Clinical and radiologic features of encephalopathy during 2011 e coli O111 outbreak in Japan

Objective: To elucidate the clinical and radiologic features and analyze factors associated with neurologic outcomes of encephalopathy secondary to Shiga toxin-producing Escherichia coli (STEC) O111. Methods: We reviewed medical records and neuroimaging in 22 patients with neurologic symptoms among 86 with STEC O111 infection. Results: Twenty-one (6 males and 15 females, 10 children and 11 adults) of the 22 patients were diagnosed with encephalopathy. All patients with encephalopathy also presented with hemolyticuremic syndrome. Five patients died, from day 1 to 6 months (days 1-5 in 4 patients), due to progressive encephalopathy with severe cerebral edema observed in neuroimaging (4 patients). Fifteen of the 16 surviving patients clinically recovered completely. Statistical analysis revealed differences between patients with poor (n = 6) and good (n = 15) outcomes in the interval from hemolytic-uremic syndrome presentation to encephalopathy, creatinine levels, and the methylprednisolone administration ratio. Conclusion: We note a high incidence of encephalopathy in the Toyama STEC O111 outbreak. All fatal cases resulted from progressive encephalopathy. Methylprednisolone pulse therapy represents a possible therapeutic choice. Classification of evidence: This study provides Class III evidence that methylprednisolone pulse therapy increases the probability of a good outcome for patients with encephalopathy associated with STEC O111.