0:01

This is the type of case where even the

0:03

scalp view is actually pretty helpful.

0:05

We see that this is a relatively large

0:08

individual with a lot of subcutaneous tissue.

0:12

So this is the substrate for which we would expect

0:16

to see a patient who has idiopathic intracranial

0:20

hypertension, usually high body mass index.

0:25

Here is the CT scan with contrast in this individual

0:28

who was complaining of headaches and visual blurring.

0:31

And the finding that is most evident here is the

0:35

empty sella, large empty sella with CSF density

0:40

on the contrast-enhanced CT scan.

0:44

You look at the optic nerve sheath complexes.

0:46

They are not dramatically enlarged.

0:49

I would probably pass them.

0:51

And we're not seeing papilledema.

0:53

We also do not see any other lesions in the brain.

0:57

We would look at Meckel's cave region.

0:59

A little bit plump here on the left side.

1:02

Not traumatic.

1:03

A little bit of remodeling of the bone,

1:05

not traumatic.

1:06

This patient was sent for MR venography for the

1:11

potential for idiopathic intracranial hypertension.

1:15

And so, you may see quite a bit of patients like

1:19

this where CT venograms are being performed.

1:22

Remember, with CT venogram, you do have to alter the

1:26

timing of the bolus and the CT scanning after the bolus

1:31

to adjust for a venographic

1:34

image, not an angiographic image.

1:36

So, the clinician might write,

1:38

IIH, Pseudotumor Cerebri, CTA.

1:42

You have to notify the technologist or

1:45

make sure the technologist is aware that

1:47

the issue here is not the arterial phase,

1:51

but in doing it in the venous phase,

1:54

so we can look for venous sinus stenosis.

1:57

So let's look at the venogram that was performed.

2:01

In this case, I'm going to be

2:02

showing you the reconstructed images.

2:06

So here we have the right transverse sinus, here

2:09

we have the left transverse sinus, and off the

2:12

bat, some of you would look at the left transverse

2:14

sinus and say, wow, that's pretty narrow.

2:18

And that could be the issue in this patient.

2:22

Actually, the abnormal sinus is the right side.

2:26

This left side is narrow throughout its course

2:30

and doesn't show any evidence of a focal stenosis.

2:34

Therefore, this left side is actually just the normal

2:38

hypoplastic left transverse sinus that I talked about

2:42

as being a normal variant from right-to-left asymmetry.

2:46

If we look on the right side, however, we see that there

2:49

is a focal area where there is narrowing of the sinus.

2:54

Here's a relatively normal-sized sinus, and then we

2:57

lose the sinus right through this portion right here.

3:01

And that is the area of sinus stenosis,

3:04

which may be implicated in pseudotumor cerebri.

3:08

In these patients, often, uh, they will be treated

3:12

medically first, either symptomatically for their

3:15

headache, or they will be given, uh, Diamox as

3:19

one of the, uh, one of the drugs that is utilized for

3:24

pseudotumor cerebri to decrease the CSF pressure.

3:29

Um, if that resolves the problem, they're done.

3:33

However, if they are medically resistant,

3:36

then there are two surgical or two

3:39

interventional procedures that may be done.

3:41

Number one is doing a stenting of

3:44

that area of venous sinus stenosis

3:46

interventionally with endovascular treatment.

3:49

The second is, if that is not successful, or they

3:52

don't see a gradient, but the patient is still

3:55

potentially losing vision, they can do optic

3:58

nerve sheath fenestration because the pressure

4:01

that's being placed on the optic nerve is

4:05

transmitted from the intracranial compartment.

4:07

If you open the optic nerve sheath up,

4:10

then that pressure is not transmitted to the optic

4:13

nerve, and you don't get pressure ischemic optic

4:16

neuropathy, which is thought to be the source of

4:19

the visual loss associated with pseudotumor cerebri.