Caloric Stimulation with Water and Air: Responses by Age and Gender

The caloric test is a well-known valuable clinical instrument that can evaluate and quantify the functional status of both lateral semicircular canals. The American National Standard Institute (ANSI) does not include air as a standard method for caloric stimulation due the lack of published data to determine response variability comparable to water. Due the controversy about air irrigators, it is worthwhile to evaluate the presence of differences between the two irrigation methods in caloric response. The goal is to compare, by age group, the post caloric responses with water and air according gender and age.

Individuals without otoneurologic complaints were selected and divided in groups. All were submitted to caloric bithermal stimulation with water at temperatures of 44°C and 30°C (Micromedical Technologies, Inc., USA) and air at temperatures of 50°C and 24°C (Micromedical Technologies, Inc., USA).

91 subjects were evaluated (46 men and 45 women) with a mean age of 43 years old. The caloric response was similar between genders (P=0,958) and no statistical difference was observed comparing both stimulus (P=0,93). It was identified that the Slow-Phase Velocity (SPV) was lower for the group older than 60 years comparing to the other groups.

For the caloric test, the stimulus with air was confirmed as similar as stimulation with water, including absolute values. Lower values for SPV were found for elderly population.