Caloric Stimulation

How is the Test Performed?

Each ear is tested separately using a computerized caloric stimulation machine. Nystagmus (quick movement of both eyes in response to certain stimuli, which is necessary for normal vision and balance) is measured using electrodes around the eye and recorded for analysis by the computer.

Cold water is placed in the ear canal with a bulb syringe. This should cause nystagmus. This test is then repeated using warm water. The nystagmus should occur in the opposite direction (towards the warm water then slowly away, rather than away from the water and slowly back).

The computer analyzes:

• The cold and warm water response for each ear
• Differences between ears
• Differences between cold and warm water responses

Occasionally, warm and cold air (if there is a hole in the ear drum) or ice cold water (in absence of any response) is used for this test.