This issue has been discussed over the years. While it is true that the sural nerve biopsy is still considered the gold standard for diagnosing SFN (small fiber neuropathy), I would argue that it is unnecessary in cases where the dx can be established by skin biopsy and clinical presentation.

BTW, I think that the overall clinical presentation, which would include things like medical history, social history, etc., is by far the most valuable tool for clinical diagnosis. That's why it is so important to find a neurologist who not only is very skilled in these areas but also very thorough (in other words, takes all the time that is needed).

If the sural nerve biopsy could tell you anything at all about causation, then it would be a whole different scenario. But the procedure will do absolutely nothing beyond giving you a more precise picture of SFN damage.

If you are thinking you need the biopsy because you are still not certain that the diagnosis is correct, then you need to ask yourself why do I feel that way (neuro not thorough enough, etc.). And then you can take the appropriate actions to get the certainty that you need, without a sural nerve biopsy.