Fatal H1N1-Related Acute Necrotizing Encephalopathy in an Adult

Figure 1

(a) FLAIR MRI sequence demonstrates widespread abnormal signal in the subcortical white matter, internal capsule, putamen, globus pallidus, and thalamus bilaterally. (b) T1 post-gadolinium axial MRI sequence demonstrates diffuse leptomeningeal enhancement over the convexities bilaterally and foci of parenchymal enhancement within the cortex bilaterally. (c) Gradient echo (GRE/T2*) MRI sequence demonstrates hemorrhage in the deep cerebellar white matter bilaterally (mottled black signal, representing magnetic susceptibility). (d) T1 post-gadolinium coronal MRI sequence demonstrates basal leptomeningeal enhancement surrounding the brainstem. (e) Postmortem axial section through the brainstem and cerebellum demonstrates severe bilateral hemorrhage and necrosis of the cerebellar hemispheres. (f) Postmortem coronal section demonstrates widespread but patchy areas of hemorrhage and necrosis in the deep gray nuclei bilaterally and the cerebral hemispheres bilaterally.