Electronystagmography versus videonystagmography in diagnosis of vertigo

Abstract

Vertigo is a very common symptom mainly caused by the lesion of vestibular system (peripheral or central) and often accompanied by some work-related diseases and occupational intoxications. The aim of this study was to assess the value of electronystagmography (ENG) and videonystagmography (VNG) for diagnosing vertigo of various origin. The study included four groups, 25 subjects each, of patients suffering from vestibular disorders of peripheral, central and mixed origin versus healthy controls. All were examined by means of ENG and VNG, using the bithermal caloric test with 30°C and 44°C air irrigations of the ears. The findings (frequency of induced nystagmus FRQ, its slow phase velocity SPV, canal paresis CP, directional preponderance DP, vestibular excitability VE) were analysed and compared. In all patients with vertigo due to vestibular neuritis, barotrauma and kinetosis, significant CP, the important sign of peripheral site of vestibular lesion was identified both in ENG and VNG. None of the patients with central origin disorders showed CP in VNG; in the majority of cases DP was observed. However, in ENG we found CP in 5 patients with central origin disorders. There were no essential differences between ENG and VNG in measurements of FRQ and SPV except for higher values in VNG in controls and patients with mixed vertigo. The results suggest that the VNG should be recommended in preference as the valuable method to assess vertigo and to discriminate between the peripheral and the central vestibular lesions.