Vestibular and Audiologic Function Studies Form

Summary Of Evidence

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Analysis of Evidence

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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

Vestibular tests are tests of function. Their purpose is to determine if there is something wrong with the vestibular portion of the inner ear. If dizziness is not caused by the inner ear, it might be caused by the brain, medical disorders such as low blood pressure or psychological problems such as anxiety. Studies have documented that vestibular tests are more accurate than clinical examination in identifying inner ear disorders. Hearing pathway tests (audiometry, Auditory Brainstem Response [ABR], Electrocochleography [ECoG]) can also be used for the same purpose and are frequently combined with vestibular tests.

Diagnostic otologic evaluation services are performed to detect presence or absence of a hearing deficit and to identify the factors responsible for the deficit. The assessment of a deficit involves both physical and physiological measurements for appropriate diagnosis and referral.

Accurate assessment of hearing (audiometry) is vital to the diagnostic evaluation of patients with suspected otologic disorders for the determination of the underlying process, as well as in the planning of rehabilitation of hearing loss. Originally, audiometry was limited to the psychophysical measurement of the sensation of hearing; thus, patient cooperation was essential. However, other tests have been developed over the years that permit more objective assessment of hearing even in infants, small children, malingerers and hysterics.

Most humans hear sounds in the range of 20 to 20,000 Hertz (Hz). Sensitivity varies as a function of frequency, with sounds in the middle frequencies being heard best.

Basic Audiometry: Adequate testing requires an audiometer (device for presenting sounds to the patient at precisely controlled intensity), a controlled acoustic environment that meets American National Standards Institute (ANSI) specifications, a competent audiologist and a cooperative patient. The standard testing battery may vary depending on purpose.

• Pure Tone Audiometry, Speech Audiometry and Immittance Audiometry
  
  
  • Pure Tone Audiogram: This is a graphic plot of the patient’s thresholds of audiometry sensitivity for pure tone (sine wave) stimuli. Threshold hearing levels are indicated for each frequency tested. By convention, normal hearing levels are shown at the top of a graph; a decrease in hearing sensitivity is indicated by larger values of hearing level. Hearing level is plotted on a logarithmic decibel scale. Sounds are tested with presentation by air conduction (earphones) as well as bone conduction (skull vibrator). An air bone gap indicates a conductive component of hearing loss. A decrease in threshold sensitivity by bone conduction reflects a sensory or neural loss.
    
    
  • Speech Audiometry: These tests utilize spoken words and sentences rather than pure tones. Tests are designed to assess sensitivity (threshold) or understanding (intelligibility).
    
    
    • Threshold – The level at which the patient can correctly repeat 50 percent of test materials: Phoneme-Balanced (PB) words, synthetic sentences, etc.
    • Intelligibility – By convention, the percentage of words or sentences a patient can correctly repeat when presented at suprathreshold levels.
    • These tests provide information about a hearing handicap. The hearing deficit may be worse than indicated by Pure Tone Average (PTA) for the speech frequencies. Useful to determine candidacy for hearing aid.
    • Very poor results that are out of proportion to PTA testing, suggest probable retrocochlear cause of hearing loss.

• Immittance Audiometry: These hearing tests utilize an electroacoustic immittance bridge. This device is designed to quantify the impedance (resistance to movement) of the conductive mechanism of the ear by bouncing a probe tone off the tympanic membrane and measuring the proportion of reflected sound. Impedance testing can measure either the impedance or admittance (the American Speech-Language-Hearing Association term that encompasses both is “immittance”). Typically, today’s equipment measures admittance. The purpose of the test is to assess middle ear integrity. Maximal reflection of sound occurs when the mechanism is very stiff, while a compliant system transmits more sound and reflects less. There are two principal applications of this device:
  
  
  • Tympanometry: A tympanogram is a graphic representation of the relationship of external auditory canal air pressure to impedance; the latter is usually reported in terms of tone of its derivatives, compliance in arbitrary units. Pressure in the external auditory canal is varied from -200 daPa through +200 daPa while monitoring impedance. Impedance is the lowest (maximal compliance) when pressure in the canal equals pressure in the middle ear. Ears can be classified into three basic groups (Type A, Type B and Type C) on the basis of the configuration of the tympanogram.
  • Acoustic Reflex (AR): Contraction of the stapedius muscle occurs with loud sounds, producing a measurable change in compliance.

