VNG: The VNG (videonystagmogram) determines if an inner ear or brain-related disease may be causing dizziness, vertigo or imbalance. During this test, the patient wears infrared video goggles that record eye movements. The vestibular system, which controls your equilibrium or sense of balance, is then monitored through eye movements. This test has several different parts. One portion of the test consists of measuring slow and quick eye movements. Another portion monitors eye movements when lying in different positions. The final portion of this test requires blowing cool and warm air into the ear, 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 division of the 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) through the horizontal semicircular canal and superior division of the vestibular nerve. 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.