Neurology – Autonomic Testing

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To schedule an appointment or ask any questions about this testing, contact the Neurophysiology Lab at 717-531-4940.

Your autonomic nervous system takes care of body functions over which you have no control, such as heart rate and blood pressure regulation and sweating – your body’s thermal regulator.
Autonomic tests will indicate if your autonomic nervous system is functioning as it should.

Autonomic testing may be required for the following conditions and symptoms:

  • Stomach and intestinal, including: 
    • Constipation (hard stools) 
    • Diarrhea (loose stools) 
    • Feeling full after only a few bites (early satiety) 
    • Nausea after eating 
    • Problems controlling bowel movements
    • Swallowing problems 
    • Swollen abdomen 
    • ­ Vomiting of undigested food 
  • Heart and lungs, including: 
    • Abnormal heart rate or rhythm 
    • Blood pressure changes with position that cause dizziness when standing 
    • Palpitations (racing heart, especially positional)
    • Fainting (syncope) upon standing
  • Bladder, including: 
    • Difficulty beginning to urinate 
    • Feeling of incomplete bladder emptying 
  • Other symptoms, including: 
    • Heat intolerance brought on by activity and exercise 
    • Sexual concerns, including erection problems in men and vaginal dryness and orgasm difficulties in women 
    • Small pupil in one eye 
    • Sweating too much or not enough 

Autonomic testing consists of the following four, separate tests: 

Quantitative Sudomotor Axon Reflex Test (QSART)

The machine used for testing at our facility is the Quantitative Sweat Measurement System, or Q-Sweat. This test can be done by itself for small fiber neuropathy or in conjunction with other autonomic testing for autonomic failure concerns.

  • We place four capsules on the skin – one on the foot, two on the leg and one on the arm – and secure each capsule with an elastic band. 
  • Acetylcholine (ACH, which is what causes us to sweat) is placed in each capsule. 
  • A small static stimulation is administered to activate the ACH. The stimulation is slightly uncomfortable, but typically subsides within the first one to two minutes of the test. 
  • The test runs for five minutes with the stimulation and five minutes without the stimulation, with sweat volumes measured at each site. 

Breathing Exercises (two tests)

  • Heart Rate Deep Breathing – the patient is asked to do some relaxation-type breathing while heart rate and blood pressure are monitored.
  • Valsalva Maneuver – the patient is asked to do some labored breathing exercises while heart rate and blood pressure are monitored.

Head-up Tilt-Table Testing

The patient is tilted at a 70 degree angle for up to 20 minutes while heart rate and blood pressure are monitored.

These four tests take approximately two hours to perform and require the patient to change into a hospital gown. The patient is not required to have a driver to take him to and from the exam, although one is recommended. Due to limited space, and for safety reasons, the patient will be the only one allowed in the exam room during the test. 

Testing Preparations

  • Do NOT eat or drink four hours before the test.
  • Avoid ALL caffeinated products, including coffee, tea, soda, chocolate and energy drinks.
  • No nicotine (smoking) is permitted eight hours before the test.
  • No alcohol is permitted on the day of the test.
  • NO over-the-counter cold and cough medications within 24 hours before the test.
  • Skin should be clean and dry.
  • Do NOT apply any lotions or creams to skin the day of the test.
  • Do NOT wear any compressive stockings (Jobst stockings) or corsets the day of the test.
  • Do NOT take any beta blocker medications 24 hours before the test. 
  • Do NOT take any antihistamines 48 hours before the test.
  • Do NOT take any tricyclic antidepressants one week before the test. 
  • Do NOT take any SSRI antidepressants 48 hours before the test.
  • Do NOT take any opioid analgesics on the day of the test.
  • If you have any questions about your medications, CHECK WITH THE PRESCRIBING DOCTOR.