A Case of COVID-Related MERS (Clinically Mild Encephalitis/Encephalopathy with a Reversible Splenial Lesion) with a Typical Imaging Course and Hyponatremia in Adults—A Case Report and Literature Review
Mieko Tokano,
Norihito Tarumoto,
Iichiro Osawa,
Jun Sakai,
Mariko Okada,
Kazuhide Seo,
Yoshihiko Nakazato,
Toshimasa Yamamoto,
Takuya Maeda,
Shigefumi Maesaki
Affiliations
Mieko Tokano
Department of Infectious Disease and Infection Control, Saitama Medical University, 38 Morohongo, Saitama 350-0495, Japan
Norihito Tarumoto
Department of Infectious Disease and Infection Control, Saitama Medical University, 38 Morohongo, Saitama 350-0495, Japan
Iichiro Osawa
Department of Radiology, Faculty of Medicine, Saitama Medical University, 38 Morohongo, Saitama 350-0495, Japan
Jun Sakai
Department of Infectious Disease and Infection Control, Saitama Medical University, 38 Morohongo, Saitama 350-0495, Japan
Mariko Okada
Department of Neurology, Faculty of Medicine, Saitama Medical University, 38 Morohongo, Saitama 350-0495, Japan
Kazuhide Seo
Department of Neurology, Faculty of Medicine, Saitama Medical University, 38 Morohongo, Saitama 350-0495, Japan
Yoshihiko Nakazato
Department of Neurology, Faculty of Medicine, Saitama Medical University, 38 Morohongo, Saitama 350-0495, Japan
Toshimasa Yamamoto
Department of Neurology, Faculty of Medicine, Saitama Medical University, 38 Morohongo, Saitama 350-0495, Japan
Takuya Maeda
Department of Clinical Laboratory, Faculty of Medicine, Saitama Medical University, 38 Morohongo, Saitama 350-0495, Japan
Shigefumi Maesaki
Department of Infectious Disease and Infection Control, Saitama Medical University, 38 Morohongo, Saitama 350-0495, Japan
Clinically mild encephalitis/encephalopathy with reversible splenial lesions (MERS) is a mild form of encephalitis/encephalopathy that appears in association with various conditions, including infection. COVID-19 is also known to cause MERS. MERS more commonly occurs in children, and adult cases are relatively rare. Typical head MRI findings include a round lesion in the mid-layer of the corpus callosum with a high signal intensity on diffusion-weighted images. Most improve within a week. Although the exact mechanism by which the cerebral corpus callosum is affected is still unknown, several hypotheses have been proposed, including the involvement of electrolyte abnormalities (e.g., hyponatremia) and inflammatory cytokines (e.g., IL-6). In this report, we describe the first case of COVID-associated MERS with a typical imaging course and hyponatremia, with a review of the relevant literature. When psychiatric symptoms and the disturbance of consciousness appear in COVID patients, MERS should be considered in addition to delirium due to fever and hypoxia.
