Electronystagmography (ENG)

Explained in simple words

1ENG stands for Electronystagmography. It is a test that studies your eye movements to understand your balance problem.

2It does the same job as the VNG test, but instead of a camera it uses small sensors placed on the skin.

3Deep inside each ear there is a balance organ. It works like a spirit level, telling the brain which way your head is moving.

4The balance organs are joined to the eye muscles by nerves. So whenever the balance organ works, the eyes move in a particular way.

5By recording those eye movements, we can find out whether the balance organ and its nerve are healthy.

6For this test, the skin around your eyes is cleaned gently. Then small flat stickers, called electrodes, are stuck on the skin near the corners of the eyes and on the forehead.

7These stickers only listen. They do not give any current, shock or pain. Nothing enters your body.

8The stickers are joined by thin wires to a machine that records the signals and draws them on a computer screen.

9You will be asked to sit quietly, then to look at a light that moves left, right, up and down, and to follow it only with your eyes.

10Next, you will be asked to lie down, turn your head, and change position slowly while the machine keeps recording.

11In one part of the test, warm and cool air or water is put into the ear canal for a short time. This is called the caloric part.

12That warm and cool stimulus makes the balance organ react, and the machine records how strongly it reacts. A weak reaction shows a weak balance organ.

13It is normal to feel giddy for a minute or two during this part. It settles quickly and you will be resting on a bed.

14The test does not involve X-rays, radiation, injections or cutting of any kind.

15The whole test usually takes about thirty to forty minutes.

16Before the test, we will normally ask you to stop anti-vertigo tablets and sedatives for one to two days, because they can mask the problem. Do not stop heart, blood-pressure, sugar or epilepsy medicines.

17Please avoid a heavy meal just before. Eye make-up should be avoided because the stickers need clean, dry skin.

18It is best to bring a relative or friend with you, as you may feel slightly unsteady afterwards.

19Once the recording is finished, the doctor studies the pattern of the lines drawn by the machine.

20The pattern shows whether the problem is in the right ear or the left ear, and whether the ear itself or the nerve is at fault.

21This is very useful in older patients or where camera goggles cannot be used comfortably.

22Finding the exact cause means the treatment can be exact — and most balance problems improve a great deal once the cause is known.