Most representative papers by Nadege Roche-Labarbe
Developmental psychobiology, 2017
Funding information Fondation de France; The Region Normandie council Preterm infants frequently ... more Funding information Fondation de France; The Region Normandie council Preterm infants frequently develop atypical sensory profiles, the tactile modality being particularly affected. However, there is a lack of recent investigation of neonatal tactile perception in a passive context, especially in preterms who are particularly exposed to this tactile stimuli. Our aims were to provide evidence of orienting responses (behavioral modifications directing subject's attention towards stimuli) and habituation to passive tactile stimuli in preterm neonates, to explore their ability to perceive spatial and temporal aspects of the stimulus, and to evaluate the effect of clinical factors on these abilities. We included 61 preterm neonates, born between 32 and 34 weeks of gestational age. At 35 weeks of corrected gestational age, we measured orienting responses (forearm, hand, and fingers movements) during vibrotactile stimulation of their hand and forearm; during a habituation and dishabituation paradigm, the dishabituation being either a location change or a pause in the stimulation sequence. Preterm newborns displayed a manual orienting response to vibrotactile stimuli which significantly decreased when the stimulus was repeated, regardless of the stimulated location on the limb. Habituation was delayed in subjects born at a younger gestational age, smaller birth weight, and having experienced more painful care procedures. Preterm neonates perceived changes in stimulus location and interstimulus time interval. Our findings provide insights on several aspects of the perception of repeated tactile stimuli by preterm neonates, and the first evidence of the early development of temporal processing abilities in the tactile modality. Future work will investigate the links between this ability and neurodevelopmental disorders. K E Y W O R D S
Epilepsia, 2010
Purpose: Absence epilepsy may be severe and is frequently accompanied by cognitive delay, yet it... more Purpose: Absence epilepsy may be severe and is frequently accompanied by cognitive delay, yet its metabolic/hemodynamic aspects have not been established. The Genetic Absence Epilepsy Rats from Strasbourg (GAERS) are an isomorphic, predictive, and homologous model of human absence epilepsy. We studied hemodynamic changes related to generalized spike-and-wave discharges (GSWDs) in GAERS by using a technique with high temporal resolution: near-infrared spectroscopy (NIRS). We hypothesized that conflicting results from other techniques might be due to the averaging of a biphasic response such as the one we described in children.Methods: NIRS is particularly suitable for monitoring changes in the concentrations of oxy-, deoxy-, and total hemoglobin (HbO2, HHb, and HbT), using the specific absorption properties of living tissues in the near infrared range. We obtained concomitant high quality electroencephalography (EEG)–NIRS recordings in six GAERS (total of 444 seizures), and tested whether the discharges were related to changes in cardiac or respiration rates.Results: The onset of GSWDs was preceded by a deactivation, followed by an activation that was possibly due to seizure-suppression mechanisms. The end was marked by a deactivation. The onset of GSWDs was associated with a decrease and the end with a brief increase in respiratory rate.Discussion: Our results differ partially from those of previous studies on hemodynamic aspects of GSWDs (many of which describe a simple deactivation), probably due to differences in temporal resolution and data processing; however, they are consistent with metabolic studies, functional magnetic resonance imaging (fMRI) studies on WAG/Rij rats, and some results in children with absence epilepsy.
Epilepsia, 2008
Purpose: Absence epilepsy is characterized by 3-Hz generalized spike-and-wave discharges (GSWD) ... more Purpose: Absence epilepsy is characterized by 3-Hz generalized spike-and-wave discharges (GSWD) on the electroencephalogram, associated with behavioral arrest. It may be severe, and even in childhood benign absence epilepsy cognitive delay is frequent, yet the metabolic/hemodynamic aspects of this kind of epilepsy have not been established. We aimed to determine if the GSWD were related to hemodynamic changes by using a new technique with high temporal resolution: near infrared spectroscopy (NIRS).Methods: NIRS is gaining acceptance as a technique particularly suitable for routine follow-up in children, using the specific absorption properties of living tissues in the near infrared range to measure changes in the concentrations of oxy-, deoxy- and total hemoglobin (HbO2, HHb, and HbT, respectively). We performed simultaneous electroencephalography (EEG) and left frontal NIRS recordings in six children with GSWD. We also tested if the discharges were related to changes in cardiac or respiratory rates.Results: GSWD were associated in the frontal area with an oxygenation (beginning 10 s before the GSWD) followed by strong deoxygenation, then oxygenation again with [HbT] increase, and a return to baseline. We did not identify any relationship between the onset of the GSWD and heart or respiratory rates.Discussion: Our results partially differ from previous studies on GSWD hemodynamic aspects (many of which described a simple deactivation), probably due to differences in temporal resolution and data processing. Simultaneous acquisition of EEG and NIRS can optimize the use of both techniques and help shed light on the mechanisms underlying spike-and-wave discharges.
