The Videonystagmography (VNG) is utilized for assessing the inner ear and central functions of the motor system. It is the only test that can differentiate between a unilateral (one ear) and bilateral (both ears) inner ear deficit. VNG testing consists of a battery of tests intended to record a patient’s ability to follow visual stimulation and corresponding eye movements following information from the vestibular system.
The VNG is composed of three primary components. The first is the oculomotor examination, which allows the audiologist to observe the patient’s eye movements as they follow a moving target. The second component is performed with different positions of the patient’s head while lying on an examination table. Third is the caloric test, which independently evaluates the horizontal semicircular canals and superior portion of the vestibular nerve from each ear.