Neurophysiology Evoked Potentials (NEPs)

This LCD supplements but does not replace, modify or supersede existing Medicare applicable National Coverage Determinations (NCDs) or payment policy rules and regulations for neurophysiology evoked potentials. Federal statute and subsequent Medicare regulations regarding provision and payment for medical services are lengthy. They are not repeated in this LCD. Neither Medicare payment policy rules nor this LCD replace, modify or supersede applicable state statutes regarding medical practice or other health practice professions acts, definitions and/or scopes of practice. All providers who report services for Medicare payment must fully understand and follow all existing laws, regulations and rules for Medicare payment for neurophysiology evoked potentials and must properly submit only valid claims for them. Please review and understand them and apply the medical necessity provisions in the policy within the context of the manual rules. Relevant CMS manual instructions and policies may be found in the following Internet-Only Manuals (IOMs) published on the CMS Web site.

IOM Citations:

• CMS IOM Publication 100-02, Medicare Benefit Policy Manual, Chapter 15, Section 80 Requirements for Diagnostic X-Ray, Diagnostic Laboratory, and Other Diagnostic Tests
• CMS IOM Publication 100-03, Medicare National Coverage Determinations (NCD) Manual,Chapter 1, Part 2, Section 160.10 Evoked Response Tests
• CMS IOM Publication 100-08, Medicare Program Integrity Manual, Chapter 13, Section 13.5.4 Reasonable and Necessry Provision in an LCD

Social Security Act (Title XVIII) Standard References:

• Title XVIII of the Social Security Act, Section 1862(a)(1)(A) states that no Medicare payment shall be made for items or services which are not reasonable and necessary for the diagnosis or treatment of illness or injury.
• Title XVIII of the Social Security Act, Section 1862(a)(7). This section excludes routine physical examinations.
• Title XVIII of the Social Security Act, Section 1833(e) states that no payment shall be made to any provider for any claims that lacks the necessary information to process the claim.

Federal Register References:

• Title 42 Code of Federal Regulations (CFR) section 410.32(d)(3) Diagnostic x-ray tests, diagnostic laboratory tests, and other diagnostic tests: Conditions. Diagnostic laboratory tests; Claims review

Notice: It is not appropriate to bill Medicare for services that are not covered (as described by this entire LCD) as if they are covered. When billing for non-covered services, use the appropriate modifier.

Compliance with the provisions in this policy may be monitored and addressed through post payment data analysis and subsequent medical review audits.

History/Background and/or General Information

Neurophysiology Evoked Potentials (NEPs) for the purpose of this LCD include:

1. Somatosensory Evoked Potentials/Responses (SEPs/SERs),
2. Brainstem Auditory Evoked Potentials/Responses (BAEPs/BAERs), and
3. Visual Evoked Potentials/Responses (VEPs/VERs)

Evoked potential studies are recorded electrical responses to stimulation of a sensory system. When a sensory impulse reaches the brain, a specific Electroencephalographic (EEG) response is produced (evoked) in the cortical area appropriate to the modality and site of the stimulus. By computer averaging techniques, the evoked responses of repetitive stimuli can be separated from the spontaneous EEG activity. Evoked potentials are clinically useful in evaluating the functional integrity of the somatosensory or special sensory pathways. Different latencies and wave patterns help to localize lesions ranging from the end organ through the nervous system to the cerebral cortex. Often defects in these pathways are not otherwise evident. Evoked potentials are also used to monitor neural pathways when patients are anesthetized during surgery and to document brain death. The following are tests that evaluate potentials evoked by stimulation of the peripheral or cranial nerves:

SEPs/SERs evaluate the pathways from nerves in the extremities through the spinal cord, to the brainstem or cerebral cortex upon stimulation of peripheral axon.

SEPs have an advantage in that it evaluates the entire somatosensory pathway and it is possible to distinguish between lesions located in the peripheral nerve, in the dorsal column pathway, or both.

VEPs/VERs evaluate the visual nervous system pathways from the eyes to the occipital cortex of the brain. VEP or VER involves stimulation of the retina and optic nerve with a shifting checkerboard pattern or flash method. This external visual stimulus causes measurable electrical activity in neurons within the visual pathways. This is called the Visual Evoked Response (VER) and is recorded by electroencephalography electrodes located over the occiput. Using special computer techniques, the evoked responses measured over multiple trials are amplified and averaged. A characteristic waveform is produced. With pattern-shift VER, the waveform normally appears as a straight line with a single positive peak (100 msec after stimulus presentation). Abnormalities in this characteristic waveform may be seen in a variety of pathologic processes involving the optic nerve and its radiations. Pattern-shift VER is a highly sensitive means of documenting lesions in the visual system. It is especially useful when the disease process is subclinical, e.g., ophthalmologic exam is normal and patient lacks visual symptoms.

