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Leavy A, Phelan J, Jimenez-Mateos EM. Contribution of microglia to the epileptiform activity that results from neonatal hypoxia. Neuropharmacology 2024; 253:109968. [PMID: 38692453 DOI: 10.1016/j.neuropharm.2024.109968] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/22/2024] [Revised: 04/13/2024] [Accepted: 04/22/2024] [Indexed: 05/03/2024]
Abstract
Microglia are described as the immune cells of the brain, their immune properties have been extensively studied since first described, however, their neural functions have only been explored over the last decade. Microglia have an important role in maintaining homeostasis in the central nervous system by surveying their surroundings to detect pathogens or damage cells. While these are the classical functions described for microglia, more recently their neural functions have been defined; they are critical to the maturation of neurons during embryonic and postnatal development, phagocytic microglia remove excess synapses during development, a process called synaptic pruning, which is important to overall neural maturation. Furthermore, microglia can respond to neuronal activity and, together with astrocytes, can regulate neural activity, contributing to the equilibrium between excitation and inhibition through a feedback loop. Hypoxia at birth is a serious neurological condition that disrupts normal brain function resulting in seizures and epilepsy later in life. Evidence has shown that microglia may contribute to this hyperexcitability after neonatal hypoxia. This review will summarize the existing data on the role of microglia in the pathogenesis of neonatal hypoxia and the plausible mechanisms that contribute to the development of hyperexcitability after hypoxia in neonates. This article is part of the Special Issue on "Microglia".
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Affiliation(s)
- Aisling Leavy
- Discipline of Physiology, School of Medicine, Trinity College Dublin, The University of Dublin, Dublin, Ireland
| | - Jessie Phelan
- Discipline of Physiology, School of Medicine, Trinity College Dublin, The University of Dublin, Dublin, Ireland
| | - Eva M Jimenez-Mateos
- Discipline of Physiology, School of Medicine, Trinity College Dublin, The University of Dublin, Dublin, Ireland.
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2
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Shahdadian S, Wang X, Liu H. Directed physiological networks in the human prefrontal cortex at rest and post transcranial photobiomodulation. Sci Rep 2024; 14:10242. [PMID: 38702415 PMCID: PMC11068774 DOI: 10.1038/s41598-024-59879-7] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/28/2023] [Accepted: 04/16/2024] [Indexed: 05/06/2024] Open
Abstract
Cerebral infra-slow oscillation (ISO) is a source of vasomotion in endogenic (E; 0.005-0.02 Hz), neurogenic (N; 0.02-0.04 Hz), and myogenic (M; 0.04-0.2 Hz) frequency bands. In this study, we quantified changes in prefrontal concentrations of oxygenated hemoglobin (Δ[HbO]) and redox-state cytochrome c oxidase (Δ[CCO]) as hemodynamic and metabolic activity metrics, and electroencephalogram (EEG) powers as electrophysiological activity, using concurrent measurements of 2-channel broadband near-infrared spectroscopy and EEG on the forehead of 22 healthy participants at rest. After preprocessing, the multi-modality signals were analyzed using generalized partial directed coherence to construct unilateral neurophysiological networks among the three neurophysiological metrics (with simplified symbols of HbO, CCO, and EEG) in each E/N/M frequency band. The links in these networks represent neurovascular, neurometabolic, and metabolicvascular coupling (NVC, NMC, and MVC). The results illustrate that the demand for oxygen by neuronal activity and metabolism (EEG and CCO) drives the hemodynamic supply (HbO) in all E/N/M bands in the resting prefrontal cortex. Furthermore, to investigate the effect of transcranial photobiomodulation (tPBM), we performed a sham-controlled study by delivering an 800-nm laser beam to the left and right prefrontal cortex of the same participants. After performing the same data processing and statistical analysis, we obtained novel and important findings: tPBM delivered on either side of the prefrontal cortex triggered the alteration or reversal of directed network couplings among the three neurophysiological entities (i.e., HbO, CCO, and EEG frequency-specific powers) in the physiological network in the E and N bands, demonstrating that during the post-tPBM period, both metabolism and hemodynamic supply drive electrophysiological activity in directed network coupling of the prefrontal cortex (PFC). Overall, this study revealed that tPBM facilitates significant modulation of the directionality of neurophysiological networks in electrophysiological, metabolic, and hemodynamic activities.
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Affiliation(s)
- Sadra Shahdadian
- Department of Bioengineering, University of Texas at Arlington, Arlington, TX, 76019, USA
| | - Xinlong Wang
- Department of Bioengineering, University of Texas at Arlington, Arlington, TX, 76019, USA
| | - Hanli Liu
- Department of Bioengineering, University of Texas at Arlington, Arlington, TX, 76019, USA.
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Sissons C, Saeed F, Carter C, Lee K, Kerr K, Shahdadian S, Liu H. Unilateral Mitochondrial-Hemodynamic Coupling and Bilateral Connectivity in the Prefrontal Cortices of Young and Older Healthy Adults. Bioengineering (Basel) 2023; 10:1336. [PMID: 38002460 PMCID: PMC10669330 DOI: 10.3390/bioengineering10111336] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/05/2023] [Revised: 11/02/2023] [Accepted: 11/09/2023] [Indexed: 11/26/2023] Open
Abstract
A recent study demonstrated that noninvasive measurements of cortical hemodynamics and metabolism in the resting human prefrontal cortex can facilitate quantitative metrics of unilateral mitochondrial-hemodynamic coupling and bilateral connectivity in infraslow oscillation frequencies in young adults. The infraslow oscillation includes three distinct vasomotions with endogenic (E), neurogenic (N), and myogenic (M) frequency bands. The goal of this study was to prove the hypothesis that there are significant differences between young and older adults in the unilateral coupling (uCOP) and bilateral connectivity (bCON) in the prefrontal cortex. Accordingly, we performed measurements from 24 older adults (67.2 ± 5.9 years of age) using the same two-channel broadband near-infrared spectroscopy (bbNIRS) setup and resting-state experimental protocol as those in the recent study. After quantification of uCOP and bCON in three E/N/M frequencies and statistical analysis, we demonstrated that older adults had significantly weaker bilateral hemodynamic connectivity but significantly stronger bilateral metabolic connectivity than young adults in the M band. Furthermore, older adults exhibited significantly stronger unilateral coupling on both prefrontal sides in all E/N/M bands, particularly with a very large effect size in the M band (>1.9). These age-related results clearly support our hypothesis and were well interpreted following neurophysiological principles. The key finding of this paper is that the neurophysiological metrics of uCOP and bCON are highly associated with age and may have the potential to become meaningful features for human brain health and be translatable for future clinical applications, such as the early detection of Alzheimer's disease.
