It depends. If you biopsied a lot of the people with 'Fibromyalgia' you would find a small fiber neuropathy. Dysautonomia is a SFN.

My autonomic symptoms came on simultaneously to the sensory. I have some kind of autoimmune junk...possibly Sjogren's or Lupus. There seem to be a lot of opinions as to what my labs and symptoms mean, but for sure SFN is a given.

I don't think every case becomes autonomic, but I don't think they know the incidence.