I have had SFN for 6 years but was not diagnosed until 3 months ago. My symptons are the same as yours. There are a number of causes of SFN and apparently you need to find the cause in order to determine the treatment. I have been given 4 medications so far and none has given any relief. As of now it could be negative reactions to Acid Blockers, Statins or nerve compression in my lower spinal nerves!

I have yet to be told the cause, so I am trying to find out so I can give my Neuroligist some clues. Sometimes you have to be bold to get the doctors to react since they only take about 10 minutes to help you!

I can't answer what the progression is, it all depends on the cause.

Check out the following site to get some idea what your cause may be related to.

http://www.livestrong.com/article/15...al-neuropathy/