Supplementary Material for: Multiple cerebral infarctions and clinically mild encephalitis/encephalopathy with a reversible splenial lesion associated with streptococcal toxic shock syndrome: A case report

Introduction: Streptococcal toxic shock syndrome (STSS) is a rapidly progressing, fatal disease. Sepsis can be complicated by multiple cerebral infarctions, clinically mild encephalitis/encephalopathy with a reversible splenial lesion (MERS), and sepsis-related encephalopathy, resulting in a poor prognosis. To our knowledge, there have been no reported cases of sepsis complicated by both multiple cerebral infarctions and MERS. We report a case based on a literature review. Case presentation: The patient was a 49-year-old man who experienced fever and a sore throat for two weeks prior to his visit. He was diagnosed with tonsillitis. Two days prior to his visit, he was confused and was transported to his previous hospital, where he was diagnosed with sepsis and treated conservatively. Although his confusion had improved the day before coming to the hospital, head MRI revealed multiple cerebral infarctions, and he was transferred to our hospital for intensive care. At the time of transfer, high signal intensity observed in the splenium of the corpus callosum on MRI was thought to be MERS. Blood tests revealed septic coagulopathy. He received intensive care and was discharged home on day 32. Head MRI performed during outpatient follow-up on the 15th day after discharge, we made a definitive diagnosis of MERS. Conclusion: We encountered a very rare case of STSS complicated by multiple cerebral infarctions and MERS, which had a favorable prognosis. The associations among sepsis, multiple cerebral infarctions, and MERS remain poorly understood and further investigation is warranted.