Fatal H1N1-related acute necrotising encephalopathy in an adult

Cerebrospinal fluid (CSF) analysis was not attempted given the presence of tonsillar herniation. ANE is an uncommon parainfectious condition that is usually triggered by viral infections, most commonly influenza A, B and human herpesvirus 6.3 Although the pathogenesis of ANE is unclear, it is suggested that hypercytokinemia or ‘cytokine storm’ may play an important role.4 ANE secondary to influenza is a relatively common complication of the infection seen in children but such presentation in adulthood is extremely rare with only about eight cases documented in the literature. In a 2-year surveillance study conducted through the National British Surveillance Study, 25 cases (21 children and 4 adults) had neurological manifestations and only 7 cases (6 children and 1 adult) had acute encephalopathy syndromes.5 The mortality associated with ANE is as high as 30%.6 There have been no recommended therapies for ANE.