Latest Review Date: June 2024

Category:  Medical                                                  

POLICY:

Quantitative sensory testing, including but not limited to current perception threshold testing, pressure-specified sensory device testing, vibration perception threshold testing, and thermal threshold testing, is considered investigational.

DESCRIPTION OF PROCEDURE OR SERVICE:

Quantitative sensory testing (QST) systems are used for the noninvasive assessment and quantification of sensory nerve function in individuals with symptoms of or the potential for neurologic damage or disease.  Types of sensory testing include current perception threshold testing, pressure-specified sensory testing, vibration perception testing (VPT), and thermal sensory testing. Information on sensory deficits identified using QST has been used in research settings to better understands neuropathic pain. It could be used to diagnose conditions linked to nerve damage and disease, and to improve individual outcomes by impacting management strategies.

Nerve Damage and Disease

Nerve damage and nerve diseases can reduce functional capacity and lead to neuropathic pain.

Treatment

There is a need for tests that can objectively measure sensory thresholds. Moreover, quantitative sensory testing (QST) could aid in the early diagnosis of disease. Also, although the criterion standard for evaluation of myelinated, large fibers is the electromyography nerve conduction study, there are no criterion standard reference tests to diagnose small fiber dysfunction.

Quantitative Sensory Testing

Quantitative sensory testing (QST) systems measure and quantify the amount of physical stimuli required for sensory perception to occur. As sensory deficits increase, the perception threshold of QST will increase, which may be informative in documenting progression of neurologic damage or disease. Currently, QST has not been established for use as a sole tool for diagnosis and management but has been used with standard evaluative and management procedures (e.g., physical and neurologic examination, monofilament testing, pinprick, grip and pinch strength, Tinel sign, and Phalen and Roos test) to enhance the diagnosis and treatment-planning process, and to confirm physical findings with quantifiable data. Stimuli used in QST include touch, pressure, pain, thermal (warm and cold), or vibratory stimuli.

The criterion standard for evaluation of myelinated large fibers is the electromyographic nerve conduction study. However, the function of smaller myelinated and unmyelinated sensory nerves, which may show pathologic changes before the involvement of the motor nerves, cannot be detected by nerve conduction studies. Small fiber neuropathy has traditionally been a diagnosis of exclusion in individuals who have symptoms of distal neuropathy and a negative nerve conduction study.

Depending on the type of stimuli used, QST can assess both small and large fiber dysfunction. Touch and vibration measure the function of large myelinated A-alpha and A-beta sensory fibers. Thermal stimulation devices are used to evaluate pathology of small myelinated and unmyelinated nerve fibers; they can be used to assess heat and cold sensation, as well as thermal pain thresholds. Pressure-specified sensory devices (PSSD) assess large myelinated sensory nerve function by quantifying the thresholds of pressure detected with light, static, and moving touch. Finally, current perception threshold testing involves the quantification of the sensory threshold to transcutaneous electrical stimulation. In current perception threshold testing, typically three frequencies are tested: 5 Hz, designed to assess C fibers; 250 Hz, designed to assess A-delta fibers; and 2,000 Hz, designed to assess A-beta fibers. Results are compared with those of a reference population.

Because QST combines the objective physical, sensory stimuli with the subject individual response. It is psychophysical and requires individuals who are alert, able to follow directions, and cooperative. Also, to get reliable results, examinations need to contain standardized instructions to the individuals, and stimuli must be applied consistently by trained staff. Psychophysical tests have greater inherent variability, making their results more difficult to reproduce.

Primarily, QST has been applied in individuals with conditions associated with nerve damage and neuropathic pain. A retrospective analysis of a prospective database maintained by the German Research Network on Neuropathic Pain by Forstenpointner et al (2021) compared QST profiles between individuals with painful neuropathic conditions (n=332), individuals with neuropathic conditions who did not report pain (n=111), and healthy controls (n=112). After extensive QST testing, including thermal, mechanical/vibration, and pain sensitivity, the researchers found similar QST profiles between individuals who reported pain and individuals who did not report pain, which raises concern about the role of QST in general indecision-making for neuropathic conditions. There have also been preliminary investigations to identify sensory deficits associated with conditions such as autism spectrum disorder, Tourette syndrome, restless legs syndrome, musculoskeletal pain, and response to opioid treatment.

KEY POINTS:

The most recent literature review was updated through April 10, 2024.

