BlueCross and BlueShield of Montana Medical Policy/Codes
Surface Scanning Electromyography (EMG) (SEMG), Paraspinal Surface EMG, and Spinoscopy
Chapter: Medicine: Tests
Current Effective Date: September 24, 2013
Original Effective Date: December 01, 2003
Publish Date: September 24, 2013
Revised Dates: July 9, 2008; June 27, 2011; February 1, 2012; July 29, 2013
Description

Surface electromyography (SEMG), a noninvasive procedure that records the summation of muscle electrical activity, has been investigated as a technique to evaluate the physiological functioning of the back.  In contrast to anatomic imaging, SEMG records the summation of muscle activity from groups of muscles.  SEMG, a noninvasive procedure, is contrasted with needle EMG, an invasive procedure, in which the electrical activity of individual muscles is recorded.  

Paraspinal SEMG, also referred to as paraspinal EMG scanning, has been explored as a technique to evaluate abnormal patterns of electrical activity in the paraspinal muscles in patients with back pain symptoms such as spasm, tenderness, limited range of motion, or postural disorders. The technique is performed using one or an array of electrodes placed on the skin surface, with recordings made at rest, in various positions, or after a series of exercises. Recordings can also be made by using a handheld device, which is applied to the skin at different sites. Electrical activity can be assessed by computer analysis of the frequency spectrum (i.e., spectral analysis), amplitude, or root mean square of the electrical action potentials.  In particular, spectral analysis focusing on the median frequency has been used to assess paraspinal muscle fatigue during isometric endurance exercises.  Paraspinal SEMG is an office-based procedure that may be most commonly used by physiatrists or chiropractors.  SEMG devices approved by the U.S. Food and Drug Administration (FDA) include those that use a single electrode or a fixed array of multiple surface electrodes. The following clinical applications of the paraspinal SEMG have been proposed:

  • Clarification of a diagnosis (i.e., muscle, joint, or disc disease),
  • Select a course of medical therapy,
  • Select a type of physical therapy,
  • Pre-operative evaluation,
  • Postoperative rehabilitation,
  • Follow-up of acute low back pain,
  • Evaluation of exacerbation of chronic low back pain, and
  • Evaluation of pain management treatment techniques.   

Spinoscopy (Spinoscope®, Spinex Corp.) consists of SEMG with associated video-recordings that records vertebral movement and the corresponding muscular activity during movements of the back.

Policy

Each benefit plan, summary plan description or contract defines which services are covered, which services are excluded, and which services are subject to dollar caps or other limitations, conditions or exclusions.  Members and their providers have the responsibility for consulting the member's benefit plan, summary plan description or contract to determine if there are any exclusions or other benefit limitations applicable to this service or supply.  If there is a discrepancy between a Medical Policy and a member's benefit plan, summary plan description or contract, the benefit plan, summary plan description or contract will govern.

Investigational

Blue Cross and Blue Shield of Montana (BCBSMT) considers the following noninvasive electromyography (EMG) tests experimental, investigational and unproven as techniques to evaluate, diagnose or monitor neck/back pain or any other neuromusculoskeletal condition:

  • Surface EMG (SEMG) or surface scanning EMG, OR
  • Paraspinal SEMG or paraspinal EMG, OR
  • Spinoscopy.

 Rationale

This policy was originally created in 2003 and was updated regularly with searches of the MEDLINE database. The most recent literature search was performed through July 2012. The following is a summary of the key literature to date:

Surface electromyography (SEMG) has been used as a research tool to evaluate the performance of paraspinal muscles in patients with back pain and to further understand the etiology of low back pain. (1-5) However, validation of its use as a clinical diagnostic technique involves a sequential 3-step procedure as follows:

  1. Technical performance of a device is typically assessed by studies that compare test measurements with a gold standard and those that compare results taken with the same device on different occasions (test-retest).
  2. Diagnostic performance is evaluated by the ability of a test to accurately diagnose a clinical condition in comparison with the gold standard. The sensitivity of a test is the ability to detect a disease when the condition is present (true-positive), while specificity indicates the ability to detect patients who are suspected of disease but who do not have the condition (true-negative). Evaluation of diagnostic performance, therefore, requires independent assessment by the 2 methods in a population of patients who are suspected of disease but who do not all have the disease.
  3. Evidence related to improvement of clinical outcomes with use of this testing assesses the data linking use of a test to changes in health outcomes (clinical utility). While in some cases, tests can be evaluated adequately using technical and diagnostic performance, when a test identifies a new or different group of patients with a disease; randomized trials are needed to demonstrate impact of the test on the net health outcome.

The following discussion focuses on these three steps as they apply to SEMG.

