The MR images were obtained on an adult patient, showing asymmetric abnormal signal in both temporal lobes, extending to the insular cortex. The CT images are from a pediatric patient, showing extensive hemorrhagic necrotic changes throughout both cerebral hemispheres with sparing of the cerebellum.
Intraventricular hemorrhage is present as well.
The hemorrhagic process is centered in the temporal lobes. Signal abnormality involving both temporal lobes has a relatively limited differential diagnosis and is nearly pathognomonic for herpes encephalitis. Trauma with multifocal contusions and shear injury could be considered if there was appropriate history. Other less likely considerations include metastatic disease or multiple venous infarctions.