So take it as you will.
The three parts that make the body work are; the Brain, central nervous system (nerves and spinal cord) and muscles including tendons, ligaments and everything else. The most important is the central nervous system. It works as the body and brain's information highway, everything goes through it and it's a two lane highway. More about that in a bit. M.S. as we know is a scaring on the nerves in the brain and on the spinal cord, we all understand it sucks. None of us would wish it on anyone!
So much is still unknown like how or why the central nervous system, continues sending signals from the brain to the muscles and the muscles keeps sending signals back to the brain. When so many seem to get lost. This is painful because the scars in the brain get in the way, of the message from the muscle saying it's done, doesn't always get through so it just keeps doing what the brain told it to do pull. Even though the other muscle's used to do what needed doing is done, those messages got through and the muscle's stopped pulling right away. Getting people who don't have m.s. to understand this rarely happens, even as they watch the tears of pain roll down my cheeks some just turn away! The few that have helped by rubbing the muscle, have told me it's a bone but when it finally stops pulling a few thought they broken something, but the look of relief on my face tells them the truth. The central nervous system keeps sending the messages back and forth giving the brain and muscle a chance to make a new connection it's not a reconnect. As long as the brain is learning it's making new connections all the time. No I'm not saying it can make anyone better, a lot of the time there is no way to repair all or any of the damage done by M.S. and to stroke victims and people with head injury. However there are some that are able to regain abilities again, in the research studies of people. That Doctors have said they will need to be in long term care for the rest of their life. Because to much of the brain has been damaged. There are many case studies of people who, can and do end up living alone. There are many theories as to how this happens, but with no smoking gun to prove anyone of them right, it seems to be hit or miss. The One theory that I think makes sense to me anyway. Is that the brain and muscles are making or finding new or different pathways of communication, by passing or working around the damage. Of course it's hard to prove this theory, partly because the people are busy living their life. To sit through all the tests Doctor's who told them they would never be capable of anything that they are doing. Don't blame them one bit, when they don't feel anything is wrong with them. Only a very few get back most of what was lost, to function as they did before but somehow they seem to find a way to enjoy what they have and continue doing the best they can with what they have to work with.
This of course is only my opinion from the research I've done, and my own experience of watching and seeing what the brain is capable of recovering from.
My Auntie Jo after her stroke while having triple by pass surgery done. The only MRI they had was the one right after her heart surgery. According to the Doctor she had lost 2/3 of brain function. She never would sit still so they could do another MRI. It took her two years of rehabilitation to be capable of living alone and for over 14 years that exactly what she did. She did her own cooking, cleaning, bathing and dressing. Later she moved out to California easier to get around no snow, most of her children had moved out there years ago. Twice a year she came back to Minnesota for the state fair in the summer and in February to go with her two sister's on vacation to a resort in northern MN. The one thing she said when I asked her how do you do it? "Do what! Just move it or lose it that's all, ain't nothing to it!" as she shrugged her one shoulder.
With this and the research I've done in the last month, reading what people with seemly just mind over matter and heart, are able to do. All I'm able to do is stand in awe of them. Here are a few of the statements some of the people from the research I've look at, have used to describe how they do that they do: The impossible just takes longer. It all just figured it's self out. Patience, persistence and thank God for some good luck. My Doctor quit on me, telling my kids I was too old! Heard he died a few year ago, I don't give up or quit maybe that why I'm still kicking and he isn't!
As I'm sure you have noticed, not one of them really told how they do that they do. Not sure if they really know how they do it or not. Understanding now why research in this area maybe harder to do. When it seems people don't know how they do what do themselves.