Technical performance

Several studies using different SEMG devices have suggested that paraspinal SEMG, in general, is a reliable technique, based on coefficients of variation or test-retest studies. (2, 3) No studies were identified that compared the performance of SEMG to a gold standard reference test.

Diagnostic performance

No articles that compare the results of SEMG (which tests groups of muscles) with needle electromyography (which tests individual muscles) for diagnosing any specific muscle pathology were identified in literature searches. However, the pathology of individual muscles (i.e., radiculopathy, neuropathy, etc.) may represent a different process than the pathology of muscle groups (i.e., muscle strain, spasm, etc.), and thus SEMG may be considered by its advocates as a unique test for which there is currently no gold standard. Nevertheless, even if one accepts this premise, there are inadequate data to evaluate the diagnostic performance of SEMG. For example, no articles were identified in the published peer-reviewed literature that established definitions of normal or abnormal SEMG. In some instances, asymmetrical electrical activity may have been used to define abnormality, results may be compared to a “normative data base.” However, there was no published literature defining what degree of asymmetry would constitute abnormality or how a normative database was established. (4)

In the absence of a gold standard diagnostic test, correlation with the clinical symptoms and physical exam is critical. De Luca has published a series of studies investigating a type of SEMG called the Back Analysis System (BAS), consisting of surface electrodes and other components to measure the electrical activity of muscles during isometric exercises designed to produce muscle fatigue. (5) Using physical exam and clinical history as a gold standard, the author found that BAS was able to accurately identify control and back pain patients 84% and 91% of the time, respectively, with the values increasing to 100% in some populations of patients. (Accuracy is the sum of true-positive and true-negative results.) However, these studies were not designed as a clinical diagnostic tool per se but were intended to investigate the etiology of back pain and to investigate muscular fatigue patterns in patients with and without back pain.

A 2010 study from Hong Kong used a different type of analysis of SEMG findings called dynamic topography. (6) Using SEMG, they evaluated 20 healthy men and 15 men with low-back pain and found different dynamic topography e.g., a more symmetric pattern in healthy controls. After physical therapy, the dynamic topography images of back pain patients were more similar to the healthy controls on some of the parameters that were assessed. However, there are no data that analyze how changes in the SEMG correlate to clinical response, whether a clinical response in the face of persisting SEMG abnormalities suggests ongoing pathology, or whether persistent symptoms in the face of a normal SEMG represent malingering.

Improvement of clinical outcomes

Several articles describe the use of SEMG as an aid in classifying low back pain. (7-9) Much of the research in this application has focused on the use of spectral analysis to assess muscle fatigability. However, it is unclear how this information may be used in the management of the patient. For example, while the innovators of the BAS system indicate that SEMG can suggest potential therapies by distinguishing deconditioning from muscle inhibition secondary to pain-related behavior, (7) no clinical studies describe the use of SEMG in suggesting therapy. In another application of SEMG, Arena and colleagues assessed the amplitude of SEMG recordings as a measure of paraspinal muscle tension in 66 patients and reported that the degree of muscle tension did not correlate with pain levels. These findings raised questions about the role of biofeedback, muscle relaxants, or other therapies designed to reduce muscle tension. (10)

While SEMG may be used to objectively document muscle spasm or other muscular abnormalities, it is unclear how such objective documentation would supplant or enhance clinical evaluation, or how this information would be used to alter the treatment plan. Part of the difficulty in clinical interpretation is understanding to what extent the SEMG abnormalities are primary or secondary. In addition, as noted in the Background section, no specific workup is recommended for acute low back pain without warning signs.

There are no data regarding the final health outcome. For example, SEMG has been proposed as a technique to differentiate muscle spasm from muscle contracture, with muscle spasm treated with relaxation therapy and contracture treated with stretching exercises. However, there are no data to validate that such treatment suggested by SEMG results in improved outcomes. (11,12)

A review of spinal muscle evaluation in low-back pain patients, published in 2007, indicates that the validity of SEMG remains controversial. (13) The authors note that although many studies show increased fatigability of the paraspinal muscles in patients with low back pain, it is not known whether these changes are causes or consequences of the low back pain. Also, “the considerable inter-individual variability and the absence of normative data complicate the description of normal or abnormal profiles, thereby limiting the diagnostic usefulness of SEMG.”

Practice Guidelines and Position Statements

In 2007, the American College of Physicians and the American Pain Society issued a joint clinical guideline on the diagnosis and treatment of low-back pain. The guideline did not specifically mention paraspinal surface electromyography. (14) It included the recommendations:

  • “Clinicians should not routinely obtain imaging or other diagnostic tests in patients with nonspecific low back pain (strong recommendation, moderate-quality evidence).”
  • “Clinicians should perform diagnostic imaging and testing for patients with low back pain when severe or progressive neurologic deficits are present or when serious underlying conditions are suspected on the basis of history and physical examination (strong recommendation, moderate-quality evidence).”

