0:00

So, case number seven is a 73-year-old male

0:03

who had profound visual hallucinations.

0:06

Also delusions, gait difficulties,

0:09

a resting tremor, frequent falls,

0:12

and had some memory loss,

0:14

but the memory loss was minimal.

0:16

So the first MRI was in 2013.

0:19

This was an MRI of the brain without contrast.

0:22

This is the DWI here,

0:24

which does not show anything acute.

0:26

This is the GRE sequence,

0:28

where we do have a single small focus of

0:32

GRE susceptibility artifact right here.

0:35

We can't really make too much

0:37

of it on this initial study.

0:38

I'll show you on a later study what

0:40

this is going to turn out to be.

0:41

But on this initial study,

0:43

it just looks like a little punctate

0:44

focus of old hemosiderin staining.

0:47

If you look here on this non-contrast study,

0:50

the left IAC looks abnormal.

0:52

It looks like you can see here on

0:55

the right side, the nerve roots.

0:56

This is not a dedicated IAC study,

0:58

but you can see here,

0:59

it looks like there's almost like

1:01

a mass filling the left IAC.

1:03

So this is looking very suspicious

1:04

for a vestibular schwannoma.

1:06

I would have recommended that the patient come

1:08

back for a dedicated post-contrast IAC study.

1:13

Incidentally,

1:14

the patient also has a small left middle

1:16

cranial fossa arachnoid cyst.

1:18

These typically are of no

1:19

clinical significance.

1:20

The patient also had a partially empty sella,

1:23

which is always easier to see

1:24

in the sagittal plane.

1:27

And that's it for this initial study.

1:29

They then came back in 2014 for an

1:33

MRI of the brain with neuroquant,

1:35

and they also had an MRI IAC to shortly follow

1:39

that with post-contrast in 2014.

1:42

So let's take a look at the 2014 MRIs.

1:45

So this is the 2014 IAC study.

1:50

And you can see here on the

1:52

axial fiesta sequence,

1:54

there is indeed a mass here in the left

1:57

cerebellopontine angle cistern extending

2:00

into the left internal auditory canal.

2:02

So it projects through the porous acousticus.

2:04

It extends about two thirds of the way in the

2:06

left IAC but does not abut the fungus.

2:08

This is the T1 pre-contrast.

2:10

Here's T1 post-contrast.

2:12

You can see central necrosis within the mass.

2:15

And so this is a left-sided

2:17

vestibular schwannoma.

2:18

You note that there's no dural tail here that

2:20

would indicate a meningioma. And also,

2:22

typically,

2:23

meningiomas don't tend to extend

2:25

this far into the IAC.

2:27

Here's a look at it here in the coronal plane.

2:31

And then, other than this,

2:33

better characterization of

2:34

the vestibular schwannoma.

2:35

There's otherwise no interval change in the

2:38

appearance of the brain. So in 2014,

2:41

we also see that the patient has some cerebral

2:45

atrophy, mild to moderate in degree,

2:47

with a parietal and also an occipital

2:51

lobe predilection.

2:53

The patient then came back for an amyloid

2:57

study in 2017. So let's take a look at that.

2:59

That here is the brain PET amyloid study in

3:03

2017, and this is a weakly positive exam.

3:07

So when you look down at the lower,

3:09

you could say, oh,

3:10

I'm not entirely sure if there is

3:11

binding here in the cortex,

3:13

although I do see some here in the temporal

3:15

lobe. But if you look up higher,

3:17

it is definitely extending out to

3:19

the cortex in multiple regions.

3:21

So this is definitely a positive amyloid PET

3:24

study, albeit a weakly positive study.

3:27

In 2018,

3:28

the patient then came back for

3:30

an MRI of the brain and IACs.

3:32

So this is the 2018 study on top, the axial

3:36

and the coronal post-contrast.

3:38

And this again was the earlier study.

3:40

This was the 2014 Brain and IAC study.

3:43

And look how much smaller this left

3:45

sided vestibular schwannoma is.

3:48

Here's the coronal plane on the 18 study,

3:50

2018, and here's the prior study.

3:52

Here's in the axial plane on the 2018,

3:55

and here's the prior.

3:56

So this patient has clearly had some

3:59

stereotactic radiation therapy in the interim

4:01

since the prior exam. Then in 2019,

4:04

the patient had a CT PET study and we'll

4:09

review this on the summary slides in

4:12

PowerPoint because it's easier

4:13

to see in PowerPoint.

4:15

They then came back for an MRI of the brain

4:17

in 2021. So let's take a look at that.

4:20

This is the MRI in 2021.

4:23

The amount of cerebral atrophy in the

4:25

bilateral parietal lobes and bilateral occipital

4:28

lobes has progressed since this prior study,

4:30

which we see down here in the

4:31

lower right-hand corner.

4:33

So there has been progression

4:35

in atrophy over time.

