부산대학교 도서관

Mild Encephalopathy with a Reversible Splenial lesion (MERS) is a clinical-radiological syndrome characterised by an acute, transient encephalopathy with radiological evidence of a reversible lesion in the splenium of the corpus callosum (SCC). Since it was first described in 2004, MERS has been reported most frequently in children and young adults in East Asia. We report two cases of para/post-infectious MERS in the UK. Case 1, a 13-year-old African-Caribbean boy and Case 2, an 11-year-old Caucasian girl with ulcerative colitis controlled on mesalazine and mercaptopurine. Both cases presented with encephalopathy, ataxia, and pseudobulbar features. Case 1 had a febrile prodrome with headache. Case 2 had an afebrile prodrome with sore throat, vomiting and diarrhoea. Both received treatment with acyclovir and cefotaxime. The only abnormality on lumbar puncture was 10 white cells in the cerebrospinal fluid of case 1. Viral PCRs were negative. In both children, MRI revealed abnormal signal on T2/FLAIR and diffusion-weighted imaging in the SCC with no gadolinium enhancement, with Case 2 showing additional abnormal signal in the cerebellar hemispheres. Both received a course of intravenous methylprednisolone, 1 g OD, for 3 and 5 days respectively. Case 1 had evidence of a recent Mycoplasma pneumoniae infection (serum IgM antibody titre 1/640); he made a full recovery within two weeks with resolution of MRI changes. Case 2 had residual upper limb dyspraxia and mild cognitive problems 5 weeks after symptom onset; follow-up MRI at 3 months showed atrophy of the cerebellar hemispheres and resolution of the hyperintensity in the splenium of the corpus callosum. The two cases add to the number of cases of MERS reported outside of East Asia, and highlight MERS as a differential for para or post-infectious encephalopathy. Our case with an incomplete recovery also adds to the phenotype and suggests that if additional imaging changes are present, the prognosis may need to be more guarded.