Bitherinal caloric test tests:
In Fitzgerald-Hallpike test/ bithermal caloric test, patient lies supine with head tilted 30deg forward so that horizontal canal is veical. Ears are irrigated for 40 seconds alternatively with water at 30degC and at 44deg C (70 below & above normal temperature) & observed for appearance of nystagmus till its end point
Anterior semicircular canal
Horizontal semicircular canal
Superior semicircular canal
Posterior semicircular canal