What is Videonystagmography (VNG) Testing?
VNG testing determines if a vestibular (inner ear) disease is the source of your dizziness or balance problems. This series of tests evaluates your ability to follow objects with your eyes and measures how well the eyes respond to information from the vestibular (inner ear) system.
What do your eyes have to do with your ears?
Neural pathways connect the inner ear balance mechanism to eye muscles. A disorder of the balance mechanism can result in quick eye movements that can only be detected with advanced optics.
An older test, called electronystagmography (ENG), used electrodes to measure the muscle activity around the eye. VNG testing, which uses a special infrared camera to measure eye movements, is much more comfortable for patients and yields more accurate results. VNG is also the only test that can distinguish between unilateral (one ear) and bilateral (two ear) vestibular loss, so it’s easy to understand why audiologists have adopted it as the new best-practice technique for evaluating inner ear functions.
VNG testing also addresses ear functionality to determine if a vestibular deficit might be causing your balance or dizziness problems.
What to Expect During VNG Testing
You’ll wear goggles fitted with an infrared camera that will record your eye movements as you look back and forth between designated points, track moving lights, and move your head and body into different positions.
Although you might feel minor discomfort from wearing the goggles, VNG testing is painless and non-invasive. Appointments last about 1 ½ hours, and all insurances cover the testing.
Steps of VNG Testing
The 4 main parts of VNG testing include:
- Ocular Mobility: Here, you’ll use your eyes to follow objects that jump from place to place, stand still and move smoothly. As you follow these visual targets, our team will look for inaccuracies or slowness that could indicate a neurological or central nervous condition, or trouble with the pathway between the brain to the vestibular system.
- Optokinetic Nystagmus: Your team will ask you to view a large, moving image to see if your eyes properly track such movements. Like the ocular mobility segment, we’ll be examining your ability to follow visual targets.
- Positional Nystagmus: Our technician will place your body and head into different positions to ensure that there aren’t inappropriate rapid eye movements as you move. This test examines your inner ear system and the endolymph fluid in your semi-circular ear canals. We’re verifying that otoconia, or small calcium carbonate particles, aren’t disturbing the natural flow of fluid.
- Caloric Testing: One at a time, our team will simulate your inner ears with warm, followed by cool, air. We’ll monitor your eye movements to ensure that both of your ears sense and respond to stimulation. This is the portion of the test that can distinguish between unilateral and bilateral vestibular loss.
Based on your VNG test results, your audiologist may recommend hearing aids or other medical treatments to correct your dizziness or balance disorder. Schedule your VNG testing with Hearing Associates by calling 888.760.2032.