Summary of Evidence

For individuals who have conditions linked to nerve damage or disease (e.g., diabetic neuropathy, carpal tunnel syndrome) who receive current perception threshold testing, the evidence includes several studies on technical performance and diagnostic accuracy. Relevant outcomes are test accuracy and validity, symptoms, and functional outcomes. The existing evidence does not support the accuracy of current perception threshold testing for diagnosing any condition linked to nerve damage or disease. Studies comparing current perception threshold testing with other testing methods have not reported on sensitivity or specificity. Also, there is a lack of direct evidence on the clinical utility of current perception testing and, because there is insufficient evidence on test performance, an indirect chain of evidence on clinical utility cannot be constructed. The evidence is insufficient to determine that the technology results in an improvement in the net health outcome.

For individuals who have conditions linked to nerve damage or disease (e.g., diabetic neuropathy, carpal tunnel syndrome) who receive pressure-specified sensory testing, the evidence includes several studies on diagnostic accuracy. Relevant outcomes are test accuracy and validity, symptoms, and functional outcomes. Current evidence does not support the diagnostic accuracy of pressure-specified sensory testing for diagnosing any condition linked to nerve damage or disease. A systematic review found that pressure-specified sensory testing had low accuracy for diagnosing spinal conditions. Also, there is a lack of direct evidence on the clinical utility of pressure-specified sensory testing and because there is insufficient evidence on test performance, an indirect chain of evidence on clinical utility cannot be constructed. The evidence is insufficient to determine that the technology results in an improvement in the net health outcome.

For individuals who have conditions linked to nerve damage or disease (e.g., diabetic neuropathy, carpal tunnel syndrome) who receive vibration perception testing (VPT), the evidence includes several studies on diagnostic accuracy. Relevant outcomes are test accuracy and validity, symptoms, and functional outcomes. A few studies have assessed the diagnostic performance of vibration testing using devices not cleared by the U.S. Food and Drug Administration (FDA). Also, there is a lack of direct evidence on the clinical utility of VPT and, in the absence of sufficient evidence on test performance, an indirect chain of evidence on clinical utility cannot be constructed. The evidence is insufficient to determine that the technology results in an improvement in the net health outcome.

For individuals who have conditions linked to nerve damage or disease (e.g., diabetic neuropathy, carpal tunnel syndrome) who receive thermal sensory testing, the evidence includes diagnostic accuracy studies. Relevant outcomes are test accuracy and validity, symptoms, and functional outcomes. Two studies identified evaluated the diagnostic accuracy of thermal quantitative sensory testing (QST) using the same FDA -cleared device. Neither found a high diagnostic accuracy for thermal QST but both studies found the test had potential when used with other tests. An additional study using a different device also supports the potential of thermal QST in combination with other tests. The optimal combination of tests is currently unclear. Also, there is a lack of direct evidence on the clinical utility of thermal sensory testing and, because there is insufficient evidence on test performance, an indirect chain of evidence on clinical utility cannot be constructed. The evidence is insufficient to determine that the technology results in an improvement in the net health outcome.

Practice Guidelines and Position Statements

American Academy of Neurology

The American Academy of Neurology (2003; reaffirmed 2022) concluded that quantitative sensory testing (QST) is probably (level B recommendation) an effective tool for documenting of sensory abnormalities and changes in sensory thresholds in longitudinal evaluation of patients with diabetic neuropathy.  Evidence was weak or insufficient to support the use of QST in individuals with other conditions (small fiber sensory neuropathy, pain syndromes, toxic neuropathies, uremic neuropathy, acquired and inherited demyelinating neuropathies, or malingering).

American Association of Neuromuscular & Electrodiagnostic Medicine

In 2004, The American Association of Neuromuscular & Electrodiagnostic Medicine (AANEM) published a technology literature review on QST (light touch, vibration, thermal, pain). The review concluded that QST is a reliable psychophysical test of large- and small-fiber sensory modalities but is highly dependent on the full patient cooperation. Abnormalities do not localize dysfunction to the central or peripheral nervous system, and no algorithm can reliably distinguish between psychogenic and organic abnormalities. The AANEM review also indicated that QST has been shown to be reasonably reproducible over a period of days or weeks in normal subjects, but, for individual patients, more studies are needed to determine the maximum allowable difference between two QSTs that can be attributed to experimental error.

