caloric tests for nystagmus
Last reviewed 09/2023
Caloric testing involves the irrigation of the external auditory meatus with hot (44øC) or cold (30øC) water with the head raised 30ø from the supine position. It produces a temporary nystagmus secondary to convection currents set up in the lateral semicircular canal.
Each ear can be tested separately and is irrigated for 40 seconds with 5 minutes being allowed between irrigations. The time elapsed between the commencement of irrigation and the cessation of nystagmus is recorded.
Ice water ensures a maximal stimulus and is used for testing for brain stem death or head injury prognostication.