遅発性内リンパ水腫について

―ことにメニエール病との比較において―

抄録

Delayed endolymphatic hydrops (DEH) is a Ménière’s syndrome that typically occurs in patients suffering from longstanding unilateral profound inner-ear hearing loss. Approximately 55 to 65% of the hearing loss preceding DEH is due to juvenile unilateral profound deafness (early childhood unilateral profound sensorineural hearing loss of unknown etiology). The incidence of ipsilateral DEH (approximately 60%), in which the ear with profound hearing loss suffers progressive endolymphatic hydrops, is higher than that of the contralateral type of DEH (about 40%), in which the formation of progressive endolymphatic hydrops takes place in the ear opposite to the previously deafened ear. The prevalence of DEH in the general population (23 or less per 100,000) is similar to that of definitive Ménière’s disease, and the distribution of age at onset of DEH closely resembles that of Ménière’s disease except for some patients with childhood onset of DEH. Further, the rate of patients with the contralateral type of DEH (about 40%, although the rate is about 15% if the contralateral type is restricted to patients showing typical Ménière’s symptoms) is similar to that of patients with bilateral Ménière’s disease (about 40%, with a rate of about 14% if Ménière’s disease in the second ear is restricted to definitive Ménière’s disease). Since DEH is closely similar to Ménière’s disease not only in symptoms, but also in many clinical-statistical characteristics, the diseases may be identical in pathogenesis and the pathophysiology of progressive endolymphatic hydrops, although the two conditions have different etiologies.