Background: Acute necrotizing encephalopathy (ANE) is a rare disease characterized by multiple, symmetrical brain lesions, affecting thalami, brainstem tegmentum, and cerebellar medulla; more inconstantly, other structures are involved, i.e., internal capsules, posterolateral putamen, and deep periventricular white matter.
Features: The clinical picture consists of rapidly deteriorating acute monophasic encephalopathy preceded by prodromal febrile illness; the symptoms include hyperpyrexia, convulsions, recurrent vomiting, and coma within 24 h.
Prognosis: The outcome is usually poor and approximately 70% of the patients die within a few days from the onset of fever. There is no specific therapy for ANE but, in some patients, the clinical status improved with steroid treatment.