--some neuropathies are linked to poor microcirculation; there are vascultic neuropathies associated with ANA autoimmunities in which this is a factor, and the mechanism of diabetic/impaired glucose tolerance neuropathy is at least in part microcirculatory.

Many of the tests designed to find gross circulatory damage, such as those for peripheral artery disease, may be "normal" and miss damage on the level of the smaller vessels (though without lifestyle intervention or other steps, small level damage has a tendency to get to larger levels in time).

It does sound as if you might have some small-fiber autonomic involvement with your report of the anhydrosis--there are certainly tests that can be done to confirm that, such as sudomotor axon reflex testing. Some level of autonomic involvement, typically disturbances in regulating blood pressure and in sweating, is not uncommon with small-fiber neuropathies.