Introduction
Bilateral profound hearing loss, whether congenital or acquired, is one
of the most disabling anomalies a child can have. As the child grows up,
there is associated delay in development of speech leading to social and
functional stigmata for the child as well as the caregivers. Here comes
the importance of early diagnosis and intervention. Out of the
well-studied causes, Inner Ear Malformations (IEMs) comprise 20% of
causes of congenital hearing loss (1,2). IEMs have been classified
exhaustively by various authors depending on the site of involvement,
each category displaying a variable degree and type of hearing loss. A
normal cochlea has 2 ½ or 2 ¾ turns with modiolus as the central axis
and interscalar septum as a partition between cochlear inner wall and
modiolus (2,3). The cochlea is said to be hypoplastic when there are
less than 2.5 turns. There are four types of cochlear hypoplasia (I to
IV) with hearing status ranging from normal to profound loss; it being
very rare to have normal hearing (2). When the cochlea has 1.5 turns
then it is termed as Mondini dysplasia. Before proceeding to any
intervention in case of IEMs, it is imperative to look for the presence
of cochlear nerve and various audiologic parameters (4). Here we are
reporting two cases, one with cochlear hypoplasia type IV and one
patient with Mondini dysplasia. The point of interest in these cases was
a preserved audiologic status inspite of severe malformations of the
inner ear. The clinico-radiological discrepancies piqued our interest
and thus, we would like to share these cases owing to their rarity.