It has been reported that systemic release of proinflammatory cytokines may be responsible for the coordination of acute inflammatory processes in some children with haemolytic-uremic syndrome (HUS). 1 We encountered the case of a Japanese girl with post-diarrhoeal HUS who subsequently fell into a convulsive state and prolonged unconsciousness caused by HUS encephalopathy. Because pre-existing pro-inflammatory hypercytokinaemia was probably involved in her clinical condition, anti-inflammatory treatment with methylprednisolone pulse therapy (MPT) and high-dose i.v. immunoglobulin (IVIG) was initiated. The treatment proved effective and the patient recovered with no sequelae.A 5 year old girl was taken to a regional hospital with a 3 day history of fever, diarrhoea and colicky abdominal pain.The stool culture and latex aggregation test for Vero toxin 2 were positive, indicating recent enterohaemorrhagic Escherichia coli infection. Because the child presented oliguria, haemodialysis was promptly initiated. The patient had mild disturbance of consciousness (Glasgow Coma Scale 4-4-6). Laboratory studies revealed typical HUS manifestations and markedly increased levels of plasma ferritin and serum soluble interleukin-2 receptor. Three days later, she developed generalized tonic seizures. Magnetic resonance imaging (MRI) performed on hospital day 12 showed areas of high intensity on fluid attenuated inversion recovery (FLAIR) images in the left putamen and the cerebellar vermis, which were compatible with the diagnosis of HUS encephalopathy (Fig. 1). Because residual pro-inflammatory hypercytokinaemia was strongly suspected, anti-pro-inflammatory cytokine therapy consisting of MPT (25 mg/kg daily for 3 consecutive days, two sessions) and IVIG (1 g/kg per day, twice) was initiated. 2 Following this therapy, her clinical condition significantly improved. Interestingly, we observed a dramatic and rapid improvement of her level of consciousness after IVIG. The follow-up MRI performed on hospital day 30 showed the areas of high signal intensity had completely disappeared. These favourable MRI changes suggested that her encephalopathy had mimicked posterior reversible encephalopathy syndrome 3 which could be A B Fig. 1 Magnetic resonance imaging performed on hospital day 12 showed areas of high intensity on FLAIR images in the left putamen (A) and the cerebellar vermis (B).Nephrology 15 (2010) 659-662