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This is an MRI of the brain

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in an approximately nine-year-old child

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with tuberous sclerosis complex.

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You can see multifocal areas of cortical

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dysplasia in both cerebral hemispheres.

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These cortical dysplasia,

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these areas of cortical dysplasia are

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also known as cortical tubers.

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So, multifocal areas of dysplasia throughout

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both cerebral hemispheres,

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we also see this area here in the

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overlying the right cerebral hemisphere.

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You can see this is an Arachnoid cyst.

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That's a normal variant,

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little to no clinical implications in most

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cases and is unrelated to tuberous

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sclerosis complex.

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This is just an Arachnoid cyst in a

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patient who happens to have

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tuberous sclerosis complex.

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Now,

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we see this area of T2 hyperintense

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signal here along the lateral margin

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of the body of the right

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lateral ventricle.

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And that is a calcified

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subependymal nodule.

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So if we look at this on post

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contrast enhancement,

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the calcified subependal nodule

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doesn't enhance

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but just anterior to it where we barely

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see on T2-weighted imaging is this enhancing

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lesion by zoom in to measure its

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approximately nine millimeters

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in cranial caudal dimension,

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approximate eight millimeters in AP

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dimension in approximately five millimeters

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in transverse dimension

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and looking closely,

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it's probably not immediately at threat

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of obstructing the foramen of Monroe,

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but something to keep an eye on,

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especially since there's subtle asymmetric

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enlargement of the right lateral ventricle.

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This patient received a follow-up study

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and it looked fairly similar.

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A year later,

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they received another follow-up study

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and it looked fairly similar.

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Another year later,

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they received a follow-up study

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and this had grown.

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This has grown significantly, how

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big it the ground? Well,

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at least 18 millimeters by 13 millimeters

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by approximately 14 millimeters.

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So this had grown significantly in size,

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noticed it almost doubled

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in each linear dimension.

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So way more than doubled in terms

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of volume. Fortunately,

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we haven't yet seen a significant change

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in the size of the ventricular system.

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But the patient is definitely at risk for

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developing obstructive hydrocephalus.

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Notice that the lesion is sort of no

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longer spherical because we see almost a

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linear boundary where it pushes on the

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septum pellucid and along the inferior

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margin of the corpus callosum.

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So it is growing to conform to its uh

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surroundings. What are the options?

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Historically,

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one of the most common treatments

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for this would be surgery,

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surgery can be performed to resect it.

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Other options. Well,

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you could place a shunt.

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If you place a shunt on the

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right lateral ventricle,

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you might be able to drain the body in

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atrium and temporal and occipital horns,

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the right lateral ventricle,

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it will not stop structure of the frontal

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horn, right lateral ventricle,

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they could fenestrate the septum pellucid.

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It also may not fully address it.

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It also fenestration of the septum

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pellucid while it would allow CSF to go to

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the left lateral ventricle and through the

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left foramen of Monroe that would not help

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things if either this lesion became so

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large that it obstructed both foramen of

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Monroe or if there was a left-sided lesion

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that obstructed the left foramen

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of Monroe. So what are,

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what are the non-surgical options

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in this patient? Well,

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we now know that the tuber

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sclerosis complex,

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the manifestations of tuber sclerosis

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complex are related to an abnormality

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in the MTOR pathway.

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MTOR, or means mammalian target of

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Rapamycin inhibitors of the MTOR pathway

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have been shown to result in involution of

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subependymal giant astrocytoma like

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this one here, six months later,

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this lesion had decreased in size from

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17 or 18 millimeters down to 11

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millimeters. That's without surgery.

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Just the mTOR inhibitor resulted

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in involution of this lesion.

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So this is a patient with tuber sclerosis

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complex with multiple subependymal

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nodules with a dominant lesion on the

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lateral margin of the body of the right

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lateral ventricle representing a sub

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ependymal giant cell astrocytoma or SEGA.

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And that SEGA responded to

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mTOR inhibitor therapy.