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This is an MRI scan of the brain in a

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five-year-old child with seizures.

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And we start by looking at the T2-weighted image

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and we can see a slightly atypical

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appearance of the ventricular system.

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The right lateral ventricle is a little bit

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larger than the left lateral ventricle.

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But the bigger thing we see is an

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asymmetry in the sulcation,

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the normal sulcation pattern we can see here in

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the frontal poles, where we can see the

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normal undulation of these gyri.

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We have the cortical gray matter at the periphery.

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And this darker area subjacent to that

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is the white matter.

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This is a normal sulcation pattern.

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If we go over here to the right middle frontal

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gyrus, for instance,

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we can see very shallow,

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narrowly spaced gyri.

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We see a similar appearance

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over here on the left.

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And then,

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if I go to the sagittal T1-weighted image,

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it becomes even more evident that compared to

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the normal sulcation pattern here in the

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temporal lobe, we have very shallow,

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narrowly spaced gyri.

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And this is what's called polymicrogyria.

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Poly, mini, micro, small gyri.

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We have polymicrogyria here in

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the inferior frontal gyrus.

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This is along the sylvian fissure.

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So, this falls under the heading

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of perisylvian polymicrogyria.

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But that term is not uniquely descriptive of a

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given disease pattern

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because if we see in this individual,

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we can see some abnormality in the superior

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aspect of the superior temporal gyrus.

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And if we go superiorly,

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I'm going to go to an axial thin

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section T1-weighted image.

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We have polymicrogyria in the bilateral

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middle frontal gyri.

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Here's the left middle frontal gyrus,

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the right middle frontal gyrus

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extending posteriorly past the central sulcus

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involving the right inferior parietal lobule

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right here,

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and portions of the right parietal lobe.

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So, this is a case of a bilateral relatively

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symmetric polymicrogyria,

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involving the perisylvian white matter,

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as well as additional portions of both parietal

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and frontal lobes.