Comparative analysis of caloric nystagmus test results obtained using the method of ENG and VNG in healthy subjects
Introduction: Nystagmus test is the most important and objective method of assessing balance disorders. The caloric test, as the sole test illustrates the excitability of individual labyrinths, enabling the assessment of each of them separately. The aim of the study is a comparative analysis of results of caloric nystagmus test obtained using the method of ENG and VNG in healthy subjects. Material and methods: The study included a group of 20 healthy people, including 10 women and 10 men aged 22-26 years. In all patients were performed medical interview and subject otoneurologic examination. Subsequently, among all subjects the ENG and after 7 days the VNG were performed tests with calibration, evaluation of spontaneous nystagmus and attempts by Hallpike caloric test. The caloric test was conducted by means of HOMOTH air calorimeter in the air temperatures of 30°C and 44°C, and the exposure of the ear lasting 40 sec. Results: In the caloric tests there were no canal paresis that goes beyond the boundaries of accepted norms in any of examined persons. It was observed that averages of slow phases velocities (SPV) were lower in ENG than VNG. The VNG also allow to designate value of absolute directional preponderance of nystagmus and labyrinths excitability. Conclusions: The obtained results show that the VNG test for ENG test is more precise and allows to better describe Hallpike caloric test. The value of Hallpike’s caloric test was significantly increased by the analysis of absolute directional preponderance in VNG.