The Syndrome of Enlarged Vestibule and Dysplasia of the Lateral Semicircular Canal in Congenital Deafness.

A 5-year-old deaf-mute girl was shown on petrous bone tomography to have bilateral enlarged vestibules with assimilation of the lateral semicircular cannals, bilateral absence of the cochlea, aplasia of the left internal auditory canal with only the facial nerve compartment being present, and hypoplasia of the right internal auditory canal. The embryological basis of these inner ear abnormalities is discussed.