In 2005, the AANEM with American Academy of Neurology and American Academy of Physical Medicine & Rehabilitation developed a formal case definition of distal symmetrical polyneuropathy based on a systematic analysis of peer-reviewed literature supplemented by consensus from an expert panel. QST was not included as part of the final case definition, given that the reproducibility of QST ranged from poor to excellent, and the sensitivities and specificities of QST were found to vary widely among studies. 

American Diabetes Association

The American Diabetes Association annually updates standards for retinopathy, neuropathy, and foot care. Although temperature and vibration testing are recommended as part of the evaluation of small fiber and large fiber function, respectively, the specific screening tests for diabetic peripheral neuropathy that are described in the standard are manual/clinical rather than quantitative. Therefore, QST does not appear to have a role in the current routine evaluation or diagnosis of diabetic peripheral neuropathy.

U.S. Preventive Services Task Force Recommendations

Not applicable.

KEY WORDS:

Neurometer, current perception threshold testing, CPT, nerve conduction study, NCS,  quantitative sensory testing, sensory testing, pressure-specified sensory devices, PSSD, vibration perception threshold devices, VPT, CASE IV, CASE IV Computer Aided Sensory Evaluator, Thermal Threshold Tester, TTT, Thermal Sensory Analyzer, TSA, Nk Pressure-Specified Sensory Device, Medi-Dx 7000®, Air Pulse Sensory Stimulator, AP-4000, Neural-Scan, Pain Vision Model PS-2100, Modified Contact-Heat Evoked Potential Stimulator (CHEPS), Pathway Model ATS/CHEPS

APPROVED BY GOVERNING BODIES:

A number of QST devices have been cleared for marketing by the U.S. Food and Drug Administration (FDA) through the 510(k) process. Examples are listed in Table 1.

Table 1. FDA-Approved Quantitative Sensory Testing Devices

FDA: Food and Drug Administration.

BENEFIT APPLICATION:

Coverage is subject to member’s specific benefits.  Group-specific policy will supersede this policy when applicable.

ITS: Home Policy provisions apply

FEP: Special benefit consideration may apply.  Refer to member’s benefit plan.  

CURRENT CODING: 

CPT codes:

HCPCS:

The following codes should NOT be billed for these procedures:

CODING:

CPT codes:

REFERENCES:

