Ocular vestibular-evoked myogenic potentials in unilateral Ménière's disease: a narrative literature review.

The ocular vestibular-evoked myogenic potential (oVEMP) is a promising non-invasive tool for assessing utricular function and superior vestibular nerve integrity. In the context of definite unilateral Ménière's disease, studies have consistently reported altered oVEMP responses in affected ears, including altered amplitudes, higher stimuli needed before receiving a verifiable response or prolonged latencies. These findings are thought to reflect the presence and accumulation of endolymphatic hydrops. However, variability across studies is substantial. This inconsistency may reflect fluctuating changes in endolymphatic pressure or volume and consequent variability in otolith function that characterise Ménière's disease symptoms, as well as differences in disease stage and progression, stimulus parameters and recording methodologies. The specificity of oVEMP findings for Ménière's disease remains limited by variation in stimulus modality (air- versus bone-conducted), stimulus intensity, stimulus settings (e.g., rise and fall time, and duration) and recording protocol. Because oVEMP primarily assesses utricular function, it provides information that complements conventional vestibular tests of other vestibular end organs or neural pathways such as caloric testing, video head impulse testing and cervical VEMP. While oVEMP may contribute to a multimodal assessment of Ménière's disease, further standardisation is required before its diagnostic value can be reliably compared across clinical and experimental studies. Longitudinal studies are also needed to establish how oVEMP responses change with disease stage, disease progression, and following treatment.