Meniere's disease: overview, epidemiology, and natural history.

Meniere's disease is a disease of the inner ear characterized by a triad of symptoms: vestibular symptoms, auditory symptoms, and pressure. The pathologic correlate of Meniere's disease is endolymphatic hydrops and the etiopathogenesis involves a deficiency in the absorption of endolymph. The pathophysiology of the symptoms is still disputed: membranous ruptures, pressure and mechanical displacement of the end organs, or obstruction followed by an abrupt clearance of the endolymphatic duct. The course of the disease may be progressive or nonprogressive and, in addition to the typical presentation of Meniere's disease, two variations of the disorder have been identified: cochlear Meniere's disease, and vestibular Meniere's disease. It can be further broken into two subsets: Meniere's syndrome, with a known and well-established cause, and Meniere's disease, in which the cause seems to be idiopathic. It is likely that there are racial (genetic) as well as environmental factors that influence differences in incidence among countries and among various sections of countries. The disease is much more common in adults, with an average age of onset in the fourth decade, the symptoms beginning usually between ages 20 and 60 years. Meniere's disease is (grossly) equally common in each sex, and right and left ears are affected with fairly equal frequency. The diagnosis of Meniere's disease is by exclusion, and a careful history is the most important guide to a correct diagnosis. Its medical treatment is largely empiric. Surgery can be considered when, even after medical therapy, the disease progresses and the symptoms become intractable. Surgery may be either conservative or destructive. Bilaterality must be considered when deciding the best surgical option for a patient with Meniere's disease. It is the authors' opinion that endolymphatic sac surgery is an extension of conservative treatment.