Endolymphatic hydrops in Ménière's disease: cause, consequence, or epiphenomenon?

OBJECTIVE: To determine the relationship of endolymphatic hydrops to Ménière's disease. DATA SOURCES: Comprehensive review of articles from 1938 through 2012 via Medline and Index Medicus. STUDY SELECTION: Articles discussing Ménière's disease and/or endolymphatic hydrops that include temporal bone autopsy data. DATA EXTRACTION: Fifty-three case reports and series were studied containing examination of 541 hydropic temporal bones and including 276 patients with Ménière's disease. These were divided into those meeting the 1995 American Academy of Otolaryngology-Head and Neck Surgery criteria for Ménière's disease and those that failed to meet these criteria. CONCLUSION: An individual meeting the 1995 criteria for Ménière's disease has a near certain probability of having endolymphatic hydrops in at least 1 ear. Autopsy data do not support the view that the association of MD and EH is an epiphenomenon or that MD causes EH; this leaves us with the probability that EH causes MD. If it is causative, hydrops alone is insufficient to cause Ménière's disease, indicating that there must be one or more additional cofactors that cause asymptomatic hydrops to become symptomatic Ménière's disease. Vascular risk factors should be studied as possible cofactors.