I am only familiar with TENS machine which is also a nerve stimulation machine. I have used one for years to help with Pain management. This has worked well for me for several years. As I have developed new symptoms I don't find the TENS is working well for me. It is not a cure but usually takes the edge off the pain so I can have a fairly good nights sleep. I still couldn't be without my TENS machine. I have it on FULL power for at least 3hours especially when I have been standing for more than half an hour and the pain is so bad. This doesn't take the arm pain away. I do most of my housework and cooking by pacing myself. Which means taking breaks between each job I do. If I can't manage something I leave it. Will try another day. I cannot do the same level of work I used to do. I have not been diagnosed with MS but I seem to have many of the symptoms expressed on this site. I am going to explore this with my GP soon and hope I do get some results.