--many people with predominantly small-fiber syndromes do report that they have autonomic symptoms of some sort from time to time, even though for many these are minor or "sublcinical", and they tend to affect the blood pressure and sweat systems more often than the gastric tract. This makes sense in that the autonomic nerves are predominantly of the small-fiber, unmyelinated sort, and molecular mimicry process autoimmune reactions may attack the polypeptides that these nerves may share with an individual's small-fiber sensory axons.

Autonomic disruption is also very common in diabetes, which is sort of the "model" for small-fiber syndromes.

Take a look at:

http://www.neuro.wustl.edu/neuromusc...tml#idiopathic

http://www.neuro.wustl.edu/neuromusc....htm#autonomic

http://www.neuro.wustl.edu/neuromuscular/autonomic.html