To Örebro University

Aim: To assess prevalence of non-optimal neurological condition and associations with motor function in children born extremely preterm (EPT) up to early adolescence, and to examine potential changes in neurological con-dition between 6.5 and 12 years.

Method: A prospective cohort of one hundred six children (EPT n = 62, term n = 44) was assessed at 6.5 and 12 years. Four domains derived from the Touwen Neurological Examination (coordination and balance, posture and muscle tone, reflexes, and nerve function of the eyes and face) were used to assess the presence of a non-optimal neurological condition (defined as the presence of any abnormal domain). The Movement Assessment Battery for Children 2nd ed. was used to evaluate motor function.

Results: Twenty-seven children born EPT (44%) were assessed as having a non-optimal neurological condition compared with 4 (9%) in the control group (p=<0.001) at 12 years. Between age 6.5 and 12 years the number of children born EPT with a non-optimal neurological condition decreased from 37 to 27 (p = 0.007). At 12 years these children also had significantly lower MABC-2 total test scores, compared to those with normal neurology: median (range) 57 (32-79) versus 75 (43-99), respectively (p=<0.001). The same was shown for subscale scores; manual dexterity (p=<0.001), aiming/catching (p = 0.004), and balance (p = 0.004).

Conclusion: The prevalence of a non-optimal neurological condition reduced with increasing age. However, still, at 12 years, these neurological impairments remained significantly more common in the EPT group than in their term-born peers and was shown to be related to a reduced motor function.

Children born extremely preterm, especially those with intraventricular haemorrhage (IVH), are at increased risk of adverse cognitive outcomes during childhood. The present study aimed to explore the effects of IVH (grades I-II) on hippocampal volumes, and their correlates with cognitive performance. The sample consisted of 94 participants, including 54 children born extremely preterm (19 with IVH, grades I-II), and 40 children born at term. All participants underwent a magnetic resonance imaging study at the age of 10 (M-age = 10.20 years; SDage = 0.78), and 74 of them (45 extremely preterm and 29 full-term) carried out a cognitive assessment at 12 years old. Children born extremely preterm had lower scores in cognitive performance compared to their full-term peers. Significant positive partial correlations were observed between global bilateral hippocampus, left CA-field, and left subiculum volumes with processing speed in the full-term group, while no significant correlations were found in the extremely preterm group. Moderation analyses in the extremely preterm sample revealed that low-grade IVH moderated the relationship between right hippocampal volume and full-IQ (F((4,40) = )5.42, p = 0.001, R-2 = 0.35). Having greater right hippocampal volume had a protective effect on full-IQ in those children born extremely preterm with low-grade IVH.

Aim: Little is known about the prevalence of discrete white matter abnormalities (WMA) beyond the first years in children born extremely preterm (EPT) and the relation to neurodevelopmental outcomes. Our aim was to investigate the prevalence of discrete WMA in children born EPT and the relationship to neonatal white matter injuries (WMI), white matter (WM) volume, WM diffusivity and neurodevelopment.

Methods: The study was a part of a longitudinal follow-up study of EPT neonates. All children were scanned at Karolinska University hospital 2004-2007 (neonates) and 2014-2015 (children at 8-11 years). WMA was qualitatively assessed by visual inspection. Developmental assessment was conducted at 12 years.

Results: In total, 112 children (median age 10.3 years, 56 girls) underwent MRI of the brain (68 EPT, 45 controls). In the EPT group, a subset had MRI around term equivalent age (n = 61). In the EPT group, the prevalence of discrete WMA at 8-11 years was 52%. There was a positive association between WMI at TEA and 8-11 years. There was no association between WMI and WM volumes or diffusivity at 8-11 years. Discrete WMA was not related to neurodevelopmental outcomes.

Conclusion: Discrete WMA was prevalent in children born EPT at 8-11 years but were not related to neurodevelopmental outcomes.