Dynamic posturography tests a patient’s balance control in situations intended to isolate factors that affect balance in everyday experiences. It provides quantitative information regarding balance.

Dynamic posturography attempts to provide more quantitative information regarding the 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 the eyes are open or closed, whether the platform is fixed or sway-referenced, and whether the visual surround is fixed or sway-referenced. Sway-referencing involves making instantaneous computer-aided alteration in 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 that are 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. Dynamic posturography cannot be used to localize the site of a lesion.

Complaints of imbalance are common in older individuals and contribute to the risk of falling in the elderly population. Falls are the most common 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, proprioceptive/somatosensory system, and central reflex mechanisms and is influenced by the general health of the patient (i.e., muscle tone, strength, and range of motion). Therefore, identifying and treating the underlying balance disorder may be difficult. Commonly used balance function tests such as electronystagmography (ENG) and rotational chair tests attempt to measure the extent and site of a vestibular lesion, but do not attempt to assess the functional ability of the patient to maintain balance. 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. The 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 NeuroCom EquiTest® is a dynamic posturography device which 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.

Dynamic posturography is considered not medically necessary.

CPT code 92548 describes computerized dynamic posturography.

BlueCard/National Account Issues

State or federal mandates (e.g., FEP) may dictate that all FDA-approved devices may not be considered investigational and thus these devices may be assessed only on the basis of their medical necessity.

This policy is based on a 1996 TEC Assessment (1), which offered the following conclusions:

• There is insufficient evidence to determine whether dynamic posturography detects vestibular dysfunction or whether dynamic posturography distinguishes between peripheral and central vestibular dysfunction. In particular, the available studies fail to evaluate sensitivity and specificity relative to a reliable and valid reference standard.
• In the absence of a valid reference standard, the usefulness of dynamic posturography could be assessed by whether its use improves treatment decision making and health outcomes. However, no studies are available that address the health outcome effects of treatment decisions based on dynamic posturography.

Literature review updates to identify additional studies published since the 1996 TEC Assessment failed to identify any studies that would address the issues raised by the 1996 TEC Assessment. Therefore, the policy statement remains unchanged. Computerized dynamic posturography can be used in 3 general settings: 1) to further evaluate the etiology of balance disorders; 2) to provide a risk assessment for falling; or 3) to assess improvement after a program of vestibular rehabilitation. However, literature searches of the MEDLINE database have not identified any studies that focused on health outcomes related to treatment decisions based on the results of dynamic posturography in any of the above clinical situations or compared the quantitative results of dynamic posturography with the qualitative results of clinical assessment (i.e., history and physical exam alone). For example, regarding the risk of falling, Girardi and colleagues evaluated the results of computerized dynamic posturography in a group of 65 elderly patients who had a history of falling. (2) While 78% of patients had abnormal results on computerized dynamic posturography testing, results in a broader group of patients is required to determine whether or not results of CPD can identify those at risk for falling. Baloh and colleagues studied balance control in a group of elderly patients who complained of balance disorders and a group of age-matched controls; the subjects were tested in a variety of situations (i.e., eyes open and closed, while standing on a foam pad to disrupt sensory cues, tilting of the platform, etc.). (3) The authors concluded that posturography data provided little information about the cause of imbalance and did not correlate with the frequency of reported falls. Other authors have pointed out that there is uncertainty about how results of computerized dynamic posturography may correlate to functional activities, such as gait. (4) For example, measurements of gait, frequently gait velocity, are often used in the elderly to assess balance and mobility. A variety of patient questionnaires have been designed to measure self-perceived dizziness or balance. The correlation between the results of these clinical tests, questionnaires, and computerized dynamic posturography are uncertain. (5)

Other studies identified in the literature review updates include the use of posturography in the assessment of post-surgical acoustic neuroma patients (6); for the assessment of fall risk (7-9); to assess the effects of vestibular rehabilitation (10); and to assess results from balance and high-intensity resistance training in idiopathic Parkinson's disease patients. (11) However, none of these studies demonstrated improved treatment decision making and/or health outcomes based on the results of dynamic posturography. Therefore, the policy is unchanged.

2007 Update

A search of the MEDLINE database through February 2007 did not identify any randomized or controlled trials using this technique. Several retrospective studies were published that describe a customized exercise program based on results of a complete medical and neuro-otologic history and physical examination that included platform posturography. (12, 13) However, the contribution of dynamic posturography to the overall assessment and customization of the exercise program is unclear. In particular, the reports do not describe how (or whether) the exercise programs were modified based on specific deficits identified by platform posturography. Customized vestibular rehabilitation programs can be devised with a standard battery of tests. (14) These retrospective reports are also limited by selection bias and lack of follow-up. Moreover, while these studies show that individualized therapy can improve patient outcomes, no controlled trials have assessed whether individually customized therapy programs are more effective than generic vestibular exercises. Other recent studies indicate that the Sensory Organization Test (SOT) with dynamic posturography may be predictive of the subsequent number of falls (15, 16), but the utility of this information on patient management is unknown. Thus, evidence remains insufficient to determine whether the incremental information provided by dynamic posturography improves health outcomes in patients with balance disorders.