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Affiliation(s)
- Claire Sissons
- Department of Bioengineering, University of Texas at Arlington, Arlington, TX 76019, USA
| | - Fiza Saeed
- Department of Bioengineering, University of Texas at Arlington, Arlington, TX 76019, USA
| | - Caroline Carter
- Department of Bioengineering, University of Texas at Arlington, Arlington, TX 76019, USA
| | - Kathy Lee
- School of Social Work, University of Texas at Arlington, Arlington, TX 76019, USA
| | - Kristen Kerr
- School of Social Work, University of Texas at Arlington, Arlington, TX 76019, USA
| | - Sadra Shahdadian
- Department of Bioengineering, University of Texas at Arlington, Arlington, TX 76019, USA
| | - Hanli Liu
- Department of Bioengineering, University of Texas at Arlington, Arlington, TX 76019, USA
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Harvey-Jones K, Lange F, Verma V, Bale G, Meehan C, Avdic-Belltheus A, Hristova M, Sokolska M, Torrealdea F, Golay X, Parfentyeva V, Durduran T, Bainbridge A, Tachtsidis I, Robertson NJ, Mitra S. Early assessment of injury with optical markers in a piglet model of neonatal encephalopathy. Pediatr Res 2023; 94:1675-1683. [PMID: 37308684 PMCID: PMC10624614 DOI: 10.1038/s41390-023-02679-y] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/03/2023] [Revised: 04/25/2023] [Accepted: 05/08/2023] [Indexed: 06/14/2023]
Abstract
BACKGROUND Opportunities for adjunct therapies with cooling in neonatal encephalopathy are imminent; however, robust biomarkers of early assessment are lacking. Using an optical platform of broadband near-infrared spectroscopy and diffuse correlation spectroscopy to directly measure mitochondrial metabolism (oxCCO), oxygenation (HbD), cerebral blood flow (CBF), we hypothesised optical indices early (1-h post insult) after hypoxia-ischaemia (HI) predicts insult severity and outcome. METHODS Nineteen newborn large white piglets underwent continuous neuromonitoring as controls or following moderate or severe HI. Optical indices were expressed as mean semblance (phase difference) and coherence (spectral similarity) between signals using wavelet analysis. Outcome markers included the lactate/N-acetyl aspartate (Lac/NAA) ratio at 6 h on proton MRS and TUNEL cell count. RESULTS CBF-HbD semblance (cerebrovascular dysfunction) correlated with BGT and white matter (WM) Lac/NAA (r2 = 0.46, p = 0.004, r2 = 0.45, p = 0.004, respectively), TUNEL cell count (r2 = 0.34, p = 0.02) and predicted both initial insult (r2 = 0.62, p = 0.002) and outcome group (r2 = 0.65 p = 0.003). oxCCO-HbD semblance (cerebral metabolic dysfunction) correlated with BGT and WM Lac/NAA (r2 = 0.34, p = 0.01 and r2 = 0.46, p = 0.002, respectively) and differentiated between outcome groups (r2 = 0.43, p = 0.01). CONCLUSION Optical markers of both cerebral metabolic and vascular dysfunction 1 h after HI predicted injury severity and subsequent outcome in a pre-clinical model. IMPACT This study highlights the possibility of using non-invasive optical biomarkers for early assessment of injury severity following neonatal encephalopathy, relating to the outcome. Continuous cot-side monitoring of these optical markers can be useful for disease stratification in the clinical population and for identifying infants who might benefit from future adjunct neuroprotective therapies beyond cooling.
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Affiliation(s)
| | - Frederic Lange
- Department of Medical Physics and Biomedical Engineering, University College London, London, UK
| | - Vinita Verma
- Institute for Women's Health, University College London, London, UK
| | - Gemma Bale
- Department of Engineering and Department of Physics, University of Cambridge, Cambridge, UK
| | | | | | - Mariya Hristova
- Institute for Women's Health, University College London, London, UK
| | - Magdalena Sokolska
- Medical Physics and Biomedical Engineering, University College London Hospital, London, UK
| | - Francisco Torrealdea
- Medical Physics and Biomedical Engineering, University College London Hospital, London, UK
| | - Xavier Golay
- Institute of Neurology, University College London, London, UK
| | - Veronika Parfentyeva
- ICFO-Institut de Ciències Fotòniques, The Barcelona Institute of Science and Technology, Castelldefels (Barcelona), Spain
| | - Turgut Durduran
- ICFO-Institut de Ciències Fotòniques, The Barcelona Institute of Science and Technology, Castelldefels (Barcelona), Spain
- Institució Catalana de Recerca i Estudis Avançats (ICREA), Barcelona, Spain
| | - Alan Bainbridge
- Medical Physics and Biomedical Engineering, University College London Hospital, London, UK
| | - Ilias Tachtsidis
- Department of Medical Physics and Biomedical Engineering, University College London, London, UK
| | | | - Subhabrata Mitra
- Institute for Women's Health, University College London, London, UK.
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5
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Shahdadian S, Wang X, Liu H. Directed physiological networks in the human prefrontal cortex at rest and post transcranial photobiomodulation. RESEARCH SQUARE 2023:rs.3.rs-3393702. [PMID: 37886539 PMCID: PMC10602070 DOI: 10.21203/rs.3.rs-3393702/v1] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 10/28/2023]
Abstract
Cerebral infra-slow oscillation (ISO) is a source of vasomotion in endogenic (E; 0.005-0.02 Hz), neurogenic (N; 0.02-0.04 Hz), and myogenic (M; 0.04-0.2 Hz) frequency bands. In this study, we quantified changes in prefrontal concentrations of oxygenated hemoglobin ( Δ [ H b O ] ) and redox-state cytochrome c oxidase ( Δ [ C C O ] ) as hemodynamic and metabolic activity metrics, and electroencephalogram (EEG) powers as electrophysiological activity, using concurrent measurements of 2-channel broadband near-infrared spectroscopy and EEG on the forehead of 22 healthy participants at rest. After preprocessing, the multi-modality signals were analyzed using generalized partial directed coherence to construct unilateral neurophysiological networks among the three neurophysiological metrics (with simplified symbols of HbO, CCO, and EEG) in each E/N/M frequency band. The links in these networks represent neurovascular, neurometabolic, and metabolicvascular coupling (NVC, NMC, and MVC). The results illustrate that the demand for oxygen by neuronal activity and metabolism (EEG and CCO) drives the hemodynamic supply (HbO) in all E/N/M bands in the resting prefrontal cortex. Furthermore, to investigate the effect of transcranial photobiomodulation (tPBM), we performed a sham-controlled study by delivering an 800-nm laser beam to the left and right prefrontal cortex of the same participants. After performing the same data processing and statistical analysis, we obtained novel and important findings: tPBM delivered on either side of the prefrontal cortex triggered the alteration or reversal of directed network couplings among the three neurophysiological entities (i.e., HbO, CCO, and EEG frequency-specific powers) in the physiological network in the E and N bands, demonstrating that during the post-tPBM period, both metabolism and hemodynamic supply drive electrophysiological activity in directed network coupling of the PFC. Overall, this study revealed that tPBM facilitates significant modulation of the directionality of neurophysiological networks in electrophysiological, metabolic, and hemodynamic activities.
