Concurrent ENG and VNG recording in healthy people - preliminary report

The aim of the study was to evaluate concurrent recording of ENG and VNG measurements in selected diagnostic tests in healthy subjects so as to explore potential sensitivity and applicability of this kind of testing in the diagnostics of vertigo.

The study was carried out in 50 healthy subjects including 24 women and 26 men aged 20-22 (mean age of 20.5 years) reporting no otorhinolaryngological organ-related complaints and no history of any balance disorders or vertigo. Every patient underwent subjective and objective otoneurological tests, electronystagmographic (ENG) examination including calibration, head-tracking test, optokinetic nystagmus test, rotatory chair test, positional tests according to Cawthorne and Rosen, and Hallpike caloric test as well as videonystagmographic (VNG) examination which included calibration, spontaneous nystagmus evaluation, head-tracking test, positional tests according to Cawthorne and Rosen with neck rotation test, and Hallpike caloric test. At first, ENG and VNG examinations were carried out separately at a 24-hour interval. Concurrent ENG and VNG recording was carried out 48 hours following the last test, with calibration being performed again before both evaluations. The concurrent recording included the spontaneous nystagmus evaluation, positional tests according to Cawthrone and Rose with the neck rotation test, and Hallpike caloric test.

No negative mutual interference of the conducted tests has been observed. Both in the concurrent and in the separate recordings, the caloric test revealed lower values of the mean velocity of the nystagmus free phase in the ENG test as compared to the VNG test. No signs of spontaneous nystagmus, as well as no signs of optokinetic and positional nystagmus, were detected in any case.

The conducted tests did not reveal any mutual excludability between the selected ENG and VNG diagnostic tests upon concurrent recording. However, the concurrent use of both examinations in the diagnostics of balance disorders and vertigo requires further studies.