Abstract
In the present study, we examined the temperature of aural air stimulation that was equivalent to aural stimulation with water at 20°C in the caloric test. In 10 ears of 5 healthy volunteers, the maximum slow phase eye velocities (MSPEVs) of nystagmus induced by aural stimulation with air at 22°C, 46°C and 16°C were the same as those with water at 30°C, 44°C and 20°C, respectively. These findings suggest that caloric stimulation with air at 16°C is equivalent to that with water at 20°C that is commonly used in the caloric test in Japan. The MSPEVs of nystagmus induced by aural stimulation with air at 16°C were over 20°/sec in all ears except one, in which the MSPEV was 19.7°/sec. The criteria of canal paresis where the MSPEV of caloric nystagmus induced by aural stimulation with water at 20°C is less than 20°/sec can be used in the caloric test with aural air stimulation at 16°C.