Human Brain Mapping, 2009
With the causes of perinatal brain injuries still unclear and the probable role of hemodynamic in... more With the causes of perinatal brain injuries still unclear and the probable role of hemodynamic instability in their etiology, bedside monitoring of neonatal cerebral hemodynamics with standard values as a function of age are needed. In this study, we combined quantitative frequency domain near infrared spectroscopy (FD-NIRS) measures of cerebral tissue oxygenation (StO 2 ) and cerebral blood volume (CBV) with diffusion correlation spectroscopy (DCS) measures of a cerebral blood flow index (CBF ix ) to test the validity of the CBV-CBF relationship in premature neonates and to estimate cerebral metabolic rate of oxygen (rCMRO 2 ) with or without the CBF ix measurement. We measured 11 premature neonates (28-34 weeks gestational age) without known neurological issues, once a week from one to six weeks of age. In nine patients, cerebral blood velocities from the middle cerebral artery were collected by transcranial Doppler (TCD) and compared with DCS values. Results show a steady decrease in StO 2 during the first six weeks of life while CBV remains stable, and a steady increase in CBF ix . rCMRO 2 estimated from FD-NIRS remains constant but shows wide interindividual variability. rCMRO 2 calculated from FD-NIRS and DCS combined increased by 40% during the first six weeks of life with reduced interindividual variability. TCD and DCS values are positively correlated. In conclusion, FD-NIRS combined with DCS offers a safe and quantitative bedside method to assess CBV, StO 2 , CBF, and rCMRO 2 in the premature brain, facilitating individual follow-up and comparison among patients. A stable CBV-CBF relationship may not be valid for premature neonates.
Journal of Cerebral Blood Flow and Metabolism, 2012
Journal of visualized experiments : JoVE, 2013
Perinatal brain injury remains a significant cause of infant mortality and morbidity, but there i... more Perinatal brain injury remains a significant cause of infant mortality and morbidity, but there is not yet an effective bedside tool that can accurately screen for brain injury, monitor injury evolution, or assess response to therapy. The energy used by neurons is derived largely from tissue oxidative metabolism, and neural hyperactivity and cell death are reflected by corresponding changes in cerebral oxygen metabolism (CMRO 2 ). Thus, measures of CMRO 2 are reflective of neuronal viability and provide critical diagnostic information, making CMRO 2 an ideal target for bedside measurement of brain health.
NeuroImage, 2007
Electroencephalography of premature neonates shows a physiological discontinuity of electrical ac... more Electroencephalography of premature neonates shows a physiological discontinuity of electrical activity during quiet sleep. Near infrared spectroscopy (NIRS) shows spontaneous oscillations of hemoglobin oxygenation and volume. Similar oscillations are visible in term neonates and adults, with NIRS and other functional imaging techniques (fMRI, Doppler, etc.), but are generally thought to result from vasomotion and to be a physiological artifact of limited interest. The origin and possible relationship to neuronal activity of the baseline changes in the NIRS signal have not been established. We carried out simultaneous EEG-NIRS recordings on six healthy premature neonates and four premature neonates presenting neurological distress, to determine whether changes in the concentration of cerebral oxy-and deoxy-and total hemoglobin were related to the occurrence of spontaneous bursts of cerebral electric activity. Bursts of electroencephalographic activity in neonates during quiet sleep were found to be coupled to a transient stereotyped hemodynamic response involving a decrease in oxy-hemoglobin concentration, sometimes beginning a few seconds before the onset of electroencephalographic activity, followed by an increase, and then a return to baseline. This pattern could be either part of the baseline oscillations or superimposed changes to this baseline, influencing its shape and phase. The temporal patterns of NIRS parameters present an unique configuration, and tend to be different between our healthy and pathological subjects. Studies of physiological activities and of the effects of intrinsic regulation on the NIRS signal should increase our understanding of these patterns and EEG-NIRS studies should facilitate the integration of NIRS into the set of clinical tools used in neurology.
