The Sudopath machine is used to test the galvanic skin response for evaluating the sympathetic nervous system and sudomotor function. It is a noninvasive tool for detecting diabetic small fiber neuropathy and autonomic dysfunction.
Sudomotor dysfunction is one of the earliest detectable neurophysiologic abnormalities in distal small fiber neuropathy. Sudomotor is a simple 2 minute test used to evaluate postganglionic sympathetic cholinergic activation through measuring (axon-reflex mediated) galvanic sweat response. Sweat glands are stimulated via iontophoresis of a cholinergic agent and the sweat production is measured as an increase of humidity through a foot electrode.