Localizing retrocochlear hearing loss.
1996; National Institutes of Health; Volume: 17; Issue: 4 Linguagem: Inglês
Autores
Barry E. Hirsch, John D. Durrant, Sertaç Yetışer, D B Kamerer, William H. Martin,
Tópico(s)Ear Surgery and Otitis Media
ResumoThe origin of acute/sudden hearing loss is multifactorial. The association of vestibular symptoms does not necessarily isolate the pathologic condition to the inner ear. The audiogram provides a screen for differentiating conductive from sensorineural loss but often fails to provide more localizing information.Three unusual patients with a variety of retrocochlear presentations of hearing loss are presented. Along with conventional auditory brainstem response (ABR) testing, newer auditory tests, including otoacoustic emissions and three-dimensional ABR analysis, can facilitate site-of-lesion testing. Magnetic resonance imaging (MRI) also provides graphic documentation for sources of retrocochlear hearing loss.One patient had gamma-knife treatment of an arteriovenous malformation, incurring a localised lesion to the inferior colliculus contralateral to the side of hearing loss. This effectively eliminated wave V, as confirmed by three-dimensional ABR analysis. A second patient with human immunodeficiency virus developed sudden complete hearing loss with retained otoacoustic emissions, confirming a retrocochlear lesion. A third patient with acute otitis media with sudden hearing loss and vertigo had an abnormal ABR and "mass lesion" on MRI. Hearing subsequently returned to normal, as did a repeated scan.The unique aspects of each case of retrocochlear hearing loss and the applied auditory electrophysiologic tests are reviewed.
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