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6
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Devaux JBL, Hedges CP, Birch N, Herbert N, Renshaw GMC, Hickey AJR. Electron transfer and ROS production in brain mitochondria of intertidal and subtidal triplefin fish (Tripterygiidae). J Comp Physiol B 2023:10.1007/s00360-023-01495-4. [PMID: 37145369 DOI: 10.1007/s00360-023-01495-4] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/23/2023] [Revised: 04/01/2023] [Accepted: 04/27/2023] [Indexed: 05/06/2023]
Abstract
While oxygen is essential for oxidative phosphorylation, O2 can form reactive species (ROS) when interacting with electrons of mitochondrial electron transport system. ROS is dependent on O2 pressure (PO2) and has traditionally been assessed in O2 saturated media, PO2 at which mitochondria do not typically function in vivo. Mitochondrial ROS can be significantly elevated by the respiratory complex II substrate succinate, which can accumulate within hypoxic tissues, and this is exacerbated further with reoxygenation. Intertidal species are repetitively exposed to extreme O2 fluctuations, and have likely evolved strategies to avoid excess ROS production. We evaluated mitochondrial electron leakage and ROS production in permeabilized brain of intertidal and subtidal triplefin fish species from hyperoxia to anoxia, and assessed the effect of anoxia reoxygenation and the influence of increasing succinate concentrations. At typical intracellular PO2, net ROS production was similar among all species; however at elevated PO2, brain tissues of the intertidal triplefin fish released less ROS than subtidal species. In addition, following in vitro anoxia reoxygenation, electron transfer mediated by succinate titration was better directed to respiration, and not to ROS production for intertidal species. Overall, these data indicate that intertidal triplefin fish species better manage electrons within the ETS, from hypoxic-hyperoxic transitions.
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Affiliation(s)
- Jules B L Devaux
- School of Biological Sciences, The University of Auckland, Auckland Mail Centre, Private Bag 92019, Auckland, 1142, New Zealand.
| | - Chris P Hedges
- School of Biological Sciences, The University of Auckland, Auckland Mail Centre, Private Bag 92019, Auckland, 1142, New Zealand
| | - Nigel Birch
- School of Biological Sciences, The University of Auckland, Auckland Mail Centre, Private Bag 92019, Auckland, 1142, New Zealand
| | - Neill Herbert
- Institute of Marine Science, The University Auckland, Auckland, 1142, New Zealand
| | - Gillian M C Renshaw
- School of Allied Health Sciences, Griffith University, Gold Coast Campus, Gold Coast, QLD, 4222, Australia
| | - Anthony J R Hickey
- School of Biological Sciences, The University of Auckland, Auckland Mail Centre, Private Bag 92019, Auckland, 1142, New Zealand
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7
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Acquarelli J, van Laarhoven T, Postma GJ, Jansen JJ, Rijpma A, van Asten S, Heerschap A, Buydens LMC, Marchiori E. Convolutional neural networks to predict brain tumor grades and Alzheimer’s disease with MR spectroscopic imaging data. PLoS One 2022; 17:e0268881. [PMID: 36001537 PMCID: PMC9401174 DOI: 10.1371/journal.pone.0268881] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/13/2021] [Accepted: 05/10/2022] [Indexed: 11/23/2022] Open
Abstract
Purpose To evaluate the value of convolutional neural network (CNN) in the diagnosis of human brain tumor or Alzheimer’s disease by MR spectroscopic imaging (MRSI) and to compare its Matthews correlation coefficient (MCC) score against that of other machine learning methods and previous evaluation of the same data. We address two challenges: 1) limited number of cases in MRSI datasets and 2) interpretability of results in the form of relevant spectral regions. Methods A shallow CNN with only one hidden layer and an ad-hoc loss function was constructed involving two branches for processing spectral and image features of a brain voxel respectively. Each branch consists of a single convolutional hidden layer. The output of the two convolutional layers is merged and fed to a classification layer that outputs class predictions for the given brain voxel. Results Our CNN method separated glioma grades 3 and 4 and identified Alzheimer’s disease patients using MRSI and complementary MRI data with high MCC score (Area Under the Curve were 0.87 and 0.91 respectively). The results demonstrated superior effectiveness over other popular methods as Partial Least Squares or Support Vector Machines. Also, our method automatically identified the spectral regions most important in the diagnosis process and we show that these are in good agreement with existing biomarkers from the literature. Conclusion Shallow CNNs models integrating image and spectral features improved quantitative and exploration and diagnosis of brain diseases for research and clinical purposes. Software is available at https://bitbucket.org/TeslaH2O/cnn_mrsi.
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Affiliation(s)
- Jacopo Acquarelli
- Radboud University Nijmegen, Institute for Computing and Information Science, Nijmegen, The Netherlands
- Radboud University Nijmegen, Institute for Molecules and Materials, Nijmegen, The Netherlands
- * E-mail: (JA); (AH); (EM)
| | - Twan van Laarhoven
- Radboud University Nijmegen, Institute for Computing and Information Science, Nijmegen, The Netherlands
| | - Geert J. Postma
- Radboud University Nijmegen, Institute for Molecules and Materials, Nijmegen, The Netherlands
| | - Jeroen J. Jansen
- Radboud University Nijmegen, Institute for Molecules and Materials, Nijmegen, The Netherlands
| | - Anne Rijpma
- Department of Radiology and Nuclear Medicine, Radboud University Medical Center Nijmegen, Nijmegen, The Netherlands
| | - Sjaak van Asten
- Department of Radiology and Nuclear Medicine, Radboud University Medical Center Nijmegen, Nijmegen, The Netherlands
| | - Arend Heerschap
- Department of Radiology and Nuclear Medicine, Radboud University Medical Center Nijmegen, Nijmegen, The Netherlands
- * E-mail: (JA); (AH); (EM)
| | - Lutgarde M. C. Buydens
- Radboud University Nijmegen, Institute for Molecules and Materials, Nijmegen, The Netherlands
| | - Elena Marchiori
- Radboud University Nijmegen, Institute for Computing and Information Science, Nijmegen, The Netherlands
- * E-mail: (JA); (AH); (EM)
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Optical Monitoring in Neonatal Seizures. Cells 2022; 11:cells11162602. [PMID: 36010678 PMCID: PMC9407001 DOI: 10.3390/cells11162602] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/28/2022] [Revised: 07/30/2022] [Accepted: 08/16/2022] [Indexed: 11/17/2022] Open
Abstract
BACKGROUND Neonatal seizures remain a significant cause of morbidity and mortality worldwide. The past decade has resulted in substantial progress in seizure detection and understanding the impact seizures have on the developing brain. Optical monitoring such as cerebral near-infrared spectroscopy (NIRS) and broadband NIRS can provide non-invasive continuous real-time monitoring of the changes in brain metabolism and haemodynamics. AIM To perform a systematic review of optical biomarkers to identify changes in cerebral haemodynamics and metabolism during the pre-ictal, ictal, and post-ictal phases of neonatal seizures. METHOD A systematic search was performed in eight databases. The search combined the three broad categories: (neonates) AND (NIRS) AND (seizures) using the stepwise approach following PRISMA guidance. RESULTS Fifteen papers described the haemodynamic and/or metabolic changes observed with NIRS during neonatal seizures. No randomised controlled trials were identified during the search. Studies reported various changes occurring in the pre-ictal, ictal, and post-ictal phases of seizures. CONCLUSION Clear changes in cerebral haemodynamics and metabolism were noted during the pre-ictal, ictal, and post-ictal phases of seizures in neonates. Further studies are necessary to determine whether NIRS-based methods can be used at the cot-side to provide clear pathophysiological data in real-time during neonatal seizures.
