Neuroimaging Findings in Parechovirus Encephalitis: A Case Series of Pediatric Patients

Background: Human parechovirus infection can cause parechovirus encephalitis in neonates and should be considered as a differential diagnosis in the emergency department. Neuroimaging features of parechovirus encephalitis have been described in neonates and young infants, but there is a paucity of literature regarding magnetic resonance imaging brain injury patterns in older children. We aim to present three cases of parechovirus encephalitis, showing distinctive magnetic resonance imaging brain patterns of injury in two newborns and, for the first time, in an adolescent.

Methods: We conducted a retrospective review of parechovirus encephalitis cases in our pediatric hospital. Clinical information and neuroimaging findings are described in detail.

Results: Classical neuroimaging findings in neonatal parechovirus encephalitis include restricted diffusion of the subcortical and periventricular white matter with frontoparietal predominance, in association with corpus callosum signal abnormality and bilateral swollen thalami. Parechovirus encephalitis in the adolescent appeared with an additional pattern of white matter signal abnormality in the corona radiata in continuity with the corticospinal tracts.

Conclusions: Parechovirus encephalitis should be considered in the differential diagnosis when magnetic resonance imagingdemonstrates white matter injury with typical (sunburst type) distribution in the deep and periventricular white matter in both neonates and adolescents, especially in those with comorbidities or therapy that lead to an immunosuppressive status.