Research Centre for Early Origins of Health and Disease, Robinson Institute, School of Paediatrics & Reproductive Health, University of Adelaide, SA 5005, Australia.
J Physiol. 2012 Nov 15;590(22):5827-44. doi: 10.1113/jphysiol.2012.239269. Epub 2012 Sep 10.
The mechanisms underlying the altered neurodevelopment commonly experienced by children born preterm, but without brain lesions, remain unknown. While individuals born the earliest are at most risk, late preterm children also experience significant motor, cognitive and behavioural dysfunction from school age, and reduced income and educational attainment in adulthood. We used transcranial magnetic stimulation and functional assessments to examine corticomotor development in 151 children without cerebral palsy, aged 10-13 years and born after gestations of 25-41 completed weeks. We hypothesized that motor cortex and corticospinal development are altered in preterm children, which underpins at least some of their motor dysfunction. We report for the first time that every week of reduced gestation is associated with a reduction in corticomotor excitability that remains evident in late childhood. This reduced excitability was associated with poorer motor skill development, particularly manual dexterity. However, child adiposity, sex and socio-economic factors regarding the child's home environment soon after birth were also powerful influences on development of motor skills. Preterm birth was also associated with reduced left hemisphere lateralization, but without increasing the likelihood of being left handed per se. These corticomotor findings have implications for normal motor development, but also raise questions regarding possible longer term consequences of preterm birth on motor function.
早产儿在没有脑损伤的情况下经历神经发育改变的机制尚不清楚。虽然最早出生的婴儿风险最大，但晚期早产儿在学龄期也会经历显著的运动、认知和行为功能障碍，并在成年后面临收入和教育程度降低的问题。我们使用经颅磁刺激和功能评估检查了 151 名无脑瘫、胎龄 25-41 周的 10-13 岁儿童的皮质运动发育。我们假设运动皮层和皮质脊髓的发育在早产儿中发生改变，这至少是他们运动功能障碍的部分原因。我们首次报告称，每减少一周的孕期与皮质运动兴奋性降低相关，这种兴奋性降低在儿童晚期仍然明显。这种兴奋性降低与运动技能发育较差有关，特别是手的灵巧度。然而，儿童肥胖、出生后家庭环境的性别和社会经济因素也对运动技能的发展有重要影响。早产还与左侧大脑半球侧化减少有关，但并没有增加惯用左手的可能性。这些皮质运动发现对正常运动发育有影响，但也提出了关于早产对运动功能可能产生的长期影响的问题。