BAEPs/BAERs evaluate the auditory nerve pathways from the ears through the brain stem. A clicking sound is presented to one ear at a time. The electrical activity of this signal is recorded by electrodes on the scalp. The averaged response is displayed as a waveform that contains peaks and troughs, which correspond to various points along the hearing pathway. The time between these peaks is measured and compared to normal data. A delay in a component of the response might indicate an abnormality at specific anatomic sites in the acoustic nerve or brainstem.

Covered Indications

Somatosensory Evoked Potentials and Responses (SEPs/SERs) are appropriate for the following indications:

1. Spinal cord trauma
2. Degenerative, non-traumatic spinal cord lesions (e.g., cervical spondylosis with myelopathy)
3. Multiple sclerosis
4. Spinocerebellar degeneration
5. Myoclonus
6. Coma
7. Intraoperative monitoring
8. Subacute combined degeneration
9. Other diseases of myelin (e.g., adrenoleukodystrophy, adrenomyeloneuropathy, metachromatic leukodystrophy, and Pelizaeus-Merzbacher disease)
10. Syringomyelia
11. Hereditary spastic paraplegia

 Brainstem Auditory Evoked Potentials and Responses (BAEPs/BAERs) are appropriate:

1. For one or more of the following conditions:
   
   • Asymmetric hearing loss
   • Unilateral tinnitus
   • Sudden hearing loss
   • Cerebellopontine angle tumor
   • Demyelinating disorder
   • Functional hearing loss
   • Ototoxic drug therapy monitoring including chemotherapy or antibiotics
   • Auditory neuropathy
   • Acoustic neuroma
2. Preoperative baseline for:
   
   • Posterior fossa surgery
   • Cochlear implant
3. Postoperative testing for:
   
   • Cochlear implant

Note: Please refer to LCD L35007, Vestibular and Audiologic Function Studies for additional information regarding BAEPs/BAERs.

Visual Evoked Potentials or Responses (VEPs/VERs) are appropriate for the following indications:

1. Confirm diagnosis of multiple sclerosis when clinical criteria are inconclusive.
2. Detect optic neuritis at an early, subclinical stage.
3. Evaluate diseases of the optic nerve, such as:
   
   • Ischemic optic neuropathy
   • Pseudotumor cerebri
   • Toxic amblyopias
   • Nutritional amblyopias
   • Neoplasms compressing the anterior visual pathways
   • Optic nerve injury or atrophy
   • Hysterical blindness (to rule out)
4. Monitor the visual system during optic nerve (or related) surgery (monitoring of short-latency evoked potential studies).

 Limitations

The following are considered not reasonable and necessary and therefore will be denied:

1. SEP studies are appropriate only when a detailed clinical history and neurologic examination and appropriate diagnostic tests such as imaging studies, electromyogram, and nerve conduction studies make a lesion (or lesions) of the central somatosensory pathways a likely and reasonable differential diagnostic possibility.
2. There is no need for SEPs in the diagnosis of most neuropathies because the conventional nerve conduction study can identify them and no added information is obtained from SEPs.

Place of Services (POS)

For additional information on services performed in an Independent Diagnostic Testing Facility (IDTF), please refer to Local Coverage Determination (LCD) L35448 Independent Diagnostic Testing Facility (IDTF).

Provider Qualifications

Testing shall be performed by physicians who have evidence of training, and expertise to perform and interpret these tests. Physicians must have knowledge, training, and expertise to perform and interpret these tests, and to assess and train personnel working with them. This Training and expertise must have been acquired within the framework of an accredited school, residency or fellowship program.

Notice: Services performed for any given diagnosis must meet all of the indications and limitations stated in this policy, the general requirements for medical necessity as stated in CMS payment policy manuals, any and all existing CMS national coverage determinations, and all Medicare payments rules. Refer to Billing and Coding: Neurophysiology Evoked Potentials (NEPs), A56773, for applicable CPT/HCPCS codes and diagnosis codes.

