What is Videonystagmography (VNG)?
For individuals having difficulties with their balance and equilibrium, videonystagmography (VNG) is a valuable diagnostic procedure that is simple and painless, and it can help more accurately determine the cause of your dizziness symptoms.
The test uses a camera to trace quick eye movements (or nystagmus) in response to certain visual cues and positional changes. This information is illuminating because there are neural pathways that connect the balance mechanism of the inner ear to the muscles of the eye. A disorder of the balance mechanism can result in quick eye movements that can only be detected with advanced optics.
In our testing, a camera attached to a pair of goggles worn by the patient records eye movement as the patient looks back and forth between designated points, tracks moving lights, and moves the head and body into different positions in a dark room.
A final portion of the test involves the insertion of cool and warm air into the ear to determine if the balance system is responding predictably to temperature stimulation. Because the hearing and balance functions of your inner ear are so closely related, we routinely administer a hearing test before VNG to assess the condition of this system.
Important Instructions For VNG Testing
To ensure the most accurate VNG results, it is important to observe the following:
- Avoid certain medications for 48 hours before the test, including sleeping pills, diuretics, tranquilizers, sedatives, antihistamines, muscle relaxants, anti-dizziness medications, barbiturates, anti-depressants, anti-anxiety medications, and pain medication.
**Please do not discontinue prescription medications without checking with the physician who prescribed them. If you cannot go without a medication listed above, please call our office prior to arriving for the evaluation.
- Avoid alcohol consumption for 48 hours before the test.
- No food or beverages (except water) for 4 hours before the test.
- No smoking for 3 hours before the test.
- No eye makeup (eyeliner or mascara, especially) should be worn to the test.
- Please dress comfortably to facilitate the physical movement portion of the test. Women may wish to wear comfortable pants as opposed to a dress or skirt.
What to Expect at Your VNG Test
The test will likely cause some dizziness, though this is critical for measuring your physiological response to the symptom. This generally passes within a few minutes. It’s a good idea to make arrangements for someone to drive you home in the unlikely event of prolonged dizziness. Expect your test to take approximately 60–90 minutes.
Please contact us at least 24 hours in advance should you need to cancel or change this appointment.