Human parechovirus causes encephalitis with white matter injury in neonates

OBJECTIVE: To assess the role of human parechoviruses (HPeVs) as a cause of neonatal cerebral infection and to report neuroimaging findings of newborn infants with encephalitis caused by HPeVs. METHODS: Clinical presentation, cranial ultrasonography, magnetic resonance imaging (MRI) findings, and neurodevelopmental outcome of 10 infants admitted to a neonatal intensive care unit and diagnosed with encephalitis caused by HPeVs are reported. RESULTS: Nine of 10 infants, with a gestational age of 29 to 41 weeks, presented at 36 to 41 weeks postmenstrual age with clinical seizures. Seven had a fever and six had a rash. Clinical presentation was similar to that of infants with enterovirus infection. Cranial ultrasonography showed increased echogenicity in the periventricular white matter in all infants. Neonatal MRI confirmed white matter changes in nine infants, which changed to gliosis on later MRI. Outcome was variable with cerebral palsy in one, a suspect outcome at 18 months in one, learning disabilities at 7 years of age in one, epilepsy in one, and normal neurodevelopmental outcome in five children. Follow-up of one infant was only 9 months. INTERPRETATION: HPeVs should be added to the list of neurotropic viruses that may cause severe central nervous system infection in the neonatal period. White matter injury can be visualized with cranial ultrasonography, but more detailed information is obtained with MRI and especially diffusion-weighted imaging. Because clinical presentation of HPeV encephalitis is similar to that of enterovirus, real-time polymerase chain reaction for both viruses should be performed in atypical presentation of neonatal seizures.