0:00

This patient was being evaluated

0:02

for a cervical myelopathy.

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As we scroll through the T1-weighted

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and T2-weighted scans,

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we're looking at the degree of canal

0:10

compromise to see whether there is cord

0:14

compression or abnormal signal intensity

0:16

in the spinal cord, given that the patient has a myelopathy.

0:20

Frankly, in looking at this,

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I don't see anything that looks that

0:23

bad. When we look on the sagittal scan,

0:26

there seems to be a large disc

0:28

herniation at the C3-C4 level.

0:31

So we go to our gradient echo scan,

0:33

which is our sequence that is the best for identifying

0:37

disc herniations. Here at the...

0:39

I believe this is the C2 level.

0:42

Yeah. So we're at the C2 level.

0:44

We see this large area of signal intensity abnormality,

0:49

which is not bright on the gradient echo scan.

0:52

Here's the gradient echo scan where you

0:55

have high signal intensity.

0:57

This is actually at the C3-C4 level where

0:59

we have that large disc herniation.

1:01

But at the C2-C3 level,

1:05

it's not bright. It's actually dark.

1:07

So we'd probably say that there's

1:09

osteophyte present at C2-C3 with a disc

1:14

herniation at C3-C4 extending to the

1:18

right side greater than the left,

1:19

with likely compression of the C4 nerve root.

1:24

Now, remember that the cervical spine

1:28

has eight cervical nerve roots.

1:31

So at the L4-L5 foramen, what's going

1:35

through the foramen at L4-L5 is the L4 nerve root.

1:39

But at the C4-C5 foramen, it's the C5 nerve root.

1:45

So C8 goes through C7-T1.

1:48

So it's the lower nerve root number that

1:51

is going through the foramen.

1:53

So, here at the C3-C4 level,

1:57

it's the C4 nerve root that's getting

2:00

compressed by this soft tissue to the right of midline.

2:05

And it looks predominant like disc herniation.

2:08

And then as we scroll through the

2:09

remainder of the cervical spine,

2:11

we don't see all that much.

2:12

Well, this is just a little warning to tell

2:16

you that there is a role yet

2:20

for cervical spine CT.

2:23

Let me demonstrate that by showing

2:25

you what the cervical

2:27

spine CT looks like.

2:29

Here we have the cervical spine CT.

2:31

And look at what we missed.

2:34

Here behind each of the vertebral bodies

2:37

is ossification of the posterior

2:41

longitudinal ligament, which is not readily evident.

2:46

Let's just take C4.

2:48

So here's C2, C3,

2:50

C4 looks pretty good.

2:51

But when we look at the CT scan, C2, C3, C4.

2:56

This tissue, this bone tissue that is

3:00

along that posterior margin of the vertebra

3:02

is ossification of the posterior longitudinal ligament.

3:05

It's present at C5.

3:06

It's present at C6.

3:08

Okay, not so much.

3:09

A little bit at C7.

3:11

And at the C1, C2, C3 level,

3:15

all of this is OPLL.

3:17

It's actually...

3:18

and look at this big raft of it here.

3:21

It's not really disc material.

3:25

So, this is a word to the wise.

3:29

When you are looking at patients who show

3:31

demonstration of narrowing

3:33

of the spinal canal, but the etiology of it is not

3:36

as clear on the MRI scan,

3:38

it may be that we're dealing with

3:39

something that is bony,

3:41

that is relatively invisible on the MRI,

3:43

such as ossification of the posterior

3:46

longitudinal ligament.

3:47

You notice that this patient also has

3:48

flowing osteophytes anteriorly.

3:50

So as yet another example of a patient

3:53

who has associated diffused idiopathic

3:56

skeletal hyperostosis

3:58

in association with

4:01

OPLL.