Light and Scaning Electromicroscopic Study on the Experimental on the Experimental Endolymphatic Hydrops in Guinea Pigs

Oh, Seung Ha; Jung, Ha Won; Kang, Beom Seung; Kwon, Tack Kyun; Kim, Chong Sun

Abstract

BACKGROUND: Despite numerous investigations, the pathogenesis of Meniere's disease is uncertain. Endolymphatic hydrops (ELH) has been the main histologic finding of Meniere's disease. Experimentally induced ELH in animal model has been developed in order to understand better the consequences of this morphopathology on inner ear structure and function.
OBJECTIVES
The aim of this study is to develope the animal model of ELH. MATERIAL AND METHODS: We made an animal endolymphatic hydrops model on giunea pigs by mechanically obliterating the right endolympatic sac and duct. The left ears were used as a controls.
RESULTS
After twelve weeks, the temporal bones were prepared for light and electron microscopic examination. The light microscopic study showed the distension and folding of Reissner's membrane, however other pathologic changes were uncertain in hydropic aminal. Under scanning electron microscopic examination, the cellular population of Reissner membrane remained normal but the microvilli of Reissner membrane were significantly decreased in hydrops group. The damage pattern of stereocilia were most severe in the apical turns, followed by the middle and the basal turns, in the order of severeity. The outer hair cell third row was most severely damaged in the entire cochlea, whereas the outer hair cell first row was relatively spared. On the single hair cell examination, abnormal distensions of the tip of stereocilia started from longer stereocilia. The number of microvilli on marginal cell was reduced in stria vascularis, but atrophic change was not observed.