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This is an MRI of the brain.

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in a four-year-old child.

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with neurofibromatosis type 1,

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performed for routine surveillance.

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If we look at some of the areas where

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we commonly see myelin vacuolization,

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the globus pallidus, the thalami,

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we're not seeing anything very obvious.

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We look at the brainstem and the cerebellum,

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we're not seeing anything very obvious.

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At a young age, you may not see a lot.

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This was performed several years later.

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We can see this area of myelin vacuolization,

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that's T2 hyperintense,

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perhaps minimally expansile.

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In the region of the right globus palladis.

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We can see some smaller areas.

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In the left globus pallidus.

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We can see some heterogeneous

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signal in the midbrain,

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can see an abnormality in the left ventral pons

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and in the left cerebellar hemisphere

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at the junction of the dentate nucleus and

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the deep cerebellar white matter.

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So, this shows that myelin vacuolization can

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occur and develop as the child ages.

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Now,

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one additional thing to be aware of on patients

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with neurofibromatosis type 1,

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this is a coronal T2 fat-suppressed image

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through the posterior aspect of the orbits.

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And you can see there's an asymmetry in the

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posterior orbital segment of the optic nerves.

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The left optic nerve is slightly more

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hypertensed than the right.

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If we look on this post-contrast image,

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we can see some subtle increased signal in the

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posterior orbital segment of the left optic nerve.

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Now, both of these on their own are fairly subtle,

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but they corroborate with one another.

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And we know that patients

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with neurofibromatosis type 1

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have a propensity for developing

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optic pathway gliomas.

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So, in the setting of neurofibromatosis type 1,

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this is suspicious for a possible

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subtle optic pathway glioma.

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Fortunately, over the course of years,

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this appearance did not change.

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It did persist,

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so no additional treatment is performed.

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It is important to recognize this and describe it,

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but recognize also they're not going

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to immediately institute treatment.

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An optic pathway glioma cannot be resected

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without sacrificing vision.

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It cannot be easily treated unless you use,

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for instance, radiation therapy.

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But that can also impair vision.

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So what do they do?

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They watch it closely with imaging surveillance.

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They can also use detailed ophthalmology exams,

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including things such as visual

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field examinations,

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looking for color desaturation

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and look for signs of vision changes.

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In the absence of signs of vision changes,

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you do not treat every single imaging lesion in

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a patient with neurofibromatosis type 1,

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but you need to be aware of it.

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You need to identify it.

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That way,

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the clinical team and the patient are aware

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of what is there and that they can follow it.