Differential Diagnosis of Autonomic Disturbances and Recognition by History and Physical Findings

Abstract

Autonomic failure may be related to primary autonomic disorders, such as multiple system atrophy or pure autonomic failure, or be secondary to diseases, such as diabetes mellitus or malignancies.

Autonomic disorders manifest with autonomic failure or hyperactivity, which may be generalized or focal, and can be classified according to the presence or absence of associated neurological manifestations, such as peripheral neuropathy or Parkinsonism, and their temporal profile, which may be either acute, subacute, or chronic. The temporal evolution of autonomic disturbances has important implications in guiding the diagnostic pathway.

Autonomic dysfunction may result in impairment of cardiovascular, thermoregulatory, gastrointestinal, urogenital, sudomotor, and pupillomotor functions in different combinations and degrees of severity. Orthostatic hypotension is the main feature of cardiovascular autonomic failure in primary autonomic diseases, but such symptoms may also be drug-related, or be the first manifestation of malignancy or anemia. The aim of the present chapter is to guide the differential diagnosis process through aspects of onset, temporal evolvement, and associated manifestations of various diseases.