taken to a pool with also a hot tub. She would get into the cold pool water then get out and get diretly into the hot tub, over a period of a few months, enough feeling came back into her feet that she could walk again albeit very slowly but limping as well. The cold/hot treatment stimulated the nerves enough to allow her to walk again. I found this quite remarkable.