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Shahdadian S, Wang X, Kang S, Carter C, Chaudhari A, Liu H. Prefrontal cortical connectivity and coupling of infraslow oscillation in the resting human brain: a 2-channel broadband NIRS study. Cereb Cortex Commun 2022; 3:tgac033. [PMID: 36072711 PMCID: PMC9441674 DOI: 10.1093/texcom/tgac033] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/10/2022] [Revised: 07/19/2022] [Accepted: 07/23/2022] [Indexed: 11/12/2022] Open
Abstract
Abstract
The resting-state infraslow oscillation (ISO) of the cerebral cortex reflects the neurophysiological state of the human brain. ISO results from distinct vasomotion with endogenic (E), neurogenic (N), and myogenic (M) frequency bands. Quantification of prefrontal ISO in cortical hemodynamics and metabolism in the resting human brain may facilitate the identification of objective features that are characteristic of certain brain disorders. The goal of this study was to explore and quantify the prefrontal ISO of the cortical concentration changes of oxygenated hemoglobin (Δ[HbO]) and redox-state cytochrome c oxidase (Δ[CCO]) as hemodynamic and metabolic activity metrics in all 3 E/N/M bands. Two-channel broadband near-infrared spectroscopy (2-bbNIRS) enabled measurements of the forehead of 26 healthy young participants in a resting state once a week for 5 weeks. After quantifying the ISO spectral amplitude (SA) and coherence at each E/N/M band, several key and statistically reliable metrics were obtained as features: (i) SA of Δ[HbO] at all E/N/M bands, (ii) SA of Δ[CCO] in the M band, (iii) bilateral connectivity of hemodynamics and metabolism across the E and N bands, and (iv) unilateral hemodynamic–metabolic coupling in each of the E and M bands. These features have promising potential to be developed as objective biomarkers for clinical applications in the future.
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Affiliation(s)
- Sadra Shahdadian
- Department of Bioengineering, The University of Texas at Arlington , 500 UTA Blvd, Arlington, TX 76019, United States
| | - Xinlong Wang
- Department of Bioengineering, The University of Texas at Arlington , 500 UTA Blvd, Arlington, TX 76019, United States
| | - Shu Kang
- Department of Bioengineering, The University of Texas at Arlington , 500 UTA Blvd, Arlington, TX 76019, United States
| | - Caroline Carter
- Department of Bioengineering, The University of Texas at Arlington , 500 UTA Blvd, Arlington, TX 76019, United States
| | - Akhil Chaudhari
- Department of Bioengineering, The University of Texas at Arlington , 500 UTA Blvd, Arlington, TX 76019, United States
| | - Hanli Liu
- Department of Bioengineering, The University of Texas at Arlington , 500 UTA Blvd, Arlington, TX 76019, United States
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Advances in Neuroimaging and Monitoring to Defend Cerebral Perfusion in Noncardiac Surgery. Anesthesiology 2022; 136:1015-1038. [PMID: 35482943 DOI: 10.1097/aln.0000000000004205] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
Abstract
Noncardiac surgery conveys a substantial risk of secondary organ dysfunction and injury. Neurocognitive dysfunction and covert stroke are emerging as major forms of perioperative organ dysfunction, but a better understanding of perioperative neurobiology is required to identify effective treatment strategies. The likelihood and severity of perioperative brain injury may be increased by intraoperative hemodynamic dysfunction, tissue hypoperfusion, and a failure to recognize complications early in their development. Advances in neuroimaging and monitoring techniques, including optical, sonographic, and magnetic resonance, have progressed beyond structural imaging and now enable noninvasive assessment of cerebral perfusion, vascular reserve, metabolism, and neurologic function at the bedside. Translation of these imaging methods into the perioperative setting has highlighted several potential avenues to optimize tissue perfusion and deliver neuroprotection. This review introduces the methods, metrics, and evidence underlying emerging optical and magnetic resonance neuroimaging methods and discusses their potential experimental and clinical utility in the setting of noncardiac surgery.
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11
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Broadband-NIRS System Identifies Epileptic Focus in a Child with Focal Cortical Dysplasia—A Case Study. Metabolites 2022; 12:metabo12030260. [PMID: 35323703 PMCID: PMC8951122 DOI: 10.3390/metabo12030260] [Citation(s) in RCA: 6] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/31/2022] [Revised: 03/03/2022] [Accepted: 03/12/2022] [Indexed: 12/10/2022] Open
Abstract
Epileptic seizures are transiently occurring symptoms due to abnormal excessive or synchronous neuronal activity in the brain. Previous functional near-infrared spectroscopy (fNIRS) studies during seizures have focused in only monitoring the brain oxygenation and haemodynamic changes. However, few tools are available to measure actual cellular metabolism during seizures, especially at the bedside. Here we use an in-house developed multichannel broadband NIRS (or bNIRS) system, that, alongside the changes in oxy-, deoxy- haemoglobin concentration (HbO2, HHb), also quantifies the changes in oxidised cytochrome-c-oxidase Δ(oxCCO), a marker of cellular oxygen metabolism, simultaneously over 16 different brain locations. We used bNIRS to measure metabolic activity alongside brain tissue haemodynamics/oxygenation during 17 epileptic seizures at the bedside of a 3-year-old girl with seizures due to an extensive malformation of cortical development in the left posterior quadrant. Simultaneously Video-EEG data was recorded from 12 channels. Whilst we did observe the expected increase in brain tissue oxygenation (HbD) during seizures, it was almost diminished in the area of the focal cortical dysplasia. Furthermore, in the area of seizure origination (epileptic focus) ΔoxCCO decreased significantly at the time of seizure generalization when compared to the mean change in all other channels. We hypothesize that this indicates an incapacity to sustain and increase brain tissue metabolism during seizures in the region of the epileptic focus.
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12
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Siddiqui MF, Pinti P, Lloyd-Fox S, Jones EJH, Brigadoi S, Collins-Jones L, Tachtsidis I, Johnson MH, Elwell CE. Regional Haemodynamic and Metabolic Coupling in Infants. Front Hum Neurosci 2022; 15:780076. [PMID: 35185494 PMCID: PMC8854371 DOI: 10.3389/fnhum.2021.780076] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/20/2021] [Accepted: 11/01/2021] [Indexed: 11/13/2022] Open
Abstract
Metabolic pathways underlying brain function remain largely unexplored during neurodevelopment, predominantly due to the lack of feasible techniques for use with awake infants. Broadband near-infrared spectroscopy (bNIRS) provides the opportunity to explore the relationship between cerebral energy metabolism and blood oxygenation/haemodynamics through the measurement of changes in the oxidation state of mitochondrial respiratory chain enzyme cytochrome-c-oxidase (ΔoxCCO) alongside haemodynamic changes. We used a bNIRS system to measure ΔoxCCO and haemodynamics during functional activation in a group of 42 typically developing infants aged between 4 and 7 months. bNIRS measurements were made over the right hemisphere over temporal, parietal and central cortical regions, in response to social and non-social visual and auditory stimuli. Both ΔoxCCO and Δ[HbO2] displayed larger activation for the social condition in comparison to the non-social condition. Integration of haemodynamic and metabolic signals revealed networks of stimulus-selective cortical regions that were not apparent from analysis of the individual bNIRS signals. These results provide the first spatially resolved measures of cerebral metabolic activity alongside haemodynamics during functional activation in infants. Measuring synchronised changes in metabolism and haemodynamics have the potential for uncovering the development of cortical specialisation in early infancy.
