(Left) T1-weighed axial MRI; (Right) T2-weighted axial MRI. Note the well demarcated lesion in the distribution of the superior division of the right middle cerebral artery, involving the right frontal lobe above the sylvian fissure. On the T1-weighted scan, note the stroke is dark, similar to CSF. In the chronic state, strokes result in encephalomalcia, with the destroyed area of brain undering necrosis leading to essentially a cystic space. Also note that the ventricle on the right is slightly larger than the contralateral side (i.e., hydrocephalus, ex vacuo). This is the picture of a remote superior division MCA stroke. In this case, this was the etiology of the patient's seizures. Indeed, in older individuals, remote stroke is the most common cause of new onset seizures.
Revised
04/23/06.
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School of Medicine.