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So, let's first talk about seizures.

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The imaging findings are gyriform restricted

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diffusion in a nonvascular distribution,

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occasionally due to the breakdown

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of the blood-brain barrier,

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can have cortical and pial enhancement.

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Frequently on MRA and CTA,

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you have increased vascularity and the

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most common location is hippocampus.

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But you can also see it in other locations.

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Etiology is cytotoxic edema / failure of

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sodium / potassium ATPase pumps.

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Some people have thought it may be partly

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due to spreading depression.

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The changes you're going to see

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are sometimes reversible.

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It depends on how long the seizures last and

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how quickly the patient recovers.

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So here,

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images of a 44-year-old who was

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found unresponsive and found to

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be in status epilepticus.

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He has diffuse restricted diffusion throughout

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the right hemisphere, which would be very

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unusual for stroke. As you can see,

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this involves the MCA, PCA,

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and ACA distributions.

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Furthermore,

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when we look at the vessels,

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the common internal and external

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carotid arteries look normal.

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The whole right MCA and ACA look normal.

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So, it'd be unlikely for this to be a large,

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acute stroke with all the vessels

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appearing normal.

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So, this is a patient who had extensive

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restricted diffusion throughout

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the right cerebral hemisphere due to seizures.

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These are images of a four-year-old,

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female, who had B-cell chronic lymphocytic leukemia,

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and had prolonged seizures.

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We have diffusion-weighted images and ADC maps,

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and as we go up through these,

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you can see that there's restricted diffusion

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in the posterior right temporal lobe and the

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occipital lobe and the mesial temporal

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and occipital regions.

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And it extends up into the parietal cortex.

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And you can see this only involves cortex.

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It doesn't involve subcortical white matter.

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And again,

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there's restricted diffusion on the ADC maps.

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Also note that there's involvement of the

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thalamus, which also has restricted diffusion,

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and it continues up along

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the right parietal lobe.

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So, this is a classic appearance for seizures,

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restricted diffusion, cortex only.

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It's a non-arterial distribution.

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Remember, this would be MCA,

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and this would be PCA,

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and then involvement of the thalamus.

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Because the thalamus is a relay station

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between the cortex and the brainstem.

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So, this is classic seizures.

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And I'm going to just show you...

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There was also a T2 weighted image,

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and this was a fast T2.

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You can maybe see

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a little T2 hyperintensity in the cortex.

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A little bit hard to see there.

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Can't really see the thalamic lesion.

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There was no associated hemorrhage.

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And we also got an MRA because,

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you know,

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she had some visual changes.

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People were worried about stroke.

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And on the MRA,

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you can see that, basically, the right-middle

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cerebral artery, intercerebral arteries are all normal.

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So, it would be unusual to have a big stroke

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and have completely normal arteries.

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There's a vein here that wasn't

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adequately suppressed.

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But basically, the whole MRA looked normal.

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You could also look...

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think about venous sinus thrombosis.

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It would be unusual to just have cortex only,

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but it can cause restricted diffusion,

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non-arterial distributions.

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But we also got an MR venogram,

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that was normal as well.

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So, you can see normal superior sagittal sinus

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and transverse sinuses bilaterally.

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So, this is a great example of seizures.