Superior semicircular canal dehiscence : auditory mechanisms

Superior semicircular canal dehiscence (SCD) syndrome is a recently defined clinical disorder in which patients present to the clinic with vestibular symptoms, auditory symptoms, or both. Understanding the effect of SCD, a hole in the bony superior canal, on hearing will broaden our understanding of the mechanics of the inner ear and lead to better diagnosis and treatment of SCD syndrome. We evaluate the effect of SCD on cochlear responses to both air- and bone- conducted sound. In chinchilla SCD produces reversible changes in cochlear potential: an increased sensitivity to bone-conducted sound and a decreased sensitivity to air-conducted sound. Such differences in air- and bone-conducted sound (air-bone gaps) are typically associated with a conductive hearing loss due to middle-ear pathology; however, a SCD is an inner-ear pathology. We hypothesize that the SCD acts as a 'third window' into the inner ear, shunting volume velocity away from the cochlea and through the dehiscent canal, altering cochlear responses to sound. To qualitatively evaluate this hypothesis we measured sound-induced fluid motion within the SCD as well as the effect of SCD on sound-induced stapes velocity and middle-ear input admittance.

Department dc:contributor.department

Harvard University--MIT Division of Health Sciences and Technology.

Grantor dc:publisher

Massachusetts Institute of Technology

Year dc:date.issued

2006

Author dc:creator

• Songer, Jocelyn Evelyn

Advisor dc:contributor.advisor

• John J. Rosowski and Saumil N. Merchant.

• Harvard University--MIT Division of Health Sciences and Technology.

Statement dc:rights

• M.I.T. theses are protected by copyright. They may be viewed from this source for any purpose, but reproduction or distribution in any format is prohibited without written permission. See provided URL for inquiries about permission.

Licence dc:rights.uri

• http://dspace.mit.edu/handle/1721.1/7582

Language dc:language.iso

eng

Handle dc:identifier.uri

http://hdl.handle.net/1721.1/36165

OAI identifier oai:identifier

oai:dspace.mit.edu:1721.1/36165