Other autonomic tests include a skin punch biopsy, to determine if the number of small fibers in, say, your foot, have diminished - one sign of Peripheral (especially length-dependant) neuropathy. Also sudomotor sweat testing (an autonomic function). I know these are used to diagnose erythromelqalgia, which is an assortment of autonomic symptoms.

I'm going to get that book. Thanks!