--can also involve dysfunction of the small autonomic nerves that help to control blood pressure, circulation, even the rate at which food passes through the intestinal tract.

It is not unusual for those with small-fiber neuropathy to have some degree of autonomic dysfunction, though it usually doesn't rise to the level of full blown dysautonomia. Often, it is subtle (and, as the researchers say, "subclinical".)

See:

Autonomic Differential Diagnosis

Small Fiber Sensory

Pain Differential Diagnosis