Approach to a case of autonomic peripheral neuropathy

Autonomic neuropathy is the term used to describe autonomic disturbances resulting from diseases of the peripheral autonomic nervous system. This is a group of disorders in which the small, lightly myelinated and unmyelinated autonomic nerve fibers are selectively targeted. Most often, autonomic neuropathies occur in conjunction with a somatic neuropathy (i.e. with motor weakness and/or sensory loss), but they can occur in isolation. Causes of autonomic neuropathies are immune-mediated, paraneoplastic, infectious, toxic and drug-induced, hereditary, nutritional and idiopathic. Amongst all, diabetes mellitus is the most common cause. Autonomic features, which involve the cardiovascular, gastrointestinal, urogenital, sudomotor, and pupillomotor systems, occur in varying combination in these disorders. Orthostatic hypotension is often the first recognized and most disabling symptom. Noninvasive, well-validated clinical tests of autonomic functions along with a host of laboratory tests are of immense value to diagnose the presence and to demonstrate the distribution of autonomic failure. Treatment aims to treat specific cause of the autonomic neuropathy (if possible) and to control symptoms of autonomic dysfunction. Present review attempts to outline clinical approach to a case of autonomic peripheral neuropathy.