In caloric testing, cold water irrigation produces horizontal nystagmus towards the opposite side.
-Fitzgerald-Hallpike test/bithermal caloric test: In this test, the patient lies supine with head tilted 30° forward so that the horizontal canal is vertical. Ears are irrigated for 40 seconds alternatively with water at 30°C and at 44°C (i.e., 7 below and above normal body temperature) and eyes are observed for the appearance of nystagmus till its endpoint.
-Time taken from the start of irrigation to the end point of nystagmus is recorded and charted on a calorigram.
-If no nystagmus is elicited from any ear, the test is repeated with water at 20°C for 4 min before labeling the labyrinth dead.
-A gap of 5 min should be allowed between two ears.