Gastroenteritis associated encephalopathy with reversible splenial lesion: three cases

Aims: Encephalopathy with or without seizures is a complication of gastroenteritis seen mainly in rotavirus infection. In some rare cases of rotavirus or adenovirus infection associated encephalopathy a reversible splenial lesion is described. This combination is called MERS (mild encephalitis/encephalopathy with reversible splenial lesion) and has a favourable outcome.

Methods: Case reports.

Results: We report three children between three and six years with clinical signs of gastroenteritis, ataxia, dysarthria and encephalopathic symptoms like disturbed consciousness, lethargy and confusion. Two children had a single afebrile seizure, one child suffered from two febrile seizures. Additionally one child showed acute transient monoparesis. None of them had hypoglycemia or hypernatremia and none of them were treated with antiepileptic drugs. In all patients MRI exclusively revealed a circumscribed lesion in the splenium of corpus callosum with restricted diffusion and increased T2 signal intensity. CSF investigations resulted in mild pleocytosis in one child and gave normal results in the others. Rotavirus was detected in the stool of two cases, whereas the stool of the third patient contained norovirus. Virus PCR in CSF remained negative in all cases. Clinical symptoms and MRI changes disappeared completely within a few days to weeks.

Conclusion: Reversible splenial lesions occur in mild encephalitis/encephalopathy associated with viral gastroenteritis and other infections like influenza (MERS). They are also found in patients with epilepsy or metabolic diseases. Although diffusion restriction indicates cytotoxic edema there is no hypothesis concerning the lesion's pathogenesis or distribution. Recognizing this rare MRI change helps to avoid unnecessary diagnostic and therapeutic procedures in children with gastroenteritis associated encephalopathy. Especially the benign nature of the lesion is assuring for the team treating the patients as well as the caregivers. To the best of our knowledge this is the first reported case of a norovirus associated encephalopathy with reversible spenial lesion.

Gastroenteritis associated encephalopathy - reversible splenial lesion