Automated Point-of-Care Nerve Conduction Tests

POLICY NUMBER

L.2.01.440

DESCRIPTION

Portable devices have been developed to provide point-of-care (POC) nerve conductions studies (NCSs). These devices have computational algorithms that can drive stimulus delivery, measure and analyze the response, and report study results. Automated nerve conduction could be used in various settings, including primary care, without the need for specialized training or equipment.

Electrodiagnostic Testing

Nerve conduction studies (NCS) and needle electromyography (EMG), when properly performed by a trained practitioner, are considered the criterion standard of electrodiagnostic testing for the evaluation of focal and generalized disorders of peripheral nerves. However, the need for specialized equipment and personnel may limit the availability of electrodiagnostic testing for some patients.

Carpal Tunnel Syndrome

Carpal tunnel syndrome is a pressure-induced entrapment neuropathy of the median nerve as it passes through the carpal tunnel, resulting in sensorimotor disturbances. This syndrome is defined by its characteristic clinical symptoms, which may include pain, subjective feelings of swelling, and nocturnal paresthesia.

DiagnosisA variety of simple diagnostic tools are available, and a positive response to conservative management (steroid injection, splints, modification of activity) can confirm the clinical diagnosis. Electrodiagnostic studies may also be used to confirm the presence or absence of a median neuropathy at the wrist, assess the severity of the neuropathy, and assess associated diagnoses. Nerve conduction is typically assessed before the surgical release of the carpal tunnel, but the use of EMG in the diagnosis of carpal tunnel syndrome is controversial. One proposed use of automated nerve conduction devices is to assist in the diagnosis of carpal tunnel syndrome.

Lumbosacral Radiculopathy

Electrodiagnostic studies are useful in the evaluation of lumbosacral radiculopathy in the presence of disabling symptoms of radiculopathy or neuromuscular weakness. These tests are most commonly considered in patients with persistent disabling symptoms when neuroimaging findings are inconsistent with clinical presentation. Comparisons of automated point-of-care (POC) NCSs with EMGs and standardized NCSs have been evaluated as alternative electrodiagnostic tools.

Peripheral Neuropathy

Peripheral neuropathy is relatively common in patients with diabetes, and the diagnosis is often made clinically through the physical examination. Diabetic peripheral neuropathy can lead to morbidity including pain, foot deformity, and foot ulceration.

DiagnosisClinical practice guidelines have recommended using simple sensory tools such as the 10-g Semmes-Weinstein monofilament or the 128-Hz vibration tuning fork for diagnosis. These simple tests predict the presence of neuropathy defined by electrophysiologic criteria with a high level of accuracy. Electrophysiologic testing may be used in research studies and may be required in cases with an atypical presentation. Point-of-care nerve conduction testing has been proposed as an alternative to standard electrodiagnostic methods for the diagnosis of peripheral neuropathy and, in particular, for detecting neuropathy in patients with diabetes.

Normative Values

NeuroMetrix (2009) published reference ranges for key nerve conduction parameters in healthy subjects. Data analyzed were pooled from 5 studies, including from 92 to 848 healthy subjects with data on the median, ulnar, peroneal, tibial, and sural nerves. Subject age and height were found to affect the parameters. In addition to providing reference ranges for clinicians to use (providing that NCS techniques are consistent with those described in the article), the authors stated that clinicians could use the same method to develop their reference ranges. At this time, the proposed reference ranges have not been validated in a clinical patient population.

Due to the lack of uniform standards in nerve conduction testing in the United States, the American Association of Neuromuscular & Electrodiagnostic Medicine (AANEM) identified 7 criteria that would identify high-quality NCS articles that would be appropriate for using as reference standards (2016).AANEM identified normative criteria for nerve conduction velocity tests based on a review of high-quality published studies (see Table 1). In March 2017, the American Academy of Neurology affirmed AANEM’s recommendations.

Table 1. Criteria for Evaluating Published Sources for Normative Standards

*Adapted from Dillingham et al (2016)

Chen (2016) published reference values for upper and lower NCSs in adults, as a companion study to the Dillingham et al (2016) report (above), to address the need for greater standardization in the field of electrodiagnostic medicine. Using the consensus-based criteria developed by AANEM, a comprehensive literature search was conducted for 11 routinely performed sensory and motor NCS from 1990 to 2012. Over 7,500 articles were found, but after review, a single acceptable study meeting all criteria was identified for the 11 nerves. Reviewers determined there were multifactorial reasons that so few studies met the criteria. Large-scale normative studies are time intensive, requiring significant resources and cost. Data from many studies did not address the non-Gaussian distribution of NCS parameters and often derived cutoff values using the mean and standard deviations rather than percentiles.

Multiple devices have been cleared for point-of-care neural conduction testing. For example, in 1986, Neurometer® CPT/C (Neurotron®) was cleared for marketing by the U.S. Food and Drug Administration (FDA) through the 510(k) process (K853608). The device evaluates and documents sensory nerve impairments at cutaneous or mucosal sites. The evaluation detects and quantifies hyperesthesia in early stages of progressive neuropathy and hypoesthesia in more advanced conditions.

