Vestibular Function Testing
VNG: The VNG (videonystagmogram) determines if an inner ear or brain-related disease may be causing dizziness, vertigo or imbalance. During testing, the patient wears infrared goggles that record eye movements. The vestibular system, which controls your equilibrium or sense of balance, is then monitored through the eyes during tasks that consist of slow and quick eye movements, lying in different positions, and lying down and sitting up quickly. The final portion of the test requires cooling or warming the air in the ear canal in order to determine if the balance mechanism of each ear can be stimulated normally and equally between ears. During the VNG, the patient’s eyes will be continuously monitored and recorded to determine if there are abnormal eye movements that may signal a vestibular system abnormality.
VEMP: The VEMP (vestibular evoked myogenic potential) test determines if the saccule, one portion of the inner ear, as well as the inferior vestibular nerve and central connections, are intact and working normally. This test is performed while the patient is lying back in a recliner. Electrodes are placed on each side of the neck, on the forehead, and at the top of the chest. Earphones are placed in the ears and the patient hears pulsed tones. The presence or absence of a small contraction in the muscles on the sides of the neck will signal whether parts of the vestibular system noted above are working correctly.
Rotary Chair: The Rotary Chair is used to assess the Vestibular Ocular Reflex (VOR). The VOR allows us to maintain visual clarity of objects during head movement. It permits us to perform such routine activities as reading street signs while walking down a sidewalk. We take the VOR for granted until it does not function properly. During testing, the patient sits in a darkened room with goggles on. The patient’s eye movements are measured while the chair slowly spins at different speeds. It is a quick and painless test, lasting approximately 10-15 minutes.