| Discussion: |
Mondini described a case of a congenital deafness in which the cochlea was shortened to 1.5 turns. The true Mondini deformity occurs secondary to an arrest at the seventh week. Only the basilar turn of the cochlea has undergone complete development. Typically the interscalar septum or osseous spiral lamina is incomplete, resulting in a confluency of the apical and middle cochlea turns (incomplete partition). The vestibule and semicircular canal may or may not be normal. Mondini's malformation is associated in 20% of cases with anomalies of the vestibule, semicircular canals and endolymphatic duct/sac. Deafness may only be in the lower frequency ranges. Have increased risk of CSF leak following head trauma.