Brain CT scans throughout the hospital stay. A) admission CT scan showing an unremarkable brain parenchyma with preserved grey-white matter demarcation. There was also small left frontal scalp hematoma (not shown). B) A follow-up CT showing decreasing attenuation of the white matter diffusely. C) CT done 3 weeks of admission following patient clinical deterioration revealing evidence of progressive diffuse hypoattenuation the cerebral white matter, basal ganglia and thalami bilaterally. There is left occipital gray-white matter hypodensity consistent with infarct, explained by trantentorial herniation trapping the left posterior cerebral artery against tentorium cerebelli.