Balance and Dizziness Testing

WHAT IS A VIDEONYSTAGMOGRAPHY (VNG) TESTING

     Videonystagmography (VNG) is used to help your doctor determine why you are dizzy and off balance and perhaps falling. The VNG tests inner ear and central motor functions. VNG testing is considered the new standard for testing inner ear functions over Electronystagmography (ENG), because VNG measures the movements of the eyes directly through infrared cameras, instead of measuring the mastoid muscles around the eyes with electrodes like the previous ENG version. VNG testing is more accurate, more consistent, and more comfortable for the patient. By having the patient more comfortable and relaxed, consistent and accurate test results are more easily achieved.

     VNG testing is used to determine if a vestibular (inner ear) disease may be causing a balance or dizziness problem. It is one of the only tests available today that can decipher between a unilateral (one ear) and bilateral (both ears) vestibular loss. VNG testing is a series of tests designed to document a person’s ability to follow visual objects with their eyes and how well the eyes respond to information from the vestibular system.

Be Prepared: Test Instructions for VNG testing

• Please dress comfortably.
• Wear flat comfortable shoes for testing.
• No facial makeup (especially eye makeup) should be worn on the day of testing. This includes mascara, eyeliner and eye shadow.
• Do not drink coffee, tea, soda or any beverage containing caffeine or alcohol within 12 hours of the test.
• Do not eat for three (3) hours before the test, unless you are diabetic.
• Ears should be checked for infection and cleared of wax buildup prior to arriving for the test. Debrox or Cerumenex can be obtained at your pharmacy to clear out the wax buildup. This should be done the day prior to the test.
• Continue to take heart, high blood pressure and anticonvulsant medications.
• The following medications must not be taken for at least 12 hours before test:
• Anti-vertigo medication: Antivert, Meclizine, etc.
• Tranquilizers: Valium, Librium
• Anti-nausea medication: Dramamine, Compazine, Bonine, Marezine, Phernergan,Thorazine, etc.
• Narcotics: Codeine
• Antihistamines.
• Questions about other medications should be discussed with your referring doctor or your primary care physician.
• Do not partake of any alcohol in any quantity, including beer, wine and cough medicines containing alcohol.
• If you have not been here before, please arrive thirty minutes before your appointment time to register.
• Our technician will escort you to the Balance & Dizziness Lab.

     This is a multi-part test. The first portion is done by our technician. Parts 2-5 are done by our physician who is specially trained in Physical Medicine and Rehabilitation.

1. Computerized Dynamic Posturography (CDP)
You will be asked to stand on a balance measurement platform. This is a large circle about one yard in diameter and it is fixed in a very stable position. There will be a TV screen in front of you. A target will appear on the screen. The technician will instruct you to follow this target with your eyes and your body. Once you are balanced doing this, the technician may adjust the platform several times and have you repeat the test. There is a rail in front of you should you need to hold on at any point during the testing. The technician who is doing the test will watch you very carefully to make sure you do not become unbalanced and will stand directly behind you in case you need assistance. For part 2 & part 3 you will sit in front of a TV screen and will be asked to put on a pair of goggles. These goggles will record your eye movements during the testing.


2. Occular Mobility
You will be asked to have your eyes follow objects that jump from place to place, stand still, or move smoothly. The physician will be looking for any slowness or inaccuracies in your ability to follow visual targets. This may indicate a central or neurological problem, or possibly a problem in the pathway connecting the vestibular system to the brain.


3. Optokinetic Nystagmus
You will be asked to view a large, continuously moving visual image to see if your eyes can appropriately track these movements. Like the occular mobility tests, the physician will be looking for any slowness or inaccuracies in your ability to follow visual targets. This may indicate a central or neurological problem, or possibly a problem in the pathway connecting the vestibular system to the brain. For part 4 & part 5 you will be asked to lie down on an exam table with your head extended just beyond the edge of the table. You will still be wearing the goggles.


4. Positional Nystagmus (Also known as the Dix-Halpike Maneuver)
The physician will move your head and body into various positions to make sure that there are no inappropriate eye movements (nystagmus) when your head is in different positions. This test is looking at your inner ear system and the condition of the endolymph fluid in your semi-circular canals. The physician is verifying that small calcium carbonate particles called otoconia are not suspended in the fluid and causing a disturbance to the flow of the fluid.


5. Caloric Testing
The physician will stimulate each of your inner ears (one at a time) with warm and then cold air. The physician will be monitoring the movements of your eyes using goggles to make sure that both of your ears can sense this stimulation. This test will confirm that your vestibular system for each ear is working and responding to stimulation. This is the only test available that can decipher between a unilateral and bilateral loss.

This test will give your doctor valuable information. However a lot depends upon your cooperation.
VNG and Balance Testing lasts approximately 1 ½ hours, and is usually covered by your insurance.