Abstract
The Autonomic Nervous System is represented by neurons in ganglia outside the brain and spinal cord that seemed to have functions independent of the Central Nervous System. Autonomic failure may be due to primary autonomic disorders such as Multiple System Atrophy or Pure Autonomic Failure or be secondary to diseases, such as diabetes mellitus or malignancies.
The temporal profile of the disease and its manifestations may be either acute, subacute for post-infective or paraneoplastic syndromes, or chronic for diabetes, alcoholism, and amyloidosis. 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 a frequent cause of syncope, especially in the older patient; is the main feature of cardiovascular autonomic failure in clinically established Multiple System Atrophy, but may also be drug-related, or be the first manifestation of malignancy or anemia.
The present paper will discuss the different causes of dysautonomia in the older patient, focusing on neurodegenerative forms and paraneoplastic neuropathies, from clinical presentation to differential diagnosis.