The effects of superior semicircular canal dehiscence on the labyrinth: does size matter?

BACKGROUND

Superior semicircular canal dehiscence (SSCD) is characterized by lack of bony covering of the superior semicircular canal in the inner ear, resulting in a third mobile window with altered functioning of the superior semicircular canal. Vertigo in association with sound and pressure changes often occurs. This study examines the relationship between dehiscence size and frequency of sound-induced vertigo.

METHOD: Retrospective review of 22 patients with SSCD, noting the auditory frequency producing the maximal electronystagmographic response.

RESULTS

The study found a correlation between dehiscence size and stimulator frequency of r = 0.856, p < 0.001. The larger the dehiscence, the lower the frequency of stimuli required to provoke a vestibular response.

CONCLUSION

The relationship found between the superior canal dehiscence size and the stimulator frequency has clinical implications in the diagnosis and management of patients with SSCD.