Multiple cavitations in posterior reversible leukoencephalopathy syndrome associated with hemolytic-uremic syndrome.

We describe a 4-year-old boy with posterior reversible leukoencephalopathy syndrome associated with hemolytic-uremic syndrome. He exhibited bloody stool by Escherichia coli O157: H7 infection with acute renal failure. He subsequently presented high blood pressure, followed by visual disturbance and loss of consciousness. Brain MRI revealed bilateral occipital high intensities by T2-weighted images and high value by apparent diffusion coefficient map, thus we made a diagnosis of posterior reversible leukoencephaly syndrome associated with hemolytic-uremic syndrome. In spite of immediate blood pressure control, occipital lesions developed day by day, resulting in multiple subcortical cavitations. Although posterior reversible leukoencephalopathy syndrome is originally characterized by reversible vasogenic edema, this case rarely resulted in irreversible changes with cystic formation. We concluded that precipitating factors, i.e., clotting abnormalities, Shiga toxin, vasospasms and endothelial dysfunction might have synergistically induced irreversible brain infarcts, and caused unusual cavitations.