2008 Update
A search of the MEDLINE database was performed for the period of March 2007 through March 2008. The literature indicates that dynamic posturography is used primarily as a research tool. One small ('n=15) randomized treatment study in patients with Parkinson’s disease found similar improvements using dynamic posturography or standard balance physical therapy. (17) The literature has not demonstrated any improvement in health outcomes over standard physical therapy, and it has not been shown to be clinically appropriate for diagnosis or treatment. Dynamic posturography is therefore considered not medically necessary.

2009 Update

A MEDLINE search from March 2008 through August 2009 was conducted for this update. Posturography was used to evaluate the efficacy of rehabilitation programs in two recent studies. Nocera and colleagues used posturography to evaluate the effectiveness of a home-based exercise program on postural control for 10 patients with Parkinson disease. (18) In a study by Teggi et al., 40 patients recently hospitalized for acute vestibular disorders underwent an active rehabilitation program or were advised to perform their normal activities and were evaluated with a number of assessment tools including posturography. (19) The relative utility of one method of assessment over another was not reported in this study. These studies do not provide evidence that would lead to a change in the policy statement; no change to the policy statement is indicated at this time.

References:

1. 1996 TEC Assessments; Tab 11
2. Girardi M, Konrad HR, Amin M et al. Predicting fall risks in an elderly population: computer dynamic posturography versus electronystagmography test results. Laryngoscope 2001; 111(9):1528-32.
3. Baloh RW, Jacobson KM, Enrietto JA et al. Balance disorders in older persons: quantification with posturography. Otolaryngol Head Neck Surg 1998; 119(1):89-92.
4. Evans MK, Krebs DE. Posturography does not test vestibulospinal function. Otolaryngol Head Neck Surg 1999; 120(2):164-73.
5. Clendaniel RA. Outcome measures for assessment of treatment of the dizzy and balance disorder patient. Otolaryngol Clin North Am 2000; 33(3):519-33.
6. Cohen HS, Kimball KT, Jenkin HA.Factors affecting recovery after acoustic neuroma resection. Acta Otolaryngol 2002; 122(8):841-50.
7. Carter ND, Khan KM, McKay HA et al. Community-based exercise program reduces risk factors for falls in 65- to 75-year-old women with osteoporosis: randomized controlled trial. CMAJ 2002; 167(9):997-1004.
8. ReidVA, Adbulhadi H, Black KR et al. Using posturography to detect unsteadiness in 13 patients with peripheral neuropathy: a pilot study. Neurol Clin Neurophysiol 2002; 2002(4):2-8.
9. Sinaki M, Lynn SG. Reducing the risk of falls through proprioceptive dynamic posture training in osteoporotic women with kyphotic posturing: a randomized pilot study. Am J Phys Med Rehabil 2002; 81(4):241-6.
10. Cohen HS, Kimball KT. Decreased ataxia and improved balance after vestibular rehabilitation. Otolaryngol Head Neck Surg 2004; 130(4):418-25.
11. Hirsch MA, Toole T, Maitland CG et al. The effects of balance training and high-intensity resistance training on persons with idiopathic Parkinson's disease. Arch Phys Med Rehabil 2003; 84(8):1109-17.
12. Badke MB, Shea TA, Miedaner JA et al. Outcomes after rehabilitation for adults with balance dysfunction. Arch Phys Med Rehabil 2004; 85(2):227-33.
13. Badke MB, Miedaner JA, Shea TA et al. Effects of vestibular and balance rehabilitation on sensory organization and dizziness handicap. Ann Otol Rhinol Laryngol 2005; 114(1 pt 1):48-54.
14. Brown KE, Whitney SL, Marchetti GF et al. Physical therapy for central vestibular dysfunction. Arch Phys Med Rehabil 2006; 87(1):76-81.
15. Buatois S, Gueguen R, Gauchard GC et al. Posturography and risk of recurrent falls in healthy non-institutionalized persons aged over 65. Gerontology 2006; 52(6):345-52.
16. Whitney SL, Marchetti GF, Schade AI. The relationship between falls history and computerized dynamic posturography in persons with balance and vestibular disorders. Arch Phys Med Rehabil 2006; 87(3):402-7.
17. Qutubuddin AA, Cifu DX, Armistead-Jehle P, et al. A comparison of computerized dynamic posturography therapy to standard balance physical therapy in individuals with Parkinson's disease: a pilot study. NeuroRehabilitation 2007; 22(4):261-5.
18. Nocera J, Horvat M, Ray CT. Effects of home-based exercise on postural control and sensory organization in individuals with Parkinson disease. Parkinsonism Relat Disord 2009 Jul 27. [Epub ahead of print]
19. Teggi R, Caldirola D, Fabiano B et al. Rehabilitation after acute vestibular disorders. J Laryngol Otol 2009; 123(4):397-402.

Computerized Dynamic Posturography
Dynamic Posturography
Equitest™ (See Dynamic Posturography)
Metitur™ (See Dynamic Posturography)
Moving Platform Posturography
Posturography, Dynamic