Evaluation of the air caloric test as a routine examination procedure

Abstract

Abstract The nystagmus responses of normal subjects to air and water caloric irrigations of comparable temperatures were compared. Irrigations of 0° air for 60 sec were found to produce nystagmus responses equal in amplitude, frequency and eye‐speed to those evoked by irrigations of 5 cc of ice water. Ice water produced significantly longer responses than did 0° air (mean difference = 11.6 sec). Responses to bithermal air stimuli of 24° C and 50° C were compared to those produced by 30°C and 44° C water. No significant differences were found between the cool stimuli for any of the measures. The warm stimuli produced responses of equal eye‐speed, but the water responses were significantly greater than those of air when the measures of total amplitude, frequency and duration were compared; thus, air stimulation was the preferred method of performing the standard caloric test, since the air responses were equal in reliability to those of water and because of the advantages of the use of air, which include greater convenience, patient tolerance, applicability, and flexibility.