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Pure Autonomic Failure


Phillip Low

, MD, College of Medicine, Mayo Clinic

Last full review/revision Sep 2021| Content last modified Sep 2021
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Pure autonomic failure is dysfunction of many of the processes controlled by the autonomic nervous system, such as control of blood pressure. It is not fatal.

  • Pure autonomic failure is caused by abnormal accumulation of synuclein in the brain.

  • Blood pressure may decrease when people stand, and they may sweat less and may have eye problems, retain urine, become constipated, or lose control of bowel movements.

  • Doctors do a physical examination and tests to look for signs of autonomic malfunction.

  • Treatment focuses on relieving symptoms.

In pure autonomic failure (previously called idiopathic orthostatic hypotension or Bradbury-Eggleston syndrome), many processes regulated by the autonomic nervous system Overview of the Autonomic Nervous System The autonomic nervous system regulates certain body processes, such as blood pressure and the rate of breathing. This system works automatically (autonomously), without a person’s conscious... read more Overview of the Autonomic Nervous System malfunction. These processes malfunction because the number of nerve cells that control them decreases. The affected cells are located in clusters (called autonomic ganglia) on either side of the spinal cord or near or in internal organs. Only the autonomic ganglia are affected. No other nerves are affected, and the brain and spinal cord are not affected.

Pure autonomic failure affects more women and tends to begin in a person’s 40s or 50s. It does not lead to death.

Symptoms of Pure Autonomic Failure

The most common symptom of pure autonomic failure is

People may sweat less and become intolerant of heat.

The pupils may not widen (dilate) and narrow (constrict) normally. Vision may be blurred.

Diagnosis of Pure Autonomic Failure

  • A doctor's evaluation

  • Tests to rule out other possible causes

If people have REM sleep behavior disorder and orthostatic hypotension due to autonomic dysfunction, they probably have pure autonomic failure.

Doctors may do a blood test to measure levels of norepinephrine. Norepinephrine is one of the chemical messengers (neurotransmitters) used by nerve cells to communicate with each other. This blood test may distinguish pure autonomic failure from other autonomic nervous system disorders that cause similar symptoms. Low levels of norepinephrine suggest pure autonomic failure.

Treatment of Pure Autonomic Failure

  • Symptom relief

There is no specific treatment, so the focus is on relieving symptoms:

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