Recent advances in understanding molecular bases of Ménière's disease.

Abstract

Ménière's disease (MD) is a rare syndromic disorder of the inner ear defined by sensorineural hearing loss (SNHL) associated with episodes of vertigo and tinnitus. The phenotype is variable, and it may be associated with other comorbidities, such as migraine, asthma, and several autoimmune disorders. The condition has a significant heritability according to epidemiological and genetic data, with a difference in comorbidities according to ethnicity. Familial MD is found in 10%, the most commonly found genes being OTOG, MYO7A and TECTA, previously associated with autosomal dominant and recessive SNHL. These findings suggest that proteins involved in the tectorial membrane and stereocilia links are critical in the pathophysiology of MD. Moreover, proinflammatory cytokines may have a role in some patients with MD by promoting a persistent inflammatory status. Preliminary data suggest that sodium intake could be related to the release of cytokines, and this may influence the relapsing course of the condition. The ionic homeostasis of the otolithic and tectorial membranes could be critical in suppressing the innate motility of individual hair cell bundles, and focal detachment of the otolithic, or tectorial membranes may cause random depolarization of hair cells and explain changes in tinnitus loudness or the triggering of vertigo attacks.