Quantitation of cerebral blood volume in human infants by near-infrared spectroscopy

Wyatt, John; Cope, M; Delpy, David T.; Richardson, C. E.; Edwards, Anthony; Wray, Susan; Reynolds, E. O. R.

doi:10.1152/jappl.1990.68.3.1086

Cited by 439 publications

(245 citation statements)

References 22 publications

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“…We have confirmed the physiologic response of CBV to changing Paco, and have demonstrated an increase in cerebrovascular reactivity with gestational age. In a previous study, we found no obvious relationship between total CBV in newborn infants and gestational age (18). Thus, the calculated percentage change in CBV per kPa increased from about 4% at 26 wk to about 25% at 40 wk of gestation.…”

Section: Materlals and Methodsmentioning

confidence: 60%

“…Information on the response of the cerebral circulation may be of considerable significance for improved understanding of the pathogenesis of hypoxic-ischemic brain injury and periventricular hemorrhage in these infants. NIRS, first described by Jobsis (16) in 1977, allows continuous, noninvasive, quantitative monitoring of cerebral blood volume (17,18) in sick newborn infants. It is thus possible to determine at the bedside the response of the cerebral vasculature to changing Pacoz.…”

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confidence: 99%

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Response of Cerebral Blood Volume to Changes in Arterial Carbon Dioxide Tension in Preterm and Term Infants

et al. 1991

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ABSTRACT. The response of cerebral blood volume (CBVR) to a small induced change in arterial carbon dioxide tension was studied by near-infrared spectroscopy in 17 newborn infants born from 26 wk of gestation to term. All 17 infants were undergoing mechanical ventilation but had apparently normal brains. The CBVR per kPa change in arterial carbon dioxide tension within the range 3.9 to 9.6 kPa was calculated from the change in total cerebral Hb concentration (

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Section: Materlals and Methodsmentioning

confidence: 60%

mentioning

confidence: 99%

Response of Cerebral Blood Volume to Changes in Arterial Carbon Dioxide Tension in Preterm and Term Infants

et al. 1991

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“…The fNIR raw signals are light intensity measurements (See Figure 1). By measuring optical density (OD) changes at two wavelengths, the relative change of oxy-Hb and deoxy-Hb versus time can be obtained using the modified Beer-Lambert Law [21][22][23] . OD at a specific input wavelength (λ) is the logarithmic ratio of input light intensity (I in ) and output (detected) light intensity (I out ).…”

Section: Processing the Fnir Data And Analysismentioning

confidence: 99%

Using MazeSuite and Functional Near Infrared Spectroscopy to Study Learning in Spatial Navigation

Ayaz

Shewokis

Curtin

et al. 2011

JoVE

173

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MazeSuite is a complete toolset to prepare, present and analyze navigational and spatial experiments 1 . MazeSuite can be used to design and edit adapted virtual 3D environments, track a participants' behavioral performance within the virtual environment and synchronize with external devices for physiological and neuroimaging measures, including electroencephalogram and eye tracking.Functional near-infrared spectroscopy (fNIR) is an optical brain imaging technique that enables continuous, noninvasive, and portable monitoring of changes in cerebral blood oxygenation related to human brain functions [2][3][4][5][6][7] . Over the last decade fNIR is used to effectively monitor cognitive tasks such as attention, working memory and problem solving [7][8][9][10][11] . fNIR can be implemented in the form of a wearable and minimally intrusive device; it has the capacity to monitor brain activity in ecologically valid environments.Cognitive functions assessed through task performance involve patterns of brain activation of the prefrontal cortex (PFC) that vary from the initial novel task performance, after practice and during retention 12 . Using positron emission tomography (PET), Van Horn and colleagues found that regional cerebral blood flow was activated in the right frontal lobe during the encoding (i.e., initial naïve performance) of spatial navigation of virtual mazes while there was little to no activation of the frontal regions after practice and during retention tests. Furthermore, the effects of contextual interference, a learning phenomenon related to organization of practice, are evident when individuals acquire multiple tasks under different practice schedules 13,14 . High contextual interference (random practice schedule) is created when the tasks to be learned are presented in a non-sequential, unpredictable order. Low contextual interference (blocked practice schedule) is created when the tasks to be learned are presented in a predictable order.Our goal here is twofold: first to illustrate the experimental protocol design process and the use of MazeSuite, and second, to demonstrate the setup and deployment of the fNIR brain activity monitoring system using Cognitive Optical Brain Imaging (COBI) Studio software 15 . To illustrate our goals, a subsample from a study is reported to show the use of both MazeSuite and COBI Studio in a single experiment. The study involves the assessment of cognitive activity of the PFC during the acquisition and learning of computer maze tasks for blocked and random orders. Two right-handed adults (one male, one female) performed 315 acquisition, 30 retention and 20 transfer trials across four days. Design, implementation, data acquisition and analysis phases of the study were explained with the intention to provide a guideline for future studies. Video LinkThe video component of this article can be found at https://www.jove.com/video/3443/ ProtocolMaze-Suite consists of three main applications; an editing program to construct maze environments (MazeMaker), a visualiz...

