0:00

So let's start with spontaneous intracranial hypotension. Um,

0:04

it's basically just a decrease in hydrostatic pressure that results in a

0:07

postural headache. Most ti most of the time patients will denote that they, um,

0:10

have a headache that gets worse after about 10 or 15 minutes of sitting up gets

0:14

better after lying down for a similar period of time.

0:18

It can result from a C S F leak, excess reabsorption, or excess production.

0:23

Um,

0:24

and essentially spontaneous leaks can occur in the spine due to a dural tear,

0:28

um,

0:29

or degenerative spondylosis or even just dural ectasia resulting in potentially

0:33

A C S F venous fistula, which will cover later. Um,

0:37

spontaneous skull base leaks can be due to an osseous dehy or an encephalocele.

0:42

Um,

0:42

it most frequently occurs in the temporal bone and it's usually associated with

0:46

eaa, uh, or rhinorrhea.

0:47

And sometimes there are also associated perinasal sinuses, fu perinasal,

0:51

sinus effusions, um, particularly the,

0:53

the mastoid air cells will fill up when it's the temporal bone. Again,

0:56

we're gonna primarily be focusing on spinal C S F leaks today. Um,

1:01

typically, um, the patients, again present with postural headache.

1:04

A lot of 'em will, uh, complain of nausea, vomiting, neck pain,

1:06

visual disturbances, and essentially, um,

1:08

cranial lower cranial nerve issues like tinnitus and,

1:11

and vertigo and things like that. Um,

1:15

generally clinically you're gonna note that their opening pressure,

1:18

we do an LP is usually less than six centimeters of water. Um,

1:22

ideally this would be done in the lateral decubitus position to get the most

1:25

accurate pressure possible. Um, and essentially, um,

1:29

if they have a skull base leak,

1:30

they should have some history of clear oor Rhea or rhinorrhea. If it's,

1:33

if it's the skull base that we're talking about, um,

1:35

most of them will have pacu, meningeal, thickening and some degree of brain sag,

1:39

if not, um, full-blown tonsor act topia. Um, and then, um,

1:43

most of them will also have some degree of pituitary engorgement or, um,

1:46

decreased, uh, um, width of the super cellar cistern.

1:49

A lot of them will also have venous sinus distension.

1:51

Some of them will actually even have full-blown subdural collections and

1:54

superficial CIDRs, sometimes the ventricles can even start to look slit.

1:58

Like very rarely when you have a very high flow C S F leak,

2:01

people can have a full minute course where they actually develop cerebral edema

2:04

and, and go into a coma and require very rapid treatment and correction of this

2:08

problem. Um, initially the way that I normally screen a patient, um,

2:13

that comes into my clinic is I get an m r I of the brain with contrast, uh,

2:17

or with, and without contrast, I should say,

2:19

and we get thin section cts in the temporal bone and or MAC space,

2:22

depending on whether or not they complain of ear stuffiness or rhinorrhea

2:26

otorrhea or if they have fluid behind their eardrum. For instance,

2:29

when I examine them, if there's no dehiscence on the ct,

2:32

then I do a full spine survey with flow compensated fiesta images and fat

2:36

saturated two T two weighted images. Um,

2:39

and essentially at that point I make a decision between doing a more rapidly

2:44

acquired myelogram or doing a pressure augmented myelogram. And really it's,

2:48

it's more of an imaging, um, uh, acuity,

2:51

like how quick is the contrast gonna leak from the fecal sac?

2:54

And MRI is pivotal in deciding what the next step is. Basically, if I'm

2:58

Seeing, seeing a pseudomeningocele where there's an actual, uh,

3:02

collection of fluid outside of the dura, normally those,

3:05

those leaks actually happen very quickly and the communication is very rapid.

3:08

Whereas if I'm seeing perineural cysts,

3:10

it's usually more of a slower communication,

3:12

either a C S F venous fistula or a small type two leak. In those cases,

3:16

I'm gonna opt more for pressure augmentation and lateral decubitus positioning,

3:19

which we'll get into a little bit later. Um, if I think it's a skull base leak,

3:23

again, I'll do a nuclear medicine sonogram,

3:24

but that's not really gonna be the focus of the lecture today.

3:26

But that's normally what I would do.

3:27

I do a nuclear medicine sonogram if I think there's a dehiscence and just

3:30

confirm it and make sure that we're not just dealing with sinus disease. And,

3:33

and, um, a patient who has, uh, con commitment C S F hypotension,

3:38

um, one of the things that comes up often is, uh, uh, the burn score.

3:42

So the burn score is actually a screening score scale that we can do for

3:47

patients based on their M R I.

3:48

And there are minor criteria and major criteria for C ss F hypotension or spinal

3:54

C S F leaks, um, engorgement of the sinuses, chy,

3:57

meningeal enhancement and super cellar Cistern, um, uh,

4:00

flattening or or CLO closure of the super cell cistern down to less than four

4:04

millimeters, um, is a major criteria.

4:06

So you're talking about two points for each of those in the minor criteria or

4:09

having, um, a subdural collection,

4:11

a pre pontine cistern distance of less than five millimeters or a malo pontine

4:15

distance of less than 6.5. So this burn score can kind of help put,

4:19

you put the patients into risk categories. If their score is less than two, we,

4:23

we generally consider them low risk intermediates between two and four,

4:26

and then greater than five, uh, points on the burn scale, uh,

4:29

is the highest risk, obviously for a spontaneous C S F leak,

4:32

and in most cases they are spinal leaks. Um, patients who have, uh,

4:37

cranial leaks generally don't have as many of these elements on the burn score

4:41

particularly, they don't tend to have the brains bag component of it, and their,

4:45

their packing NAL enhancement can be more focal surrounding wherever the leak is

4:49

as opposed to being more diffuse. And that's,

4:51

that's not an uncommon finding when it's a cranial C S F leak.

4:54

So this is a patient with a typical spinal C S F leak.

4:57

We can see that they have, um, uh,

4:59

diffuse pa meningeal enhancement and thickening. They have subdural collections.

5:04

Their pituitary is engorged, their straight sinus is engorged.

5:09

Um, their super stellar cistern is very, very narrow,

5:12

much less than four millimeters.

5:13

It'd be very difficult to even measure because the, the size of the pituitary,

5:16

the pre pontine distance or pre pontine cistern width is very narrow as well.

5:20

You could al you, you almost can't even measure it.

5:22

And then the malo pontine distance is almost completely closed as well.

5:26

In addition to that, we have an acquired tonsor ectopia.

5:29

So this is a patient who has a, basically a nine on the burn score.

5:32

There's really, there's, they have, they cover every single point.

5:35

So this patient is extremely high risk for, uh,

5:38

spontaneous intracranial hypertension.

5:40

This is what we would consider a positive screen on M R I for spontaneous

5:42

intracranial hypertension, hypertension.