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Let's look at another patient who

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has inner ear anomalies. And again,

0:05

patients usually will present with congenital

0:07

sensorineural hearing loss,

0:08

so you're usually seeing them as a child.

0:11

So in this case,

0:11

we're going to start with looking at the external

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auditory canal and that looks like a normal

0:16

cartilaginous and bony portion

0:17

of the external auditory canal.

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We're going to focus on the left side for this example.

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We have a normal ice cream, ice cream,

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cone of the head of the malleus and

0:25

short process of the incus.

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We have the parallel lines of the neck of the

0:29

malleus and the long process of the incus.

0:32

Then we come down to the oval window where we

0:35

will be able to see portions of the stapes.

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When we look at the vestibular aqueduct,

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we see that there is a vestibular aqueduct seen

0:45

bilaterally. It's a little bit widened.

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We're not having a good canal

0:50

the way we normally would see.

0:52

I would probably pass these vestibular aqueducts in the

0:56

absence of having an MRI scan

0:58

showing enlargement of the endolymphatic sac.

1:01

However, when I look at the cochlea,

1:04

I'm struck on the left side by the poor development

1:07

of the modiolus beyond the basal turn.

1:11

So here we have the middle and apical turn, again,

1:16

kind of a bulbous with no separation

1:20

between the middle and apical turn.

1:22

So no separation between the middle and apical turn

1:25

in here. This is what would be called the Mondini

1:29

malformation in the absence of the enlargement

1:32

of the vestibular aqueduct.

1:34

So with enlarged vestibular aqueduct,

1:36

we would call this incomplete partition type 2.

1:39

If we thought that the vestibular aqueduct was normal

1:42

and this was just incomplete spiralization and a

1:46

bulbous basal and middle turn of the cochlea,

1:49

we would call it a Mondini malformation.