Extremely Preterm Infants with a Near-total Absence of Cerebellum: Usefulness of Quantitative Magnetic Resonance in Predicting the Motor Outcome.

ABSTRACT

This study aims to evaluate in extremely premature infants the severity of brain structural injury causing total absence or near-total absence of cerebellar hemispheres by using MRI visual and volumetric scoring systems. It also aims to assess the role of the score systems in predicting motor outcome. We developed qualitative and quantitative MRI scoring systems to grade the overall brain damage severity in 16 infants with total absence or near-total absence of cerebellar hemispheres. The qualitative scoring system assessed the severity of macrostructural abnormalities of cerebellum, brainstem, supratentorial gray and white matters, ventricles while the quantitative scoring system weighted the loss of brain tissue volumes, and gross motor function classification system (GMFCS) was used to assess motor function at 1- and 5-year follow-ups.Positive correlations between both MRI scores and GMFCS scales were detected at follow-ups (p > 0.05), but only the volumetric score could identify those infants developing higher levels of motor impairment.Brain volumetric MRI offers an unbiassed assessment of prenatal brain damage. The quantitative scoring system, performed at term equivalent age, can be a helpful tool for predicting the long-term motor outcome in extremely preterm infants with a near-total absence of cerebellum.