The Developmental Trajectory of Brain-Scalp Distance from Birth through Childhood: Implications for Functional Neuroimaging
The Developmental Trajectory of Brain-Scalp Distance from Birth through Childhood: Implications for Functional Neuroimaging
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DOI：
10.1371/journal.pone.0024981
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发表时间：
2011-09-21
期刊：
影响因子：
3.7
通讯作者：
Oghalai, John S.
中科院分区：
文献类型：
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作者：
Beauchamp, Michael S.;Beurlot, Michelle R.;Oghalai, John S.
认知神经科学对儿童大脑功能的测量越来越感兴趣。许多用于儿童的脑测绘技术，包括功能性近红外光谱（fNIRS）、脑电图（EEG）、脑磁图（MEG）和经颅磁刺激（TMS），都使用放置在头皮上或附近的探针。头皮和大脑之间的距离是这些技术的一个关键变量，因为光、电和磁信号会因距离而衰减。然而，对于儿童不同皮质区域间头皮-大脑距离的差异，以及随着发育的变化，我们所知甚少。我们研究了71名从新生儿到12岁的儿童的头脑距离，使用全头部的结构t1加权MRI扫描。从头皮表面创建三维重建，以便精确计算脑-头皮距离。根据已发表的fNIRS文献，在每个受试者中手动选择不同皮质区域的9个脑地标。对年龄、皮质区域和半球有显著影响。幼儿的脑-头皮距离最低，随着年龄的增长而增加，最高可达新生儿距离的两倍。大脑区域之间也存在巨大差异，地标之间的差异高达50%。在额叶和颞叶区域，右半球的头脑距离明显大于左半球。脑-头皮距离发育变化的最大贡献者是脑脊液（CSF）和头盖骨内表的增加。这些结果对儿童的功能成像研究具有重要意义：年龄和脑区域相关的fNIRS信号差异可能是由于脑-头皮距离的混淆因素，而不是大脑活动的真正差异。
Measurements of human brain function in children are of increasing interest in cognitive neuroscience. Many techniques for brain mapping used in children, including functional near-infrared spectroscopy (fNIRS), electroencephalography (EEG), magnetoencephalography (MEG) and transcranial magnetic stimulation (TMS), use probes placed on or near the scalp. The distance between the scalp and the brain is a key variable for these techniques because optical, electrical and magnetic signals are attenuated by distance. However, little is known about how scalp-brain distance differs between different cortical regions in children or how it changes with development. We investigated scalp-brain distance in 71 children, from newborn to age 12 years, using structural T1-weighted MRI scans of the whole head. Three-dimensional reconstructions were created from the scalp surface to allow for accurate calculation of brain-scalp distance. Nine brain landmarks in different cortical regions were manually selected in each subject based on the published fNIRS literature. Significant effects were found for age, cortical region and hemisphere. Brain-scalp distances were lowest in young children, and increased with age to up to double the newborn distance. There were also dramatic differences between brain regions, with up to 50% differences between landmarks. In frontal and temporal regions, scalp-brain distances were significantly greater in the right hemisphere than in the left hemisphere. The largest contributors to developmental changes in brain-scalp distance were increases in the corticospinal fluid (CSF) and inner table of the cranium. These results have important implications for functional imaging studies of children: age and brain-region related differences in fNIRS signals could be due to the confounding factor of brain-scalp distance and not true differences in brain activity.