Pure autonomic failure (PAF) is an idiopathic and sporadic disorder resulting from the neurodegeneration of the autonomic nervous system. The condition is also known as Bradbury-Eggleston syndrome. The hallmarks of PAF are orthostatic hypotension and syncope. Other common presenting cardiac symptoms include supine hypertension, palpitations, and post-prandial hypotension.

Patients may also develop other symptoms of autonomic failure including dysfunction of urinary and bowel function (urgency, frequency, incontinence, retention, constipation), inadequate thermoregulation (anhidrosis or hyperhidrosis), and sleep disruption with rapid eye movement sleep behavior disorder.

PAF occurs due to deposition of alpha-synuclein in autonomic nerves and ganglia. Most patients with PAF do not have any central nervous system dysfunction but may progress to other central synucleinopathies such as Parkinson disease, multiple system atrophy, and dementia with Lewy bodies.

PAF is rare and no genetic cause has been identified. PAF tends to affect older men more than women, with age of symptom onset after 50 years. Most patients display a slowly progressive course over years to decades. There is no cure for PAF, and management is symptomatic.