Concurrent ENG and VNG recording in healthy people – preliminary report

Introduction: The aim of the work was to evaluate one-time recording of ENG and VNG in healthy subjects selected for the given diagnostic tests with reference to the sensitivity and usefulness of this kind of testing in vertigo diagnostics. Material and methods: The tests covered 50 healthy subjects, including 24 women and 26 men aged 20-22 (the mean age of 20,5 years) who did not report any inconvenience from otorhinolaryngological organs and the conducted interview did not reveal any balance disorder or vertigo. Every patient underwent otoneurological subjective and objective tests, electronystagmography (ENG), including a calibration test, head-tracking test, optokinetic nystagmus test, rotatory chair test, positional tests according to Cawthorne and Rose, a Hallpike caloric test as well as videonystagmography which included a calibration test, spontaneous nystagmus evaluation, head-tracking test, positional tests according to Cawthorne and Rose with a head rotation test and Hallpike caloric test. The above tests were performed separately, 24 hours one by one. One-time recording of ENG and VNG was made 48 hours following the last test while each of the two tests was preceded by an additional calibration test. The final recording included the spontaneous nystagmus evaluation, positional tests according to Cawthrone and Rose together with the head rotation test and Hallpike caloric test. Results: Any negative mutual influence of the conducted tests has not been observed. Both in the one-time and separate recording, the caloric test revealed lower values of the mean velocity of the nystagmus free phase in ENG with relation to VNG. No signs from spontaneous nystagmus, as well as optokinetic and positional nystagmus, could be found in any case. Conclusions: The conducted tests did not show any possibility of mutual exclusion of the given ENG and VNG diagnostic tests one-time recording. However, their use in diagnostics of balance disorders and vertigo requires further studies