Diagnostic Audiometry consists of a battery of tests intended to determine the site of lesion in patients with otologic or neurologic disorders. The constellation of tests varies according to the available test battery and provisional diagnosis.

• Immittance audiometry: See above.
• PI-PB functions: Speech discrimination is plotted as a function of sound intensity. Normally, discrimination improves with intensity up to a maximal level, then plateaus. In eighth nerve disorders, discrimination often declines dramatically as intensity increases above the level yielding maximum performances.
• Bekesy Audiometry: This test has a significant historical interest in the development of assessment of hearing; however, today it is used predominantly in industrial and military hearing screening situations. Patients trace their own auditory threshold by means of a self-recording audiometer. Tracings are obtained for pulsed as well as continuous tones. The relationship between the two categories can be categorized into diagnostic patterns.
• Tone Decay Tests: Abnormal adaptation to a continuous tone is seen in retrocochlear lesions.
• Stenger Test: Performed to detect malingering of unilateral loss. If sound is presented to both ears, the patient will deny hearing in the ear with the feigned loss. If sound is presented to the “good” ear at a suprathreshold level, simultaneous to a louder sound in the questionable ear, a malingerer will localize the sound to his “bad” ear, and therefore deny hearing anything at all.
• Evoked ABRs: Scalp electrodes measure electrical activity in response to sound clicks. The response is quite small in relation to other ongoing brain activity, but by presenting a large number of clicks and averaging the responses by computer, unrelated events can be canceled out. This is useful for documenting hearing in uncooperative or unresponsive patients. The disadvantage is that it tests mainly the 1,000–4,000 Hz frequency range of hearing and is a poor indicator of the overall auditory function. An abnormal ABR is seen in eighth nerve or brainstem lesions.
• ECoG: Electrical activity is measured from the promontory and responses to a large number of clicks are averaged. These will be abnormal in eighth cranial nerve lesions and certain cochlear disorders.

Audiologist’s Services

The practice of the profession of audiology means the application of principles, methods and procedures of measurement, testing, evaluation, consultation, counseling, instruction and rehabilitation related to hearing, its disorders and related communication and impairments for the purpose of non-medical diagnosis, prevention, identification, amelioration or modification of such disorders and conditions in individuals or groups of individuals.

Audiological tests require the skills of an audiologist and shall be furnished by qualified audiologists or by a physician who satisfies the "Training and Competency Requirements" as listed in this LCD.

Please refer to CMS IOM Publication 100-02, Medicare Benefit Policy Manual, Chapter 15, Section 80.3 for complete information related to audiologist services.

Individuals Who Provide Audiological Tests: Diagnostic audiological tests that require both the technical and professional components, the skills of an audiologist to perform the test and interpret not only the data output but also the manner of the patient’s response to the test must be personally furnished by an audiologist or a physician. The skills of an audiologist required, when furnishing the ordered diagnostic tests, involve skilled judgment or assessment including but not limited to:

• Interpretation, comparison or consideration of the anatomical or physiological implications of test results or patient responsiveness to stimuli during the test.
• Modification of the stimulus based on responses obtained during the test.
• Choices for subsequent presentations of stimuli or tests in a battery of tests.
• Tests related to implantation of auditory prosthetic devices, central auditory processing or contralateral masking.
• Tests designed to identify central auditory processing disorders, tinnitus or non-organic hearing loss.

The technical components of certain audiological diagnostic tests, e.g., vestibular function tests that do not require the skills of an audiologist may be performed by a qualified technician or by an audiologist, physician or NPP acting within his/her scope of practice when the qualifications as outlined in the Training and Competency section of the policy are met. If performed by a technician, the service must be provided under the direct supervision (42 CFR §410.32(3)) of a physician who is responsible for all clinical judgment and for the appropriate provision of the service. The physician or NPP bills the directly supervised service as a diagnostic test.

Note: For additional information regarding services performed in an Independent Diagnostic Testing Facility (IDTF), please refer to Local Coverage Determination (LCD) L35448 Independent Diagnostic Testing Facility (IDTF) and Local Coverage Article A53252 Independent Diagnostic Testing Facility (IDTF).

