LCD L33966: Vestibular Function Tests

History/Background and/or General Information

The vestibular system is the system of balance and equilibrium. This system works with other sensorimotor systems in the body, such as our visual system and skeletal system, to check and maintain the position of our body at rest or in motion. The vestibulo-ocular reflex (VOR) is a reflex that acts at short latency to generate eye movements that compensate for head rotations in order to preserve clear vision during locomotion. The VOR is the most accessible gauge of vestibular function and forms the basis for many of the clinical tests used to evaluate balance function.

Vestibular function tests are tests of function. The tests are used to determine potential causes of balance disturbances, and help to determine if there is a problem with the vestibular portion of the brainstem and inner ear. The balance system depends on the inner ear, the eyes, and the muscles and joints to send information related to the body’s movement and orientation in space. When there are problems with the inner ear or other parts of the balance system, the patient may present with symptoms of vertigo, dizziness, imbalance or other symptoms.

This Local Coverage Determination (LCD) will define the vestibular function tests and the criteria for coverage. This LCD does not address Computerized Dynamic Posturography (CDP) or Tympanometry.

The following vestibular function tests are covered under this LCD:

• Caloric vestibular test with recording, bilateral; bithermal (ie, one warm and one cool irrigation in each ear for a total of four irrigations).

• Caloric vestibular test with recording, bilateral; monothermal (ie, one irrigation in each ear for a total of two irrigations).

• Basic vestibular evaluation, includes spontaneous nystagmus test with eccentric gaze fixation nystagmus, with recording, positional nystagmus test, minimum of 4 positions, with recording, optokinetic nystagmus test, bidirectional foveal and peripheral stimulation, with recording, and oscillating tracking test, with recording.

• Spontaneous nystagmus test, including gaze and fixation nystagmus, with recording. Electronystagmography (ENG) electrodes or video goggles are placed and the patient is asked to look straight ahead, 30-45 degrees to the right and 30-45 degrees to the left. Recordings are made to detect spontaneous nystagmus.

• Positional nystagmus test, minimum four positions, with recording. The patient is placed in a variety of positions, including supine with head extended dorsally, left and right and sitting, in an attempt to induce nystagmus. With the patients eyes closed, an ENG recording is made or with the patients eyes wide open in total darkness a Videonystagmography (VNG) recording is made to detect nystagmus.

• Optokinetic nystagmus test, bidirectional, foveal or peripheral stimulation, with recording. This test is usually performed with moving LED lights, with the patient watching the movement of the lights to the right and left. ENG electrodes or VNG recordings are used to record nystagmus.

• Oscillating tracking test, with recording. With ENG electrodes or video goggles in place, the patient watches an LED light moving in a pendular motion. A recording is made of the eye tracking motion. The recording is then analyzed for smoothness.

• Sinusoidal vertical axis rotational testing. The patient is seated in a rotary chair with the head bent forward 30 degrees. ENG electrodes are placed or VNG goggles are placed to measure nystagmus while the chair is rotated with the patient’s eyes closed. A recording is made and studies to determine an abnormal labyrinthine response on one side or the other. This test requires the use of a chair capable of rotating around a vertical axis. There are several models of an appropriate chair for this test. This test is NOT performed by having the patient sit or stand on any kind of substitute platform or surface. This test is not a head-shake test.

• Use of vertical electrodes in addition to the primary procedure. ENG electrodes are placed to measure vertical and rotary nystagmus.

For the purpose of this LCD, both VNG and ENG are acceptable methods used to record findings from the above- mentioned tests.

Covered Indications

Indications for vestibular function testing:

A complete picture of the patient is necessary to determine if diagnostic testing is warranted. A complete history, physical exam and review of medications must be performed before ordering diagnostic tests. These expected medical activities can often elicit a likely cause of the problem. A complete picture of the patient is necessary before testing decisions can be made. The test that would identify a common cause of balance problems should be conducted first, with progression in testing toward the least common cause of balance problems.

By performing the history and physical and medication review, the physician can often differentiate between vestibular and non-vestibular dizziness. The differentiation of the two is important because true spinning vertigo is often inner ear related and non-vertigo symptoms may be due to inner ear problems as well as central nervous system (CNS), cardiovascular, or systemic diseases or by medications that cause cardiovascular, CNS, or ototoxic symptoms. In the case where it is clearly evident that the symptoms are non-vestibular in nature, then vestibular testing should not be done. However, if the physician cannot definitively differentiate between the two and feels vestibular testing is justified, then the medical record should clearly support the need to proceed with vestibular testing.

Dizziness may support the medical necessity for hearing tests in the initial otolaryngologic evaluation of patients in whom general medical causes (i.e., anemia, cardiovascular, and metabolic disorders) have been excluded. However, since dizziness is a vague complaint, a diagnosis of dizziness alone does not qualify for coverage for vestibular function testing. There must be sufficient evaluation of the patient that vestibular testing is likely to contribute directly to the patient’s therapy.

