Visual Nystagmography (VNG) Test

The ear, nose and throat (ENT) specialist has referred you to the Audiology Department at West Middlesex University Hospital for a specialised balance test. 

How do I prepare for my appointment?

Please follow these instructions:

• Do not take anti-dizziness tablets or sedatives for at least 48 hours beforehand. You must continue to take essential medications. If you are not sure about this, please contact your doctor.
• Do not eat or drink tea/coffee for four hours before the test.
• Do not drink alcohol for 24 hours beforehand.
• It is not wise to drive a car/operate machinery immediately after the test.
• Please refrain from wearing eye make-up as this can interfere with recording eye movements.

How long will my appointment take?

The appointment will be allocated 2 hours. We aim to see you on time but sometimes Audiology clinics can be unavoidably delayed. We will keep you informed if there is a delay to your appointment.

What will happen at my appointment?

The Audiologist will go through your completed questionnaire which is attached. A pressure test will be carried out of your ears to ensure that your eardrums are normal. This is a simple test and will not cause any discomfort. If there is a problem with this test the VNG will not be carried out, and an appointment will be made for you to see the ENT doctor.

The VNG test is divided into three parts. The Doctor does not always request all three parts of the test. For the tests a set of goggles is placed over your eyes. These goggles have cameras in them to record your eye movements, you will also be asked to lie down on a bed, throughout the three parts of the test. It is important that you keep your eyes opened during the test. The test is carried out in darkness. The reason for this is that if you are dizzy you will focus on an item to stop the dizziness, if the room is in darkness you are not able to do this, therefore allowing the cameras to record your eye movement.

EYE TRACKING: The room will be in darkness and you will be requested to follow lights on a light bar. It is important in this part of the test, that you track the moving lights, with your eyes and do not move your head.

POSITIONAL TESTING: Again the room will be in darkness. You will be moved into various positions on the bed.

CALORIC TESTING: This part of the test takes the longest time. This is where we irrigate your ears with water which creates a dizzy spell.

Your body is at a constant temperature of 37 degrees centigrade. We initially irrigate water into one of your ears at 44 degrees centigrade which is 7 degrees above your body’s temperature. You may feel that the water is very warm, but it is 7 degrees centigrade above your body temperature and gives an illusion of being very warm.

We irrigate your ear canal for 30 seconds. During this time you may start to feel dizzy, the dizziness will last only for a few minutes; it will give the sensation of being on a merry-go-round. Again you will be in darkness and we will request that you keep your eyes open so that the cameras can record your eye movements. We then repeat in your other ear. We then decrease the temperature of the water to 30 degrees centigrade and repeat the procedure on both ears. You have a short rest between each irrigation, before we start the next side.

What happens after my appointment?

At the end of the appointment you will be asked if you have a follow up ENT appointment to obtain the results of the test.

If you do not have an appointment one will be arranged for you. If you have any queries regarding your ENT appointment to obtain the results of your test you must contact the ENT department on 020 8321 5904.