Simultaneous NIRS and EEG recordings in premature neonates, six healthy and four presenting neuro... more Simultaneous NIRS and EEG recordings in premature neonates, six healthy and four presenting neurological distress (29 to 35 weeks GA) showed bursts of neuronal activity during quiet sleep are associated with a stereotyped haemodynamic response.
Neuroimage, 2007
Electroencephalography of premature neonates shows a physiological discontinuity of electrical ac... more Electroencephalography of premature neonates shows a physiological discontinuity of electrical activity during quiet sleep. Near infrared spectroscopy (NIRS) shows spontaneous oscillations of hemoglobin oxygenation and volume. Similar oscillations are visible in term neonates and adults, with NIRS and other functional imaging techniques (fMRI, Doppler, etc.), but are generally thought to result from vasomotion and to be a physiological artifact of limited interest. The origin and possible relationship to neuronal activity of the baseline changes in the NIRS signal have not been established. We carried out simultaneous EEG-NIRS recordings on six healthy premature neonates and four premature neonates presenting neurological distress, to determine whether changes in the concentration of cerebral oxy- and deoxy- and total hemoglobin were related to the occurrence of spontaneous bursts of cerebral electric activity. Bursts of electroencephalographic activity in neonates during quiet sleep were found to be coupled to a transient stereotyped hemodynamic response involving a decrease in oxy-hemoglobin concentration, sometimes beginning a few seconds before the onset of electroencephalographic activity, followed by an increase, and then a return to baseline. This pattern could be either part of the baseline oscillations or superimposed changes to this baseline, influencing its shape and phase. The temporal patterns of NIRS parameters present an unique configuration, and tend to be different between our healthy and pathological subjects. Studies of physiological activities and of the effects of intrinsic regulation on the NIRS signal should increase our understanding of these patterns and EEG-NIRS studies should facilitate the integration of NIRS into the set of clinical tools used in neurology.
NeuroImage, 2014
The hemodynamic functional response is used as a reliable marker of neuronal activity in countles... more The hemodynamic functional response is used as a reliable marker of neuronal activity in countless studies of brain function and cognition. In newborns and infants, however, conflicting results have appeared in the literature concerning the typical response, and there is little information on brain metabolism and functional activation. Measurement of all hemodynamic components and oxygen metabolism is critical for understanding neurovascular coupling in the developing brain. To this end, we combined multiple near infrared spectroscopy techniques to measure oxy-and deoxy-hemoglobin concentrations, cerebral blood volume (CBV), and relative cerebral blood flow (CBF) in the somatosensory cortex of 6 preterm neonates during passive tactile stimulation of the hand. By combining these measures we estimated relative changes in the cerebral metabolic rate of oxygen consumption (rCMRO 2 ). CBF starts increasing immediately after stimulus onset, and returns to baseline before blood volume. This is consistent with the model of pre-capillary arteriole active dilation driving the CBF response, with a subsequent CBV increase influenced by capillaries and veins dilating passively to accommodate the extra blood. rCMRO 2 estimated using the steady-state formulation shows a biphasic pattern: an increase immediately after stimulus onset, followed by a post-stimulus undershoot due to blood flow returning faster to baseline than oxygenation. However, assuming a longer mean transit time from the arterial to the venous compartment, due to the immature vascular system of premature infants, reduces the post-stimulus undershoot and increases the flow/consumption ratio to values closer to adult values reported in the literature. We are the first to report changes in local rCBF and rCMRO 2 during functional activation in preterm infants. The ability to measure these variables in addition to hemoglobin concentration changes is critical for understanding neurovascular coupling in the developing brain, and for using this coupling as a reliable functional imaging marker in neonates.
