Medical Policy: 02.01.08
Original Effective Date: December 2000
Reviewed: July 2017
Revised: August 2015
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.
Computerized Dynamic Posturography (CDP), (also known as dynamic posturography, balance board testing, equilibrium platform testing (EPT), and moving platform posturography), is a unique assessment technique used to objectively quantify and differentiate among the wide variety of possible sensory, motor and central adaptive impairments to balance control.
Complaints of imbalance are common in older adults and contribute to the risk of falling in this population, and are a
cause of death and disability in this population in the United States. Maintenance of balance is a complex physiologic process, requiring interaction of the vestibular, visual and proprioceptive/somatosensory system, and central reflex mechanisms. Balance is also influenced by the general health of the patient (i.e. muscle tone, strength, range of motion). Therefore, identifying and treating the underlying balance disorder can be difficult. Commonly used balance function tests (e.g. electronystagmography, rotational chair tests) attempt to measure the extent and site of a vestibular lesion but do not assess the functional ability to maintain balance.
Computerized dynamic posturography aims to provide quantitative information on a patient’s functional ability to maintain balance. The patient, wearing a harness to prevent falls, stands on an enclosed platform surrounded by a visual field. By altering the angle of the platform or shifting the visual field, the test assesses movement coordination and the sensory organization of visual, somatosensory, and vestibular information relevant to postural control. The patient undergoes 6 different testing situations designed to evaluate the vestibular, visual and proprioceptive/somatosensory components of balance. In general terms, the test measures an individual’s balance (as measured by a force platform to calculate the movement of the patient’s center of mass) while visual and somatosensory cues are altered. These tests vary by whether eyes are open or closed, the platform is fixed or sway-referenced, and whether the visual surround is fixed or sway-referenced. Sway-referencing involves making instantaneous computer-aided alterations to the platform or visual surround to coincide with changes in body position produced by sway. The purpose of sway-referencing is to cancel out accurate feedback from somatosensory or visual systems that are normally involved in maintaining balance. In the first 3 components of the test, the support surface is stable, and visual cues are either present, absent or sway-referenced. In tests 4 to 6, the support surface is sway-referenced to the individual, and visual cues are either present, absent or sway-referenced. In tests 5 and 6, the only accurate sensory cues available for balance are vestibular cues. Results of computerized dynamic posturography have been used to determine what type of information (i.e., visual, vestibular, proprioceptive) can and cannot be used to maintain balance. Computerized dynamic posturography cannot diagnose pathology or be used to localize the site of a lesion.
Posturography tests a patient’s balance control in situations intended to isolate factors that affect balance in everyday experiences. Balance can be rapidly assessed qualitatively by asking the patient to maintain a steady stance on a flat or compressible surface (i.e foam pads) with the eyes open or closed. By closing the eyes, the visual input into balance is eliminated. Use of foam pads eliminates the sensory and proprioceptive cues. Therefore, only vestibular input is available when standing on a foam pad with eyes closed.
The purpose of computerized dynamic posturography in patients who have balance dysfunction is to inform a decision whether to pursue additional diagnostic workup (e.g. imaging studies that would not have been indicated based on clinical presentation alone) or immediate treatment.
The relevant population(s) of interest are patients presenting with balance dysfunction or dizziness. It would be expected that these patients will have had an initial basic evaluation directed by symptoms that will have included a clinical examination and history, with appropriate vital signs and orthostatic blood pressure measurements, and may have had basic evaluations as directed by their symptoms (e.g. electrocardiogram).
Depending on the clinical presentation, patients with balance dysfunction may be managed with clinical evaluation alone or with more intensive evaluations including vestibular functioning testing, which can be used to localize the cause of the dysfunction. The ultimate goal of evaluation is to correctly diagnose and treat the underlying condition.
Patients with balance dysfunction being evaluated with computerized dynamic posturography are generally seen in the outpatient setting. Testing may be conducted by audiologists, physical therapists, or technologists under the supervision of physicians.
Technical performance of a posturography device is typically assessed with 2 types of studies: those that compare test measurements with a criterion standard and those that compare results taken with the same device on different occasions (test-retest).
Diagnostic accuracy is evaluated by the ability of a test to accurately diagnose a clinical condition compared with the criterion 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 accuracy, therefore, requires independent assessment by the 2 methods in a population of patients suspected of disease but who do not all have the disease.
Based on review of the literature no studies have been identified that evaluate the sensitivity and specificity of computerized dynamic posturography for diagnosing any specific balance disorder compared with commonly accepted balance tests. There is also no “criterion standard” test for measuring balance, which is a physiologic parameter. Diagnostic performance (diagnostic accuracy) of dynamic posturography is lacking.
The evidence related to improvement in clinical outcomes with the use of a test assesses the data linking use of the test to changes in health outcomes (clinical utility). Based on review of the literature no randomized or nonrandomized controlled studies were identified that compared health outcomes in patients when treatment decisions were made with or without the results of computerized dynamic posturography. Direct evidence of how computerized dynamic posturography can be used to improve health outcomes is lacking.
Based on the peer reviewed medical literature the evidence for computerized dynamic posturography in individuals who have suspected balance disorders includes technical performance studies, cross-sectional comparisons of results in patients with balance disorders and healthy controls, and retrospective case series reporting outcomes of patients assessed with dyanamic posturography as part of clinical care. There are no generally accepted reference standards for computerized dynamic posturography (CDP), which makes it difficult to determine how the results can be applied in clinical care. There is a lack of evidence on test performance characteristics for clinically important conditions, such as identifying patients who are at risk of falls. There are no studies demonstrating the clinical utility of the test that would lead to changes in the management that improve health outcomes (e.g. symptoms and function). The evidence is insufficient to determine the effects of this technology on net health outcomes and therefore, computerized dynamic posturography (CDP) is considered investigational for all indications.
The American Academy of Otolaryngology – Head and Neck Surgery have issued a position statement and a guideline that mention dynamic posturography:
The NeuroCom EquiTest® is a dynamic posturography device that received 510(k) marketing clearance from the U.S. Food and Drug Administration (FDA). Other dynamic posturography device makers include Micromedical Technology, Metitur, and Vestibular Technologies.
Computerized Dynamic Posturography (CDP) is considered investigational for all indications.
Based on the peer reviewed medical literature there are no generally accepted reference standards for computerized dynamic posturography which makes it difficult to determine how the results can be applied to clinical care. There are no studies that demonstrate the clinical utility of the test that leads to changes in management and improves net health outcomes. Therefore, computerized dynamic posturography (CDP) testing is considered investigational for all indications.
Wellmark medical policies address the complex issue of technology assessment of new and emerging treatments, devices, drugs, etc. They are developed to assist in administering plan benefits and constitute neither offers of coverage nor medical advice. Wellmark medical policies contain only a partial, general description of plan or program benefits and do not constitute a contract. Wellmark does not provide health care services and, therefore, cannot guarantee any results or outcomes. Participating providers are independent contractors in private practice and are neither employees nor agents of Wellmark or its affiliates. Treating providers are solely responsible for medical advice and treatment of members. Our medical policies may be updated and therefore are subject to change without notice.
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