BlueCross BlueShield of Tennessee Medical Policy Manual

Autonomic Nervous System Testing


The autonomic nervous system (ANS) controls physiologic processes that are not under conscious control. ANS disorders, also called dysautonomia, are heterogeneous in etiology, clinical symptoms, and severity. These disorders can be limited and focal, such as individuals with isolated neurocardiogenic syncope or idiopathic palmar hyper hidrosis. At the other extreme, some ANS disorders can be widespread and severely disabling, such as multiple system atrophy, which leads to widespread and severe autonomic failure.

ANS testing consists of a battery of tests intended to evaluate the integrity and function of the ANS. Although there is not a standard battery of tests for ANS testing, testing generally consists of individual tests in three areas; cardiovagal function, vasomotor adrenergic function (the primary method for evaluating individuals with syncope, orthostatic hypotension, postural tachycardia syndrome, and postural dizziness) and sudomotor function or sweat testing. Autonomic testing by well-established methods performed under controlled conditions, can take 90-120 minutes. The results of the battery of tests requires interpretation by a physician familiar with autonomic nervous system physiology.

According to the American Academy of Neurology (AAN) standard techniques used in autonomic testing include:

Numerous automated ANS testing devices have been cleared for marketing by the U.S. Food and Drug Administration through the 510k process (e.g., QHRV System, VitalScan®, ANSAR® ANX, ZYTO® Scan Hand Cradle, Neuropad®, Sudoscan®, EZScan®, Natus VikingQuest, Bodytronic® 200). These devices, along with newer methodologies (e.g., quantitative direct and indirect testing of sudomotor function [QDIRT]) propose to generate data after approximately 10-15 minutes of testing and without physician interpretation. According to the American Academy of Neurology, these methods and/or devices have insufficient published literature to establish clinical utility. These automated devices perform a simplified battery of autonomic tests, typically the heart rate response to deep breathing, the heart rate response to a Valsalva maneuver, and the blood pressure response to standing. Many devices are severely limited in the validity of the data they generate because they do not measure or control for expiratory pressure or include beat-to-beat blood pressure measurement, both of which are requirements, not only for scientifically accurate assessment, but also for billing of autonomic testing.





ANS testing should be performed in the setting of a dedicated ANS testing laboratory, under closely controlled conditions and interpretation of results performed by an individual with expertise in ANS testing. Automated testing in which software generates an interpretation has not been validated by clinical studies and has a greater potential to lead to erroneous results.


American Academy of Neurology. (2014, September). Autonomic testing – model coverage policy. Retrieved February 18, 2015 from

American Academy of Neuromuscular & Electrodiagnostic Medicine. (2009). Evaluation of distal symmetric polyneuropathy: Role of autonomic testing, nerve biopsy, and skin biopsy (an evidence-based review).Retrieved April 14, 2021 from

American Association of Neuromuscular & Electrodiagnostic Medicine. (2017, May). Proper performance of autonomic function testing. Retrieved December 28, 2017 from

BlueCross BlueShield Association. Evidence Positioning System. (7:2020). Autonomic nervous system testing (2.01.96). Retrieved from (26 articles and/or guidelines reviewed)

Yousif, D., Bellos, I., Penzlin, A., Hijazi, M.M., Illigens, B.M., Pinter, A., & Siepmann, T. (2019). Autonomic dysfunction in preeclampsia: a systematic review. Frontiers in Neurology, 10, 816. Abstract retrieved August 28, 2019 from PubMed database.

Ziemssen, T & Siepmann, T. (2019). The investigation of the cardiovascular and sudomotor autonomic nervous system - a review. Frontiers in Neurology, 10, 53. (Level 2 evidence)




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