Book chapters by Nadege Roche-Labarbe
Handbook of Biophotonics - Wiley-VCH, 2013
Other papers by Nadege Roche-Labarbe
Clinical Neurophysiology, 2011
Multimodal Biomedical Imaging VI, 2011
NIRS is safe, non-invasive and offers the possibility to record local hemodynamic parameters at t... more NIRS is safe, non-invasive and offers the possibility to record local hemodynamic parameters at the bedside, avoiding the transportation of neonates and critically ill patients. In this work, we evaluate the accuracy of the frequency-domain multi-distance (FD-MD) method to retrieve ...
PURPOSE With the advent of therapeutic hypothermia (TH) as a promising neuroprotective treatment ... more PURPOSE With the advent of therapeutic hypothermia (TH) as a promising neuroprotective treatment in hypoxic-ischemic brain injury, non-invasive bedside approaches to monitor cooling-induced physiologic changes have become necessary. Frequency-domain near-infrared spectroscopy (FD-NIRS) and diffuse correlation spectroscopy (DCS) can quantitatively assess cerebral blood volume (CBV), cerebral tissue oxygenation (StO2) and cerebral blood flow (CBF). The combination of these devices allows us to estimate CMRO2 with fewer assumptions about blood flow-volume relationship, which is advantageous, as this relationship is not well characterized in neonates undergoing TH. Our purpose was to measure CBV, StO2 and CBF, assess their changes during TH and provide more accurate estimates of CMRO2. Our hypothesis was that TH reduces CMRO2. METHOD AND MATERIALS We recruited three term babies who were admitted to the NICU for therapeutic hypothermia (33.5ºC for 72 hrs) with a diagnosis of hypoxic-isch...
Biomedical Optics Express, 2011
The near infrared spectroscopy (NIRS) frequency-domain multi-distance (FD-MD) method allows for t... more The near infrared spectroscopy (NIRS) frequency-domain multi-distance (FD-MD) method allows for the estimation of optical properties in biological tissue using the phase and intensity of radiofrequency modulated light at different source-detector separations. In this study, we evaluated the accuracy of this method to retrieve the absorption coefficient of the brain at different ages. Synthetic measurements were generated with Monte Carlo simulations in magnetic resonance imaging (MRI)-based heterogeneous head models for four ages: newborn, 6 and 12 month old infants, and adult. For each age, we determined the optimal set of sourcedetector separations and estimated the corresponding errors. Errors arise from different origins: methodological (FD-MD) and anatomical (curvature, head size and contamination by extra-cerebral tissues). We found that the brain optical absorption could be retrieved with an error between 8-24% in neonates and infants, while the error increased to 19-44% in adults over all source-detector distances. The dominant contribution to the error was found to be the head curvature in neonates and infants, and the extra-cerebral tissues in adults.
Biomedical Optics, 2008
1. Introduction Electroencephalography (EEG) of premature neonates during quiet sleep normally sh... more 1. Introduction Electroencephalography (EEG) of premature neonates during quiet sleep normally shows a spontaneous, physiological discontinuity of electrical activity [1]. The discontinuous spontaneous EEG bursts of activity of sharp onset and high amplitude occurring in a ...
Biomedical Optics and 3-D Imaging, 2010
Near infrared spectroscopy and imaging of breast cancer has seen rapid progress over the past dec... more Near infrared spectroscopy and imaging of breast cancer has seen rapid progress over the past decade [1]. Recently, significant effort has been expended towards the development of faster instrumentation to enable dynamic optical imaging. Time-resolved measurements of ...
Methods: Seventy-two newborns (24-42 weeks PMA with no suspicion of brain injury were recruited t... more Methods: Seventy-two newborns (24-42 weeks PMA with no suspicion of brain injury were recruited to investigate regional and hemispheric cortical differences. We used a customized FDNIRS system (ISS Inc., Champaign, IL, USA) to measure SO2 and cerebral blood ...
Abstract: We use Frequency-Domain Near-Infrared Spectroscopy to detect brain injuries in neonates... more Abstract: We use Frequency-Domain Near-Infrared Spectroscopy to detect brain injuries in neonates by noninvasively measuring cerebral oxygenation and blood volume. Correlation of our data with subsequent diagnoses suggests the effectiveness of FD-NIRS as a bedside monitor. ...
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Most representative papers by Nadege Roche-Labarbe
Book chapters by Nadege Roche-Labarbe
Other papers by Nadege Roche-Labarbe