Case studyMR imaging for accurate prediction of outcome after perinatal arterial ischemic stroke: Sooner not necessarily better

•Early MRI is increasingly used to predict neurodevelopmental outcome of newborn infants with PAIS.•Signal intensity changes in the descending corticospinal tracts are predictive of adverse motor development.•This case series shows delayed onset of “pre-Wallerian” degeneration.•Optimal timing of MRI imaging in PAIS patients for diagnosis and prognosis may be different.

BackgroundInvolvement of the corticospinal tracts after perinatal arterial ischemic stroke (PAIS) is strongly correlated with adverse motor outcome.MethodsTwo full-term infants with PAIS, with two early MRI scans available, are reported.ResultsDiffusion weighted imaging (DWI)-MRI, performed within 24 h following onset of seizures and repeated 48 h later, clearly showed restricted diffusion within the middle cerebral artery territory on both MRIs, but clear patterns of signal intensity changes in the descending corticospinal tracts on the second MRI only.ConclusionSince involvement of the corticospinal tracts is essential for prediction of motor outcome, we may need to reconsider optimal timing of MR imaging for prediction of neurodevelopmental outcome after PAIS.