1. Abraham A, Albulaihe H, Alabdali M, et al. Elevated vibration perception thresholds in CIDP patients indicate more severe neuropathy and lower treatment response rates. PLoS One. 2015; 10(11):e0139689.
2. American Academy of Neurology. Quantitative Sensory Testing. 2003 (reaffirmed 2022). www.aan.com/Guidelines/home/GuidelineDetail/87. 
3. Anand P, Privitera R, Yiangou Y, et al. Trench foot or non-freezing cold injury as a painful vaso-neuropathy: clinical and skin biopsy assessments. Front Neurol.  2017; 8:514.
4. Azzopardi K, Gatt A, Chockalingam N, et al. Hidden dangers revealed by misdiagnosed diabetic neuropathy: A comparison of simple clinical tests for the screening of vibration perception threshold at primary care level. Prim Care Diabetes. Apr 2018; 12(2):111-115.
5. Chong PS and Cros DP. Technology literature review: Quantitative sensory testing. Muscle Nerve 2004; 29(5): 734-747. 
6. Devigili G, Tugnoli V, Penza P, et al. The diagnostic criteria for small fibre neuropathy: from symptoms to neuropathology. Brain. Jul 2008; 131(Pt 7): 1912-25.
7. El Sayed NA, Aleppo G, Aroda VR, et al. 12. Retinopathy, Neuropathy, and Foot Care: Standards of Care in Diabetes-2023. Diabetes Care. Jan 01 2023; 46(Suppl 1): S203-S215.
8. England JD, Gronseth GS, Franklin G et al. Distal symmetrical polyneuropathy: definition for clinical research. Muscle Nerve 2005; 31(1):113-23.
9. Fabry V, Gerdelat A, Acket B, et al. Which Method for Diagnosing Small Fiber Neuropathy?. Front Neurol. 2020; 11: 342.
10. Ferdousi M, Kalteniece A, Azmi S, et al. Corneal confocal microscopy compared with quantitative sensory testing and nerve conduction for diagnosing and stratifying the severity of diabetic peripheral neuropathy. BMJ Open Diabetes Res Care. Dec 2020; 8(2).
11. Forstenpointner J, Ruscheweyh R, Attal N, et al. No pain, still gain (of function): the relation between sensory profiles and the presence or absence of self-reported pain in a large multicenter cohort of patients with neuropathy. Pain. Mar 01 2021; 162(3): 718-727.
12. Goel A, Shivaprasad C, Kolly A, et al. Comparison of electro-chemical skin conductance and vibration perception threshold measurement in the detection of early diabetic neuropathy. PLoS One. 2017; 12(9):e0183973.
13. Hubscher M, Moloney N, Leaver A et al. Relationship between quantitative sensory testing and pain or disability in people with spinal pain-A systematic review and meta-analysis. Pain 2013; 154(9):1497-504.
14. IOM (Institute of Medicine). 2011. Clinical Practice Guidelines We Can Trust. Washington, DC: The National Academies Press.
15. Lefaucheur JP, Wahab A, Plante-Bordeneuve V, et al. Diagnosis of small fiber neuropathy: A comparative study of five neurophysiological tests. Neurophysins Clin. Dec 2015; 45(6):445-455.
16. Mythili A, Kumar KD, Subrahmanyam KA et al. A comparative study of examination scores and quantitative sensory testing in diagnosis of diabetic polyneuropathy. Int J Diabetes Dev Ctries. Jan 2010; 30(1):43-8.
17. Nath RK, Bowen ME, Eichhorn MG. Pressure-specified sensory device versus electrodiagnostic testing in brachial plexus upper trunk injury. J Reconstr Microsurg. May 2010; 26(4):235-42.
18. Papanas N, Pafili K, Demetriou M, et al. The Diagnostic Utility of VibraTip for Distal Symmetrical Polyneuropathy in Type 2 Diabetes Mellitus. Diabetes Ther. Jan 2020; 11(1): 341-346.
19. Park R, Wallace MS, Schulteis G. Relative sensitivity to alfentanil and reliability of current perception threshold vs. von Frey tactile stimulation and thermal sensory testing. Journal Peripheral Nervous System. Dec 2001; 6(4): 232-240.
20. Shy ME, et al. Quantitative sensory testing: Report of the therapeutics and technology assessment subcommittee of the American Academy of Neurology. Neurology. March 25 2003; 60(6): 898-904.
21. Spanakis EK, Golden SH. Race/ethnic difference in diabetes and diabetic complications. Curr Diab Rep. Dec 2013; 13(6):814-23.
22. Suokas AK, Walsh DA, McWilliams DF et al. Quantitative sensory testing in painful osteoarthritis: A systematic review and meta-analysis. Osteoarthritis Cartilage. Oct  2012; 20(10):1075-85.
23. Taylor YJ, Davis ME, Mahabaleshwarkar R et al. Racial/ethnic disparities in diabetes care and outcomes: A mixed methods study. Journal of Health Disparities Research and Practice. 2018; 11(2).
24. Weber R, Schuchmann J, Albers J et al. A prospective blinded evaluation of nerve conduction velocity versus Pressure-Specified Sensory Testing in carpal tunnel syndrome. Ann Plast Surg. Sep 2000; 45(3):252-7.
25. Ziccardi VB, Dragoo J, Eliav E et al. Comparison of current perception threshold electrical testing to clinical sensory testing for lingual nerve injuries. J Oral Maxillofac Surg. Feb 2012; 70(2):289-94. 

POLICY HISTORY:

Medical Policy Group, September 2002 (1)

Medical Policy Administration Team, September 2002

Available for comment October 29-December 12, 2002

Medical Policy Group, July 2005 (1)

Medical Policy Administration Committee, July 2005

Available for comment August 6-September 19, 2005

Medical Policy Group, September 2006 (1)

Medical Policy Group, September 2008 (1)

Medical Policy Group, April 2009 (1)

Medical Policy Administration Committee, May 2009

Available for comment May 12-June 24, 2009

Medical Policy Group, June 2010 (1)

Medical Policy Panel September 2010

Medical Policy Group, February 2011 (2): Key Points, References Updated

Medical Policy Group, September 2011 (1): Update to Key Points and References

Medical Policy Group, October 2012 (1): 2012 Update to Key Points and References

Medical Policy Panel, October 2013

Medical Policy Group, January 2014 (2): Policy statement unchanged.  Key Point, Key Words, References updated with findings from literature search.

