Comparison of water and air caloric stimulation using videonystagmography

Introduction: The basic methods for assessing the vestibular system are the caloric tests, which can be performed using air or water stimulation. The aim of the study was to compare the parameters of nystagmus provoked during air caloric stimulation with the parameters obtained during water caloric stimulation in subjects with and without vertigo. Material and methods: The study included 102 subjects divided into two groups: Group I-patients with peripheral or mixed vertigo, Group II-healthy individuals without vertigo. Two caloric tests were carried out in all subjects: air stimulation (30°C, 44°C, application time: 45 seconds) and water stimulation (30°C, 44°C, application time: 30 seconds). The obtained parameters of nystagmus were analyzed using videonystagmography (VNG). Results: There were statistically significant differences concerning the angular velocity of the slow nystagmus phase as well as nystagmus frequency and excitability during water and air caloric stimulation in both groups. No significant difference in vestibular deficit was observed in relation to the applied stimulus. Conclusions: The results clearly show that water caloric stimulation produces considerably stronger reactions than air caloric stimulation. Despite significant differences in the values of individual parameters of nystagmus, both tests can be successfully used to evaluate vestibular system function.