Autonomic testing, also known as autonomic reflex screen or autonomic response testing, is a non-invasive test that measures how the nervous system works to control blood pressure, heart rate and sweating.
Autonomic testing is used to help physicians diagnose the presence and severity of dysautonomia, a disorder of the autonomic nervous system (ANS). Your doctor or neurologist may recommend autonomic testing if you’re experiencing symptoms including:
- Abnormal sweating
- Fluctuating blood pressure
- Numbness and burning in your hands or feet
- Rapid heart rate
- Shortness of breath
Your doctor may order this test for other reasons as well.
Autonomic testing consists of activities designed to stimulate the autonomic nervous system to produce changes in blood pressure, heart rate, breathing and sweating in a controlled setting. We’ll review the procedure with you before starting.
The test includes two main parts — a quantitative sudomotor axon reflex test and a cardiovascular autonomic test.
To prepare for your autonomic test, please follow these instructions:
- No medications that may interfere with the test. Once your test is scheduled, you will receive a list of medications that may need to be stopped before the test because they may affect the results.
- No nicotine (cigarettes) for eight (8) hours before the test.
- No caffeine (coffee, cola, energy drinks, tea, etc.) for eight (8) hours before the test.
- No alcohol the evening before the test.
- No medical or recreational marijuana for at least three (3) days prior to test.
- Eat and drink normally for 24 hours prior to testing and make sure you are hydrated before your test.
Autonomic testing is considered safe. Some people may faint or collapse during the head-up tilt. When a patient’s symptoms and continuous recording of heart rate and blood pressure suggest pre-syncope (near fainting), the patient will be tilted back to a flat position immediately.
Autonomic testing results are considered normal when the physiological measurements obtained in both parts of the test (the QSART and the cardiovascular autonomic test with head-up tilt) are normal and suggest no evidence of dysautonomia.
Abnormal test results can help physicians diagnose, evaluate, monitor and treat disorders of the autonomic nervous system, including:
- Abnormal sweating
- Autonomic neuropathy
- Baroreflex failure
- Certain degenerative diseases, such as multiple system atrophy and autonomic failure in Parkinson’s disease
- Orthostatic intolerance
- Postural tachycardia
- Pure autonomic failure
- Syncopal seizures
Your physician will discuss your test results with you and let you know the next steps.
We perform autonomic testing at the Autonomic Neurology Lab located in the Division of Neurology at the John R Anderson V Medical Pavilion in La Jolla.