Department of Pediatrics, University of Texas Health Science Center, Houston, TX 77030, USA.
Dev Med Child Neurol. 2010 Aug;52(8):760-6. doi: 10.1111/j.1469-8749.2010.03633.x. Epub 2010 Feb 24.
To understand the relationship between cognition and white-matter structure in adolescents born preterm without obvious brain injury.
Thirty-two adolescents from a longitudinal study of child development were selected according to risk of developmental disorders at birth (born at term: eight males, five females; median age 16y 1mo, interquartile range 10mo; low risk preterm: four males, five females, median age 16y, range 4mo; high risk preterm: three males, seven females, median age 16y 2mo, range 1y 2mo) and reading ability (good: three males, eight females, median age 16y, range 7mo; average: six males, three females, median age 16y 10mo, range 1y; poor: six males, six females, median age 16y, range 6mo). Preterm birth was defined as a gestational age of 36 weeks or less and a birthweight of 1600g or less. All participants had normal clinical neuroimaging findings. We examined fractional anisotropy, radial diffusivity, and volume of three major white-matter fasciculi. The relationship between structural measures and birth risk, hemisphere, and cognitive ability (attention, lexical and sublexical decoding, auditory phonological awareness, and processing speed) were analysed using mixed-model regression.
Left-hemisphere superior longitudinal fasciculus (SLF) fractional anisotropy and radial diffusivity were linked to reading-related skills (fractional anisotropy vs letter-word identification, r((30))=-0.37, p<0.05; fractional anisotropy vs phoneme reversal, r((30))=-0.34, p=0.05; radial diffusivity vs letter-word identification, r((30))=0.31, p<0.10; radial diffusivity vs phoneme reversal, r((30))=0.40, p<0.05), whereas right-hemisphere SLF fractional anisotropy was related to attention skills (fractional anisotropy vs inattentiveness, r((30))=-0.38, p<0.05). SLF volume decreased as these skills declined for adolescents born preterm (volume vs phoneme reversal, r((17))=0.58, p<0.01; volume vs inattentiveness, r((17))=-0.69, p<0.01), but not for those born at term.
The relationship between cognitive skills and SLF volume suggests that in adolescents born preterm, cryptic white-matter injury may exist, possibly related to oligodendrocyte or axonal loss, despite normal clinical neuroimaging.
了解无明显脑损伤的早产儿认知与白质结构之间的关系。
根据出生时发育障碍的风险，从儿童发育的纵向研究中选择了 32 名青少年（足月出生：8 名男性，5 名女性；中位年龄 16 岁 1 个月，四分位距 10 个月；低危早产儿：4 名男性，5 名女性，中位年龄 16 岁，范围 4 个月；高危早产儿：3 名男性，7 名女性，中位年龄 16 岁 2 个月，范围 1 年 2 个月）和阅读能力（好：3 名男性，8 名女性，中位年龄 16 岁，范围 7 个月；平均：6 名男性，3 名女性，中位年龄 16 岁 10 个月，范围 1 年；差：6 名男性，6 名女性，中位年龄 16 岁，范围 6 个月）。早产定义为胎龄 36 周或更小，出生体重 1600g 或更小。所有参与者均有正常的临床神经影像学表现。我们检查了三个主要白质束的分数各向异性、径向扩散和体积。使用混合模型回归分析结构测量值与出生风险、大脑半球和认知能力（注意力、词汇和次词汇解码、听觉语音意识和处理速度）之间的关系。
左半球上纵束（SLF）的分数各向异性和径向扩散与阅读相关技能有关（分数各向异性与字母-单词识别，r((30))=-0.37，p<0.05；分数各向异性与语音反转，r((30))=-0.34，p=0.05；径向扩散与字母-单词识别，r((30))=0.31，p<0.10；径向扩散与语音反转，r((30))=0.40，p<0.05），而右半球 SLF 的分数各向异性与注意力技能有关（分数各向异性与注意力不集中，r((30))=-0.38，p<0.05）。尽管早产儿的临床神经影像学表现正常，但 SLF 体积随着早产儿认知技能的下降而减小（体积与语音反转，r((17))=0.58，p<0.01；体积与注意力不集中，r((17))=-0.69，p<0.01），但足月出生者则无此变化。
认知技能与 SLF 体积之间的关系表明，在无明显脑损伤的早产儿中，可能存在隐匿性白质损伤，这可能与少突胶质细胞或轴突丢失有关，尽管临床神经影像学表现正常。
