Frequency dependence of the ocular-recorded vestibular evoked myogenic potentials (oVEMP) and their significance for the diagnosis of endolymphatic hydrops

Introduction The detection of oVEMP with the potentials n10 and p15 is predominantly specific for the contralateral utriclular function. A shift in the amplitude maximum from a stimulus frequency of 0.5 kHz to 4 kHz is said to indicate an increase in pressure in the endolymphatic space.

Material and Methods We examined 20 patients each with "definitive" Menière's disease and 20 patients with unilateral or bilateral vestibulopathy. The stimulus was applied to the investigated ear via a bone conduction sounder at 500 Hz, 1, 2 and 4 kHz. The occurrence of oVEMP at 500 Hz and 4 KHz as well as the relative amplitude height at the two stimulus frequencies were evaluated.

Results In the group of Menière's patients (14f, 6m, average age 56.8 years), oVEMP could be recorded at 500Hz in 16 cases and at 4kHz in 12 cases on at least one side. In 7 cases the amplitude height at 4kHz was greater than at 500 Hz. The diseased side correlated with the occurrence of oVEMP at 4kHz in 5 cases. In patients with vestibulopathy (11f, 9m, 55.0 years), oVEMP were detectable at 500Hz in 17 cases and at 4kHz in 10 cases, of which in 6 cases with a higher amplitude at 4kHz than at 500 Hz. In 4 cases the oVEMP detection at 4 kHz correlated with the healthy side.

Conclusion There is evidence for a shift in the amplitude maximum from 500Hz to 4kHz in patients with endolymphatic hydrops. This is said to occur physiologically with older age, but in this study 17 of 22 patients with positive oVEMP at 4kHz were younger than 61 years. oVEMP are not suitable as the sole criterion for the diagnosis of Menière's disease, but they provide additional evidence if the side correlation is positive.

Publikationsverlauf

Artikel online veröffentlicht:
19. April 2024