0:01

Seems like all the cases have right-sided pulsatile

0:04

tinnitus, and that was the case as well with this patient.

0:07

We know what to look for.

0:09

We're going to look at the internal carotid artery,

0:11

and make sure that there's no aberrancy,

0:14

and that the posterior wall is intact.

0:16

We're going to look at the jugular bulb.

0:18

And although it's thinned right here,

0:21

it's not dehiscent and it's not high.

0:23

And that it's not above the internal auditory canal,

0:27

which is seen here.

0:28

Now, we're going to look over the cochlear promontory and see

0:31

whether we see a mass, which...

0:33

This is the cochlear promontory,

0:35

the round window niche. There's no mass on the right side.

0:39

However, we notice that the facial nerve appears a little bit thickened.

0:43

And as we continue towards the geniculate ganglion,

0:47

we have this moth-eaten in appearance to the bone.

0:50

So it's irregular appearance to the bone.

0:52

Let's compare it to the contralateral side where the

0:56

bone is nice and dense and not moth-eaten.

0:59

But over here,

1:00

we've got this woven appearance to the...

1:04

or trabeculated appearance to the bone,

1:06

right as we go from the labyrinthine

1:09

portion to the geniculate ganglion portion

1:11

and then the tympanic portion.

1:13

So right at the geniculate ganglion in the first genu,

1:16

and we're seeing this irregularity here and moth-eaten,

1:20

trabeculated appearance to the bone.

1:23

So this is what we are concerned for,

1:26

what's called a facial nerve hemangioma.

1:29

In point of fact, it is effectively like a bone hemangioma,

1:33

which is in reality,

1:34

a venous vascular malformation of the bone.

1:38

And it is seen as this woven appearance to the bone,

1:42

trabeculated appearance to the bone on CT.

1:46

The patient had an MRI scan that was performed as well,

1:51

to look for the facial nerve abnormality.

1:55

On the right side, as we look at the thin-section

1:59

post-gadolinium enhanced scan,

2:00

you come to a portion where you see contrast-enhancing soft

2:04

tissue, associated with the expected location of the facial

2:09

nerve tympanic portion and geniculate ganglion.

2:14

And this is exemplified by the contrast-enhancing material here.

2:19

You notice that the patient has a mastoid effusion,

2:22

which is not showing contrast enhancement.

2:24

But the presence of enhancing tissue in the expected

2:27

location of the facial nerve venous vascular malformation,

2:31

confirms the diagnosis of a facial nerve hemangioma.

2:36

Pathognomonic feature on the CT scan with that trabeculated

2:41

appearance to the bone is really what makes the diagnosis.

2:46

Based on these images alone on the MRI scan,

2:49

we couldn't differentiate this from a, for example,

2:53

a facial nerve schwannoma or, for that matter,

2:56

a middle ear adenoma.