In 2009 a novel swine-origin Influenza A H1N1 virus was identified in Mexico and 
Southern California. Since it was first recognized, neurological complications 
including acute necrotizing encephalopathy (ANE) have been globally documented 
in association with this viral infection. ANE is mostly known to occur in the 
paediatric population. We describe a fatal case of ANE in a previously healthy 
40-year-old man infected with influenza A H1N1 virus presenting with severe 
neurologic decline. Computed tomography (CT) scan and magnetic resonance imaging 
(MRI) findings were consistent with ANE. CT and MR findings typically documented 
in paediatric cases of ANE - including bilateral thalamic necrosis with 
petechial hemorrhage - have been seldom described in adulthood.