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BACKGROUND: To explore the associations between histologic chorioamnionitis with brain injury, maturation and size on magnetic resonance imaging (MRI) of preterm infants at term equivalent age. METHODS: Preterm infants (23-36 weeks gestational age) were recruited into two longitudinal cohort studies. Presence or absence of chorioamnionitis was obtained from placental histology and clinical data were recorded. MRI at term-equivalent age was assessed for brain injury (intraventricular haemorrhage, cysts, signal abnormalities), maturation (degree of myelination, gyral maturation) and size of cerebral structures (metrics and brain segmentation). Histologic chorioamnionitis was assessed as a predictor of MRI variables using linear and logistic regression, with adjustment for confounding perinatal variables. RESULTS: Two hundred and twelve infants were included in this study, 47 (22%) of whom had histologic chorioamnionitis. Histologic chorioamnionitis was associated with higher odds of intraventricular haemorrhage (odds ratio [OR] (95% confidence interval [CI]) = 7.4 (2.4, 23.1)), less mature gyral maturation (OR (95% CI) = 2.0 (1.0, 3.8)) and larger brain volume (mean difference in cubic centimeter (95% CI) of 14.1 (1.9, 26.2)); but all relationships disappeared following adjustment for perinatal variables. CONCLUSION: Histologic chorioamnionitis was not independently associated with IVH, less mature gyral maturation or brain volume at term-equivalent age in preterm infants.

Traditionally early brain insult (EBI) has been considered to have better outcome than later injury, consistent with the notion that the young brain is flexible and able to reorganize. Recent research findings question this view, suggesting that EBI might lead to poorer outcome than brain insult at any other age. Exploring this early vulnerability perspective, we investigated whether skills developing later in childhood, for example, executive functions (EF), would be at greater risk of disruption from EBI. The aim of this study was to investigate EF in children sustaining EBI at different developmental stages. We expected that brain insult during gestation and infancy, before the emergence of EF, would lead to global EF deficits. In contrast, we predicted that brain injury in late childhood would have fewer consequences. Using a cross-sectional, retrospective, group design we compared six groups of children (Total N = 164), with a history of brain insult and documented focal brain pathology, aged 10-16 years on a range of measures of EF. Groups were based on age of EBI: (1) "Congenital"; (2) "Peri-natal"; (3) "Infancy"; (4) "Preschool"; (5) "Middle Childhood"; and (6) "Late Childhood". Children with EBI were at increased risk for impairment across all aspects of EF. Presence of seizures and/or frontal pathology were not predictive of outcome, but age at insult was. Children sustaining EBI before age 3 recorded more global and severe EF deficits, while children with later EBI performed closer to normal expectations. With the exception of attentional control, skills emerging at time of insult were found to be more vulnerable to disruption than those previously established, supporting the "early vulnerability" model for EBI. (Contains 7 tables.)

Objective. Predicting long-term outcome in infants with hypoxic-ischemic encephalopathy (HIE) is a difficult task. Magnetic resonance imaging, particularly diffusion imaging, holds promise in this regard as it is more sensitive to brain injury than any other available imaging modality. Previous studies have suggested that abnormal signal intensity in the posterior limb of the internal capsule (PLIC), detectable on inversion-recovery T1-weighted imaging, is a strong predictor of outcome. The aim of this study was to assess the relationship between apparent diffusion coefficient (ADC) values from the PLIC, measured by diffusion imaging, and neuromotor outcome in term infants with HIE. Methods. Twenty-eight term infants with a clinical diagnosis of HIE underwent magnetic resonance imaging as soon as practicable after birth (mean age: 5.6 days), including diffusion-weighted imaging, from which ADC values in the PLIC were measured. Motor outcome was assessed in 12 of 16 survivors. Results. The ADC value in the PLIC was significantly associated with survival in term infants with HIE. For survivors, the mean ADC value in the PLIC was 0.89 [+ or -] 0.17 [micro][m.sup.2]/ms, whereas the mean ADC value for nonsurvivors was 0.75 [+ or -] 0.17 [micro][m.sup.2]/ms (t = 2.25). Among survivors, the ADC value in the PLIC was also associated with neuromotor outcome (F = 5.60). Conclusion. The ADC value in the PLIC is an indicator of ischemic injury and may be of use as an objective prognostic marker for infants with HIE. Pediatrics 2004; 114:999-1003; apparent diffusion coefficient, perinatal asphyxia, magnetic resonance imaging., ABBREVIATIONS. MRI, magnetic resonance imaging; HIE, hypoxic-ischemic encephalopathy; PLIC, posterior limb of internal capsule; DWI, diffusion weighted imaging; ADC, apparent diffusion coefficient. Magnetic resonance imaging (MRI) is established as the [...]