0:00

This was a patient who presented to the

0:02

emergency room for suspected infarction

0:06

involving the brainstem.

0:08

Here we have the axial T2-weighted scan,

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the axial FLAIR scan,

0:13

and I suppose we should have the diffusion

0:15

weighted scan if we're evaluating

0:17

a patient for infarction.

0:19

As we can see on the diffusion-weighted

0:22

imaging to the far right,

0:24

there is no evidence of high signal intensity

0:27

commensurate with an infarction,

0:29

and the distribution of the lesions on the MR scan

0:34

are atypical for an infarct.

0:39

What you see,

0:40

if we focus on the FLAIR scan,

0:43

is abnormal signal intensity in the dentate

0:45

nucleus of the cerebellum,

0:47

as well as the posterior brainstem,

0:50

extending to the white matter of the middle

0:53

cerebellar peduncles, bilaterally.

0:55

You see involvement of the periaqueductal gray matter

0:59

extending to the superior cerebellar

1:04

peduncle on the left side.

1:06

In addition,

1:07

there are areas of abnormal signal intensity

1:09

in the white matter in an arc-like fashion

1:12

in the subcortical white matter.

1:15

We also see bilateral involvement

1:17

of the red nuclei,

1:18

as well as the central brain

1:22

stem and the thalami.

1:26

Further peripherally,

1:28

we see white matter involvement

1:29

in the corona radiata on the left side,

1:33

and then crossing the corpus callosum,

1:36

superiorly.

1:38

There is subcortical involvement bilaterally

1:42

in the frontal lobes.

1:43

There aren't too many disorders that are going

1:47

to affect so much variable anatomy in the brain,

1:53

that is, cerebellar white matter,

1:56

brainstem, midbrain extensively,

2:00

going down into the white matter,

2:03

into the corpus callosum.

2:05

This is a very bizarre pattern.

2:07

It's a little bit too extensive and bilateral

2:10

and too many disjointed lesions for

2:13

it to represent an astrocytoma,

2:15

although that's a possibility.

2:17

One might also consider lymphoma,

2:19

and therefore we would look at the ADC maps

2:22

to see whether there is diffusion restriction,

2:26

which there was not.

2:29

What else could we be dealing with?

2:30

We could be dealing with encephalomyelitis

2:34

and encephalitis, and that is a possibility,

2:37

particularly in a patient who has

2:39

an abrupt onset of disease,

2:42

that you could be representing a potentially

2:45

viral or tick-related encephalitis.

2:50

When we look at the post-contrast scan,

2:53

it's somewhat helpful because there is

2:56

absence of contrast enhancement.

3:00

That would pretty much exclude

3:02

most high-grade neoplasms,

3:03

as well as in our differential

3:06

diagnosis of lymphoma.

3:09

When we think about a child that might have

3:12

white matter lesions,

3:13

deep gray matter lesions,

3:15

brainstem lesions,

3:16

and cerebellar lesions,

3:17

we have to raise the possibility of acute

3:20

disseminated encephalomyelitis,

3:23

which is indeed what this patient

3:25

finally had a final diagnosis.

3:29

What else would be in our

3:30

differential diagnosis?

3:32

Kind of hard to think of other lesions that

3:36

affect such a wide swath of the brain

3:39

besides an infectious encephalitis

3:42

or a demyelinating disorder such as ADEM.