My understanding is that a big part of the problem may be that the people who specialise in diagnosing SFN do not understand it and one of the bad things that happens is that it is diagnosed without reliable evidence.
An EMG (or strictly neuroelectrophysiological study) is worth doing if there is any suggestion of any sort of neuropathy. SFN is a polyneuropathy, just a restricted type one. You would want to know if others fibres are affected. But it isn't very pleasant and as you say it does not exclude a pure SFN.
Thank you for your answer.
When I'm really heated up before an EMG, does that mean in my simple words, that the nerves are wide open, to let the current run through easier? That must be vasodilation, right?
I suspect vasoconstriction, OI, probably low bood volume, are causing SFN, made worse by diabetes.(Joseph..Systrom, 2021)
The clinical picture was polyneuropathy, the neurologist said. The EMG just showed that I have nerves and they work.
Compare it to this.
A specialist ordered a new car, a nice grey BMW, but the salesman only has a yellow VW beetle and says you have to take this, they are both german, for the same price as the other one? Ridiculous, isn't it. Not in the medical world. Or compare it with diagnosing ME/CFS. Just a bit of testing to rule out some things, concluding it must be ME/CFS.
SFN to me feels as problems with the the nerves just under the skin. I've had over 40 years of restless legs, that felt as inside my body, Diabetes/Metformin stopped that. To be replaced by SFN soon after.
I once had to undergo a knee-arthroscopy while the sedation didn't work, I made a (concious) decision not to ask for more sedation, I could handle it, I just wanted to go home early.
The surgeon tapped my upper leg and told me to relax my muscles. With an epidural should I not have been incapable to contract my muscles? Or feel the tapping?
So normally I was not overreacting to pain. I'm still the same person.
With SFN there must be plenty(poly) of nerves reacting, because they are all screaming at me, at it's worst when I lie down. It can take up to two hours before the pain eases and I can finally sleep.