Videonystagmography (VNG)

The inner ear’s balance system and the muscles that move the eyes are closely connected. When the balance system is working normally, the eyes stay steady as the head moves. When part of the system is not working properly, the eyes can make small involuntary movements called nystagmus. Recording these movements helps show whether a balance problem is coming from the inner ear, from the brain, or from the pathways between them.

During VNG you wear goggles fitted with small infrared cameras. The cameras record your eye movements, and a computer measures and analyzes them. The test usually has three parts:

• Eye-movement testing. You follow lights or targets with your eyes while keeping your head still. This checks how well the eyes track and move on their own.
• Positional testing. You are guided into different head and body positions, such as lying down or turning your head, while your eye movements are recorded. This looks for movements triggered by position, as seen in benign paroxysmal positional vertigo (BPPV).
• Caloric testing. Warm and cool air or water is introduced gently into each ear canal to stimulate the inner ear. This compares how the balance system responds on each side. It can cause a brief spinning or floating sensation, which passes shortly after that part of the test.

VNG may be recommended if you have vertigo, unsteadiness, or other balance symptoms, or if balance problems follow a head injury. It is one part of the evaluation. The results are interpreted together with your history, examination, and any other tests. See Balance Problems and Vertigo.

The office will give you instructions before your appointment. They commonly include:

• Avoiding alcohol and certain medications for a period before the test, because they can affect the results. Do not stop any prescribed medication without checking with the physician who prescribed it.
• Eating only a light meal beforehand, since parts of the test can cause temporary nausea.
• Wearing comfortable clothing, as you will lie down and change positions.

Any spinning or unsteadiness from the test usually settles soon after it ends. Dr. Kayem reviews the recordings and discusses the findings with you, including whether further testing or treatment such as vestibular rehabilitation is recommended.