Neonatal cerebral morphometry and later risk of persistent inattention/hyperactivity in children born very preterm.

BACKGROUND: Attention problems are among the most prevalent neurobehavioral morbidities affecting very preterm (VPT) born children. The first study aim was to document rates of persistent attention/hyperactivity problems from ages 4 to 9 years in a regional cohort of VPT born children. The second aim was to examine the extent to which persistent problems were related to cerebral white matter abnormality and structural development on neonatal MRI.
METHODS: Data were drawn from a prospective longitudinal study of 110 VPT (≤32 weeks gestation) and 113 full-term (FT) children born from 1998 to 2000. At term equivalent, all VPT and 10 FT children underwent cerebral structural MRI, with scans analyzed qualitatively for white matter abnormalities and quantitatively for cortical and subcortical gray matter, myelinated and unmyelinated white matter, and cerebrospinal fluid volumes. At ages 4, 6, and 9 years, each child's parent and teacher completed the Inattention/Hyperactivity subscale of the Strengths and Difficulties Questionnaire.
RESULTS: VPT born children had a fivefold increased risk of persistent attention/hyperactivity problems compared with FT children (13.1% vs. 2.8%; p = .002). No association was found between neonatal white matter abnormalities and later persistent inattention/hyperactivity risk (p ≥ .24). In contrast, measures of cerebral structural development including volumetric estimates of total cerebral tissue and cerebrospinal fluid relative to intracranial volume were associated with an increased risk of persistent attention/hyperactivity problems in VPT born children (p = .001). The dorsal prefrontal region showed the largest volumetric reduction (↓3.2-8.2 mL). These brain-behavior associations persisted and in some cases, strengthened after covariate adjustment for postmenstrual age at MRI, gender, and family socioeconomic status.
CONCLUSIONS: Just over one in 10 VPT born children are subject to early onset and persistent attention/hyperactivity problems during childhood. These problems appear to reflect, at least in part, neonatal disturbances in cerebral growth and development rather than the effects of white matter injury.