Cellular changes in Reissner's membrane in endolymphatic hydrops.

A quantitative morphologic study of the cellular changes in human Reissner's membrane (RM) was performed under light microscopy on 30 normal temporal bones from 15 subjects, and on 20 temporal bones from 10 subjects with endolymphatic hydrops. The cellular density of the epithelial and mesothelial layers of normal RMs decreased with increasing age. In endolymphatic hydrops, cellular proliferation and decreased cellular density of a distended RM were observed, and these changes occurred more remarkably in epithelial cells. Decreased cellular density in RM was correlated to the degree of endolymphatic hydrops. These findings indicate an involvement of the epithelial cellular changes in the pathogenesis of endolymphatic hydrops. Our results suggest that cellular changes in RM may cause dysfunction of radial flow leading to ionic disturbance of endolymph, which provides a possible mechanism of hearing loss in endolymphatic hydrops.