Qualitative Brain MRI at Term and Cognitive Outcomes at 9 Years After Very Preterm Birth

Abstract

WHAT'S KNOWN ON THIS SUBJECT:Cross-sectional studies have demonstrated associations between the white matter injury and cognitive impairment in very preterm born children. Longitudinal studies confirmed the relationships between cerebral MRI at term and neurodevelopmental outcomes at up to 2 years old.WHAT THIS STUDY ADDS: White matter injury (but not gray matter injury) on term MRI predicted cognitive impairments of very preterm born infants at 9 years old. Qualitative assessment of white matter signal intensities showed limited predictive values of cognitive impairments. abstract OBJECTIVE: A prospective study was performed to assess the relationship between the appearance of cerebral MRI at term and the cognitive functioning at 9 years old in very preterm born infants.METHODS: Seventy-six very preterm born infants (birth weight ,1500 g or gestational age #32 weeks) obtained cerebral MRI at term-equivalent period, which was assessed by using established composite scores for the white and gray matter; cognitive outcomes at 9 years old were assessed in 60 subjects by using Wechsler Intelligence Scale for Children, Third Edition.RESULTS: Mildly low scores on the different IQ indices (,85) were observed in 23.3% (verbal IQ), 41.7% (performance IQ), and 30.0% (full-scale IQ) of the cohort, whereas moderately low scores (,70) were noted in 3.3% (verbal IQ), 11.7% (performance IQ), and 11.7% (full-scale IQ); cerebral palsy was diagnosed in 10.0%, whereas special assistance at school was required in 56.7%. Abnormal white matter appearances predicted mildly low verbal, performance, and full-scale IQs; moderately low performance and full-scale IQs; cerebral palsy; and the requirement for special assistance at school. Abnormal white matter appearances predicted mild cognitive impairment even after the adjustment for known clinical risk factors. In contrast, abnormal gray matter appearances did not predict any of the outcome measures. CONCLUSIONS:In a cohort of very preterm born infants, abnormal white matter appearance on term MRI showed consistent associations with cognitive impairments at 9 years old, further supporting the benefit of obtaining term MRI for very preterm born infants. Pediatrics 2012;129:e1138-e1147