I have after much nagging on my part, finally been given the diagnosis of SFN caused by Sjogren's Disease. I started IvIg over a year ago thanks to a willing neurologist. I say that it took some months to help, so don't lose patience with it but I have noticed some improvement. It seems to be the only hope for me and I will likely be on it the rest of my life. But at least it helps. Do your own research even if you have to look everything up.