Clinically mild encephalitis/encephalopathy with a reversible splenial lesion caused by methicillin-sensitive Staphylococcus aureus bacteremia with toxic shock syndrome: a case report.
BACKGROUND
Clinically mild encephalitis/encephalopathy with a reversible splenial lesion (MERS) is a mild encephalopathy caused by various pathological processes, but encephalopathy due to bacteria is rare.


METHODS
We report the case of a 45-year-old Japanese woman who on receiving chemotherapy for advanced breast cancer developed an altered mental status and dysarthria soon after fever from infection of a subcutaneous implantable port. Staphylococcus aureus was detected in her blood cultures. Magnetic resonance imaging (MRI) revealed an ovoid lesion in the central portion of the splenium of the corpus callosum (SCC). Although hypotension was not observed, we diagnosed probable toxic shock syndrome (TSS) based on fever (temperature: >38.9 °C), altered mental status, erythema, desquamation, thrombocytopenia, liver dysfunction, and creatine phosphokinase elevation. We administered antimicrobial therapy and her neurological symptoms improved gradually. The lesion in the SCC completely disappeared on MRI 7 days after disease onset.


CONCLUSIONS
We diagnosed this case as MERS caused by S. aureus bacteremia with TSS. This is the first report of such a case, and we suggest that when a TSS patient presents with neurological symptoms, the possibility of MERS should be considered.
Division of General Internal Medicine, Jichi Medical University Hospital, Shimotsuke, Japan.
Koki
K
Kosami
Division of General Internal Medicine, Jichi Medical University Hospital, Shimotsuke, Japan. smile.kenzaka@jichi.ac.jp.|Division of Community Medicine and Career Development, Kobe University Graduate School of Medicine, 2-1-5, Arata-cho, Hyogo-ku, Kobe, Hyogo, 652-0032, Japan. smile.kenzaka@jichi.ac.jp.
Tsuneaki
T
Kenzaka
Department of Breast Surgery, Jichi Medical University, Shimotsuke, Japan.
Yuka
Y
Sagara
Division of General Internal Medicine, Jichi Medical University Hospital, Shimotsuke, Japan.|Department of General Medicine, Toyooka Public Hospital, Toyooka, Japan.
Kensuke
K
Minami
Division of General Internal Medicine, Jichi Medical University Hospital, Shimotsuke, Japan.
Masami
M
Matsumura
D000900:Anti-Bacterial Agents / Q000627:therapeutic use; D000970:Antineoplastic Agents / Q000627:therapeutic use; D001927:Brain Diseases / Q000175:diagnosis*; D001943:Breast Neoplasms / Q000188:drug therapy; D003337:Corpus Callosum / Q000000981:diagnostic imaging; D004660:Encephalitis / Q000175:diagnosis*; D005260:Female; D005334:Fever / Q000209:etiology; D006801:Humans; D008279:Magnetic Resonance Imaging; D008875:Middle Aged; D012772:Shock, Septic / Q000150:complications / Q000175:diagnosis*; D013203:Staphylococcal Infections / Q000150:complications / Q000175:diagnosis* / Q000188:drug therapy; D013211:Staphylococcus aureus / Q000302:isolation & purification; D014057:Tomography, X-Ray Computed
D000900:Anti-Bacterial Agents; D000970:Antineoplastic Agents
Bacteremia; Clinically mild encephalitis/encephalopathy with a reversible splenial lesion; Staphylococcus aureus; Toxic shock syndrome