First I had my neurologist (He did my EMG also) do a Small fiber byopsy, even 'though I had no symptoms I was very positive. Then my rhummy look for and found antibodies that indecated Sjogren's. (Blood work) Sjogren's is an autoimmune disease that can attack many systems. After you have had SF problems for awhile, they can influence the Large fibers that are your autonomic nervous system, and that are involved in a lot of systems. You can start to have problems with body temp control, balance to name a few.