In the course of evaluating patients with vestibular and balance disorders, additional tests that are commonly considered include audiometry, vestibular tests, blood tests, computed tomography (CT), and magnetic resonance imaging (MRI). Such testing, especially vestibular testing, must be tailored to the history and physical findings in each case.
It should be kept in mind that the results of audiometry and vestibular testing are not diagnostic in the medical sense. For example, unilateral vestibular loss can be due to vestibular neuronitis or a vestibular schwannoma. Equally, a unilateral hearing loss can be due to Ménière disease, idiopathic sudden hearing loss, or a vestibular schwannoma. Therefore, clinicians who perform these tests should do so in the physiologic sense and must avoid the temptation to interpret the results as indicating pathologic entities.
Physicians who are responsible for the medical interpretations of these results must have the proper training and background in neurophysiology and electrophysiology if they are to use these results effectively. They also must be aware of the limitations and variability inherent in such tests.
The most commonly performed vestibular tests are as follows:
The rotating-chair test, also referred to as sinusoidal harmonic acceleration (SHA)
Computerized dynamic posturography (CDP)
Vestibular evoked myogenic potentials
Brainstem Auditory Evoked Response studies (BAER)