Autonomic testing

Your autonomic nervous system operates without you consciously directing it, controlling functions such as blood pressure, sweating and even breathing. Autonomic testing measures your body's response to stimulation to determine how well your autonomic nervous system is working.

Why would autonomic testing be recommended?

Your HonorHealth neurologist may recommend autonomic testing to see if there are any nerve or brain issues that could be causing a problem with your autonomic nervous system. Conditions include:

This is a possibility if you're reporting symptoms such as:

  • Abnormal sweating.
  • Burning or numbness in the hands or feet.
  • Digestive issues.
  • Dizziness.
  • Fainting.
  • Fatigue.
  • Impaired sexual function.
  • Impaired urination.
  • Lightheadedness.
  • Rapid heart rate.

How is autonomic testing performed?

The goal of the testing is to see how your autonomic nervous system reacts to stressors. The tests are relatively simple, but you may be at the office for a few hours and may be hooked up to several monitors.

Your blood pressure and heart rate will be tested by:
  • Tilt table test: You will lie on a table that will be raised slowly until you're in an almost fully upright position.
  • Deep breathing test: You'll be asked to take several deep breaths over the course of a minute.
  • Valsalva maneuver: You'll breathe into a tube to increase pressure in your chest.

Skin temperature and sweating will be tested by the Quantitative Sudomotor Axon Reflex Test, also known as QSART. A small plastic cup will be placed on certain spots on your arm or leg to measure the amount of sweat produced. To stimulate sweat, a chemical called pilocarpine will be delivered electrically through your skin to your sweat gland. While you'll only feel warmth, a computer will analyze the data to determine how well your nerves and sweat glands are functioning.

All tests are painless and don't require any prep work or down time, although you may need to stop certain medications before the test. Your HonorHealth neurologist will instruct you before the tests.