Autonomic Dysfunction and Syncope

Summary: Syncope may be classified into three types based primarily on causative mechanisms: neurally mediated syncope, cardiac syncope, and situational syncope associated with orthostatic hypotension. The clinical features of syncopal events are classified as prodromal symptoms, event symptoms, and post-event symptoms. Making a diagnosis of epilepsy (two or more unprovoked seizures or one seizure and an underlying condition that may provoke seizures) leads to the initiation of anti-epileptic medications that may cause significant side effects. A careful and thorough history is without substitute in making the correct diagnosis in cases of transient loss of consciousness (TLOC). Peripheral nervous system involvement leading to autonomic dysfunction and syncope has been best studied in diabetes mellitus. Overt autonomic neuropathy is delayed for several years after diagnosis of diabetes, although there is evidence that subclinical autonomic dysfunction exists early in the clinical course of type II diabetes mellitus.