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We're still dealing with the intraconal lesions

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and talking about optic neuritis.

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In this case,

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we have a patient who presented with transverse myelitis.

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However, the patient also had visual disturbance.

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We're going to just look at the post-gadolinium fat

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suppressed T1-weighted scan of the brain.

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And as we scroll through the images,

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we note that both optic nerves are showing contrast enhancement.

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On this T1-weighted post-gado fat-sat scan,

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we are seeing the optic nerve showing contrast enhancement.

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Remember that this should be dark in signal intensity

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on a post-gad fat-sat scan through the orbits.

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So, we have bilateral optic nerves that are not enlarged,

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and yet are showing contrast enhancement.

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We combine that with the findings on the spinal imaging.

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On the spinal imaging, we have a white matter lesion

1:01

in the spinal cord, which is seen at the cervicothoracic junction

1:06

on this STIR image, with cord expansion.

1:10

This suggests that the lesion is likely acute in etiology.

1:14

As we look on the post-gad fat-sat scan of the spine,

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we note that the lesion is showing contrast enhancement.

1:23

Again, showing that it is an active demyelinating process.

1:27

This combination of a relatively long segment lesion,

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in association with bilateral optic neuritis, is typical of

1:39

the NMO spectrum disorder.

1:42

As I stated previously, they need not be at the same...

1:46

occur at the same time.

1:47

And in fact, given the small size of the abnormalities on the orbits,

1:53

this may be residual from previous optic neuritis.

1:57

However, the presence of bilateral optic neuritis

2:01

is much more common in NMO than in multiple

2:05

sclerosis, where it's usually a unilateral process.

2:09

The same is true for our infectious and inflammatory

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etiologies of optic neuritis,

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which include viral infections, as well as pseudotumor,

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or idiopathic orbital inflammatory disease,

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which are generally unilateral processes.

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So, the hints to make the diagnosis of NMO in this case

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are the bilateral optic neuritis, as well as the longitudinally

2:34

extensive transverse myelitis lesion in this patient.

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And we suggest that it's an acute process because of the

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presence of enlargement of the spinal cord,

2:44

as well as enhancement of the spinal cord.