Pure autonomic failure

Mohamed Kazamel MD (Dr. Kazamel of the University of Alabama at Birmingham has no relevant financial relationships to disclose.)
Louis H Weimer MD, editor. (

Dr. Weimer of Columbia University has received consulting fees from Roche.

Originally released February 7, 2007; last updated August 28, 2018; expires August 28, 2021

This article includes discussion of pure autonomic failure, Bradbury-Eggleston syndrome, Bradbury Eggleston syndrome, and pure progressive autonomic failure. The foregoing terms may include synonyms, similar disorders, variations in usage, and abbreviations.


The author reports on the entity known as pure autonomic failure. The author details the clinical features, pathogenesis and pathophysiology, and the often times difficult differential diagnosis. In addition, the author sheds light on developments including predictive factors for phenotype conversion of patients with an earlier diagnosis of pure autonomic failure and more sinister diagnoses like multiple system atrophy or dementia with Lewy bodies.

Key points


• Pure autonomic failure remains to be a diagnosis of exclusion.


• Careful history taking, physical exam, and meticulous workup are needed to rule out other similar differential diagnoses.


• More sinister synucleinopathies, like multiple system atrophy, often start with a clinical picture that is very similar to pure autonomic failure.


• Specific attention should be directed toward some of the clinical features that were found to predict future development of multiple system atrophy or dementia with Lewy bodies in cases that are diagnosed initially with pure autonomic failure.

Historical note and terminology

In 1898, Langley coined the term “autonomic nervous system.” He identified the enteric, sympathetic, and parasympathetic components. Cannon later added the adrenal-hormonal component in the early 20th century.

It was in 1925 that Samuel Bradbury and Cary Eggleston first described the entity now known as pure autonomic failure, which encompasses the failure of both the sympathetic and the parasympathetic nervous systems. Initially, these 2 clinicians described 3 patients with idiopathic orthostatic hypotension, which is the key characteristic of this uncommon disease (Bradbury and Eggleston 1925). The nomenclature evolved from idiopathic orthostatic hypotension (Bradbury-Eggleston syndrome) into pure progressive autonomic failure and finally to the generally accepted term, pure autonomic failure. The name pure autonomic failure was introduced by Oppenheimer as one of the primary chronic autonomic failure syndromes in addition to Parkinson disease with autonomic failure and multiple system atrophy.

Pure autonomic failure was defined by the 1996 Consensus Committee of the American Autonomic Society and the American Academy of Neurology to be “an idiopathic sporadic disorder characterized by orthostatic hypotension usually with evidence of more widespread autonomic failure and no other neurological features” (Consensus Committee of the American Autonomic Society and the American Academy of Neurology 1996).

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