Caloric Test

Explained in simple words

1The caloric test is one of the oldest and most reliable tests for finding out which ear is causing giddiness.

2Each ear has a balance organ with small fluid-filled tubes inside. When the fluid moves, the brain knows the head is turning.

3In this test we make that fluid move gently — not by turning your head, but by changing the temperature inside the ear canal.

4Warm air or warm water, and then cool air or cool water, is passed into the ear canal for a short time, about half a minute each.

5The temperature change reaches the fluid inside and makes it move slightly, exactly as it would move if you turned your head.

6Because the balance organ is connected to the eyes, this makes your eyes move in a particular rhythm on their own.

7We record those eye movements with camera goggles or with small stickers near the eyes, and the computer measures them.

8The important point is this: we test the right ear and the left ear separately. No other test can do this so clearly.

9A healthy balance organ gives a strong eye response. A weak or damaged one gives a small response, or none at all.

10By comparing the two sides, the doctor can say exactly which ear is weak and by how much — for example, "the left ear is working forty per cent less than the right".

11This information decides the treatment. Exercises, medicines and rehabilitation are chosen according to which side is affected.

12The procedure is safe. Nothing sharp is used. The ear drum is not touched, and no water is forced in.

13Before starting, the doctor examines the ear to make sure the ear drum is intact. If there is a hole in the ear drum, air is used instead of water, or the test is modified.

14During the test you will lie on a bed with the head slightly raised. You will be asked to stay awake and to answer simple questions, such as naming vegetables or towns.

15This is only to keep your brain alert, because sleepiness reduces the response and spoils the result.

16It is completely normal to feel giddy or spinning for about thirty seconds to a minute after each irrigation. This is a sign that the balance organ is responding.

17The feeling settles down quickly while you rest on the bed. A few people feel slightly nauseated; this also passes.

18Please avoid a heavy meal for two to three hours before the test, and bring someone with you to take you home.

19Stop anti-giddiness medicines and sedatives for one to two days before, if the doctor advises, because they suppress the response we want to measure. Never stop your heart, blood-pressure or sugar medicines.

20The complete test takes about twenty to thirty minutes.

21There is no radiation, no injection and no operation involved at any stage.

22After the test, the results are explained to you clearly, and the treatment plan is made based on exactly which ear is weak.