Autonomic Nervous System Testing
Autonomic tests measure how the systems in the body that are controlled by the autonomic nerves respond to stimulation. The data collected during testing will indicate if the autonomic nervous system is functioning as it should, or if nerve damage has occurred.
What is Autonomic Testing?
The nervous system has three parts: motor, sensory and autonomic. The autonomic system manages all internal functions such as blood pressure, blood flow, and sweating. Autonomic tests are conducted to see if the autonomic nervous system is functioning normally.
Purpose of Autonomic Testing
Autonomic testing can help determine if a patient is suffering from certain diseases that target the autonomic nervous system, or as a way to diagnose an illness, or source of pain or other symptoms, such as dizziness and fainting, palpitations, problems with sweating, constipation or diarrhea, urinary troubles, and/or erectile dysfunction.
How is Autonomic Testing Done?
To see if a disease is affecting the autonomic nervous system, several tests are done to monitor blood pressure, blood flow, heart rate, skin temperature, and sweating. By measuring these functions, it is possible to discover whether or not the autonomic nervous system is functioning normally.
Tests to measure blood pressure and heart rate include the tilt table test, a deep breathing test and the Valsalva maneuver. The tilt table test requires that the patient lie on a table that is then raised. The deep breathing test requires the patient to take deep breaths for a minute. The Valsalva maneuver requires that the patient blow into a tube to increase pressure in the chest. While these simple tests are performed, blood pressure and heart rate are monitored.
The Quantitative Sudomotor Axon Reflex Test (QSART) is another autonomic test performed to measure sweating and skin temperature.
Other tests, like a sudoscan, may also be proposed by your physician.
Is Autonomic Testing Painful?
There is none or minimal discomfort with the different autonomic tests, since some tests like the tilt test could induce dizziness and others like the QSART utilizes small electrical currents which are usually minimally felt by the patient.