0:01

Although it's not as common as pharyngitis, tonsillitis,

0:05

and dental infections,

0:07

I did want to mention one additional inflammatory

0:10

process that you should be aware of in the emergency

0:13

evaluation of a patient. In this case, with ear pain.

0:17

Now,

0:17

this is a 73-year-old elderly gentleman

0:21

who had diabetes.

0:23

And what we see on these two images is the characteristic

0:26

features of Malignant Otitis Externa

0:29

or Necrotizing External Otitis.

0:31

There will be different terms

0:33

used for the same entity.

0:34

What you see is the inflammatory process in the

0:38

external auditory canal with some erosion

0:41

of the walls of the external auditory canal.

0:45

And then you also see some undercutting of

0:49

the clivus on the right side on the CT scan.

0:54

This patient had previously had irrigation of this

0:59

right ear by the local MD and developed cranial

1:06

neuropathies and additional sort of deep-seated

1:10

skull pain. If we look on the MRI scan,

1:13

it's really quite striking what's going on.

1:15

Now note that this is an MRI scan in which we've applied

1:19

fat suppression and giving gadolinium.

1:23

What you see is the markedly narrowed external auditory

1:27

canal with inflammatory changes on either

1:31

side of the anterior and posterior border.

1:34

We see the mastoid air cells are opacified and enhancing.

1:39

Unfortunately,

1:40

we also see the flow void of the internal carotid artery

1:43

surrounded by enhancing inflammatory tissue.

1:47

As this inflammatory process is extending to the

1:51

skull base. These are the longest colli muscles.

1:55

The right side shows enhancement.

1:58

The left side is normal, not enhancing.

2:02

So we have inflammation even in the pre

2:04

vertebral musculature on the right side.

2:08

We also notice the clivus.

2:10

The clivus has fat within it and should show

2:13

fat suppression as you see on the left side.

2:16

On the right side, we have enhancement of this bone,

2:20

the clivus.

2:22

So enhancement of this clivus section right here,

2:25

because the patient has skull base osteomyelitis.

2:29

This inflammatory process extends into the

2:32

parapharyngeal space of the nasopharynx. Here's

2:34

the normal parapharyngeal space showing

2:37

absence of enhancement.

2:39

So this entity of Malignant Otitis Externa,

2:42

which starts as an external otitis,

2:45

basically a swimmer's ear, if you will,

2:48

can go even so far as the skull base,

2:51

with skull base osteomyelitis,

2:54

vasculitis and cellulitis extending

2:58

to the parapharyngeal space.

3:00

The theory is that with the irrigation

3:03

of the external ear, the pathogen,

3:07

which in most cases is pseudomonas, gets driven into

3:12

the fissures of santorini between the bony portion of

3:16

the external auditory canal and the cartilaginous

3:19

portion of the external auditory canal,

3:21

are these things called the fissures of santorini,

3:23

which extend inferiorly and medially

3:28

into the parapharyngeal space.

3:30

And so, the irrigation under pressure actually drives the

3:35

pseudomonas into the skull base, leading to spread of

3:40

the infection to the longest musculature, the clivus,

3:45

the carotid artery and the parapharyngeal space.

3:48

This is a deadly disease.

3:49

It's not quite as deadly as what was in the pre

3:53

antibiotic era where we said

3:56

it had a 70% mortality rate.

3:58

At this juncture, we're probably at about

4:01

20% mortality rate, which is still very high.

4:04

And the reason is because the patient, who's typically

4:07

diabetic, has a hard time fighting

4:09

off this pseudomonas infection.

4:12

We are talking here about mastoiditis

4:15

and middle ear cavity disease.

4:17

I want to just mention one other factor, and that is

4:20

that from the middle ear cavity and the mastoid air

4:25

cells, you have the potential to spread to the jugular

4:30

foramen the sigmoid sinus and the transverse sinus

4:34

as one of the complications of otomastoiditis.

4:38

In this case we see a thrombus in

4:41

the transverse sinus of the brain.

4:44

It's outlined by a little bit of contrast enhancement,

4:47

and that may lead into the sigmoid sinus, and from there,

4:50

into the jugular vein and potentially be another

4:53

source of septic thromboemboli into

4:57

the lung. From the middle ear cavity,

5:00

you can also lead to meningitis by erosion of the

5:05

tegmen tympani, extending to the meninges of the

5:10

middle cranial fossa floor. And from there, we

5:12

can also involve the cavernous sinus.

5:15

So otomastoiditis has lots and lots of potential

5:18

destructive complications.

5:21

They include bony destruction with

5:22

osteomyelitis at the skull base, you can have a

5:26

subperiosteal abscess, which we've shown

5:28

an example for in the oral orbits.

5:30

You could have spread to the extraaxial space and

5:33

meningitis and epidural abscess. You could have

5:35

cranial nerve involvement as you have spread to the

5:38

petrous apex, taking out the meckel's cave and the 6th

5:42

cranial nerve in gradenigo syndrome. That's G-R-

5:46

A-D-E-N-I-G-O. And then thrombosis of the venous sinuses.