4:37

That left-sided vestibular schwannoma that we see

4:40

here in 2021 is again significantly smaller

4:43

from that baseline study in 2014 due

4:47

to the stereotactic radiation.

4:49

The patient then went on to have an

4:51

FDG brain PET CT study in 2021.

4:55

This is the FDG brain PET CT from 2021 and

4:58

it showed statistically significant

5:00

hypometabolism in the bilateral occipital

5:03

lobes as well as within the bilateral parietal

5:06

lobes and within the left posterior

5:09

cingulate gyrus.

5:10

And this was confirmed on the

5:11

MIM neuroanalysis software.

5:13

There was no statistical significance

5:15

in the bilateral temporal lobes.

5:18

So case number seven again was a 73-year-old

5:21

with profound visual hallucinations,

5:22

delusions, gait difficulties, resting tremor,

5:25

frequent falls, and only minimal memory loss.

5:28

The initial MRIs were obtained in 2013 and

5:32

2014, and they show some cerebral atrophy with

5:37

a bilateral parietal and occipital predilection.

5:41

Quantitative volumetric imaging was performed

5:43

in 2014 and it did show some borderline, well,

5:49

statistically significant hippocampal

5:51

volume loss here. This,

5:52

as you can see here right at the border.

5:54

And there was also reduction in the occipital

5:59

cortices. It was down at the 9%.

6:01

And here the hippocampi were

6:03

statistically significant.

6:04

This is icobrain and this is neuroquant.

6:06

An amyloid PET study was then obtained

6:11

in 2017 and that was positive.

6:13

Here's the PET CT images.

6:15

Here's the PET Mr. Fusion.

6:17

Diffuse binding of the tracer

6:18

throughout the cortex.

6:21

This was the Tau PET study in 2019 seen.

6:25

It shows some tau deposition in the bilateral

6:27

occipital lobes, right greater than left,

6:31

as well as in the left parietal lobe and left

6:33

posterior cingulate gyrus. Relatively subtle,

6:36

but it is present.

6:38

This was the MRI in 2021,

6:41

which we saw progression in the amount

6:43

of parietal and occipital lobe atrophy.

6:46

This was also summary slides showing that we

6:49

had a left-sided vestibular schwannoma,

6:52

which improved after radiation. Here's 2014,

6:55

and then it had shrunk by 2018.

6:58

So these are both 2014.

7:00

This is 2018 axial plane and coronal plane.

7:04

And then I wanted to mention,

7:05

we had talked about that little focus of GRE

7:08

susceptibility artifact in the right frontal

7:10

lobe when the patient returned for that

7:13

follow-up MRI. The last one, in 2021,

7:17

was actually done on a three tesla magnet,

7:18

higher resolution magnet. And with that,

7:21

you can see.

7:22

It might be difficult to see for you,

7:23

but there's a punctate focus of T two

7:25

hyperintensity here and then some rim

7:27

hemosiderin staining. It's very small in size,

7:30

but if you magnify up, you'll be able to tell.

7:33

So this is probably actually a tiny little

7:35

cavernous angioma rather than just

7:37

a nonspecific hemosiderin focus.

7:39

And here was that incidental arachnoid

7:41

cyst in the middle cranial fossa,

7:42

which is usually of no significance.

7:44

This is the FDG PET in 2021,

7:47

where we had statistically significant

7:49

cortical hypometabolism in the bilateral

7:51

occipital lobes and bilateral parietal lobes,

7:54

as well as the left posterior cingulate gyrus.

7:57

This is again the FDG PET, but this is a PET.

8:00

Mr. Fusion.

8:01

This is fused to a T2. Here I

8:03

fuse it to the FLAIR.

8:04

Again,

8:05

the statistically significant hypometabolism

8:07

in the bilateral occipital,

8:08

bilateral parietal lobes.

8:09

Here's the bilateral parietal lobes again.

8:12

This is the surface map of that PET.

8:14

Again,

8:14

the hypometabolism in the bilateral parietal

8:16

and bilateral occipital lobes.

8:18

And so this is a patient with

8:20

dementia with Lewy bodies.

8:22

And what we see is abnormal deposits of alpha

8:25

synuclein. These are the Lewy

8:27

bodies here on histology.

8:29

This is what they look like in the lab.

8:32

And dementia with Lewy bodies is less

8:34

common than Alzheimer's disease.

8:36

So there's 1 million patients living with

8:38

dementia with Lewy bodies in the US right now,

8:41

as opposed to 6 million living

8:43

with Alzheimer's disease.

8:44

The survival rate is typically five to eight

8:46

years after diagnosis. Visual hallucinations.

8:49

If ever you see that in the history,

8:51

that's a big red flag for DLB because it's

8:53

present as an initial symptom in 80% of cases.

8:58

And you can have beta-amyloid plaque

9:00

deposition and neurofibrillary tangles with

9:03

DLB. Not as much as with Alzheimer's.

9:05

But you see,

9:06

it was enough to actually turn the amyloid

9:08

PET positive in this particular case.