Computerized Dynamic Posturography is an integral component in the diagnostic workup of imbalance or dizziness when used to identify the underlying sensory (vestibular, visual, somatosensory) and motor control impairments. CDP is not considered to be a site-of-lesion test nor is it pathonomonic for vestibular disease.
Balance and dizziness disorders often have multiple causes that cannot be isolated to a single localized pathology. Clinical evidence indicates that an impairment reduction strategy is the most effective way to reduce the symptoms associated with imbalance and dizziness with multiple causes.1-4
Where as traditional site-of-lesion tests are designed to confirm the presence and anatomical location of pathology, CDP, in contrast, documents the physiological impairments that are the functional manifestations of pathology. Because the balance system is highly adaptive, patients with similar pathology can present with different impairments, depending on the stage (progression) of the disease or disorder. In many patients with chronic balance disorders, no anatomical pathology can be identified that accounts for the patient’s symptoms and impairment(s). Clinical studies have demonstrated that, because of the “disconnect” between pathology and impairments, CDP and traditional site-of-lesion tests provide complementary rather than redundant information in the diagnostic workup of the dizzy and/or unsteady patient.5
Indications for Use
CDP Information is critical to planning treatment focused on impairment reduction, and is therefore indicated whenever an impairment reduction strategy is appropriate. Based on a retrospective study of the treatment planning process in more than 4000 chronic dizzy patients, the following guidelines were developed for the use of CDP in treatment planning:3
- Symptoms persisting for an extended period of time (up to a year or more).
- Multiple inconclusive evaluations already performed by other specialists.
- Complaints of unsteadiness when standing or walking.
- History of known pathology involving postural control pathways.
In a prospective study of dizzy patients with and without secondary gain,6 the following additional guideline for direct referral to CDP was recommended:
- Suspicion of symptoms exaggeration due to secondary gain or anxiety.
Patients who do not meet the criteria for immediate CDP testing should receive a basic (limited) balance test. These patients should be referred for subsequent CDP testing based on the following criteria:
- Abnormal or questionable performance on the basic balance test.
Numerous medical organizations, associations and insurance carriers have issued policy statements regarding the accepted use of CDP in the assessment and treatment of patients with balance and mobility disorders.
- Black FO, Angel CR, Pesznecker SC, Gianna C (2000). “Outcome analysis of individualized vestibular rehabilitation protocols.” American J Otology 21:543-551.
- Calder JH, Jacobson GP (2000). “Acquired bilateral peripheral vestibular system impairment: rehabilitative options and potential outcomes.” J American Academy Audiology 11:514-521.
- Shepard NT, Telian SA (1996). Practical Management of the Balance Disorder Patient. Singular Publishing Group, Inc., San Diego, 221pp.
- Rose D, Clark S (2000). “Can the control of bodily orientation be significantly improved in a group of older adults with a history of falls?” JAGS 48:275-282.
- Stewart MG, et al (1999). Cost-effectiveness of the diagnostic evaluation of vertigo. The Laryngoscope. 108:600-605.
- Gianoli G, McWilliams S, et al (2000). Posturographic performance in patients with the potential for secondary gain. Otolaryng Head Neck Surg 122:11-18.