0:01

When we consider extradural lesions of the spinal canal,

0:05

far and away the most common are

0:06

going to be degenerative disease.

0:08

Although we will have a separate talk on degenerative

0:11

disease of the lumbar, thoracic, and cervical spine,

0:15

I did want to just take a moment to point out an example of a

0:19

case of the disease and how it would

0:21

look on this extradural talk.

0:25

So here we have a patient who has multiple levels

0:28

of degenerative changes in the cervical spine.

0:31

As I stated previously with regard to how we can

0:34

tell that a lesion is in the extradural space,

0:37

we see that the subarachnoid space at the level

0:40

of the disease is narrowed.

0:43

So for example,

0:44

we see that the subarachnoid space coming up in the thoracic

0:47

region comes to this area where there is bony osteophyte

0:51

formation and the CSF space is narrowed.

0:54

That's to be distinguished from those entities such

0:57

as in the intradural-extramedullary compartment,

1:00

where you have widening of the subarachnoid

1:02

space, and this can be seen superiorly as well.

1:06

Here we have a patient who has a cervical spine C3-C4

1:10

level disc bulge and that also narrows the spinal canal.

1:14

Extradural disease may lead to intradural-intramedullary

1:20

findings. So in this example,

1:23

we see that the patient has abnormal signal intensity in the

1:26

spinal cord from the spinal stenosis and compression

1:30

of the spinal cord leading to intradural-intramedullary

1:34

abnormality in addition to the extradural abnormality.

1:38

I just want to scroll quickly through this one, the T2-weighted

1:41

scan, to give you a sense of the impact of both osteophyte

1:47

as well as disc material and how either of them may

1:52

lead to indentation on the thecal sac.

1:54

In this case,

1:55

we have this material.

1:56

In this case, we have osteophyte indenting the thecal sac.