Fornix injury in a patient with rotavirus encephalopathy: diffusion tensor tractography study

Abstract

Rotavirus encephalopathy (RE) is a benign afebrile seizure associated with acute gastroenteritis caused by rotavirus infection. We investigated the diffusion tensor tractography (DTT) findings of a patient with RE. The patient was a 30-month-old female that had experienced a brief, generalized convulsive seizure. On the day of admission, the patient had vomiting and experienced watery diarrhea. Her stool was positive for rotavirus antigen. At onset, the patient displayed a drowsy and delirious mental status; later, a splenial lesion of the corpus callosum was found on MRI. One week later, the patient's condition improved and the splenial lesion had disappeared by conventional MRI. Initial DTI showed decreased fractional anisotropy (FA) values of fornix, as well as of the corpus callosum. A follow-up DTT showed a restored interrupted right fonical crus and increased FA values of corpus callosum and fornix. These results highlight the implications of the probability of not only a corpus callosum injury, but a fornix injury as well, in this patient with RE.

Keywords: Diffusion tensor tractography; Fornix; Rotavirus encephalopathy.

Fig. 1

Results of conventional T2-weighted MRI and DTT. (A) T2-weighted images showed an encephalomalatic lesion (arrow) in the splenial lesion of the corpus callosum that disappeared in one week later follow-up MRI. (B) DTT at onset for the corpus callosum and cingulum showed no definite abnormal finding, although a splenal lesion was apparent on conventional MRI. However, the integrity of right fornical crus (arrow) was interrupted. A second DTT taken 1 week later from onset, integrity of the fornix was restored and well preserved. DTT of corpus callosum and cingulum findings were normal at follow up DTT. DTT: Diffusion tensor tractography.