Sudden hearing loss associated with cochlear membrane rupture. Two human temporal bone reports.

Cochlear membrane ruptures occurred in the left temporal bones of two patients--one was a result of barotrauma caused by flying and was associated with sudden deafness, tinnitus, and some vertigo and the second occurred in a patient with profound deafness in a previously normal-hearing ear. Both occurred as ruptures of Reissner's membrane at the junction of the ductus reuniens with the cecum vestibulare portion of the cochlear duct. With healing, a balloon-like structure formed from the rupture site into the adjacent vestibule, resulting in a secondarily ruptured saccule duct in one case and in collapse of the saccule in the second case. Left-sided preponderance of such ruptures and the vulnerability of the ductus reuniens junction with the cochlea are described.