Neurological aspects of syncope and orthostatic intolerance.

Sudden falling with loss of consciousness from syncope and symptoms of orthostatic intolerance are common, dramatic clinical problems of diverse cause, but cerebral hypoperfusion is the ultimate mechanism in most. Cardiac, reflex, and orthostatic hypotension are important forms to consider. Syncope must be differentiated from seizures, psychiatric events, drop attacks, and other mimics.