Auditory manifestations of superior semicircular canal dehiscence.

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.