A 4-year-old girl with clinically mild encephalopathy with a reversible splenial lesion associated with rotavirus infection.

Rotavirus is a common cause of severe gastroenteritis in children. It is known that rotavirus gastroenteritis may be accompanied by neurological manifestations, including encephalitis/encephalopathy and seizures. We report a case of a 4-year-old girl with clinically mild encephalopathy with a reversible splenial lesion associated with rotavirus infection. She was admitted to our hospital because of reduced level of consciousness, seizures, diarrhea, and vomiting. Fecal rotavirus antigen testing was positive. Cell counts in the cerebrospinal fluid (CSF) were normal. She had a normal serum sodium level on admission. Brain computed tomography showed no cerebral edema. However, electroencephalography showed generalized high-voltage slow waves, and diffusion-weighted magnetic resonance imaging demonstrated a transient abnormality in the splenium of the corpus callosum. We diagnosed clinically mild encephalopathy with a reversible splenial lesion associated with rotavirus infection. She recovered well and exhibited no neurological sequelae. Rotavirus RNA and antigen were not detected in the CSF, suggesting that the reversible splenial change was caused by indirect effects on the central nervous system subsequent to viral infection. Her normal serum sodium level indicates that this change can occur without hyponatremia.