Thanks, you answered my question. My spinal fluid was normal, my blood markers have never showed inflammation (except one really high ANA elisa which ended up negative upon repeat), more sophisticated testing, my EMGs and evoked potentials were normal. IVIG did not change my autonomic testing. On that basis, they must have ruled out CIDP.

I believe the sural nerve is thinly myelinated, thus, demyelination would be noted if CIDP.

I know they are doing fewer of the sural nerve biopsies as they cause further nerve damage, and if there are other ways to come up with CIDP diagnosis, well then it makes sense to skip the sural nerve biopsy.

I am curious as to the conclusions of this, my last (for now) adventure in diagnostics...more mystery, probably.