title: [Effects of round window membrane rupture on cochlear blood flow and endocochlear potential].
abstract: The degree of hearing loss and audiogram shape vary in patients with perilymphatic fistula. The cause of variability is not well known. To determine the effect of perilymphatic fistula on cochlear function, we studied the effect of round window membrane rupture on cochlear blood flow (CBF) by placing a laser-Doppler probe to the basal turn in 20 guinea pigs. In 10, endocochlear potential (EP) was measured by inserting a glass microelectrode through the stria vascularis of the basal turn. During 60 minutes following round window membrane rupture, CBF decrease of more than 15% was observed in 9 of 20 animals, and EP decrease of more than 15% was observed in 5 of 10. A significant correlation was observed between the degree of CBF reduction and EP reduction. In 3 animals in which CBF decreased after round window membrane rupture, temporal bones were studied histologically. One cochlea showed endolymphatic hydrops and another cochlea showed significant hemorrhage in the scala tympani after rupture. These results suggested that CBF impairment is associated with cochlear dysfunction in perilymphatic fistula.
authors.affiliation: Department of Otorhinolaryngology, Nagoya University Graduate School of Medicine, Nagoya.
authors.forename: Xiuli
authors.initials: X
authors.lastname: Liu
authors.forename: Michihiko
authors.initials: M
authors.lastname: Sone
authors.forename: Mitsuo
authors.initials: M
authors.lastname: Tominaga
authors.forename: Hideo
authors.initials: H
authors.lastname: Hayashi
authors.forename: Hiroshi
authors.initials: H
authors.lastname: Yamamoto
authors.forename: Tsutomu
authors.initials: T
authors.lastname: Nakashima
mesh_terms: D000818:Animals; D003051:Cochlea / Q000098:blood supply* / Q000502:physiology*; D005072:Evoked Potentials, Auditory; D006168:Guinea Pigs; D012405:Round Window, Ear / Q000293:injuries*; D012421:Rupture