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Okay. This is a case of basilar tip embolus.

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These are images of a 49-year-old male

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with hyperlipidemia who was found down in

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his bedroom and unable to speak.

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And then, he got rushed to the emergency room.

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He couldn't move his extremities that well.

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He was unable to speak.

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So, I'm thinking already that this

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maybe a brainstem embolus.

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so this is a non-contrast head CT.

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You can see there's a little atheromatous disease

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in the right vertebral artery.

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And I'm following the basilar artery up,

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and I noticed that the center

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of the basilar artery looks dense.

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So I'm thinking, wow,

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this is a hyperdense basilar sign

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in the posterior fossa.

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It's hard to make this diagnosis because you

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can have hyperdensity from beam hardening,

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et cetera,

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but the vessel kind of looks hyperdense.

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So, I'm a little bit worried about that.

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I'm going to look at the MCA.

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You see some atheromatous disease.

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I don't see any MCA stem hyperdensity.

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The rest of the brain looks normal.

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There's some scattered calcifications

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from prior granuloma's infection

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and

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he's got a left frontal meningioma.

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And

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you can look at narrower windows.

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To try to increase this conspicuity of infarction.

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As I said previously,

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it's really hard to make the diagnosis of

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pontine and brain stem infarctions

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on non-contrast CT.

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But anyway,

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so I'm worried that there's an MCA stem embolus.

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And so, we're going to look quickly

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at our MIPS of the head,

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and here are the coronal MIPS,

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and here's the vertebral basilar junction.

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And there's no mid-basilar artery.

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It's gone.

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Quick check of the MCAs.

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The MCAs look normal.

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And we can look at our axial MIPS, as well.

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And again, MCAs,

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PCAs look pretty good here.

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So, there is good perfusion of PCA territories.

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Hard to really look at the basilar

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images on the axial MIPS.

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If you have sagittal MIPS,

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which I don't in this case,

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you can also see the basilar.

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But we're worried about the basilar,

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so we'll take a look at that.

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We're also going to take a look at the neck.

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So, let's just start looking

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at the source images.

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You know,

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so we'll look at the arch,

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and then what we notice is there's this filling

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defect in the right brachiocephalic artery.

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And then, you know,

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I'm going to follow the vertebral artery.

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There's brachiocephalic.

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Here's subclavian.

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Here's vertebral artery.

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There's a little calcification,

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but it's not that significantly narrowed.

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And the right vertebral artery is dominant.

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You know.

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So, the embolus probably came up the right

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vertebral artery and not the left vertebral artery.

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So, I follow the right vertebral artery

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all the way up,

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and then we'll just...

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you know,

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follow it up into the basilar artery,

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and then, boom, it's gone.

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So, I'm thinking there was a clot in the

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brachiocephalic artery that went up

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the subclavian into the vert

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and went into the basilar.

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And you can see there's just no opacification

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in the basal artery here.

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You see nice opacification of the carotids,

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and even all the way up to the top of the basilar.

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SCAs,

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You can see the SCAs,

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superior cerebellar arteries here.

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And here are the proximal PCAs.

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So, it's occluded from near the origin

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to just proximal to the SCA.

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So PCA,

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as we go back down, there's left SCA,

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we don't really see the right SCA well,

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or it's in here.

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It's partially occluded proximally.

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All right.

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And then, we can look at the CTA source images.

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And if you window just right,

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maybe you can see some hypodensity in the pons.

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I don't know. Hard to tell.

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So, you really don't have a good idea from this

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of how much of the brain is infarcted.

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So, what we're going to do now

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is take a look at the MR.

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So, we'll look at the diffusion-weighted images.

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So, here are the diffusion-weighted images.

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So, the patient went immediately to MRI.

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Let's start at the bottom.

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There's a little tiny stroke in the right cerebellum,

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right PICA territory,

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which confirms that we know that embolus

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probably went up the right vertebral artery.

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And then, you see this relatively large stroke

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in the central and ventral aspect of the pons.

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But the midbrain looks pretty good.

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The patient's relatively young,

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so they took the patient to I thrombolysis.

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Before I show you the follow-up,

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I'm going to show you the FLAIR images.

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The FLAIR images,

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again show this

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hyperintensity in the pons.

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So, you know that area is already infarcted.

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It's not going to recover,

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but what you're trying to do is prevent

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the midbrain and the rest of the brain stem

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from infarcting.

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So basically,

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went to thrombolysis,

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still had deficits, went to rehab,

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and slowly improved over time,

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but didn't completely recover to normal.

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So, in summary,

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clot in the brachiocephalic artery,

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went up the right vertebral artery,

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went to the mid-basilar artery.

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We saw the hyperdense basilar sign.

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The acute pontine infarct,

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hard to identify on the non-contrast CT

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and CTA source images,

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but clearly seen on the diffusion-weighted images.

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And sometimes,

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if we're suspecting a brain stem stroke

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and we don't see it on the axial images,

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then we get coronal images.

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And this one was obvious,

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but there are coronal images anyway,

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and this is what it looks like on coronal images.

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Again, that big pontine infarct.

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And as you all know,

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acute strokes have restricted diffusion,

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so it's bright on DWI and dark on the ADC maps.

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Here's the ADC map.

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You can see that the stroke is dark.