title: Hearing loss in patients with enlarged vestibular aqueduct: air-bone gap and audiological Bing test.
abstract: The Bing test is based on the principle that occlusion of the external auditory meatus improves the perception of bone-conducted sounds unless there is a conductive hearing impairment. An air-bone gap has been reported in patients with large vestibular aqueduct (LVA) syndrome without apparent middle ear dysfunction. We therefore performed the Bing test on nine patients with this syndrome to evaluate whether it is associated with an air-bone gap or middle ear dysfunction. Bone conduction thresholds did not change significantly during the Bing test in any patient. Because an air-bone gap is observed in patients with abnormal communication between the inner ear and cerebrospinal fluid through the LVA, dehiscent superior canal, or dilated inner ear meatus; we propose that a 'three windows' model (in which the abnormal communication provided by the enlarged endolymphatic duct and sac in LVA acts as the 'third window' for sound conductance) might explain the air-bone gap in such patients.
authors.affiliation: Department of Otorhinolaryngology, Nagoya University School of Medicine, Nagoya, Japan. tamiein.mimura@nifty.com
authors.forename: Tamie
authors.initials: T
authors.lastname: Mimura
authors.forename: Eisuke
authors.initials: E
authors.lastname: Sato
authors.forename: Makoto
authors.initials: M
authors.lastname: Sugiura
authors.forename: Takahiko
authors.initials: T
authors.lastname: Yoshino
authors.forename: Shinji
authors.initials: S
authors.lastname: Naganawa
authors.forename: Tsutomu
authors.initials: T
authors.lastname: Nakashima
mesh_terms: D000293:Adolescent; D000328:Adult; D001299:Audiometry / Q000379:methods*; D001301:Audiometry, Pure-Tone / Q000379:methods; D001309:Auditory Threshold / Q000502:physiology*; D001844:Bone Conduction / Q000502:physiology; D004252:DNA Mutational Analysis; D005260:Female; D006314:Hearing Loss, Conductive / Q000209:etiology* / Q000235:genetics; D006801:Humans; D008297:Male; D008962:Models, Theoretical; D016133:Polymerase Chain Reaction; D013577:Syndrome; D014723:Vestibular Aqueduct / Q000002:abnormalities*; D015837:Vestibular Diseases / Q000150:complications* / Q000235:genetics