0:00

Let's take a look at a 75-year-old woman whose

0:03

chief complaint is gait disturbance.

0:06

A secondary complaint is blurred

0:09

vision and gaze disturbance.

0:11

I have for you a magnified sagittal T1-weighted image.

0:15

Right about the midline,

0:17

there's the aqueduct of Sylvius.

0:19

I have an axial T2 spin echo, fast spin echo,

0:23

and an axial FLAIR,

0:25

which is more white matter-sensitive.

0:27

But I'm not particularly interested so much in the

0:30

white matter with gliosis and encephalomalacia

0:33

and cerebral atrophy,

0:34

which is present as I am in the brainstem.

0:37

Now, the first thing I'd like to point out in this

0:40

patient that has a gait disturbance,

0:42

so has a movement abnormality,

0:44

is that the compacta stripe,

0:46

the hyperintense compacta stripe,

0:48

which separates the iron in the substantia nigra

0:52

and the red nucleus, is preserved.

0:55

That is not the case when you have moderate to

0:58

later-stage classic Parkinson's disease.

1:02

Another key observation is the fullness

1:07

of the inferior colliculus,

1:09

but the atrophy of the superior

1:11

colliculus and the midbrain,

1:13

such that the upper portion of the midbrain comes

1:16

to a point and the mammillary body

1:18

appears conspicuous.

1:20

Above the superior colliculus sits the

1:23

habenula and posterior commissure.

1:25

But look at how small the superior colliculus is.

1:28

It should be about as big as

1:30

the inferior colliculus.

1:32

So, it should make kind of two waves in a row,

1:34

one here and then another one here.

1:37

But our second bump appears lost.

1:41

And then if I use my artistic skills,

1:44

which used to be pretty good but no more,

1:46

you can kind of see the snout of a hummingbird.

1:50

If I put a little eyeball on it,

1:52

there's the hummingbird,

1:54

there's the snout of the hummingbird,

1:56

and that's because the midbrain is atrophic

1:58

and the rest of it looks pointed.

2:00

And this hummingbird sign is a sign

2:03

of progressive supranuclear palsy,

2:06

also known as Steele-Richardson-Olszewski syndrome.

2:11

Now, there are some other signs of PSP,

2:15

which is considered one of the Parkinson plus syndromes.

2:20

Now, when I say plus,

2:21

I'm not talking about large-size clothing.

2:24

I'm talking about perhaps a misnomer of a group of

2:27

diseases that have Parkinson's-like symptoms,

2:30

and this includes progressive supranuclear palsy,

2:33

corticobasal degeneration with lots of cortical involvement,

2:37

Lewy Body dementia,

2:39

frontotemporal dementia,

2:40

formerly known as Pick's disease,

2:42

and multisystem atrophy.

2:44

There are some others that have been lumped in there,

2:46

but those are the five main ones.

2:47

I tend to stay away from that designation because

2:50

I find it a little bit confusing.

2:51

But now back to the signs.

2:53

If we draw a line through the back

2:57

of the aqueduct of Sylvius,

2:59

which I'll do right here.

3:01

And then we draw an oblique line to this notch

3:05

at the level of the cerebral peduncle,

3:07

where the tectum and tegmentum have a transition.

3:10

You should see a little bit of tissue protruding

3:13

outside that line, and you see just a wisp of it.

3:16

I'm going to go to another slice, actually.

3:18

I'm going to go to the next slice down and do the

3:22

same thing. In fact, I'm going to blow it up.

3:23

So it's a little more obvious to you.

3:25

There's your aqueduct of Sylvius.

3:27

Now, I'm going to make my line along the

3:29

back of the aqueduct of Sylvius

3:33

and make an oblique line going this way.

3:36

And I should have some full,

3:38

rich tissue protruding outside that line.

3:42

In other words,

3:43

I should have some midbrain parenchyma doing this,

3:47

bulging outside it, and I don't.

3:49

So the more this gets sucked in,

3:52

the more it looks something like this.

3:54

You'll have your cerebral peduncle,

3:57

and then as you come back,

3:58

it'll start to go convex inward on you.

4:01

Then you'll have your collicular plate in the back.

4:04

The more convex inward it becomes,

4:06

the more obvious this sign is,

4:07

which is known as the morning glory sign,

4:12

not to be confused with morning glory syndrome,

4:15

which occurs in the optic disc of the eye

4:18

in individuals.

4:18

Completely unrelated.

4:21

So you've got the hummingbird sign,

4:23

you've got the morning glory sign.

4:26

What's another sign of progressive supranuclear palsy?

4:31

I'll give you a third sign.

4:33

When you look at this midbrain,

4:35

doesn't it look like the peduncles are a little

4:37

too big for the rest of the midbrain?

4:41

I think so.

4:42

They look a little bit like this,

4:44

kind of like two giant ears.

4:47

Not on a dog, but on a mouse.

4:51

Which mouse?

4:52

Well, Mickey Mouse.

4:54

So they're a little too big for the rest of the

4:56

midbrain. And that's sign number three,

4:59

the Mickey Mouse sign of progressive

5:02

supranuclear palsy.

5:04

Now, in the next vignette,

5:05

I'll talk about some of the

5:07

other signs that you may see in a few related

5:10

disorders that can produce secondary

5:13

progressive supranuclear palsy.

5:15

So stay tuned for the hot cross bun sign,

5:19

the hockey stick sign,

5:21

and the pulvinar sign coming to a vignette near you.