Seems to me, from your descriptions, that you've probably had mutliple things going on beyond small-fiber neuropathy--"co-morbid", as it were. The sensory and autonomic symtpoms could be explained by pathology of the small-fibers that subsume pain/temperature sensations and many autonomic functions, but I bet you've also had some large-fiber involvement, as small-fiber problems would not affect musculature. And it's entirely possible that you also have involvement from the spinal situation (especially if you have any nerve/cord compression in the thoracic spine, which doctors are not as familiar with as they are with lumbar/cervical issues).
(What kind of sample was taken--a skin biopsy to measure small-fiber intraepidermal density/condition, or direct nerve biopsy of a larger, myelinated nerve?)
You should come look at both our Peripheral Neuropathy and Spinal forums:
http://neurotalk.psychcentral.com/forum20.html
http://neurotalk.psychcentral.com/fo...sprune=-1&f=22