--is there any evidence of that? MRI's showing stenosis/spinal cord compromise?

The problem with neurological symptoms of disturbed sensation or motor function is that they can be exactly mimicked by compromise in the spinal cord or nerve roots vs. more systemic peripheral nerve problems. This is why extensive investigation is often necessary.

An isolated SMALL-FIBER problem, though, would be unlikely to stem only from the spinal cord/nerve roots. That would usually involve larger fiber nerves as well, and in specific dermatome regions (where the nerve roots go to). It seems more investigation is in order--what type of testing have you had, so far, overall?

You might want to peruse the Liza Jane spreadsheets:

www.lizajane.org

----as they're very comprehensive in detailing tests for neurological symptoms (and a good way to track test results over time as well).