Covered Indications

1. Vestibular function tests and diagnostic audiometric tests are covered when testing is for the purpose of determining the appropriate medical or surgical treatment for disorders of auditory, balance and other neural systems.
2. For conductive hearing loss, hearing should be retested after medical or surgical treatment or observation. For sensorineural hearing loss, the audiologist or physician will recommend when reasonable and necessary repeat testing should be done. Since hearing may change or fluctuate, it is important to detect this as early as possible to prevent further loss and to obtain medical treatment if needed. Billing for any testing assumes that the provider has a reasonable expectation that the patient will require medical or surgical treatment. Repeat testing for age-related hearing loss either as a follow-up or to screen for hearing aids is non-covered.
3. Pure tone audiometry (threshold); air and bone testing, comprehensive hearing testing and acoustic reflex testing may be performed for patients on continuing (current) long-term (more than 14 days) use of antibiotics known to be ototoxic, such as streptomycin and aminoglycosides.
4. If a physician refers a beneficiary to an audiologist for evaluation of signs and symptoms associated with hearing loss or ear injury, the audiologist’s diagnostic services are covered, even if the only outcome is the prescription of a hearing aid.
5. Services by an independent audiologist to beneficiaries in a Part B Skilled Nursing Facility (SNF) stay (beneficiaries who have exhausted their Part A-covered SNF stay) are payable under Part B.
6. Diagnostic analysis of cochlear or brain stem implant and programming are audiology diagnostic services covered under the “other diagnostic test” benefit. Audiological diagnostic tests before and periodically after implantation of auditory prosthetic devices are covered services.

The professional component caloric vestibular testing, nystagmus testing, Sinusoidal vertical axis rotational testing and evoked potential testing are considered reasonable and necessary when performed in inpatient, outpatient, nursing facilities (when Part A benefits have been exhausted), rehabilitation facilities, hearing and speech centers, independent clinics, and independent diagnostic testing facilities (IDTF).

Technical only services are considered reasonable and necessary in the office setting, clinics, hearing and speech centers, and nursing facilities.

Limitations

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

1. Screening evaluation or testing for hearing aid evaluation is specifically excluded. This exclusion does not apply to the evaluation for the auditory osseointegrated device, known as the Bone-Anchored Hearing Aid (BAHA) device.
2. Services are excluded under Section 1862(a)(7) of the Act when:
   
   
   • The diagnostic information required to determine the appropriate medical or surgical treatment is already known to the physician or is not under consideration.
   • The diagnostic services are performed only to determine the need for the appropriate type of hearing aid.
   
   

   Note: The above services are excluded from Medicare coverage whether performed by a physician or Non-Physician Practitioner (NPP).

3. If a beneficiary undergoes diagnostic testing performed by an audiologist without a physician’s referral, these tests are not covered even if the audiologist discovers a pathologic condition.
4. Services documented as audiological services when furnished through use of computer-administered tests that do not require the skills of an audiologist are not covered.
5. Audiological services billed as incident to the service of a physician or NPP or as services incident to an audiologist’s services are not covered.
6. When a qualified physician or NPP orders a specific audiological test using the CPT descriptor for the test, only that test may be provided. Further orders are necessary if the ordered test indicates that other tests are necessary to evaluate, for example, the type or cause of the condition. Orders for specific tests are required for technicians. However, when the qualified physician or NPP orders diagnostic audiological tests by an audiologist without naming specific tests, the audiologist may select the appropriate battery of tests.
7. It is not considered reasonable and necessary to perform these services in the home.
8. It is not considered reasonable and necessary to perform the technical components of these services in the inpatient hospital, outpatient hospital, or emergency department setting.

Training and Competency Requirements

Vestibular and audiologic testing reported for Medicare payment must be performed by or directly supervised by persons possessing appropriate knowledge and technical expertise of vestibular and hearing. Therefore, Medicare will allow payment for the following:

• Physicians who have completed training requirements sufficient to satisfy the relevant ABMS/AOA boards for certification in otolaryngology, neurology, neurologic surgery, and physical medicine and rehabilitation,
• Audiologists licensed by the state(s) in which they practice and are performing services within their state licensure’s scope of practice and Medicare regulation

For frequency limitations please refer to the Utilization Guidelines section below.

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 determination, and all Medicare payment rules.

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