0:00

Frankly,

0:01

we don't usually consider cord

0:04

ischemia or cord infarction

0:06

because it is so rare to occur.

0:09

Remember that the spinal cord

0:11

does have some redundant blood

0:15

vessel supply posteriorly with

0:18

two posterior spinal arteries

0:20

and then has an anterior spinal

0:23

artery, a single vessel in the

0:26

midline on the surface

0:27

of the spinal cord.

0:29

Vascular lesions, because they

0:30

are usually dark on T1 and

0:32

bright on T2 or isointense

0:34

on T1 and bright on T2, may

0:36

be mistaken for any other cord

0:37

lesion, including demyelinating

0:39

disorders or infectious

0:40

inflammatory etiologies.

0:42

Usually, however,

0:43

the patient's symptom is

0:45

of an abrupt onset.

0:46

So, cord infarcts usually occur

0:49

over a short period of time of

0:51

minutes to hours and the patient

0:53

has devastating complications

0:55

of pain, as well as motor

1:00

problems generally because of

1:01

the gray matter involvement.

1:03

The scenarios in which we see

1:05

cord ischemia or cord infarction

1:07

are most commonly associated

1:09

with aortic dissection or aortic

1:12

aneurysms and/or the surgeries

1:14

performed on the aortic

1:17

dissection and aortic aneurysm.

1:18

And this is because those

1:20

dissections could influence

1:23

the supply to

1:25

the main arterial supply

1:26

of the spinal cord

1:27

which is your anterior spinal

1:28

artery. In the thoracic

1:30

lumbar region,

1:31

that's the artery of Adamkiewicz.

1:32

In the cervical region,

1:34

it's usually a branch off

1:36

of the vertebral arteries.

1:37

The risk factors for cord

1:40

infarcts include patients who

1:42

are pregnant because of issues

1:44

with venous outflow, as well as

1:47

potential hypercoagulability;

1:50

patients who have vascular

1:52

malformations, either before

1:54

or after being treated;

1:55

patients who have dissections of

1:57

their vertebral arteries with

1:58

cervical cord ischemic injury;

2:01

intense hypotension

2:03

which can rarely lead

2:05

to cord infarction;

2:07

arteritis, such as Kawasaki's

2:11

disease that we described in a

2:13

previous case, or other causes of

2:15

obliterative arteritis; and

2:18

diabetes is another potential

2:21

risk factor for cord infarction.

2:25

As I said,

2:25

the problem with this entity is

2:28

that as of right now, we don't

2:30

have a means for reopening the

2:33

blood vessels and we usually are

2:36

too late in our interventions

2:38

because the cord infarcts and

2:41

leads to the gross neurologic

2:43

deficits.

2:45

Here is just a nice example of

2:48

the supply of the spinal cord.

2:51

Here we see your anterior spinal

2:54

artery, and we say that the

2:55

anterior spinal artery supplies

2:57

the anterior two thirds

2:59

of the spinal cord,

3:00

including the vast majority of

3:02

the cord gray matter. And the

3:05

posterior spinal artery

3:06

of which there are two in the

3:08

sulcus here, only supplies one

3:11

sixth each of the spinal cord.

3:13

So, the posterior one third.

3:16

But it's this anterior spinal

3:18

artery distribution that leads

3:20

to the most devastating

3:22

consequences of a cord

3:24

infarction.

3:26

As I mentioned,

3:28

the vertebral arteries are the

3:30

main supply to the anterior

3:31

spinal artery

3:34

in the cervical region.

3:35

But the artery of Adamkiewicz

3:38

which usually takes off

3:40

somewhere between

3:41

the T10 and L2

3:43

intercostal or segmental

3:47

arteries and is supplied by one

3:49

of those branches and then leads

3:52

to the hairpin turn of the

3:54

anterior spinal artery on the

3:55

surface of the spinal cord,

3:57

basically supplying the

4:00

upper to mid to lower thoracic

4:02

spinal cord. As I mentioned,

4:04

these are usually nondescript

4:06

from the standpoint of being

4:07

isointense on T1,

4:09

bright on T2,

4:10

variable enhancement,

4:11

variable cord expansion.

4:13

And the most common location for

4:15

a cord infarction is in the

4:17

thoracolumbar region, secondary

4:20

to the propensity for abdominal

4:23

aortic aneurysms and

4:25

abdominal aortic dissections

4:27

and surgery performed for

4:30

abdominal aortic aneurysms.

4:33

In the past five years,

4:35

we have developed more robust

4:38

diffusion-weighted imaging

4:40

sequences in order to best

4:42

define spinal cord infarction,

4:45

and this may be done as a simple

4:47

DWI sequence or in diffusion

4:51

tensor imaging.

4:51

Most of the time,

4:52

diffusion tensor imaging gives

4:54

a better quality study.

4:57

Here we have a patient who

5:00

has a thoracic aneurysm repair

5:03

and presented with hemiparesis

5:05

and had abnormal signal in the

5:08

spinal cord from T3/4

5:09

to T7/8

5:10

which you can see here with the

5:12

gross expansion of the spinal

5:14

cord. And in this case,

5:16

it almost looked like the

5:17

anterior spinal artery and one

5:19

of the posterior spinal arteries

5:21

was affected with just

5:23

a small sliver of

5:25

the left posterior lateral

5:27

spinal cord spared

5:28

by the aneurysm.

5:30

And I want to give courtesy

5:32

and thank Dr.

5:33

Yusuf, myself for providing

5:35

this case.

5:38

Here we have the lower images

5:40

of another patient.

5:42

You notice that the patient

5:44

has an aortic aneurysm.

5:46

There's clot here which may

5:49

strip the aorta of one of its

5:52

intercostal arteries that may be

5:54

supplying the artery

5:55

of Adamkiewicz.

5:57

You note that the cord signal

5:58

is abnormal and

6:00

the cord is slightly expanded,

6:02

and the central aspect of the

6:04

spinal cord appears to be

6:06

affected more so than the

6:07

posterior lateral portion

6:09

of the spinal cord.

6:10

Here you see the aortic aneurysm

6:12

in cross-section.

6:14

This was a different patient.

6:16

This was a patient who had a

6:17

vertebral artery dissection

6:19

which led to the cord

6:21

infarction. On the axial scan,

6:24

you see the bright signal

6:25

intensity within the

6:26

spinal cord.

6:27

Whenever you're looking at

6:29

cervical spine imaging for

6:32

degenerative changes or

6:33

for anything else,

6:35

I recommend that you make a

6:36

special comment on whether or

6:38

not you see vertebral arteries

6:41

that are patent with flow voids.

6:43

In this case,

6:43

the patient did have normal

6:46

appearance at this level of

6:48

the vertebral arteries,

6:50

but above had a vertebral

6:51

artery dissection.

6:53

The T2-weighted scan shows

6:54

enlargement of the spinal cord.

6:56

Well,

6:56

maybe this is neuromyelitis

6:58

optica or could it be

7:00

secondary to the degenerative

7:02

changes that there's

7:03

cord bright signal.

7:04

This would be unusual for it to

7:06

be extending so high. However,

7:08

on our diffusion weighted

7:10

imaging, we see a focal area of

7:13

high signal intensity on the

7:15

diffusion weighted imaging

7:16

and darker signal on the

7:18

corresponding ADC map,

7:20

identifying this as cytotoxic

7:22

edema from a cord stroke,

7:24

secondary to vertebral artery

7:27

dissection affecting the

7:29

anterior spinal artery of the

7:31

cervical spinal cord.