Hi Kevin, I wasn't exactly sure what the diagnosis was not able to find much specific information on the Mayo Clinic website. I did a search using Google Scholar (https://scholar.google.com) with your specific diagnosis and it came up with a lot of information. Not sure if it's helpful but you may want to look through the links and see if any of the titles jump out at you:
https://scholar.google.com/scholar?hl=en&q=+idiopathic+sensorimotor+axonal+polyneuropathy+treatment&btnG=&as_sdt=1%2C24&as_sdtp=
Hope this helps...

John