0:00

So first, we're going to talk about Moyamoya disease.

0:03

As I was saying,

0:04

it can be primary and idiopathic,

0:06

or it can be secondary in association

0:08

with NF1, sickle cell disease,

0:11

radiation and atherosclerosis.

0:13

What you get is progressive stenosis of

0:15

the distal internal carotid arteries,

0:17

proximal MCAs and ACAs,

0:19

with relative sparing of the posterior circulation.

0:23

Children tend to present with ischemic lesions.

0:26

Adults tend to present with basal ganglia hemorrhage,

0:29

but either can present with either.

0:32

What you notice on imaging is the severe stenosis,

0:37

and then a lot of collateral vessels.

0:39

So, these are images of a child who had

0:43

progressive white matter lesions.

0:44

And you can see these multiple

0:46

white matter lesions,

0:47

which turned out to be subcortical strokes.

0:50

You can see this FLAIR hyperintensity

0:52

throughout the sulci,

0:54

which is slow flow and collateral vessels.

0:56

Post contrast, those collaterals enhance.

0:59

So again,

1:00

you can see all these enhancing lesions in the

1:03

subarachnoid spaces.

1:05

And on CT angiography,

1:07

you see severe attenuation of the distal

1:09

ICA and the proximal ACAs and MCAs,

1:12

and worse on the right.

1:14

And then, you see all these tiny little collaterals

1:17

which form when the vessels occlude.

1:20

The posterior circulation is normal.

1:21

I haven't really shown it here.

1:23

And this is just a sagittal projection

1:26

of an occluded ICA.

1:28

And you can see all these collaterals.

1:30

It's called a puff of smoke on angiogram.

1:33

So, this case of moyamoya is a 48-year-old male

1:37

with left-sided weakness and dysarthria.

1:39

And this is the non-contrast CT.

1:42

And what I notice here is some hypoattenuation

1:48

in the top of the right basal ganglia

1:50

and the right corona radiata

1:52

and the right centrum semiovale.

1:55

I don't see any hemorrhage.

1:57

Don't really see a dense vessel sign.

2:03

And that's pretty much the non-contrast CT.

2:07

And then we got a CTA,

2:11

and I quickly reviewed the images of the neck

2:15

and see some mild,

2:18

mild to moderate stenosis in the bilateral internal

2:21

carotid arteries from some mild atheromatous disease,

2:24

but don't see too much.

2:26

The vertebral arteries look pretty good.

2:29

And we can look at the sagittal images of the neck,

2:33

and again, some mild,

2:37

mild to moderate atheromatous disease

2:38

at the carotid bifurcations bilaterally.

2:42

And the vertebral arteries look pretty good.

2:45

I don't see too much else there.

2:47

So, let's look at the circle of Willis.

2:50

So, the first thing I always do,

2:52

I look at the MIP images,

2:54

and you can see that posterior circulation is,

2:58

there's some mild stenoses,

3:00

but is relatively preserved.

3:02

But the distal right ICA and proximal MCA

3:05

and proximal ACA are not seen.

3:07

They're likely occluded.

3:09

And then, you can see some collateral vessels.

3:11

And on the left side,

3:13

you can see the A1 and A2,

3:15

but looks like there's a tangle of collateral vessels,

3:18

and then you kind of see an attenuated MCA.

3:22

So already, I'm thinking of anterior circulation,

3:24

abnormal ICAs and MCAs, and ACAs.

3:28

This looks like a Moyamoya case.

3:31

We can look at the coronal images, too.

3:34

And again, on the right side,

3:36

you see some collateral vessels.

3:38

You don't really see the

3:41

ACA and MCA well.

3:43

On the left side,

3:44

you can see the top of the ICA,

3:46

a bunch of collaterals,

3:48

and then you see an attenuated MCA.

3:51

And then, the posterior circulation,

3:54

the basilar artery,

3:56

the PCAs are relatively preserved.

3:59

So, this is a classic Moyamoya pattern.

4:02

Let's take a look at the raw data.

4:07

Again,

4:09

neck.

4:11

Just follow the left IC up.

4:14

Some mild to moderate stenosis,

4:17

has a little plaque,

4:18

but we don't see enough plaque to think

4:22

this is all due to atheromatous disease.

4:24

The left ICA looks pretty good here.

4:26

Going up into the siphon

4:29

and up to the circle of Willis.

4:30

And then, what happens here,

4:33

this never connects up.

4:35

There are...

4:35

All these little collaterals,

4:36

but it never really connects up to the MCA.

4:39

So, these are all those collaterals

4:40

you were seeing.

4:41

And then, you've got some attenuated MCA branches.

4:44

And then, the proximal ACA looks okay on the left.

4:49

And then, we'll just go through the right side.

4:51

And then the right side,

4:54

you know,

4:55

starting down here,

4:56

the common carotid artery looks normal.

4:58

The bifurcation,

4:59

we see a little bit of atheromatous disease,

5:02

but again,

5:02

not enough to explain the

5:04

circle Willis findings.

5:05

The right ICA is attenuated,

5:08

and then becomes very faint and is occluded in the siphon,

5:12

all the way up to where you see these collateral vessels

5:15

in the circle of Willis.

5:18

And there is some collateralization

5:19

of the more distal MCA branches.

5:22

So, classic moyamoya,

5:24

anterior circulation,

5:26

progressive stenosis of the distal ICAs

5:29

and proximal MCAs and ACAs.

5:32

And let me just show you the MR.

5:35

So, we've got a follow up MR.

5:38

And as we suspected,

5:39

there was involvement of the basal ganglia

5:41

corona radiata.

5:42

And you can see some lesions higher up that are

5:44

in the border zone between the MCA and ACA.

5:48

This is more MCA stem

5:51

and a couple other lesions in the MCA territory.

5:56

So, that's our case of Moyamoya.