Medical Policy Panel, October 2014

Medical Policy Group, October 2014 (5):  Policy statement unchanged.  Key Points and References updated with findings from literature.

Medical Policy Panel, November 2015

Medical Policy Group, November 2015 (6):  Updates to Key Points and References; no change to policy statement.

Medical Policy Panel, June 2017

Medical Policy Group, June 2017 (6):  Updates to Description, Key Points, Coding and References; no change to policy statement.

Medical Policy Panel, June 2018

Medical Policy Group, July 2018 (6): Updates to Key Points and References.

Medical Policy Panel, July 2019

Medical Policy Group, July 2019 (3): Updates to Description, Key Points, and References. No change to Policy Statement.

Medical Policy Panel, October 2020

Medical Policy Group, November 2020 (3): Updates to Key Points, Practice Guidelines and Position Statements, and References. No changes to policy statement or intent.

Medical Policy Panel, June 2021

Medical Policy Group, July 2021 (3): 2021 Updates to Key Points, Practice Guidelines and Position Statements, and References. Added HCPCS code: G0255 to Current Coding Section. Policy statement updated to remove “not medically necessary,” no change to policy statement or intent.

Medical Policy Panel, June 2022

Medical Policy Group, June 2022 (3): 2022 Updates to Description, Key Points, Practice Guidelines and Position Statements, and References. No changes to policy statement or intent.

Medical Policy Panel, June 2023

Medical Policy Group, June 2023 (3): 2023 Updates to Description, Key Points, Approved By Governing Bodies, Benefit Applications, and References. Key Words added: Air Pulse Sensory Stimulator, AP-4000, Neural-Scan, Pain Vision PS-2100, Modified Contact-Heat Evoked Potential Stimulator (CHEPS), Pathway Model ATS/CHEPS. No change to Policy Statement.

Medical Policy Panel, June 2024

Medical Policy Group, June 2024 (3): Updates to Description, Key Points, and References. No change to the policy statement or intent.

This medical policy is not an authorization, certification, explanation of benefits, or a contract. Eligibility and benefits are determined on a case-by-case basis according to the terms of the member’s plan in effect as of the date services are rendered. All medical policies are based on (i) research of current medical literature and (ii) review of common medical practices in the treatment and diagnosis of disease as of the date hereof. Physicians and other providers are solely responsible for all aspects of medical care and treatment, including the type, quality, and levels of care and treatment.

This policy is intended to be used for adjudication of claims (including pre-admission certification, pre-determinations, and pre-procedure review) in Blue Cross and Blue Shield’s administration of plan contracts.

The plan does not approve or deny procedures, services, testing, or equipment for our members. Our decisions concern coverage only. The decision of whether or not to have a certain test, treatment or procedure is one made between the physician and his/her patient. The plan administers benefits based on the member’s contract and corporate medical policies. Physicians should always exercise their best medical judgment in providing the care they feel is most appropriate for their patients. Needed care should not be delayed or refused because of a coverage determination.

As a general rule, benefits are payable under health plans only in cases of medical necessity and only if services or supplies are not investigational, provided the customer group contracts have such coverage.

The following Association Technology Evaluation Criteria must be met for a service/supply to be considered for coverage:

1. The technology must have final approval from the appropriate government regulatory bodies;

2. The scientific evidence must permit conclusions concerning the effect of the technology on health outcomes;

3. The technology must improve the net health outcome;

4. The technology must be as beneficial as any established alternatives;

5. The improvement must be attainable outside the investigational setting.

Medical Necessity means that health care services (e.g., procedures, treatments, supplies, devices, equipment, facilities or drugs) that a physician, exercising prudent clinical judgment, would provide to a patient for the purpose of preventing, evaluating, diagnosing or treating an illness, injury or disease or its symptoms, and that are:

1. In accordance with generally accepted standards of medical practice; and

2. Clinically appropriate in terms of type, frequency, extent, site and duration and considered effective for the patient’s illness, injury or disease; and

3. Not primarily for the convenience of the patient, physician or other health care provider; and

4. Not more costly than an alternative service or sequence of services at least as likely to produce equivalent therapeutic or diagnostic results as to the diagnosis or treatment of that patient’s illness, injury or disease.