A Videonystagmography, or VNG for short, is a test which measures involuntary eye motions, termed nystagmus. Theses involuntary eye motions can be fast or slow, and cause your eyes to move side to side, or up and down. This information is send to the brain, but conflicts with information from the inner ear. The inner ear, like our vision is one of our balance systems, providing information about where we are in space. This conflicting information often causes the symptoms of dizziness and imbalance. If this occurs, it is a sign of a vestibular hypofunction.
What happens During a VNG?
Your VNG is performed by a skilled audiologist. During this test, you will be in a dark room and wearing goggles to record your eye motions. There are three categories of tests which will be performed:
- Occular Testing- Involves following moving lights on a bar
- Positional Testing – Your head and body will be moved into different positions
- Caloric Testing – Warm and cool air is blow into your ear
What Do the Results Mean?
If your results are normal, it means you inner ear (vestibular system) is working well. If the results are abnormal, it usually indicates there is a disorder of the inner ear. These disorders include:
- Vestibular hypofunction
- Benign Positional Paroxysmal Vertigo (BPPV)
Abnormal results during some test components may also indicate a central nervous system abnormality. At this point, an MRI will be ordered. Following the test, your doctor will discuss the results with you.