Pure autonomic failure
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.
G90.9 – Disorder of the autonomic nervous system, unspecified
84438001 – Pure autonomic failure
Differential Diagnosis & Pitfalls
- Cardiac arrhythmia
- Orthostatic hypotension
- Postural orthostatic tachycardia syndrome
- Chronic isolated orthostatic tachycardia
- Vasovagal syncope
- Parkinson Disease
- Dementia with Lewy bodies
- Multiple system atrophy
- Panic disorder
- Ehlers-Danlos syndrome
- Diabetic autonomic neuropathy
- Autoimmune autonomic ganglionopathy
- Autonomic neuropathies