Videonystagmography (VNG)

Explained in simple words

1VNG stands for Videonystagmography. It is one of the main tests we use to find out why a person feels giddy.

2Inside your ears, deep in the bone, there are tiny organs that tell your brain whether you are standing straight, turning, or lying down. These are your balance organs.

3Your eyes and your balance organs are connected by nerves. When the balance organs move, your eyes move too — automatically, without you thinking about it.

4This means that by watching your eyes very carefully, a doctor can tell whether your balance organs are healthy or not.

5In the VNG test, you wear a pair of goggles, like swimming goggles. A very small video camera is fitted inside them.

6The camera does not touch your eyes. Nothing is put inside your ear or body. There is no injection and no cutting.

7The room lights are dimmed. The camera can still see your eyes clearly in the dark, because it uses infra-red light which is completely harmless.

8You will be asked to do a few simple things — look at a moving light or dot, follow it with your eyes, and keep your head still.

9Then you will be asked to lie down on a bed, turn your head to one side, and sit up again. The doctor may gently move your head into different positions.

10Each time, the camera records how your eyes move. The computer draws these movements as lines on a screen.

11Normal balance organs produce one pattern. Damaged or weak balance organs produce a different pattern. The doctor reads these patterns.

12This tells us which ear has the problem, whether it is the right ear or the left ear, and how badly it is affected.

13It also tells us whether the problem is inside the ear itself, or in the nerve, or in the brain. That is very important, because the treatment is different for each.

14The test does not hurt. There are no needles, no electricity and no radiation.

15During some parts of the test you may feel dizzy for a short while. This is expected and it means the test is working. The dizziness settles within a few minutes.

16Please do not stop your regular medicines without asking. But we will usually ask you to avoid medicines that stop dizziness for one to two days before the test, because they can hide the very thing we are trying to see.

17Come with someone who can accompany you home, and avoid a heavy meal just before the test.

18You may eat normally otherwise, and wear comfortable clothes. Ladies are advised to avoid eye make-up on the day of the test, as it can blur the camera picture.

19The whole test takes about thirty to forty-five minutes.

20After the test the doctor explains the result to you in simple words, and then decides your treatment.

21Many people who have suffered from giddiness for years get a clear answer for the first time from this test.

22Because the cause is found exactly, treatment can be given exactly — often a simple manoeuvre, exercises or medicine, instead of years of guessing.