Background

Language difficulties of very preterm (VPT) children might be related to weaker cerebral hemispheric lateralization of language. Language lateralization refers to the development of an expert region for language processing in the left hemisphere during the first years of life. Children born VPT might not develop such a dominant left hemisphere for language processing. A dichotic listening task may be a functional task to show the dominance of the left hemisphere during language processing. During this task, different acoustic events are simultaneously presented to both ears. Due to crossing fibers in the brain, right ear stimuli are transferred directly to the left hemisphere, and left ear stimuli are transferred first to the right hemisphere and then, through the corpus callosum (CC), to the left hemisphere. Dichotic listening typically shows a right ear advantage, assuming to reflect left hemispherical language dominance. The CC, in particular the splenium, is associated with auditory processing and is considered important for language lateralization. The objective of this work was to explore whether dichotic listening performance in school-aged VPT children are associated with language performance and interhemispheric connectivity.

Methods

This is a cross-sectional study of 58 VPT children and 30 full term controls at age 10 years. Language performance and dichotic digit test (DDT) were assessed. In 44 VPT children, additionally diffusion weighted imaging (DWI) was performed using a 3 T MRI scanner. Fractional anisotropy (FA) and mean diffusivity (MD) values of the splenium of the CC were extracted.

Results

Poorer right ear DDT scores were associated with poorer language performance in VPT children only (p = 0.015). Association between right ear DDT scores and MD of the splenium approached the level of significance (p = 0.051).

Conclusions

These results support the hypothesis that poor language performance in VPT children may be a consequence of weaker lateralized language organization, due to a poorly developed splenium of the CC. Dichotic listening may reflect the level of language lateralization in VPT children.

Impact

• Poor language performance in VPT children may be a consequence of weaker lateralized language organization, due to a poorly developed splenium of the CC.

• Dichotic listening performance may reflect the level of language lateralization in VPT children and right ear scores of a dichotic listening task are associated with both the splenium of the corpus callosum and language performance.

• If our results could be validated in future research, it suggests that poor CC development may indicate VPT children at risk for long-term language problems.

中文翻译：

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早产儿语言偏侧化：将双耳听力与大脑半球连接和语言表现联系起来

背景

极早产儿（VPT）的语言困难可能与大脑半球语言偏侧化较弱有关。语言偏侧化是指在生命的最初几年中左半球语言处理专家区域的发展。出生 VPT 的孩子可能不会发展出如此占主导地位的左半球来进行语言处理。双耳听力任务可能是在语言处理过程中显示左半球优势的功能性任务。在此任务期间，不同的声学事件同时呈现给双耳。由于大脑中的纤维交叉，右耳刺激直接传递到左半球，左耳刺激首先传递到右半球，然后通过胼胝体 (CC) 传递到左半球。双耳听力通常显示出右耳优势，假设反映左半球语言优势。CC，特别是压部，与听觉处理有关，被认为对语言侧化很重要。这项工作的目的是探讨学龄 VPT 儿童的双耳听力表现是否与语言表现和大脑半球连接有关。

方法

这是一项对 58 名 VPT 儿童和 30 名 10 岁足月对照组的横断面研究。评估语言表现和双耳数测试（DDT）。在 44 名 VPT 儿童中，使用 3 T MRI 扫描仪进行了额外的弥散加权成像 (DWI)。提取了 CC 压部的分数各向异性 (FA) 和平均扩散率 (MD) 值。

结果

较差的右耳 DDT 评分仅与 VPT 儿童较差的语言表现相关（p  = 0.015）。右耳 DDT 评分与压部 MD 之间的关联接近显着水平（p  = 0.051）。

结论

这些结果支持这样的假设，即 VPT 儿童的语言表现不佳可能是由于 CC 压部发育不良而导致的横向语言组织较弱的结果。双耳听力可能反映了 VPT 儿童的语言偏侧化水平。

影响

• VPT 儿童的语言表现不佳可能是由于 CC 压部发育不良而导致语言组织偏弱的结果。

• 双耳听力表现可能反映了VPT儿童的语言偏侧化水平，双耳听力任务的右耳分数与胼胝体压部和语言表现有关。

• 如果我们的结果可以在未来的研究中得到验证，则表明 CC 发育不良可能表明 VPT 儿童有长期语言问题的风险。