The redetermination process may be utilized for consideration of services performed outside of the reasonable and necessary requirements in this LCD.

N/A

N/A 

Refer to the Local Coverage Article: Billing and Coding: Neurophysiology Evoked Potentials (NEPs), A56773, for all coding information.

Documentation Requirements

1. All documentation must be maintained in the patient's medical record and made available to the contractor upon request.
2. Every page of the record must be legible and include appropriate patient identification information (e.g., complete name, dates of service[s]). The documentation must include the legible signature of the physician or non-physician practitioner responsible for and providing the care to the patient.
3. The medical record documentation must support the medical necessity of the services as stated in this policy.
4. The patient’s medical record must contain documentation that fully supports the medical necessity for NEPs as covered by Medicare (see Indications and Limitations of Coverage and/or Medical Necessity). This documentation includes, but is not limited to, relevant medical history, physical examination and results of pertinent diagnostic tests or procedures.
5. For the BAEPs/BAERs, the patient’s medical record should document the otologic exam describing both ear canals and tympanic membranes, as well as a gross hearing assessment. The medical record should also include the results of air and bone pure tone audiogram and speech audiometry.
6. The physician’s SEPs/SERs report should note which nerves were tested, latencies at various testing points, and an evaluation of whether the resulting values are normal or abnormal.

Utilization Guidelines

In accordance with CMS Ruling 95-1 (V), utilization of these services should be consistent with locally acceptable standards of practice.

Contractor is not responsible for the continued availability of websites listed.

Consultations with the representative to the Carrier Advisory Committee and other Medicare contractors.

Other Medicare Contractor's Local Coverage Determinations

Contractor Medical Directors

1. American Association of Neuromuscular and Electrodiagnostic Medicine (AANEM). Somatosensory Evoked Potentials: Clinical Uses. Chapter 5. Muscle Nerve 22: Supplement 8: S111-S118, 1999. Accessed January 14, 2011 at AANEM website. www.aanem.org
2. American Association of Neuromuscular and Electrodiagnostic Medicine (AANEM). Position Statement - Recommended Policy for Electrodiagnostic Medicine. Accessed January 14, 2011 at AANEM website. www.aanem.org
3. American Clinical Neurophysiology Society website. Various Guidelines. February 2006. Acessed January 14, 2011 at ACN website. www.acns.org
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5. Devlin VJ, et al. Intraoperative Neurophysiologic Monitoring During Spinal Surgery. Journal of the American Academy of Orthopaedic Surgeons. 2007; 15 (9): 549-560.
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7. Houlden DA, et al. Early somatosensory evoked potential grades in comatose traumatic brain injury patients predict cognitive and functional outcome. Crit Care Med. 2010; 38(1).
8. Isley MR, et al. Current Trends in Pedicle Screw Stimulation Techniques: Lumbosacral, Thoracic, and Cervical Levels. Neurodiagn J. 2012; 52: 100-175.
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10. Naismith RT, et al. Optical coherence tomography is less sensitive than visual evoked potentials in optic neuritis. Neurology 2009; 73: 46-52.
11. Nuwer MR, et al. Evidence-based guideline update: Intraoperative spinal monitoring with somatosensory and transcranial electrical motor evoked potentials. American Academy of Neurology. 2012; 78: 585-589.
12. Sala F, et al. Cost effectiveness of multimodal intraoperative monitoring during spine surgery. Eur Spine J. 2007; 16 (suppl 2): S229-S231.
13. Schwartz DM, et al. Neurophysiological Identification of Position-induced Neurologic Injury During Anterior Cervical Spine Surgery. Journal of Clinical Monitoring and Computing. 2006; 20: 437-444.
14. Thurtell MJ, et al. Evaluation of optic neuropathy in multiple sclerosis using low-contrast visual evoked potentials. Neurology 2009; 73: 1849-1857.
15. Uribe JS, et al. Brachial plexus injury following spinal surgery. J Neurosurg Spine. 2010: 13: 552-558.
16. Uribe JS, et al. Electromyographic Monitoring and Its Anatomical Implications in Minimally Invasive Spine Surgery. SPINE. 2010; 35(26S): S368-S374.
17. Xu R, et al. A role for motor and somatosensory evoked potentials during anterior cervical discectomy and fusion for patients without myelopathy: Analysis of 57 consecutive cases. Surgical Neurology International. 2011; 2:133.