Summary

There are inadequate data on the technical and diagnostic performance of paraspinal SEMG compared to a gold standard reference test. Moreover, there is insufficient evidence regarding how findings from paraspinal SEMG impact patient management and/or how use of the test improves health outcomes. Thus, paraspinal surface electromyography for diagnosing and monitoring back pain is considered experimental, investigational, and unproven.

Coding

Disclaimer for coding information on Medical Policies           

Procedure and diagnosis codes on Medical Policy documents are included only as a general reference tool for each policy.  They may not be all-inclusive.           

The presence or absence of procedure, service, supply, device or diagnosis codes in a Medical Policy document has no relevance for determination of benefit coverage for members or reimbursement for providers.  Only the written coverage position in a medical policy should be used for such determinations.           

Benefit coverage determinations based on written Medical Policy coverage positions must include review of the member’s benefit contract or Summary Plan Description (SPD) for defined coverage vs. non-coverage, benefit exclusions, and benefit limitations such as dollar or duration caps.

ICD-9 Codes

Investigational for all diagnosis codes.

ICD-10 Codes

Investigational for all diagnosis codes.

Procedural Codes: S3900
References
  1. Greenough CG, Oliver CW, Jones AP. Assessment of spinal musculature using surface electromyographic spectral color mapping. Spine 1998; 23(16):1768-74.
  2. Ahern DK, Follick MJ, Council JR et al. Reliability of lumbar paravertebral EMG assessment in chronic low back pain. Arch Phys Med Rehabil 1986; 67(10):762-5.
  3. Cram JR, Lloyd J, Cahn TS. The reliability of EMG muscle scanning. Int J Psychosom 1994; 41(1-4):41-5.
  4. Gentempo P, Kent C. Establishing medical necessity for paraspinal EMG scanning. Chiropractic: J Chiropractic Res Clin Invest 1990; 3(1):22-5.
  5. De Luca CJ. Use of the surface EMG signal for performance evaluation of back muscles. Muscle Nerve 1993; 16(2):210-6.
  6. Hu Y, Siu SH, Mak JN et al. Lumbar muscle electromyographic dynamic topography during flexion-extension. J Electromyogr Kinesiol 2010; 20(2):246-55.
  7. Roy SH, Oddsson LI. Classification of paraspinal muscle impairments by surface electromyography. Phys Ther 1998; 78(8):838-51.
  8. Peach JP, McGill SM. Classification of low back pain with the use of spectral electromyogram parameters. Spine 1998; 23(10):1117-23.
  9. Humphrey AR, Nargol AV, Jones AP et al. The value of electromyography of the lumbar paraspinal muscles in discriminating between chronic-low-back-pain sufferers and normal subjects. Eur Spine J 2005; 14(2):175-84.
  10. Arena JG, Sherman RA, Bruno GM et al. Electromyographic recordings of low back pain subjects and non-pain controls in six different positions: effect of pain levels. Pain 1991; 45(1):23-8.
  11. Bittman B, Cram JR. Surface electromyography: an electrophysiologic alternative in pain management. Presented at American Pain Society, October 1992.
  12. Ellestad SM, Nagle RV, Boesler DR et al. Electromyographic and skin resistance responses to osteopathic manipulative treatment for low-back pain. J Am Osteopath Assoc 1988; 88(8):991-7.
  13. Demoulin C, Crielaard JM, Vanderthommen M. Spinal muscle evaluation in healthy individuals and low-back-pain patients: a literature review. Joint Bone Spine 2007; 74(1):9-13.
  14. Diagnosis and treatment of low back pain: a joint clinical practice guideline from the American College of Physicians and the American Pain Society. 2007. Available online at: www.guideline.gov  . Last accessed September 2011.
  15. Paraspinal Surface Electromyography (EMG) to Evaluate and Monitor Back Pain.  Chicago, Illinois: Blue Cross Blue Shield Association Medical Policy Reference Manual (2011 November) 2.01.35.
History
June 2011 No change in policy; updated rationale and references only
February 2012 Policy updated with literature search. No changes to policy statement.
July 2013 Policy formatting and language revised.  Policy statement unchanged.  Title changed from "Paraspinal Surface Electromyography" to "Surface Scanning Electromyography (EMG) (SEMG), Paraspinal Surface EMG, and Spinoscopy".
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Surface Scanning Electromyography (EMG) (SEMG), Paraspinal Surface EMG, and Spinoscopy