Pathogenesis of Menière's disease.

While endolymphatic hydrops is a characteristic pathologic feature of Menière's disease, there are exceptions to this rule. There is evidence that hydrops develops as a result of malabsorption of endolymph. This implies dysfunction of the endolymphatic sac and duct, which normally absorb endolymph. In approximately 20% of cases of Menière's disease, a specific pathologic condition in the temporal bone can be associated as a cause of endolymphatic hydrops. Syphilis, fractures of the temporal bone, otosclerosis, and preceding chronic otitis media are some of the more commonly encountered pathologic conditions so associated. Hypoplasia of the mastoid air-cell system and of periaqueductal air cells, and especially displacement medially but also anteriorly of the sigmoid (lateral) sinus are commonly observed in patients with Menière's disease. Evidence is available to substantiate the etiologic bases of Menière's disease as including multifactorial inheritance (1). The clinical symptoms and findings result from both chemical and physical mechanisms. Pathogenesis appears to be due to malabsorption of endolymph in the environment of the endolymphatic sac, primarily affecting longitudinal flow. The possible role of such processes as autoimmune reactions and viral inflammation, especially in the endolymphatic sac, should be further investigated in the future.