In 1998 NC-stat® (NeuroMetrix) was cleared by the FDA through the 510(k) process (K982359). NC-stat® is intended “to measure neuromuscular signals that are useful in diagnosing and evaluating systemic and entrapment neuropathies.” This version is no longer commercially available. It is the predicate device for the NC-stat DPNCheck® (K041320), cleared in 2004, and the NeuroMetrix Advance (K070109), cleared in 2008. The NC-stat DPNCheck device measures the sural nerve conduction velocity and sensory nerve action potential amplitude. It is a handheld device with an infrared thermometer, noninvasive electrical stimulation probes, and a single-use biosensor for each test. NC-stat DPNCheck is designed specifically for NCS of the sural nerve in the assessment of diabetic peripheral neuropathy. The NeuroMetrix ADVANCE is a point-of-care test that can be used to perform needle EMG in addition to surface electrodes for the performance of NCSs. If the needle EMG module is used, then the device is also intended to measure signals useful in evaluating disorders of muscles.

On January 23, 2017, Cadwell Sierra Summit, Cadwell Sierra Ascent (Cadwell Industries) was cleared for marketing by the FDA through the 510K process (K162383). There are portable laptop versions and a desktop application with a handheld device. The system is used for acquisition, display, storage, transmission, analysis, and reporting of electrophysiologic and environmental data including EMG, NCS, evoked potentials, and autonomic responses (RR interval variability). The Cadwell Sierra Summit is used to detect the physiologic function of the nervous system, and to support the diagnosis of neuromuscular diseases or conditions.

FDA product code: JXE.

Other examples of devices cleared for marketing by the FDA through the 510(k) process are noted in the table below.

Table 2. Select FDA Cleared Devices for Neural Conduction Testing

POLICY

Automated point-of-care nerve conduction tests are considered investigational.

POLICY EXCEPTIONS

Federal Employee Program (FEP) may dictate that all FDA-approved devices, drugs or biologics may not be considered investigational and thus these devices may be assessed only on the basis of their medical necessity. 

POLICY GUIDELINES

The coverage guidelines outlined in the Medical Policy Manual should not be used in lieu of the Member's specific benefit plan language.

Nerve conduction studies performed without needle electromyography studies, unless contraindicated (i.e., an individual receiving anticoagulant therapy) are considered investigational.

Investigative is defined as the use of any treatment procedure, facility, equipment, drug, device, or supply not yet recognized as a generally accepted standard of good medical practice for the treatment of the condition being treated and; therefore, is not considered medically necessary. For the definition of Investigative, “generally accepted standards of medical practice” means standards that are based on credible scientific evidence published in peer-reviewed medical literature generally recognized by the relevant medical community, and physician specialty society recommendations, and the views of medical practitioners practicing in relevant clinical areas and any other relevant factors. In order for equipment, devices, drugs or supplies [i.e, technologies], to be considered not investigative, the technology must have final approval from the appropriate governmental bodies, and scientific evidence must permit conclusions concerning the effect of the technology on health outcomes, and the technology must improve the net health outcome, and the technology must be as beneficial as any established alternative and the improvement must be attainable outside the testing/investigational setting.

POLICY HISTORY

3/2/2007: Policy added.

3/22/2007: Reviewed and approved by Medical Policy Advisory Committee (MPAC).

6/14/2007: Code Reference section updated per quarterly HCPCS and Category III revisions.

10/11/2007: Code Reference section reviewed. CPT 95900, 95903, and 95904 removed from policy as non-covered for an automated point of care nerve conduction test (Note: Standard nerve conduction tests may be covered with these Copts); a specific HCPCS code for an automated point of care nerve conduction test became effective 7-1-2007.

7/6/2009: Policy reviewed, description updated, policy statement unchanged.

11/03/2010: Policy description section revised to provide a list of devices and research findings regarding portable automated nerve conduction tests compared to standard testing. Policy statement unchanged. FEP verbiage added to the Policy Exceptions section. Added the following statement to the Policy Guidelines: Nerve conduction studies performed without needle electromyography studies, unless contraindicated (i.e., an individual receiving anticoagulant therapy) are considered investigational. Code Reference section revised to add 95905, 95999, and G0255 to the Non-Covered Codes Table. A note was also added to state that CPT Codes 95900, 95903 and 95904 should not be used to bill for automated nerve conduction testing.

08/02/2011: Policy reviewed; no changes.

07/17/2012: Policy reviewed; no changes.

09/03/2013: Policy reviewed; no changes.

08/01/2014: Policy reviewed; description updated regarding devices. Policy statement unchanged.

07/08/2015: Code Reference section updated for ICD-10.

10/28/2015: Policy description updated regarding devices. Policy statement unchanged. Investigative definition updated in the policy guidelines section.

06/01/2016: Policy number A.2.01.77 added.

08/29/2017: Policy description updated regarding lumbosacral radiculopathy and devices. Policy statement updated to add "point-of-care."

06/28/2018: Policy description updated regarding data from studies and criteria used to evaluate sources for normative standards. Policy statement unchanged.

07/08/2019: Policy reviewed; no changes.

11/24/2020: Policy description updated. Policy statement unchanged.

09/01/2023: Medical policy number changed from "A.2.01.77" to "L.2.01.440." Policy reviewed. Policy statement unchanged.

10/17/2023: Code Reference section updated to remove deleted HCPCS code S3905.

08/20/2024: Policy reviewed; no changes.

SOURCE(S)

Blue Cross Blue Shield Association Policy # 2.01.77

CODE REFERENCE

This is may not be a comprehensive list of procedure codes applicable to this policy.

Investigational Codes

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