Rotary Chair Testing
Rotary chair testing provides an unparalleled clinical assessment of the vestibular system. Modern rotational chairs are capable of providing a variety of exacting rotational stimuli that can effectively identify disorders impacting both peripheral and central vestibular functions. Moreover, vestibular compensation mechanisms can be effectively evaluated, and disease progression or therapeutic processes can be efficiently monitored with rotational testing. Its ability to evaluate both the peripheral and central vestibular response characteristics across a broad frequency range is vital to providing a more comprehensive vestibular phenotype for patients with suspected bilateral vestibular areflexia as well as patients with non-specific dizziness.
Although modern-day rotational chairs offer a wide range of testing protocols, the two most common rotational tests, sinusoidal harmonic acceleration (SHA) testing and velocity step testing (VST), will be highlighted in this chapter. The salient outcome measures of each test will be discussed and the interpretation of each test will be presented. Non-specific dizziness and clinically evasive vestibular disorders represent a growing population within most otolaryngology and audiology clinics, particularly in light of the exponential growth of the geriatric population. The addition of rotational testing in the comprehensive vestibular assessment is critical to increasing the diagnostic sensitivity and specificity for vestibular pathology.
KeywordsSinusoidal harmonic acceleration (SHA) Velocity step testing (VST) Rotational vestibular testing Vestibular ocular reflex (VOR) SHA gain SHA phase SHA symmetry VOR time constant
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