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Affiliation(s)
- Maheen F. Siddiqui
- Centre for Brain and Cognitive Development, Birkbeck College, University of London, London, United Kingdom
| | - Paola Pinti
- Centre for Brain and Cognitive Development, Birkbeck College, University of London, London, United Kingdom
| | - Sarah Lloyd-Fox
- Department of Psychology, University of Cambridge, Cambridge, United Kingdom
| | - Emily J. H. Jones
- Centre for Brain and Cognitive Development, Birkbeck College, University of London, London, United Kingdom
| | - Sabrina Brigadoi
- Department of Development and Social Psychology, University of Padua, Padua, Italy
- Department of Information Engineering, University of Padua, Padua, Italy
| | - Liam Collins-Jones
- Department of Medical Physics and Biomedical Engineering, University College London, London, United Kingdom
| | - Ilias Tachtsidis
- Department of Medical Physics and Biomedical Engineering, University College London, London, United Kingdom
| | - Mark H. Johnson
- Department of Psychology, University of Cambridge, Cambridge, United Kingdom
| | - Clare E. Elwell
- Department of Medical Physics and Biomedical Engineering, University College London, London, United Kingdom
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13
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Photobiomodulation at Different Wavelengths Boosts Mitochondrial Redox Metabolism and Hemoglobin Oxygenation: Lasers vs. Light-Emitting Diodes In Vivo. Metabolites 2022; 12:metabo12020103. [PMID: 35208178 PMCID: PMC8880116 DOI: 10.3390/metabo12020103] [Citation(s) in RCA: 18] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/24/2021] [Revised: 01/17/2022] [Accepted: 01/19/2022] [Indexed: 12/13/2022] Open
Abstract
Our group previously examined 8 min photobiomodulation (PBM) by 1064 nm laser on the human forearm in vivo to determine its significant effects on vascular hemodynamics and cytochrome c oxidase redox activity. Since PBM uses a wide array of wavelengths, in this paper, we investigated (i) whether different wavelengths of lasers induced different PBM effects, and (ii) if a light-emitting diode (LED) at a similar wavelength to a laser could induce similar PBM effects. A broadband near-infrared spectroscopy (bbNIRS) system was utilized to assess concentration changes in oxygenated hemoglobin (Δ[HbO]) and oxidized cytochrome c oxidase (Δ[oxCCO]) during and after PBM with lasers at 800 nm, 850 nm, and 1064 nm, as well as a LED at 810 nm. Two groups of 10 healthy participants were measured before, during, and after active and sham PBM on their forearms. All results were tested for significance using repeated measures ANOVA. Our results showed that (i) lasers at all three wavelengths enabled significant increases in Δ[HbO] and Δ[oxCCO] of the human forearm while the 1064 nm laser sustained the increases longer, and that (ii) the 810-nm LED with a moderate irradiance (≈135 mW/cm2) induced measurable and significant rises in Δ[HbO] and Δ[oxCCO] with respect to the sham stimulation on the human forearm.
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14
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Siddiqui MF, Brigadoi S, Collins-Jones L, Lloyd-Fox S, Jones EJH, Tachtsidis I, Johnson MH, Elwell CE. Imaging Cerebral Energy Metabolism in Healthy Infants. ADVANCES IN EXPERIMENTAL MEDICINE AND BIOLOGY 2022; 1395:9-15. [PMID: 36527606 DOI: 10.1007/978-3-031-14190-4_2] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/23/2022]
Abstract
Broadband near-infrared spectroscopy (bNIRS) has the potential to provide non-invasive measures of cerebral haemodynamic changes alongside changes in cellular oxygen utilisation through the measurement of mitochondrial enzyme cytochrome-c-oxidase (oxCCO). It therefore provides the opportunity to explore brain function and specialisation, which remains largely unexplored in infancy. We used bNIRS to measure changes in haemodynamics and changes in oxCCO in 4-to-7-month-old infants over the occipital and right temporal and parietal cortices in response to social and non-social visual and auditory stimuli. Changes in concentration of oxygenated-haemoglobin (Δ[HbO2]), deoxygenated haemoglobin (Δ[HHb]) and change in the oxidation state of oxCCO (Δ[oxCCO]) were calculated using changes in attenuation of light at 120 wavelengths between 780 and900 nm, using the UCLn algorithm. For 4 infants, the attenuation changes in a subset of wavelengths were used to perform image reconstruction, in an age-matched infant model, for channels over the right parietal and temporal cortices, using a multispectral approach which allows direct reconstruction of concentration change data. The volumetric reconstructed images were mapped onto the cortical surface to visualise the reconstructed changes in concentration of HbO2 and HHb and changes in metabolism for both social and non-social stimuli. Spatially localised activation was observed for Δ[oxCCO] and Δ[HbO2] over the temporo-parietal region, in response to the social stimulus. This study provides the first reconstructed images of changes in metabolism in healthy, awake infants.
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Affiliation(s)
- M F Siddiqui
- Centre for Brain and Cognitive Development, Department of Psychology, Birkbeck College, University of London, London, UK.
| | - S Brigadoi
- Department of Development and Social Psychology, University of Padova, Padua, Italy.,Department of Information Engineering, University of Padova, Padua, Italy
| | - L Collins-Jones
- Department of Medical Physics and Biomedical Engineering, University College London, London, UK
| | - S Lloyd-Fox
- Department of Psychology, University of Cambridge, Cambridge, UK
| | - E J H Jones
- Centre for Brain and Cognitive Development, Department of Psychology, Birkbeck College, University of London, London, UK
| | - I Tachtsidis
- Department of Psychology, University of Cambridge, Cambridge, UK
| | - M H Johnson
- Department of Psychology, University of Cambridge, Cambridge, UK
| | - C E Elwell
- Department of Psychology, University of Cambridge, Cambridge, UK
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15
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Hashem M, Wu Y, Dunn JF. Quantification of cytochrome c oxidase and tissue oxygenation using CW-NIRS in a mouse cerebral cortex. BIOMEDICAL OPTICS EXPRESS 2021; 12:7632-7656. [PMID: 35003857 PMCID: PMC8713667 DOI: 10.1364/boe.435532] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/01/2021] [Revised: 10/06/2021] [Accepted: 11/05/2021] [Indexed: 05/05/2023]
Abstract
We provide a protocol for measuring the absolute concentration of the oxidized and reduced state of cytochrome c oxidase (CCO) in the cerebral cortex of mice, using broadband continuous-wave NIRS. The algorithm (NIR-AQUA) allows for absolute quantification of CCO and deoxyhemoglobin. Combined with an anoxia pulse, this also allows for quantification of total hemoglobin, and tissue oxygen saturation. CCO in the cortex was 4.9 ± 0.1 μM (mean ± SD, n=6). In normoxia, 84% of CCO was oxidized. We include hypoxia and cyanide validation studies to show CCO can be quantified independently to hemoglobin. This can be applied to study oxidative metabolism in the many rodent models of neurological disease.
