Vestibular / Balance Testing
The inner ear is comprised of two sections, the hearing portion (cochlea) and the balance portion (semicircular canals and vestibule). The semicircular canals and vestibule are sensitive to head movement and rotation as well as gravity. The interaction of these, along with our eyes and sense of touch, gives us our understanding of where we are and what positions we are in. When any of these components are not functioning properly, it can result in vertigo (spinning sensation), dizziness (off-balance), or a feeling of light headedness. There is a connection between the balance portion of the inner ear and the eyes and eye muscles. When dizziness occurs, a specific type of eye movement, called nystagmus, often results. Vestibular/balance testing records and measures these eye movements to assess the status of the vestibular system.
What is an ENG (Electronystagmography) / VNG (Videonystagmography)?
VNG is a non-invasive recording of eye movements to assess the vestibular/balance system. ENG uses recording electrodes placed on the forehead and around the eyes and measures changes in electrical potentials that occur when the eye muscles move the eyes. A newer system, often referred to as VNG, uses infrared video cameras, rather than electrodes, to record these eye movements. The VNG system allows for more precise measurements than the traditional electrode ENG’s. Capital Region Otolaryngology has been using a VNG system since 1998.
What does the test involve?
The VNG test battery is composed of three sections. The first portion involves watching and following a series of lights/dots as they move in different patterns. During this test, infrared video cameras will record your eye movements. The computer, along with the audiologist, will analyze these movements. The second portion of the test battery requires that you wear a special set of goggles that also contain infrared cameras. During these tests, you will be asked to place your head and body into different positions while lying on an examination table. Again, the cameras will record eye movements, which are analyzed by the audiologist. Finally, while wearing the special goggles, your ears will be irrigated with cool and warm water. As a result of this test you will likely feel some dizziness. This feeling only lasts a few minutes, but gives us a great deal of information about your vestibular system. As in the early sections, the cameras will record eye movements and the results are analyzed to determine if each ear’s vestibular system is functioning properly.
Please click here for instructions on how to prepare for your for VNG testing.