Human Parechovirus Meningoencephalitis: Neuroimaging in the Era of Polymerase Chain Reaction-Based Testing.

A Sarma,L Pagano,E Hanzlik,R Krishnasarma,S Pruthi

doi:10.3174/ajnr.a6118

Abstract

Human parechovirus infection is an increasingly recognized cause of neonatal meningoencephalitis. We describe characteristic clinical features and brain MR imaging abnormalities of human parechovirus meningoencephalitis in 6 infants. When corroborated by increasingly available polymerase chain reaction-based testing of the CSF, the distinctive MR imaging appearance may yield a specific diagnosis that obviates costly and time-consuming further clinical evaluation. In our study, infants with human parechovirus presented in the first 35 days of life with seizures, irritability, and sepsis. MR imaging consistently demonstrated low diffusivity within the thalami, corpus callosum, and subcortical white matter with a frontoparietal predominance. T1 and T2 shortening connoting white matter injury along the deep medullary veins suggests venous ischemia as an alternative potential pathogenetic mechanism to direct neuroaxonal injury.

Highlights

Postcontrast, MRA, and MRV results were normal. This series describes 6 infants with Human parechovirus (HPeV) meningoencephalitis and characteristic MR imaging findings that rapidly yielded a diagnosis in conjunction with polymerase chain reaction (PCR) testing of the CSF
Distinctive supratentorial white matter and callosal diffusion abnormality on MR imaging is shared between ours and other published series.[3,12,13,15,16,17]
Low diffusivity in the thalamus may be due to some combination of venous ischemia and seizure activity

Summary

Introduction

DISCUSSION This series describes 6 infants with HPeV meningoencephalitis and characteristic MR imaging findings that rapidly yielded a diagnosis in conjunction with PCR testing of the CSF. Distinctive supratentorial white matter and callosal diffusion abnormality on MR imaging is shared between ours and other published series.[3,12,13,15,16,17] Thalamic involvement and sparing of the posterior fossa structures have been reported variably but were universally present in our cases.[12,18] T1- and T2-shortening foci branching along the distribution of the deep medullary veins

Results

Conclusion