Superior Semicircular Canal Dehiscence Symptoms Unmasked by Ossicular Chain Reconstruction.

S uperior semicircular canal dehiscence (SSCD) was first described in 1998 among patients experiencing an unusual combination of auditory and vestibular symptoms. Common symptoms include autophony, aural fullness, and dizziness/vertigo. Patients often exhibit soundand pressure-induced eye movements on examination and lowfrequency conductive hearing loss on audiometric testing. The pathophysiology of SSCD lies in the thinning or absence of the bone between the middle cranial fossa and the superior semicircular canal, thus creating a ‘‘third window’’ into the inner ear. Otosclerosis, which can generate oval window immobility, can coexist with SSCD and suppress SSCD symptoms, and accordingly stapes surgery can ‘‘unmask’’ the third window. In the current case study, we describe, for the first time, the unmasking of a third window following an ossicular chain reconstruction, resulting in symptomatic SSCD.