Auditory manifestations of superior semicircular canal dehiscence

Abstract

OBJECTIVE: To understand the presenting auditory signs and symptoms and to examine the relationship between the auditory manifestations and audiometric parameters in superior semicircular canal dehiscence (SSCD). PATIENTS: Twenty consecutive patients with unilateral SSCD without a history of previous ontologic surgery. MAIN OUTCOME MEASURE: Relationship between presenting symptoms and the bone-conduction thresholds and air-bone gap (ABG) on pure-tone audiometry. RESULTS: All 20 patients presented with typical vestibular symptoms of SSCD. Seventeen (85%) patients also had auditory symptoms, including autophony (40%), hyperacusis to bodily sounds (65%), hearing loss (40%), aural pressure (45%), and tinnitus (35%). Of the 17 patients, 14 (82%) patients had an ABG on audiometry, but only 7 (41%) patients demonstrated negative bone conduction thresholds. Of 8 patients, 5 who underwent surgical repair experienced resolution of autophony and/or hyperacusis postoperatively. CONCLUSION: Auditory symptoms are common in SSCD patients. These symptoms do not show any relationship to the presence of negative bone-conduction thresholds on pure-tone audiometry. No firm conclusion could be drawn regarding the association between symptoms and ABG. Different pathways or mechanisms may exist in SSCD for bone-conducted sounds arising from different sources. Surgical repair of the dehiscence results in resolution of auditory symptoms in most patients. © 2009 Otology & Neurotology, Inc.