0:01

This is a really great example of all the potential

0:05

things that can go wrong, unfortunately,

0:08

with hearing in a child with Down syndrome.

0:11

So this patient had both conductive,

0:13

as well as sensorineural hearing loss.

0:16

So we would start with the outer ear.

0:19

And what we noticed with the outer ear is that there

0:21

is cartilaginous stenosis of the

0:24

external auditory canal.

0:26

We have somewhat of an unusual appearance

0:28

to the helix of the ear.

0:29

So this is an example of external auditory canal

0:32

stenosis. It's not atretic, but it's stenotic.

0:36

As we come to the tympanic membrane,

0:38

which of course is the border of the external

0:41

ear laterally, from the middle ear medially,

0:45

we have a myringotomy tube.

0:47

So a tube that has been placed because the patient

0:50

has had problems with chronic otitis media.

0:53

The bony external auditory canal,

0:56

which is this portion here,

0:57

looks normal in its caliber.

0:59

We next look at the ossicles and

1:01

the ossicles look pretty good.

1:03

There's the malleus and the incus, and the neck of

1:08

the malleus, and the long process of the incus.

1:10

And then we have our stapes footplate and the

1:12

incudostapedial joint. So that all looks fine.

1:16

So we can pass the middle ear, potentially.

1:19

However, when we get to the inner ear structure,

1:23

we first look at the vestibular aqueduct,

1:25

which is normal in its caliber.

1:27

And then we start looking at the

1:29

vestibule and the cochlea.

1:32

This is an example of very tight cochlear aperture

1:36

stenosis. As we come from the internal auditory

1:38

canal and we come to the cochlea,

1:40

we can barely see the opening from the internal

1:44

auditory canal to the cochlea.

1:47

So this is cochlear aperture stenosis.

1:49

Now, the measurement of this has been done by multiple

1:52

different groups and most people would say that 1.5 mm or

1:56

less represents cochlear aperture stenosis.

1:59

Now, that's right at the aperture.

2:01

The other thing that I've demonstrated previously

2:03

is you can have a bony block in the middle of a

2:06

relatively normal caliber to the aperture and we

2:11

would still call it a bony aperture stenosis.

2:14

In this case, really tight narrow aperture.

2:19

Now, I glossed over this,

2:20

but as I was talking about the internal auditory canal,

2:24

hopefully, some of you would have looked at this and

2:26

said this is not a normal width of an internal

2:29

auditory canal. It is narrowed.

2:33

When we have narrowing of the internal auditory canal,

2:36

we're obviously going to be concerned about the

2:38

potential for cochlear nerve hypoplasia.

2:42

So we would have to do the MRI scan to look

2:45

for cochlear nerve hypoplasia.

2:47

But a narrowed internal auditory canal with a cochlear

2:53

aperture stenosis is going to put the patient at high

2:56

risk of not having a normal cochlear nerve.

2:59

Finally, and this is unusual,

3:02

we note that there is a small halo of

3:05

low density around this cochlea.

3:08

What I'm referring to is this low density of bone,

3:14

which is not part of the cochlea itself nor its

3:18

modiolus. This is additional abnormality.

3:22

In this case, this patient is unfortunate enough to also

3:25

have the cochlear form of otospongiosis.

3:30

So this patient also has otosclerosis,

3:33

seen as this little halo of demineralization around

3:38

the cochlea. This low density around the cochlea,

3:42

even here, should not be there.

3:44

This is abnormal low density and is an example of the

3:50

retrofenestral or cochlear form of

3:53

otosclerosis or otospongiosis.

3:56

Let's just look at the contralateral side and

3:59

look for any abnormalities there.

4:01

So it too,

4:02

has this low density around the cochlea identifying

4:06

the otospongiosis. Once again,

4:09

we have cochlear aperture stenosis and

4:13

a narrowed internal auditory canal.

4:16

This is the singular canal coming to the vestibule here.

4:20

This patient who has Down syndrome in this example,

4:23

has a normal bone island and a normal appearing

4:25

vestibule and lateral semicircular canal.

4:29

Here you have another example of external auditory

4:33

canal stenosis with middle ear cavity inflammation.

4:38

The patient actually has some

4:39

mastoid inflammation here.

4:42

And here's the myringotomy tube

4:45

going through the tympanic

4:47

membrane to help drain the middle ear cavity.

4:51

So an unfortunate patient who has Down syndrome,

4:54

who has both congenital abnormalities in the

4:57

external ear as well as in the inner ear,

5:00

but superimposed an inflammatory process known

5:04

as otospongiosis, which we will discuss shortly.