I have idiopathic SFN diagnosed last summer, but my foot symptoms actually started 2 years ago with that kind of stabbing, electric pain on the top of my right foot. I still get it sometimes and has occurred in my other foot as well. It hits like a lightning strike and is difficult to cope with! My doctor prescribed a topical lidocaine gel to apply and I find it helps a lot in times where it's a targeted pain in a specific place. Unfortunately its the only time the gel helps cuz most of my pain is spread over many, many places.