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Affiliation(s)
- Mada Hashem
- Biomedical Engineering Graduate Program, University of Calgary, Calgary, Alberta, Canada T2N 4N1, Canada
- Department of Radiology, Faculty of Medicine, University of Calgary, Calgary, Alberta, Canada T2N 4N1, Canada
- Hotchkiss Brain Institute, University of Calgary, Alberta, Canada T2N 4N1, Canada
- Experimental Imaging Centre, Cumming School of Medicine, University of Calgary, Alberta, Canada T2N 4N1, Canada
| | - Ying Wu
- Department of Radiology, Faculty of Medicine, University of Calgary, Calgary, Alberta, Canada T2N 4N1, Canada
- Hotchkiss Brain Institute, University of Calgary, Alberta, Canada T2N 4N1, Canada
- Experimental Imaging Centre, Cumming School of Medicine, University of Calgary, Alberta, Canada T2N 4N1, Canada
| | - Jeff F. Dunn
- Department of Radiology, Faculty of Medicine, University of Calgary, Calgary, Alberta, Canada T2N 4N1, Canada
- Hotchkiss Brain Institute, University of Calgary, Alberta, Canada T2N 4N1, Canada
- Experimental Imaging Centre, Cumming School of Medicine, University of Calgary, Alberta, Canada T2N 4N1, Canada
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16
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Davidson JO, Gonzalez F, Gressens P, Gunn AJ. Update on mechanisms of the pathophysiology of neonatal encephalopathy. Semin Fetal Neonatal Med 2021; 26:101267. [PMID: 34274259 DOI: 10.1016/j.siny.2021.101267] [Citation(s) in RCA: 13] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/18/2022]
Abstract
Therapeutic hypothermia is now well established to significantly improve survival without disability after neonatal encephalopathy (NE). To further improve outcomes, we need to better understand the mechanisms of brain injury. The central finding, which offers the potential for neuroprotective and neurorestorative interventions, is that brain damage after perinatal hypoxia-ischemia evolves slowly over time. Although brain cells may die during profound hypoxia-ischemia, even after surprisingly severe insults many cells show transient recovery of oxidative metabolism during a "latent" phase characterized by actively suppressed neural metabolism and activity. Critically, after moderate to severe hypoxia-ischemia, this transient recovery is followed after ~6 h by a phase of secondary deterioration, with delayed seizures, failure of mitochondrial function, cytotoxic edema, and cell death over ~72 h. This is followed by a tertiary phase of remodeling and recovery. This review discusses the mechanisms of injury that occur during the primary, latent, secondary and tertiary phases of injury and potential treatments that target one or more of these phases. By analogy with therapeutic hypothermia, treatment as early as possible in the latent phase is likely to have the greatest potential to prevent injury ("neuroprotection"). In the secondary phase of injury, anticonvulsants can attenuate seizures, but show limited neuroprotection. Encouragingly, there is now increasing preclinical evidence that late, neurorestorative interventions have potential to improve long-term outcomes.
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Affiliation(s)
- Joanne O Davidson
- Fetal Physiology and Neuroscience Group, Department of Physiology, The University of Auckland, Auckland, New Zealand.
| | - Fernando Gonzalez
- Department of Pediatrics, University of California, San Francisco, CA, USA.
| | | | - Alistair J Gunn
- Fetal Physiology and Neuroscience Group, Department of Physiology, The University of Auckland, Auckland, New Zealand.
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17
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Htun Y, Nakamura S, Kusaka T. Hydrogen and therapeutic gases for neonatal hypoxic-ischemic encephalopathy: potential neuroprotective adjuncts in translational research. Pediatr Res 2021; 89:753-759. [PMID: 32505123 DOI: 10.1038/s41390-020-0998-z] [Citation(s) in RCA: 10] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/02/2020] [Revised: 05/08/2020] [Accepted: 05/12/2020] [Indexed: 11/09/2022]
Abstract
Numerous studies have examined the potential use of therapeutic gases for the treatment of various neurological disorders. Hydrogen gas, a promising neuroprotective agent, has been a focus of study due to its potent antioxidative properties. In translational research into adult diseases, hydrogen has been shown to be neuroprotective in disorders such as cerebral ischemia and traumatic brain injury, and in neurodegenerative diseases such as Alzheimer's disease. Animal and human studies have verified the safety and feasibility of molecular hydrogen. However, despite extensive research on its efficacy in adults, only a few studies have investigated its application in pediatric and neonatal medicine. Neonatal hypoxic-ischemic encephalopathy (HIE) is characterized by damage to neurons and other cells of the nervous system. One of the major contributing factors is excessive exposure to oxidative stress. Current research interest in HIE is shifting toward new neuroprotective agents, as single agents or as adjuncts to therapeutic hypothermia. Here, we review therapeutic gases, particularly hydrogen, and their potentials and limitations in the treatment of HIE in newborns. IMPACT: Translational animal models of neonatal HIE are a current focus of research into the therapeutic usefulness of various gases. Hydrogen ventilation as a single agent or in combination with therapeutic hypothermia shows short- and long-term neuroprotection in neonatal translational HIE models. The optimal target severity for therapeutic interventions should be well established to improve outcomes.
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Affiliation(s)
- Yinmon Htun
- Department of Pediatrics, Faculty of Medicine, Kagawa University, Kagawa, Japan.,Graduate School of Medicine, Faculty of Medicine, Kagawa University, Kagawa, Japan
| | - Shinji Nakamura
- Department of Pediatrics, Faculty of Medicine, Kagawa University, Kagawa, Japan
| | - Takashi Kusaka
- Department of Pediatrics, Faculty of Medicine, Kagawa University, Kagawa, Japan.
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18
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Kaynezhad P, Tachtsidis I, Aboelnour A, Sivaprasad S, Jeffery G. Watching synchronous mitochondrial respiration in the retina and its instability in a mouse model of macular degeneration. Sci Rep 2021; 11:3274. [PMID: 33558624 PMCID: PMC7870852 DOI: 10.1038/s41598-021-82811-2] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/23/2020] [Accepted: 01/12/2021] [Indexed: 11/09/2022] Open
Abstract
Mitochondrial function declines with age and in some diseases, but we have been unable to analyze this in vivo. Here, we optically examine retinal mitochondrial function as well as choroidal oxygenation and hemodynamics in aging C57 and complement factor H (CFH-/-) mice, proposed models of macular degeneration which suffer early retinal mitochondrial decline. In young C57s mitochondrial populations respire in coupled oscillatory behavior in cycles of ~ 8 min, which is phase linked to choroidal oscillatory hemodynamics. In aging C57s, the oscillations are less regular being ~ 14 min and more dissociated from choroidal hemodynamics. The mitochondrial oscillatory cycles are extended in CFH-/- mice being ~ 16 min and are further dissociated from choroidal hemodynamics. Mitochondrial decline occurs before age-related changes to choroidal vasculature, hence, is the likely origin of oscillatory disruption in hemodynamics. This technology offers a non-invasive technique to detect early retinal disease and its relationship to blood oxygenation in vivo and in real time.
