0:00

So I'm gonna go ahead and move on then to hydrocephalus. Um, as promised,

0:05

I'm gonna show, um, a,

0:07

an obstructive case to start just 'cause I don't want people to miss, um,

0:11

obstructive hydro thinking. They're dealing with N P H and,

0:13

and we're gonna get to N P H eventually. But this patient was sent to the,

0:16

the first patient that, that, that I'm gonna show you was sent to me with, uh,

0:19

concern for N P H. And, um, it, it was not N P H, but at any rate,

0:24

obstructive hydrocephalus is just an increase in intraventricular volume of C S

0:28

F, um,

0:28

due to impaired drainage of C S F from the lateral ventricles resulting in an

0:32

increase in intraventricular intracranial pressure. So in other words,

0:34

the C ss F is being produced normally in the ventricles.

0:37

It just can't get out of the ventricles to be absorbed by the arachnoid

0:39

granulations,

0:40

which are along the surface of the brain or along the surface of the skull.

0:43

And dura near the, the venous osis, as we talked about earlier,

0:46

normally presents with headaches, visual disturbances, cranial neuropathies,

0:48

poor balance, gait disturbance, sleepiness and seizures. Um,

0:51

etiologies can include, um,

0:53

aqueduct stenosis adhesions due to prior infection or hemorrhage, um,

0:58

particularly basler meningitis or prior subarachnoid hemorrhage can do this kind

1:02

of thing can also come from extrinsic compression or entrapment due to a tumor

1:06

like a, you know, quad trigeminal plate cistern kind of lesion, pineal lesion,

1:10

those sort of things can obstruct the aqueduct. Um,

1:13

there are congenital webs that, that occur in the aqueduct that can cause this.

1:17

Um, imaging findings usually, um,

1:19

include a significant enlargement of the lateral and the third ventricle, um,

1:23

without the sort of normal flow artifacts that you see, uh, you know,

1:26

through the, the, the cerebral aqueduct into the fourth.

1:28

And usually the fourth is, is quite a bit smaller than you'd expect to be,

1:32

but you have to keep in mind the fourth is kind of confined by the posterior

1:35

fossa, so it's not gonna get that big to begin with.

1:37

So it might not be that sensitive of the screening, uh,

1:39

evaluation for obstructive hydrocephalus. But one of the things that is,

1:42

is if you see bow of that recess of the third ventricle right above the optic

1:46

chiasm or right behind the optic chiasm. And then if you see bow, um, uh,

1:50

superiorly of the, um, uh, of the corpus callosum, uh,

1:53

that's usually indication that you're dealing with probably obstructive

1:56

hydrocephalus. And it can be treated with either a VP shunt or an uh,

1:58

endoscopic third vents.