Pure autonomic failure results from neuronal loss in autonomic ganglia, causing orthostatic hypotension and other autonomic symptoms.
Pure autonomic failure, previously called idiopathic orthostatic hypotension or Bradbury-Eggleston syndrome, denotes generalized autonomic failure without CNS involvement. This disorder differs from multiple system atrophy because it lacks central or preganglionic involvement. Pure autonomic failure affects more women, tends to begin during a person's 40s or 50s, and does not result in death.
Etiology is usually unknown. Some cases are due to a synucleinopathy (see Pathophysiology); synuclein can also accumulate in patients with Parkinson disease, multiple system atrophy, or Lewy body dementia. Some patients with pure autonomic failure eventually develop multiple system atrophy or Lewy body dementia. Occasionally, the cause is an autoimmune autonomic neuropathy.
The main symptom is orthostatic hypotension; there may be other autonomic symptoms, such as decreased sweating, heat intolerance, urinary retention, bladder spasms (possibly causing incontinence), erectile dysfunction, fecal incontinence or constipation, and pupillary abnormalities.
Diagnosis is by exclusion. The norepinephrine level is usually < 100 pg/mL supine and does not increase with standing. Postural tachycardia syndrome can be differentiated because with standing, it does not usually cause hypotension, the norepinephrine level increases, and heart rate increases by > 30 beats/min or to 120 beats/min within 10 min.
Treatment is symptomatic:
Last full review/revision April 2013 by Phillip Low, MD
Content last modified August 2013