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This is an MRI of the brain in a 6-year-old child

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who has vision abnormalities,

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developmental delay, and also seizure.

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The first thing we see is absence

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of the septum pellucidum.

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And if we look at this sagittal image,

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we see the optic chiasm is smaller

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than typically expected.

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I'm going to zoom in,

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and you can see the optic

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chiasm here on the sagittal T2-weighted image.

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Here's the pituitary pendulum,

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the pituitary gland, mammillary body,

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floor of the third ventricle.

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So in addition to a smaller-than-expected

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appearance of the optic chiasm,

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so smaller than expected appearance

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of the optic nerves,

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as well as absence of the septum pellucidum

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are the features of septo-optic dysplasia.

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Now, there's some variations on

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septo-optic dysplasia.

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This patient has more than

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just those key findings.

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They also have this abnormality in the contour

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of the lateral margin of the right lateral ventricle,

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which goes out to the periphery.

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Now, if we look at this on a coronal image,

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we can see this cleft between the lateral ventricle,

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all the way out to the periphery,

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is lined by gray matter.

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This is lined by gray matter also on this side,

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that is what's called a schizencephalic cleft.

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This is an open-lipped schizencephalic cleft

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in the setting of septo-optic dysplasia.

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Additionally, the margins of this,

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it's not normal gray matter.

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It's actually polymicrogyria

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within this gray matter.

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So this individual has polymicrogyria,

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lining an open-lip schizencephalic cleft in the setting

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of septo-optic dysplasia.