Mild Encephalopathy with a Reversible Splenial lesion during Rotavirus infection: a diagnosis… at a glance!

Key words: Rotavirus, Encephalopathy, Central Nervous System Infection, Corpus Callosum, MERS

MERS (Mild Encephalopathy with a Reversible Splenial lesion) is a rare clinico-radiological syndrome characterised by mild encephalopathy and a transient lesion of the splenium of the corpus callosum. Infections, including rotavirus, are the main trigger. The paper reports two cases of paediatric patients who were hospitalised over a period of a few months, both with gastrointestinal symptoms associated with a reduced level of consciousness. In both cases, laboratory findings revealed hyponatremia, and brain MRI showed an isolated lesion of the splenium of the corpus callosum. Rotavirus genome was detected in a stool specimen in both patients. The clinical course was rapidly favourable, with complete neurological recovery and resolution of the lesions on the neuroradiological follow-up. MERS should be considered in the differential diagnosis of acute encephalopathies occurring in the setting of gastroenteritis. The clinical presentation is generally characterised by transient neurological symptoms and typical neuroradiological findings. The pathogenesis is not fully understood, but proposed mechanisms include cytotoxic oedema associated with hyponatremia and cytokine-mediated inflammatory processes. The prognosis is generally favourable. In the presence of a typical presentation and an uncomplicated course, a supportive management approach may be appropriate.