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Affiliation(s)
- Pardis Kaynezhad
- Institute of Ophthalmology, University College London, London, EC1V 9EL, UK
| | - Ilias Tachtsidis
- Department of Medical Physics and Biomedical Engineering, University College London, London, WC1E 6BT, UK
| | - Asmaa Aboelnour
- Histology and Cytology Department, Faculty of Veterinary Medicine, Damanhour University, Damanhour, Egypt
| | - Sobha Sivaprasad
- Institute of Ophthalmology, University College London, London, EC1V 9EL, UK
| | - Glen Jeffery
- Institute of Ophthalmology, University College London, London, EC1V 9EL, UK.
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19
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Harvey-Jones K, Lange F, Tachtsidis I, Robertson NJ, Mitra S. Role of Optical Neuromonitoring in Neonatal Encephalopathy-Current State and Recent Advances. Front Pediatr 2021; 9:653676. [PMID: 33898363 PMCID: PMC8062863 DOI: 10.3389/fped.2021.653676] [Citation(s) in RCA: 11] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/15/2021] [Accepted: 03/15/2021] [Indexed: 11/19/2022] Open
Abstract
Neonatal encephalopathy (NE) in term and near-term infants is a significant global health problem; the worldwide burden of disease remains high despite the introduction of therapeutic hypothermia. Assessment of injury severity and effective management in the neonatal intensive care unit (NICU) relies on multiple monitoring modalities from systemic to brain-specific. Current neuromonitoring tools provide information utilized for seizure management, injury stratification, and prognostication, whilst systemic monitoring ensures multi-organ dysfunction is recognized early and supported wherever needed. The neuromonitoring technologies currently used in NE however, have limitations in either their availability during the active treatment window or their reliability to prognosticate and stratify injury confidently in the early period following insult. There is therefore a real need for a neuromonitoring tool that provides cot side, early and continuous monitoring of brain health which can reliably stratify injury severity, monitor response to current and emerging treatments, and prognosticate outcome. The clinical use of near-infrared spectroscopy (NIRS) technology has increased in recent years. Research studies within this population have also increased, alongside the development of both instrumentation and signal processing techniques. Increasing use of commercially available cerebral oximeters in the NICU, and the introduction of advanced optical measurements using broadband NIRS (BNIRS), frequency domain NIRS (FDNIRS), and diffuse correlation spectroscopy (DCS) have widened the scope by allowing the direct monitoring of oxygen metabolism and cerebral blood flow, both key to understanding pathophysiological changes and predicting outcome in NE. This review discusses the role of optical neuromonitoring in NE and why this modality may provide the next significant piece of the puzzle toward understanding the real time state of the injured newborn brain.
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Affiliation(s)
- Kelly Harvey-Jones
- Neonatology, EGA Institute for Women's Health, University College London, London, United Kingdom
| | - Frederic Lange
- Medical Physics and Biomedical Engineering, University College London, London, United Kingdom
| | - Ilias Tachtsidis
- Medical Physics and Biomedical Engineering, University College London, London, United Kingdom
| | - Nicola J Robertson
- Neonatology, EGA Institute for Women's Health, University College London, London, United Kingdom.,Edinburgh Neuroscience & Centre for Clinical Brain Sciences, The University of Edinburgh, Edinburgh, United Kingdom
| | - Subhabrata Mitra
- Neonatology, EGA Institute for Women's Health, University College London, London, United Kingdom
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20
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Bale G, Mitra S, Tachtsidis I. Metabolic brain measurements in the newborn: Advances in optical technologies. Physiol Rep 2020; 8:e14548. [PMID: 32889790 PMCID: PMC7507543 DOI: 10.14814/phy2.14548] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/29/2020] [Revised: 07/27/2020] [Accepted: 07/28/2020] [Indexed: 01/12/2023] Open
Abstract
Neonatal monitoring in neonatal intensive care is pushing the technological boundaries of newborn brain monitoring in order to improve patient outcome. There is an urgent need of a cot side, real time monitoring for assessment of brain injury severity and neurodevelopmental outcome, in particular for term newborn infants with hypoxic-ischemic brain injury. This topical review discusses why brain tissue metabolic monitoring is important in this group of infants and introduces the currently used neuromonitoring techniques for metabolic monitoring in the neonatal intensive care unit (NICU). New optical techniques that can monitor changes in brain metabolism together with brain hemodynamics at the cot side are presented. Early studies from these emerging technologies have demonstrated their potential to deliver continuous information regarding cerebral physiological changes in sick newborn infants in real time. The promises of these new tools as well as their potential limitations are discussed.
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Affiliation(s)
- Gemma Bale
- Medical Physics and Biomedical EngineeringUniversity College LondonLondonUK
| | - Subhabrata Mitra
- Neonatology, EGA Institute for Women's HealthUniversity College LondonLondonUK
| | - Ilias Tachtsidis
- Medical Physics and Biomedical EngineeringUniversity College LondonLondonUK
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21
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Attention and Capacity Limits in Perception: A Cellular Metabolism Account. J Neurosci 2020; 40:6801-6811. [PMID: 32747442 PMCID: PMC7455219 DOI: 10.1523/jneurosci.2368-19.2020] [Citation(s) in RCA: 20] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/03/2019] [Revised: 06/10/2020] [Accepted: 06/18/2020] [Indexed: 01/19/2023] Open
Abstract
Limits on perceptual capacity result in various phenomena of inattentional blindness. Here we propose a neurophysiological account attributing these perceptual capacity limits directly to limits on cerebral cellular metabolism. We hypothesized that overall cerebral energy supply remains constant, regardless of overall mental processing demands; therefore, an attention mechanism is required to regulate limited cellular metabolism levels in line with attended task demands. Increased perceptual load in a task (imposing a greater demand on neural computations) should thus result in increased metabolism underlying attended processing, and reduced metabolism mediating unattended processing. We tested this prediction measuring oxidation states of cytochrome c oxidase (oxCCO), an intracellular marker of cellular metabolism. Broadband near-infrared spectroscopy was used to record oxCCO levels from human visual cortex while participants (both sexes) performed a rapid sequential visual search task under either high perceptual load (complex feature-conjunction search) or low load (feature pop-out search). A task-irrelevant, peripheral checkerboard was presented on a random half of trials. Our findings showed that oxCCO levels in visual cortex regions responsive to the attended-task stimuli were increased in high versus low perceptual load, whereas oxCCO levels related to unattended processing were significantly reduced. A negative temporal correlation of these load effects further supported our metabolism trade-off account. These results demonstrate an attentional compensation mechanism that regulates cellular metabolism levels according to processing demands. Moreover, they provide novel evidence for the widely held stipulation that overall cerebral metabolism levels remain constant regardless of mental task demand and establish a neurophysiological account for capacity limits in perception. SIGNIFICANCE STATEMENT We investigated whether capacity limits in perception can be explained by the effects of attention on the allocation of limited cellular metabolic energy for perceptual processing. We measured the oxidation state of cytochrome c oxidase, an intracellular measure of metabolism, in human visual cortex during task performance. The results showed increased levels of cellular metabolism associated with attended processing and reduced levels of metabolism underlying unattended processing when the task was more demanding. A temporal correlation between these effects supported an attention-directed metabolism trade-off. These findings support an account for inattentional blindness grounded in cellular biochemistry. They also provide novel evidence for the claim that cerebral processing is limited by a constant energy supply, which thus requires attentional regulation.
