A rare case of mild encephalitis/encephalopathy with reversible splenial lesion associated with Mycoplasma pneumoniae in an adult male

Abstract

Mild encephalitis/encephalopathy with reversible splenial lesion (MERS) is a clinically mild, radiologically reversible clinical condition. MERS associated with Mycoplasma pneumoniae is rare and the diagnosis can be challenging. In this case report, an 18-year-old male patient with a history of travel from Saudi Arabia is presented with high fever, cough, headache, joint pain, nausea and vomiting. He was referred to the emergency department with increased tendency to sleep and a preliminary diagnosis of encephalitis. On physical examination, he was afebrile, hypotensive and bradycardic. Macular rashes on the chest and nystagmus in the right eye were observed. Meningeal irritation findings and Babinski sign were negative. Polymerase chain reaction (PCR) of the patient’s nasopharyngeal swab specimen revealed Mycoplasma pneumoniae. Cerebrospinal fluid (CSF) analysis showed pleocytosis with polymorphonuclear leukocyte (PMN) dominance and elevated total protein. M. pneumoniae was undetected in CSF via PCR. Cranial magnetic resonance imaging revealed a well-defined, oval-shaped lesion at the midline level of splenium of the corpus callosum. The patient was administered with intravenous ceftriaxone, moxifloxacin and a single dose of hydroxycobalamin. On day 2 of treatment, symptoms improved significantly and the patient was successfully discharged on day 7 upon clinical recovery. This report highlights that molecular tests are invaluable for the detection of rare pathogens in MERS cases.

Keywords

• Mycoplasma pneumoniae
• MERS
• molecular detection
• corpus callosum
• neuroimaging

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