With regards to the biopsy, I must caution you and others about the results. I am seeing Dr. James Berry at Mass General who specializes in SFN and he explained the difficulties of biopsy. He said at one time he did them frequently but discovered in too many cases the nerve counts were normal or near normal when there was clearly a problem. He also saw cases where the nerve counts were abnormally low and there was no associated problems. He definitely uses them when the neuropathy appears to be advancing rapidly. But in general, when the neuropathy is not advancing, it does not take him in any new diagnostic direction.