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.
The autonomic nervous system can be affected by problems involving the
nerves or brain or can occur as the result of certain medications. Symptoms
that can occur from problems with the autonomic nervous system include
dizziness, fainting, fatigue, rapid heart rate, problems with digestion,
abnormal sweating, and impaired sexual functioning. In addition, sometimes
patients with numbness and burning in their hands or feet might experience
ANS problems (this is because the same type of small nerves that operate
the ANS also play a role in sensation).
How is Autonomic Testing performed?
To see if a disease is affecting the autonomic nervous system, several
tests are done to monitor blood pressure, blood flow, heart rate, and
sweating. By measuring these functions, it is possible to discover whether
or not the autonomic nervous system is functioning normally. At Phoenix
Neurological, we use the Quantitative Sudomotor Autonomic Reflex Test
(QSART), which measures sweating and skin temperature.
Quantitative Sudomotor Autonomic Reflex Test (QSART)
QSART is used to diagnose:
- Painful, small fiber neuropathy when nerve conduction test results
- Disturbances of the autonomic nervous system, which controls
the sweat glands, heart, digestive system, other organs, and blood
- Complex pain disorders
How is QSART performed?
The test has three parts and measures resting
skin temperature, resting sweat output, and stimulated sweat output.
Measurements are typically taken on arms, legs or both. A small plastic
cup is placed on the skin and the temperature and amounts of sweat under
the skin are measured. To stimulate sweat a chemical is delivered electrically
through the skin to a sweat gland, but the patient will only feel warmth.
A computer is used to analyze the data to determine how well the nerves
and sweat glands are functioning.
How will it feel?
The patient will experience little
or no discomfort, but the test could take two or three hours to complete.