Hi! I have a rapidly progressing autoimmune mediated peripheral neuropathy and have found IVIG totally eliminates about 20 to 40% of my symptoms. Unfortunately it hasn't stopped the progression of my neuropathy but it has slowed it down somewhat. A member of my PN support group has short fiber idiopathic neuropathy and went from being disabled to being able to work full time with IVIG. A small study at MGH found 74% of people with short fiber neuropathy had positive results from using IVIG. It works if there is an autoimmune or inflammatory component of your disease. I'm not familiar with SFN but if you can get IVIG approved it is worth a chance. I had results with my first infusions although they say with some conditions it takes a while before you know if it works.