Quantification of cyclical oscillations in cerebral blood volume in human neonates using near-infrared spectroscopy

本研究的目的是用近红外地形图研究健康早产儿和足月儿的氧合和脱氧血红蛋白([oxHb]和[deoxHb])的振荡，以确定发育中脑的自发振荡的变化。健康足月婴儿10例(孕周37~40周，出生体重2358~3400g)，年龄9~12d；早产儿11例(胎周23~34周，出生体重474~2048g)，年龄36~73d(孕周37~46周)。采用24通道近红外地形图测量婴儿安静睡眠时双侧颞叶皮质[氧合Hb]和[脱氧Hb]的变化。所有婴儿均观察到脑血流动力学的自发振荡。为了关注缓慢波动，从显示最小基线漂移…的24个通道中选择了180秒期间(1801个数据点)的数据数据方面的更多内容。然后在这些时期进行了功率谱分析。功率谱密度(PSD)分为0.02~0.06、0.06~0.10、0.10~0.15赫兹3个频谱窗口。为比较足月儿和早产儿的PSD，将PSD归一化为：PSD=(PSD的频谱窗面积/PSD总面积)×100(%)。足月儿左侧颞区和右侧颞区的PSD周期波动分别为3.1±0.6(平均值±SD)和2.9±0.5个周期/min，右侧分别为3.1±0.6和2.9±0.6个周期/min。早产儿足月儿左侧分别为3.9±0.6和4.1±0.7次/min，右侧分别为4.0±0.6和4.1±0.6次/min。足月儿与早产儿在0.02~0.06和0.06~0.10赫兹之间的[OxHb]和[DeoxHb]差异有统计学意义。足月儿频率显著低于早产儿(分别为81±4%和69±15%(p=0.017)，16±4%和28±14%(p=0.017))。本研究通过近红外地形图显示足月儿和早产儿颞叶皮质中[oxoxHb]和[deoxHb]<0.10 Hz的低频振荡占优势。较少

The purpose of this study was to investigate the oscillations of oxy- and deoxy-hemoglobin ([oxyHb] and [deoxyHb]) in healthy preterm and term infants by using near-infrared topography and to determine the change in spontaneous oscillation in the developing brain. The subjects were 10 healthy term infants (gestational week : 37-40 weeks, birth weight : 2358-3400g), aged 9 to 12 days, and 11 preterm infants (gestational week : 23-34 weeks, birth weight : 474-2048g), aged 36-73 days (37-46 weeks of postconceptional age).We used 24-channel near-infrared topography to measure changes in [oxyHb] and [deoxyHb] in the bilateral temporal cortices of infants during quiet sleep at 24 measurement positions with interoptode distance of 20 mm. Spontaneous oscillations of cerebral hemodymanics were observed in all of the infants. To focus on the slow fluctuations, data over a period of 180 sec (1801 data points) were selected from the channel among the 24 channels showing the smallest baseline shift … More in data. Power spectral analysis was then performed in these epochs. The power spectral density (PSD) was divided into 3 spectral windows (0.02-0.06,0.06-0.10, and 0.10-0.15 Hz). To compare the PSDs in term infants with those in preterm infants, the PSD was normalized as follows : PSD=(Area of spectral window/Total area of PSD)x100 (%).Cyclical fluctuations of [oxyHb] and [deoxyHb] in term infants were 3.1±0.6 (mean±SD) and 2.9±0.5 cycles/min in the left temporal region and 3.1±0.6 and 2.9±0.6 cycles/min in the right temporal region, respectively. Those at term in preterm infants were 3.9±0.6 and 4.1±0.7 cycles/min on the left side and 4.0±0.6 and 4.1±0.6 cycles/min on the right side, respectively. The difference between term infants and preterm infants was statistically significant at 0.02-0.06 and 0.06-0.10 Hz for [oxyHb] and [deoxyHb]. The term infants had significantly lower frequency than did the preterm infants (Term vs. preterm at 0.02-0.06 and 0.06-0.10 Hz:81±4 % and 69±15 % (p=0.017), and 16±4 % and 28±14 % (p=0.017), respectively). This study demonstrated a predominance of low frequency oscillations in [oxyHb] and [deoxyHb] less than 0.10 Hz in the temporal cortices in both term and preterm infants by near-infrared topography. Less