Relationship between endolymphatic hydrops and vestibular-evoked myogenic potential

Conclusion: Vestibular-evoked myogenic potential (VEMP) can be used to examine endolymphatic hydrops, especially in the vestibule. Objective: To investigate the relationship between the degree of endolymphatic hydrops revealed by magnetic resonance imaging (MRI) and VEMP. Methods: Gadolinium diluted with saline was injected intratympanically in 49 ears (40 patients). One day after the injection, the endolymphatic space in the vestibule and the cochlea was visualized by 3 Tesla MRI. A VEMP test was done, and VEMP was judged as absent when the VEMP was within the noise level. Results: VEMP was present in 21 ears and absent in 28 ears. Endolymphatic hydrops was significantly associated with the disappearance of VEMP. Endolymphatic hydrops in the vestibule had a stronger effect than endolymphatic hydrops in the cochlea. Five patients with extremely large vestibular hydrops showed no response of VEMP.