Yes I went to the main campus of the Mayo Clinic in Rochester, Minnesota years ago. I have Idiopathic Small Fiber Neuropathy and was diagnosed over 6 years ago. I spent a week at Mayo and underwent exhaustive testing. I basically had about a 1% chance they would find a cause but they didn’t. I have also been elsewhere as well. ISFN is a frustrating diagnosis. I retired from the pharmaceutical industry and I can tell you there is nothing of any significance in research that will soon be approved by the FDA. There is one interesting drug called Engensis that is in Phase III trials, but the company that owns the compound will not respond to any inquiries from patients whatsoever. All drugs out there now they use are to treat symptoms and not the cause. If they do find a treatable cause, consider yourself extremely lucky! My trip to Mayo just confirmed what I already knew.