0:01

When we think of our mnemonic

0:02

of VITAMIN C and D,

0:03

the eye usually refers to infectious

0:06

inflammatory etiologies.

0:08

And that's because within the

0:10

central nervous system,

0:11

we can have inflammatory disease,

0:13

which is noninfectious and maybe

0:16

in the autoimmune category.

0:18

So some people would put multiple sclerosis,

0:21

for example,

0:22

as an autoimmune inflammatory disorder,

0:25

whereas others would call it idiopathic.

0:27

In any case,

0:29

we're up to eye for inflammation.

0:30

As with tumors and other lesions

0:33

in the spinal cord, generally,

0:35

inflammation is dark on T1 or isointense T1,

0:39

but bright on your T2 and STIR images.

0:42

It may have variable enhancement.

0:45

In general,

0:46

we say that the viral myelitides

0:48

tend to enhance less,

0:50

whereas those of bacterial etiology

0:52

are more commonly enhanced.

0:55

They also have variable cord enlargement.

0:57

They may have multiple sites. And usually,

1:00

you're relying on the clinical history to

1:02

try to understand whether this

1:03

is an infectious etiology,

1:06

such as in a patient who is septic,

1:08

or a patient who has AIDS,

1:10

versus a noninfectious inflammatory

1:13

condition,

1:13

in a patient who may have more

1:15

of a systemic process.

1:17

The viruses that we typically think

1:20

about are CMV and herpes.

1:23

We also talk about the vacuolar

1:25

myelopathy of AIDS,

1:27

although we don't necessarily isolate an

1:30

organism with vacuolar myelopathy.

1:32

Of the other pathogens,

1:34

toxoplasmosis and tuberculosis are more

1:38

common, particularly in the AIDS group,

1:41

as well as in those that

1:44

are immune compromised.

1:46

Overall, worldwide,

1:48

probably TB myelitis is the most

1:51

common infectious etiology.

1:54

When we think of noninfectious

1:56

inflammatory conditions,

1:57

we have all of those collagen vascular

1:59

diseases which include lupus.

2:02

And then we have our sarcoidosis,

2:05

and finally we think about our demyelinating

2:08

disorders and IgG-related disorders.

2:12

The myelopathy that may be associated with

2:15

the HIV infection may include

2:17

AIDS associated myelopathy,

2:19

which can cause a progressive spastic

2:21

parapheresis or a myelopathy associated with

2:25

any of the various infectious etiologies.

2:28

In addition,

2:30

patients who are HIV or have AIDS may have a

2:34

propensity for having venous thrombosis,

2:37

which could cause an ischemic etiology

2:39

to spinal cord injury,

2:42

or they may have nutritional abnormalities,

2:45

which we will talk about shortly.

2:47

AIDS patients may also have lymphoma

2:50

which can occur in the bones,

2:52

in the intradural extramedullary cavity,

2:55

as well as in the intradural intramedullary cavity.

2:59

Although, lymphoma of the spinal cord is much less

3:02

common than all the other etiologies

3:04

that I've already described.

3:06

Here is an example of a patient who has bright

3:09

signal intensity within the spinal cord over a

3:11

long distance and bright signal

3:13

intensity on the axial scan,

3:15

and this patient has a myelitis.

3:17

Now, whether this is secondary

3:19

to virus or secondary to lupus, or secondary to

3:24

other ideologies is unknown and would require

3:27

sampling of the CSF as well as serologic evaluation.

3:33

The end product of myelitis and transverse

3:39

myelitis of idiopathic etiologies

3:41

could be cord atrophy.

3:43

Here we have a patient where we see that the

3:46

spinal cord in the mid to distal portion

3:49

has decreased in volume.

3:51

It does still have some bright signal intensity.

3:54

And this is the end product of myelitis.

3:57

You see also on the axial scans that

4:00

spinal cord size has diminished.

4:05

If we look at all of the etiologies of

4:08

spinal cord pathology in patients with AIDS,

4:11

as you can see,

4:12

vacuolar myelopathy and nonspecific myelitis

4:16

where the pathogen has not been

4:20

identified...

4:20

predominate.

4:21

And then we have our opportunistic

4:23

infections, HIV, et cetera.

4:27

Sarcoidosis is an unusual entity in that

4:31

you can have involvement of bone,

4:34

you can have involvement of the meninges,

4:37

and you can have involvement of the spinal cord.

4:41

The picture of sarcoidosis,

4:44

both in the brain as well as in the spinal cord,

4:47

is something that usually starts in the periphery

4:49

on the surface of the spinal cord

4:51

or on the surface of the brain,

4:53

and then we see the infiltration centrally.

4:56

And this is a patient showing post-contrast

4:59

enhancement in the spinal

5:02

cord from sarcoidosis.