Acute Necrotizing Encephalopathy in an Infant: Observations by CT, Contrast-Enhanced MRI and Diffusion MRI. A Case Report.

Acute necrotizing encephalopathy is characterized by bilateral necrotic, hemorrhagic lesions which occur symmetrically in the thalami, dorsal brainstem and dentate nuclei. Development of an extensive breakdown of the blood-brain barrier in the prominent lesions of acute necrotizing encephalopathy was demonstrated in a seven-month-old boy with the disorder, within 14 h after hospitalization by an initially negative post-contrast CT scan, and subsequently positive post-contrast T1-weighted MRI. Diffusion MRI demonstrated concomitant cytotoxic and vasogenic edema in the lesions. By the fortieth day, the lesions apparently regressed with remaining hemorrhagic material in the thalami.