0:01

Well, up till now we have discussed the neoplastic category of

0:07

diseases with schwannomas and meningiomas dominating.

0:10

We've talked about congenital lesions and discussed

0:15

various cysts, as well as lipomas and the various

0:19

congenital lesions including epidermoids and dermoids.

0:23

We also discussed the entities associated with

0:28

vascular malformations of the spinal cord.

0:31

I want to conclude this section with some discussion

0:36

about infectious inflammatory etiologies,

0:38

the so-called "I" of VITAMIN C and D.

0:42

So within the infectious inflammatory etiologies, we're

0:44

usually talking about some form of meningitis or neuritis.

0:48

And this is usually manifested as nerve root enhancement

0:52

of the cauda equina nerve roots and there are

0:55

various etiologies of that enhancement.

1:00

We're going to start off by talking about

1:01

infectious inflammatory lesions.

1:03

You can have enhancement of the nerve roots purely

1:06

on the basis of operative irritation.

1:09

This is what we sometimes call arachnoiditis,

1:12

or adhesive arachnoiditis.

1:15

We have Guillain Barré syndrome,

1:17

which is kind of an autoimmune entity that

1:20

is associated with a previous infection.

1:24

You can have irritation from chemicals such as pantopaque,

1:28

which is one of the agents that we used to use for

1:31

myelography that irritates the nerve roots.

1:34

And of course,

1:34

we have the subarachnoid seeding neoplastic category,

1:37

which we've already described.

1:38

And here you see, once again, that patient who had the

1:42

breast cancer with the enhancing nerve roots

1:44

at the cauda equina and conus medullaris.

1:47

When we think about infectious causes of nerve root

1:51

enhancement, there are a variety of etiologies,

1:55

most common of which are going to be viral etiologies.

1:58

So West Nile virus, Cytomegalovirus, and Herpes Zoster, are three

2:04

viruses that will lead to irritation of the nerve roots

2:08

and a secondary neuritis and/or meningitis.

2:12

With respect to the infectious bacterial diseases,

2:17

we would worry about things like

2:18

Lyme's disease or tuberculosis.

2:22

You may have fungal infections also and there may be

2:25

other bacterial infections that are associated with

2:28

patients having a discitis or osteomyelitis in the

2:32

extradural compartment. Here we have an example of

2:35

thickened nerve roots that are very faintly enhancing.

2:38

And this was cryptococcus,

2:40

a type of fungal infection that was leading to

2:44

the cauda equina syndrome. As I mentioned,

2:47

Guillain-Barré syndrome is syndrome that kind of crosses

2:52

the boundaries between infectious and autoimmune

2:56

inflammatory condition, sometimes called an acquired

3:00

demyelinating polyneuropathy.

3:02

This is typically manifested by diffused

3:04

nerve root enhancement.

3:06

It tends to favor the motor nerves

3:09

over the sensory nerves.

3:10

And that's why you may see selective anterior

3:13

nerve root enhancement. With treatment,

3:16

and the treatment is usually sort

3:17

of immunosuppressive treatment,

3:19

you may see diminution in the contrast enhancement.

3:23

Many of these patients have a GI infection,

3:26

a Campylobacter infection, that may

3:28

be the antecedent infection.

3:30

That leads to the autoimmune reaction on the cauda equina

3:35

nerve roots, the peripheral nerve roots.

3:37

And here you see a pretty dramatic example.

3:39

This looks like a child based on

3:41

the configuration of the spine.

3:42

But you see this diffuse enhancement on the conus medullaris

3:46

extending to the nerve roots of the cauda equina.

3:50

Of the noninfectious inflammatory conditions,

3:54

we usually think about sarcoidosis.

3:56

Sarcoidosis, like lymphoma,

4:00

can affect all parts of the spinal canal.

4:02

So it can be extradural in the bone,

4:05

it can be intradural extramedullary affecting the nerve roots,

4:08

and it can be intramdulary with an inflammatory

4:11

condition that leads to a myelitis.

4:14

The signal intensity is variable. Most of the time

4:17

you'll see this on the surface of the spinal cord

4:20

or on the surface of the nerve roots.

4:22

And the spinal abnormality may or may not be

4:27

associated with intracranial involvement.

4:29

Here's an example of a patient who had sarcoidosis in

4:33

which there was manifestation on the surface of the

4:35

spinal cord which eventually grew into the cord.

4:39

So this is both superficial intradural extramedullary,

4:43

as well as intramedullary involvement with sarcoidosis.

4:47

The same phenomenon can occur in the brain where we

4:50

initially see the sarcoidosis affecting the

4:52

meninges, and then in its severe form,

4:55

it grows into the parenchyma of the brain, as well.

4:58

This is another example of sarcoidosis, but in this case,

5:02

basically mostly affecting the cauda equina nerve roots.

5:05

These all look alike, so this could be Guillain-Barré,

5:08

this could be subarachnoid seeding.

5:10

It's effectively enhancement of the nerve

5:12

roots and sparing of the spinal cord, in this example.

5:17

I'm showing this as an intracranial manifestation

5:20

of sarcoidosis where the patient had fifth nerve

5:23

enhancement, as well as right third

5:25

nerve enhancement intracranially.