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This is 74 year old man who s been carried for

0:04

some time seven years with a diagnosis of classic

0:08

PD or Parkinson's disease. However,

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his cinemat or DOPA response was variable to nil.

0:15

Now, a key part of this patient's history was

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dementia at presentation on MRI.

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And his dementia had been present for at least 5 years.

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So, five out of the seven years.

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So the fact that dementia was a prominent

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presentation early on,

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might have been a tip off

0:33

to the pathologic diagnosis in this case,

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which we do have.

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Let's look at the axial echoplanar image,

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an axial PD and an axial T2.

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What might strike you is the thickness

0:48

of the substantia niagara,

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the preservation of pigment in the red nucleus,

0:53

and the fact that you can see the compact zone

0:57

separating the two.

0:58

So they haven't completely bled together.

1:01

This is apparent on the PD,

1:04

the T2, less valuable because it's

1:06

not as sensitive to iron.

1:07

And I'm going to scroll up and down a little bit.

1:10

As you can see, there's iron accumulation in the putamen,

1:13

less so in the globus pallidus,

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maybe the GPE, the outer aspect of the globus

1:18

has a little bit of brain iron in it.

1:20

Let's go up and then let's go down a little bit,

1:23

back to the level of the midbrain.

1:25

We'll go a little bit below towards the midbrain

1:28

pontine junction, just so you get a feel for it.

1:31

And once again,

1:31

in somebody with really severe end stage

1:35

Parkinson's disease, quote unquote,

1:37

which this patient was alleged to have,

1:40

the preservation of the compactor

1:42

stripe goes against classic PD.

1:46

Then I'm going to pull down the sagittal,

1:50

remembering that this patient has dementia,

1:54

and I'm going to scroll from side to side.

1:56

Let's go off to one of the temporal lobes.

1:59

Actually,

2:00

let me get something that's a little thicker here.

2:02

Let's go off to one side and look at the

2:04

massive atrophy of the temporal lobe.

2:06

It's way disproportionate than you would expect

2:10

for somebody who has seven years

2:12

of Parkinson's disease.

2:13

Let's go to the other side where the temporal lobe

2:16

is also severely atrophic.

2:18

So early dementia,

2:20

disproportionate atrophy in the temporal,

2:23

hippocampal and parahippocampal regions,

2:26

and the preservation of the compacta zone

2:28

raise the possibility of a very closely

2:31

related Parkinsonian disorder,

2:33

namely LBD or Lewy Body Disease or dementia,

2:37

which includes dementia with Lewy bodies.

2:41

Dementia with Lewy bodies is also

2:43

seen in Parkinson's Disease,

2:45

but the dementia is a late component or a

2:48

later component of Parkinson's disease.

2:51

This is one of the more common forms of dementia.

2:54

It accounts for 15% of all cases at autopsy,

2:58

the most common being, ALZ or Alzheimer's disease,

3:02

but tied or maybe slightly more frequent is

3:06

frontalobar dementia.

3:07

So it goes ALZ, then DLB,

3:10

and frontal lobar dementia,

3:12

in the spectrum of dementia,

3:15

the risk of progression to dementia and

3:17

Parkinson's disease increases with age.

3:20

So if you get Parkinson's disease at age 70,

3:23

you're more like likely to have dementia

3:26

in the earlier spectrum of the disease.

3:28

Whereas if you get Parkinson's

3:30

disease when you're 30 or 40,

3:32

the dementia component doesn't appear until very,

3:35

very late.

3:36

The dementia component has been shown to affect

3:39

70% of all PD patients over an eight year

3:43

prospective longitudinal study,

3:45

and it's six times more frequent than

3:48

in healthy control subjects.

3:50

So it is related to the disorder,

3:51

not some overlap or additive disorder that causes

3:55

the dementia in PD or classic Parkinson's disease.

3:59

Now, DLB,

4:01

Lewy Body Dementia or LBD

4:04

and Parkinson's disease

4:05

are differentiated from other dementia subtypes

4:08

by the presence of Lewy body pathology.

4:12

Both groups have alphas and

4:14

nuclear fibrillary aggregates,

4:16

which form neuronal inclusion bodies that are

4:18

known as Lewy bodies and Lewy neurites.

4:22

So lewy bodies are not unique to Lewy Body Dementia.

4:26

Lewy bodies occur in PD as well.

4:29

And that's a potential exam or board question for

4:33

medical students and residents and fellows.

4:36

Let's move on.

4:37

This patient,

4:37

a Parkinsonian like syndrome,

4:40

Lewy Body Dementia,

4:42

rather than classic Parkinson's disease,

4:44

sadly confirmed at post.