Mondini Dysplasia; clinical Signs and Diagnostic Imaging

Abstract

Recent advances in imaging technique, including high resolution thin section computed tomography scanning and magnetic resonance imaging (MRI), permit the easy diagnosis of congenital malformations of the osseous labyrinth, which have so far been lumped together as "Mondini dysplasia". In the present study the anatomic patterns from the radiographic appearance and the clinical manifestation were examined in 18 patients (23 ears) with radiographic abnormalities of the inner ear. The most common abnormal configuration was a large vestibule (20 of 23 ears). This anomaly of the vestibule often involved the lateral semicircular canal, revealed as a round high signal zone on T2-weighted MRI. However, a large vestibule was not always associated with an abnormal cochlea. Abnormal cochleas were found in 8 of the 20 ears with a large vestibule, and most of these 8 ears had total or profound deafness. But 4 of the 10 ears with residual hearing had low tone deafness and 6 had fluctuating hearing loss, which was frequently associated with attacks of dizziness. These clinical manifestations of Mondini dysplasia are similar to those of patients with endolymphatic hydrops.