Female 12 years old with a history of neuroblastoma status post autologous stem cell transplant. She also has venoocclusive disease with involvement of the portal vein, as well as thrombus seen in the splenic vein on recent ultrasound, on anticoagulation. Now with acute mental status, evaluate for PRES. There is no evidence of acute infarct. There are multiple areas of abnormal increased T2/FLAIR signal in the cortex and subcortical white matter, in the bilateral parietal and occipital lobes with additional small areas in the frontal lobes, the parasagittal anterior parietal areas near the vertex (greater on the left), right posterior temporal lobe and smaller foci in bilateral cerebellar hemispheres (greater on the right). The brainstem and basal ganglia are spared. There is associated mild sulcal effacement and patchy gyriform enhancement, more conspicuous on the delayed post-contrast images. There is no intraparenchymal hemorrhage at this time.The ventricles and basal cisterns are normal in size and configuration with the left temporal horn of the lateral ventricle slightly smaller than the right as seen on CT, likely a normal variant. There is no midline shift or herniation. There is no extraaxial abnormality or osseous mass. The major cerebral flow voids are intact. The orbits, skull, paranasal sinuses, and scalp soft tissues are grossly unremarkable.
Multiple areas of bilateral supratentorial and cerebellar cortical/subcortical FLAIR abnormality with mild sulcal effacement and without diffusion restriction or susceptibility are favored to represent PRES, with mild associated patchy enhancement. Differential diagnosis would also include encephalitis, although felt to be much less likely, given lack of basal ganglia and brainstem involvement.