CT - Herniation, diffuse cerebral edema: This 15-year-old woman was admitted with acute demyelinating encephalomyelitis. Over the course of 48 hours she became progressively obtunded and eventually lapsed into coma. Neurological examination reveled mid-sized minimally reactive pupils, decorticate posturing and bilateral Babinski signs. This CT scan shows diffuse cerebral edema with effacement of the sulci, ventricles and basal cisterns.