Evaluating the VOR requires application of a vestibular stimulus and measurement of the resulting eye movements. Quantitative test of physiological processes under vestibular control can be useful in identifying the cause of the patient’s symptoms, confirming findings noted on the history and physical exam, planning therapeutic interventions and monitoring the response to those interventions.

A standard vestibular function test battery includes 1.) tests of visual ocular control; 2.) a careful search for pathologic nystagmus with fixation and with eyes open in darkness and with 3.) measurement of induced physiologic nystagmus.

Vestibular Function Tests may be covered when performed only by a qualified audiologist, with a physician’s order, or the physician treating the patient who has completed training requirements sufficient to satisfy the relevant American Board of Medical Specialties (ABMS)/American Osteopathic Association (AOA) boards for certification in Otolaryngology, Neurology, or Otology/Neurotology. For the diagnostic tests in this LCD, the audiologist or physician must have training and expertise as defined in the provider qualifications section of this LCD.

The technical component of vestibular function tests may be performed by an audiology assistant under the direct supervision of a qualified audiologist or physician with a specialty directly related to vestibular disorders.

Limitations:

• If a beneficiary undergoes diagnostic tests performed by an audiologist without a physician referral, the tests are not covered, even if the audiologist discovers a pathological condition.

• Diagnostic tests ordered before a physician performs a complete history, physical and medication review to rule out non-vestibular causes of balance problems, will not be seen as medically reasonable and necessary.

• When diagnostic information required to determine the appropriate medical or surgical treatment is already known to the physician, or the diagnostic services are performed only to determine the need for or the appropriate type of hearing aid, these services are not covered.

• Audiological services billed as incident to the service of a physician or non-physician practitioner (NPP) or as services incident to an audiologist’s services are not covered.

• When a qualified physician or NPP orders a specific audiological test using the CPT descriptor for the test, only that test may be provided on that order. 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. 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.

• It is generally not medically necessary to repeat the entire battery of vestibular function tests. In the instance where testing is performed to assess the efficacy of medical or surgical intervention, testing should be limited to those tests medically necessary to determine the success of treatment and guide further therapy. If the complete battery of tests are repeated, the medical record must clearly reflect the medical necessity of such an approach. When symptoms have resolved and then recurred absent any medical or surgical intervention, a repeat of the entire battery of tests must be substantiated by clear documentation in the medical record as to why extensive repeat testing is medically necessary.

• It is not appropriate to merely match a diagnostic test (CPT code) with a condition or diagnostic code for which it could be performed at some point and time during an episode of an illness. There must be a compelling patient care reason, and a constellation of factors that require the carrying out of this test must exist at the time when the testing is ordered and performed. Furthermore, the treating provider must be able to use the test results in the patient’s care. This rationale for ordering and performing a diagnostic test at a certain point in a patient's evaluation and treatment must be documented in the medical record.

• It is rare that a specific symptom occurs in only one disease and that the diagnosis can be established based on the presence of this symptom only - a term called pathognomic. As many conditions have "overlapping" symptoms and findings, a methodical and thorough scientific approach must be used to narrow down the possibilities. The selection of diagnostic procedures is not random. It usually follows accepted clinical paradigms. The first step in any diagnostic evaluation is the history and physical examination. From here on, the provider develops a testing strategy depending on an individual patient's situation, her or his progression in the course of an illness, and the probability of an abnormal result for a given diagnostic test. Other considerations include the predictive values, invasiveness, and risks of certain testing modalities. This is not an all-inclusive list, and all aspects and pros and cons must be placed into perspective against the background of an individual patient's situation.

As published in the CMS IOM Publication 100-08, Medicare Program Integrity Manual , Chapter 13, Section 13.5.4, an item or service may be covered by a contractor LCD if it is reasonable and necessary under the Social Security Act Section 1862 (a)(1)(A). Contractors shall determine and describe the circumstances under which the item or service is considered reasonable and necessary.

Provider Qualifications

CMS IOM Publication 100-08, Medicare Program Integrity Manual , Chapter 13, Section 13.5.4 outlines that “reasonable and necessary” services are “ordered and furnished by qualified personnel.” A qualified physician for this service/procedure is defined as follows: A) Physician is properly enrolled in Medicare. B) Training and expertise must have been acquired within the framework of an accredited residency and/or fellowship program in the applicable specialty/subspecialty in the United States or must reflect equivalent education, training, and expertise endorsed by an academic institution in the United States and/or by the applicable specialty/subspecialty society in the United States.

Please refer to the Social Security Act, Section 1861(ll)(3) and 1861(ll)(4)(B) for qualified audiologist requirements in the statute.

For Audiologists in the State of Florida, the requirements for licensure in the areas of education, supervised clinical requirements and professional experience requirements can be found in Florida Statutes. The Florida Statutes are updated annually after the conclusion of a regulator legislative session, typically published in July/August. For this LCD, an audiologist must meet all the requirements outlined in the state and federal statutes.

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