Thank you so much for replying. He did say a negative biopsy doesn't mean I don't have it, but we'll see. That's awful that you're burning so much and your doctor won't give you a firm diagnosis. Have you had other tests for SFN? I read something about a sweat test.

I really want to know why my feet burn and tingle and why I have so many autonomic issues and why my backs so bad, but it's exhausting going through lots of testing...I have a feeling my doctor is going to send me for more tests and I do not think I'll hear back from him until next week.

Thank you again very much.

Hey dreamer
So when I got my results back (a couple years ago) my ENFD was also normal - 8 at the calf and 9.71 at the thigh (they wouldnt give morphology because my age - 19 at the time). However - my SGNFD number in the thigh was significantly reduced (29.2) which was like one strike for SFN. Then I had a QSART test (http://my.clevelandclinic.org/servic...-testing/qsart here is a description) which also showed reduced sweat production in the thigh (which matched the skin biopsy SGNFD results). Did you also have SGNFD done with your biopsy? I guess what I am trying to say is that there are other ways to come to the same diagnosis!

Dreamer... I also went to a Cleveland Clinic neurologist who agreed with my local neuro that occasional axonal swellings weren't enough to DX me with PN and that they can occur in asymptomatic people. The only sweat testing I had done was one where I was hooked up to a monitor that measure sweat in response to a sudden fright. It wasn't a biopsy or SGNDT that I know of.

Thanks everyone I've got a feeling I'm in for more testing.

Was your sweat test positive?

I don't think an 'occasional axonal swelling' will be enough to firm a Dx of SFN. It may be a sign that a process has started though. Axonal swelling is NOT normal, so 'something' caused it, and therefore another test 6 months down the road may reveal more important information about what is going on. Your symptoms may be new enough that the fibers aren't showing the damage normally seen with SFN...YET. Maybe Glenntaj will see your post and comment in the morning with more detail information.

Sorry, I don't know your history...How long have you experienced the burning? If more than 6-9 months, that my theory is probably not possible.

You mentioned autonomic symptoms. Can you elaborate on this? How long have these symptoms been present?

Have they considered autoimmune disease? Have you been tested for various autoimmune conditions?

They have. I have been tested for a bunch of things, and was told to see a rheumatologist b/c of the negative bloods. My B12 was a bit low though--in the low 300's. I didn't see a rheumy b/c I knew I was seeing this neuro, and didn't want to see too many new doctors. Don't really like to go to doctors at all and so I've been basically living with this for years, but managing with modifications and Lyrica does help. I was wondering tho if it's possibly causing my joint pain and swelling in my hands.

Nope...this has been going on for years. I actually had to wait a couple years to see this doctor...and he was so confident! I've been managing well, until my feet got worse. Honestly, if someone could fix them, things would be so much easier.

I do have back problems from an accident and for years I thought my back was causing this pain, BUT I actually did suspect PN a while ago. But I have back problems so live life daily in pain...constant pain, but I thought my feet were coming from my back before I saw this doctor.

--but here's the short version.

When the norms for intraepidermal skin density number were established, after a lot of normal and symptomatic individuals were tested (mostly at Johns Hopkins), the researchers there decided--rather arbitrarily, from my view--to set the fifth and ninety-fifth percentiles as "abnormal" and indicative of small fiber neuropathy. (There is a lot of precedent for picking those numbers in medical research, though, that has a lot to do with normal--bell curves shaped--statistical distributions.)

There was a very high standard deviation noted in the research samples, though--that is, the absolute range of number of fibers per cubic centimeter of skin was quite broad. So a large range of numbers would be considered "normal". There was a tendency noted for absolute numbers to decrease with age.

The problem is that since most normal, asymptomatic people don't have skin biopsies done, we don't know what number they start at. A person could be symptomatic, have a skin biopsy performed, show up at the twentieth percentile and be told "no neuropathy". Problem is we don't know if that person was ALWAYS around that level--it's possible s/he could have once been at the fiftieth percentile, say, and if that had been known this biopsy figure would represent a diminishing of fiber density.

This is why the condition of the fibers is supposed to be examined as well. As enbloc notes, fiber swelling, along with excessive branching, may be noticed in some asymptomatic people with no symptoms, but it is not a "normal" finding and usually would prompt some more investigation or at least monitoring. Fortunately, skin biopsy is non-invasive and repeatable, so one can have these done serially (I have) and compared for further diminishing of density or deterioration of condition--or, hopefully, for improvement of density and condition. (This is how we were able to clinically document that my acute-onset body-wide small-fiber syndrome, whatever it was, was healing slowly over time--though no one knows if I will ever get back to whatever my original nerve fiber density numbers were, as we don't know these. But I have gone from the third and fifth percentiles to the sixteenth and twentieth percentiles and the nerve fibers are much less swollen and branched than they were during my first skin biopsy.)