Videonystagmography or VNG is a test that examines the balance system. It can be used to determine the cause of a patient’s dizziness if it can be attributed to a vestibular disorder.
VNG testing uses a combination of video goggles and infrared cameras to measure involuntary eye movements. While the patient is given a series of visual tasks, the camera records their eye movements. These rapid eye movements can only be captured using high-tech equipment and can indicate a balance system disorder.
VNG Testing Parts
There are generally four parts to VNG testing. They are:
- A saccade test that analyzes rapid eye movements.
- A tracking test that measures eye movements as they follow a visual target.
- A positional test that measures dizziness in relation to different head positions.
- A caloric test that evaluates responses to warm and cold water introduced through a tube in the ear canal.
Testing is non-invasive and usually lasts between 60 and 90 minutes. You are unlikely to experience side effects during the test, but there may be episodes of brief dizziness and some minor discomfort from the goggles.
You should avoid alcohol and certain medications for 48 hours before the test. These include sleeping pills, diuretics, tranquilizers, sedatives, antihistamines, muscle relaxers, anti-depressants, and pain medication. Food and smoking will also need to be avoided for 3 hours before the test with the exception of water. You may continue taking prescription medications unless instructed otherwise.
If you are interested in learning more about VNG testing, please contact North Sioux City our office at (605) 217-4320.