Meniere’s Disease, a Set of Rare Disorders with Tinnitus

Meniere’s disease (MD) is a chronic inflammatory disorder of the inner ear, characterized by recurrent episodes of vertigo associated with tinnitus and fluctuating sensorineural hearing loss with a multifactorial origin. Most patients progress to chronic imbalance, moderate to severe hearing loss in the affected ear, and may develop persistent and disabling tinnitus. The disease usually begins in one ear with tinnitus and hearing loss, but can affect both ears, causing bilateral symptoms. The diagnosis of MD is based on clinical criteria defined by the Barany Society, and five clinical subgroups have been identified according to comorbidities such as migraine, autoimmunity, and autoinflammatory markers. Genetic factors and the innate immune response seem to play a central role in the pathophysiology of the condition. Familial MD is found in 10% with dominant and recessive inheritance. It is associated with the accumulation of endolymph (endolymphatic hydrops, EH) in the cochlear duct and vestibular organs, according to human histopathological studies. However, EH is considered a late event in the pathophysiology of MD, which is associated with the development of the sensorineural hearing loss and the duration of the disease. The frequency of clinical episodes of vertigo is unpredictable, and therefore, biological markers of disease activity are necessary for therapeutic planning.