Medical Policy: 02.01.31
Original Effective Date: January 2007
Reviewed: April 2020
Revised: April 2016
This policy contains information which is clinical in nature. The policy is not medical advice. The information in this policy is used by Wellmark to make determinations whether medical treatment is covered under the terms of a Wellmark member's health benefit plan. Physicians and other health care providers are responsible for medical advice and treatment. If you have specific health care needs, you should consult an appropriate health care professional. If you would like to request an accessible version of this document, please contact customer service at 800-524-9242.
Benefit determinations are based on the applicable contract language in effect at the time the services were rendered. Exclusions, limitations or exceptions may apply. Benefits may vary based on contract, and individual member benefits must be verified. Wellmark determines medical necessity only if the benefit exists and no contract exclusions are applicable. This medical policy may not apply to FEP. Benefits are determined by the Federal Employee Program.
This Medical Policy document describes the status of medical technology at the time the document was developed. Since that time, new technology may have emerged or new medical literature may have been published. This Medical Policy will be reviewed regularly and be updated as scientific and medical literature becomes available.
Nerve conduction velocity (NCV) studies are a type of electrodiagnostic study conducted to assess the integrity and function of the peripheral nervous system and to diagnose related diseases. NCV studies measure the velocity of nerve impulses, the amplitude and the wave shapes of the motor responses. Another relevant measurement is that of nerve conduction latency. Abnormal results include slowing of the nerve conduction signal, a completely blocked conduction, failure to elicit a motor response from a nerve signal or a diminished motor response. The results of these tests may assist the physician to arrive at a differential diagnosis based on the degree of demyelination or loss of axon function in various portions of the nerve.
Studies have shown the correlation of portable automated nerve conduction test results with standard testing; however, questions remain about the diagnostic performance and clinical utility (i.e., impact on outcomes) of point-of-care automated testing. Particularly needed are data on the sensitivity and specificity of automated nerve conduction tests performed by non-specialists at the point-of-care in comparison with the "gold standard" of laboratory NCS/EMG. One study from a tertiary care clinic found high sensitivity but low specificity for the diagnosis of lumbosacral radiculopathy. Another potential clinical use could be early identification of asymptomatic diabetic neuropathy to institute-appropriate clinical management before the onset of ulcerations, but no studies were identified that assessed the influence of point-of-care nerve conduction tests on clinical outcomes in this population. Overall, evidence addressing the utility of point-of-care automated nerve conduction tests in a clinical setting is limited. There is no peer-reviewed published medical literature on the use of voltage-actuated sensory nerve conduction tests and their impact on clinical outcomes. Overall, evidence remains insufficient to evaluate the effect of automated point-of-care nerve conduction tests on health outcomes. Therefore, automated point-of-care nerve conduction tests are considered investigational.
In a position statement on the Proper Performance and Interpretation of Electrodiagnostic Studies and the Recommended Use of Electrodiagnostic Medicine from the American Association of Neuromuscular and Electrodiagnostic Medicine (AANEM, 2014), although no specific reference to or recommendation for automated nerve conduction testing devices is made, it is noted that "Nerve conduction studies performed independent of needle EMG studies may only provide a portion of the information needed to diagnose muscle, nerve root, and most nerve disorders."
Individuals without a medical education in neuromuscular disorders and without special training in EDX procedures typically are not qualified to interpret the waveforms generated by NCSs and needle EMGs or to correlate the findings with other clinical information to reach a diagnosis.
The American Academy of Orthopaedic Surgeons (2016) released guidelines on the management of carpal tunnel syndrome. The guidelines were endorsed by other specialty societies including the American College of Radiology and American College of Surgeons. The guidelines found "limited evidence" for a "hand-held nerve conduction study."
Multiple devices have been cleared for POC 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 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 POC 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 and Cadwell Sierra Ascent (Cadwell Industries) was cleared for marketing by FDA through the 510K process (K162383). There areportable 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.
Nerve conduction studies (NCV) are considered investigational when:
Nerve conduction studies (NVC) are considered investigational for screening for all diagnosis, including but not limited to: polyneuropathy of diabetes or end-stage renal disease.
Although portable, automated, noninvasive testing of nerve conduction has been suggested as an easier method for providers to obtain rapid results, the AANEM recommends that electrodiagnostic studies of EMG and NCS be performed together, except in unique situations, in a study design determined and interpreted by a trained physician, so that healthcare decisions are based on complete diagnostic information (AANEM, 2004). Currently, there is insufficient evidence in the published data to demonstrate that the use of automated nerve conduction testing devices are valid measures in the diagnosis of peripheral nerve disease. More studies are needed to prove the value of using automated, noninvasive nerve conduction testing.
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