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“…Emerging light was collected by the second optode and transmitted to the spectrophotometer. Changes in cerebral [Hb], [HbO2], and [CytOx] were calculated from the modified Lambert-Beer law by using a previously established algorithm that describes optical absorption in a highly scattering medium (45,56). The NIRS measures obtained are relative changes from zero, not absolute changes.…”

Section: Nirs Measurements Concentration Changes In Fetal Cerebral Dmentioning

confidence: 99%

Regulation of cytochrome oxidase redox state during umbilical cord occlusion in preterm fetal sheep

Roelfsema¹,

Dean²,

Wassink³

et al. 2007

American Journal of Physiology-Regulatory, Integrative and Comp

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The preterm fetus is capable of surviving prolonged periods of severe hypoxia without neural injury for much longer than at term. To evaluate the hypothesis that regulated suppression of brain metabolism contributes to this remarkable tolerance, we assessed changes in the redox state of cytochrome oxidase (CytOx) relative to cerebral heat production, and cytotoxic edema measured using cerebral impedance, during 25 min of complete umbilical cord occlusion or sham occlusion in fetal sheep at 0.7 gestation. Occlusion was followed by rapid, profound reduction in relative cerebral oxygenation and EEG intensity and an immediate increase in oxidized CytOx, indicating a reduction in electron flow down the mitochondrial electron transfer chain. Confirming rapid suppression of cerebral metabolism there was a loss of the temperature difference between parietal cortex and body at a time when carotid blood flow was maintained at control values. As occlusion continued, severe hypotension/hypoperfusion developed, with a further increase in CytOx levels to a plateau between 8 and 13 min and a progressive rise in cerebral impedance. In conclusion, these data strongly suggest active regulation of cerebral metabolism during the initial response to severe hypoxia, which may help to protect the immature brain from injury. asphyxia; preterm; umbilical cord occlusion FETAL AND NEONATAL ANIMALS are well known to be able to survive much longer periods of hypoxia than adults (9, 22). More recently, it has become clear that preterm animals can withstand even longer periods of profound hypoxia and hypotension/hypoperfusion without neural injury than at term (17,28,35). In part, this remarkable tolerance to hypoxia may be related to greater anaerobic capacity in the immature brain (48), but an important additional factor is likely to be actively regulated suppression of cerebral activity. This mechanism, which is mediated by release of endogenous inhibitory neuromodulators such as ␥-aminobutyric acid (GABA) and adenosine during hypoxia, recently has been shown to be active in near-term (0.8 to 0.9 gestation) fetal sheep (6,23,33,49). For example, hypoxemia or adenosine infusion in near-term fetal sheep increased oxidation of cerebral cytochrome oxidase (CytOx) on near-infrared measurements, indicating a rapid reduction in electron flow down the mitochondrial electron transfer chain and, thus, a fall in metabolic activity (40, 41). Conversely, blockade of adenosine A 1 receptor activity during umbilical cord occlusion in near-term fetal sheep accelerated the onset and increased the magnitude of cerebral anoxic cytotoxic edema, with subsequently increased neuronal loss (23).This regulated suppression of metabolic rate during hypoxia or ischemia, before energy stores are depleted, has been termed adaptive hypometabolism (38). It may be of considerable importance not only before birth but also during birth itself and in other settings involving adaptation to low oxygen levels (34). The near-term fetus of the high-altitude, hypoxia-adapted llama...

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Quantitation of cerebral blood volume in human infants by near-infrared spectroscopy

Cited by 439 publications

References 22 publications

Response of Cerebral Blood Volume to Changes in Arterial Carbon Dioxide Tension in Preterm and Term Infants

Response of Cerebral Blood Volume to Changes in Arterial Carbon Dioxide Tension in Preterm and Term Infants

Using MazeSuite and Functional Near Infrared Spectroscopy to Study Learning in Spatial Navigation

Regulation of cytochrome oxidase redox state during umbilical cord occlusion in preterm fetal sheep

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