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22
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Mitra S, Bale G, Meek J, Tachtsidis I, Robertson NJ. Cerebral Near Infrared Spectroscopy Monitoring in Term Infants With Hypoxic Ischemic Encephalopathy-A Systematic Review. Front Neurol 2020; 11:393. [PMID: 32536901 PMCID: PMC7267214 DOI: 10.3389/fneur.2020.00393] [Citation(s) in RCA: 33] [Impact Index Per Article: 8.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/07/2020] [Accepted: 04/17/2020] [Indexed: 12/13/2022] Open
Abstract
Background: Neonatal hypoxic ischemic encephalopathy (HIE) remains a significant cause of mortality and morbidity worldwide. Cerebral near infrared spectroscopy (NIRS) can provide cot side continuous information about changes in brain hemodynamics, oxygenation and metabolism in real time. Objective: To perform a systematic review of cerebral NIRS monitoring in term and near-term infants with HIE. Search Methods: A systematic search was performed in Ovid EMBASE and Medline database from inception to November 2019. The search combined three broad categories: measurement (NIRS monitoring), disease condition [hypoxic ischemic encephalopathy (HIE)] and subject category (newborn infants) using a stepwise approach as per PRISMA guidance. Selection Criteria: Only human studies published in English were included. Data Collection and Analysis: Two authors independently selected, assessed the quality, and extracted data from the studies for this review. Results: Forty-seven studies on term and near-term infants following HIE were identified. Most studies measured multi-distance NIRS based cerebral tissue saturation using monitors that are referred to as cerebral oximeters. Thirty-nine studies were published since 2010; eight studies were published before this. Fifteen studies reviewed the neurodevelopmental outcome in relation to NIRS findings. No randomized study was identified. Conclusion: Commercial NIRS cerebral oximeters can provide important information regarding changes in cerebral oxygenation and hemodynamics following HIE and can be particularly helpful when used in combination with other neuromonitoring tools. Optical measurements of brain metabolism using broadband NIRS and cerebral blood flow using diffuse correlation spectroscopy add additional pathophysiological information. Further randomized clinical trials and large observational studies are necessary with proper study design to assess the utility of NIRS in predicting neurodevelopmental outcome and guiding therapeutic interventions.
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Affiliation(s)
- Subhabrata Mitra
- Neonatology, Institute for Women's Health, University College London, London, United Kingdom
| | - Gemma Bale
- Medical Physics and Biomedical Engineering, University College London, London, United Kingdom
| | - Judith Meek
- Neonatology, Institute for Women's Health, University College London, London, United Kingdom
| | - Ilias Tachtsidis
- Medical Physics and Biomedical Engineering, University College London, London, United Kingdom
| | - Nicola J Robertson
- Neonatology, Institute for Women's Health, University College London, London, United Kingdom
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23
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Pruitt T, Wang X, Wu A, Kallioniemi E, Husain MM, Liu H. Transcranial Photobiomodulation (tPBM) With 1,064-nm Laser to Improve Cerebral Metabolism of the Human Brain In Vivo. Lasers Surg Med 2020; 52:807-813. [PMID: 32173886 PMCID: PMC7492377 DOI: 10.1002/lsm.23232] [Citation(s) in RCA: 34] [Impact Index Per Article: 8.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 03/02/2020] [Indexed: 12/13/2022]
Abstract
BACKGROUND AND OBJECTIVES In our previous proof-of-principle study, transcranial photobiomodulation (tPBM) with 1,064-nm laser was reported to significantly increase concentration changes of oxygenated hemoglobin (∆[HbO]) and oxidized-state cytochrome c oxidase (∆[oxi-CCO]) in the human brain. This paper further investigated (i) its validity in two different subsets of young human subjects at two study sites over a period of 3 years and (ii) age-related effects of tPBM by comparing sham-controlled increases of ∆[HbO] and ∆[oxi-CCO] between young and older adults. STUDY DESIGN/MATERIALS AND METHODS We measured sham-controlled ∆[HbO] and ∆[oxi-CCO] using broadband near-infrared spectroscopy (bb-NIRS) in 15 young (26.7 ± 2.7 years of age) and 5 older (68.2 ± 4.8 years of age) healthy normal subjects before, during, and after right-forehead tPBM/sham stimulation with 1,064-nm laser. Student t tests were used to test statistical differences in tPBM-induced ∆[HbO] and ∆[oxi-CCO] (i) between the 15 young subjects and those of 11 reported previously and (ii) between the two age groups measured in this study. RESULTS Statistical analysis showed that no significant difference existed in ∆[HbO] and ∆[oxi-CCO] during and post tPBM between the two subsets of young subjects at two study sites over a period of 3 years. Furthermore, the two age groups showed statistically identical net increases in sham-controlled ∆[HbO] and ∆[oxi-CCO]. CONCLUSIONS This study provided strong evidence to validate/confirm our previous findings that tPBM with 1,064-nm laser enables to increase cerebral ∆[HbO] and ∆[oxi-CCO] in the human brain, as measured by bb-NIRS. Overall, it demonstrated the robust reproducibility of tPBM being able to improve cerebral hemodynamics and metabolism of the human brain in vivo in both young and older adults. Lasers Surg. Med. © 2020 The Authors. Lasers in Surgery and Medicine published by Wiley Periodicals, Inc.
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Affiliation(s)
- Tyrell Pruitt
- Department of Bioengineering, University of Texas at Arlington, 500 UTA Blvd, Arlington, Texas, 76019.,Department of Psychiatry, UT Southwestern Medical Center, 5323 Harry Hines Blvd, Dallas, Texas, 75390
| | - Xinlong Wang
- Department of Bioengineering, University of Texas at Arlington, 500 UTA Blvd, Arlington, Texas, 76019
| | - Anqi Wu
- Department of Bioengineering, University of Texas at Arlington, 500 UTA Blvd, Arlington, Texas, 76019
| | - Elisa Kallioniemi
- Department of Psychiatry, UT Southwestern Medical Center, 5323 Harry Hines Blvd, Dallas, Texas, 75390
| | - Mustafa M Husain
- Department of Psychiatry, UT Southwestern Medical Center, 5323 Harry Hines Blvd, Dallas, Texas, 75390
| | - Hanli Liu
- Department of Bioengineering, University of Texas at Arlington, 500 UTA Blvd, Arlington, Texas, 76019
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24
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Broadband NIRS Cerebral Evaluation of the Hemodynamic and Oxidative State of Cytochrome-c-Oxidase Responses to +Gz Acceleration in Healthy Volunteers. ADVANCES IN EXPERIMENTAL MEDICINE AND BIOLOGY 2020; 1232:339-345. [PMID: 31893429 PMCID: PMC7612835 DOI: 10.1007/978-3-030-34461-0_43] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Indexed: 11/27/2022]
Abstract
We used a miniature broadband NIRS system to monitor concentration changes in brain oxygenation (oxy- and deoxy- haemoglobin [HbO2], [HHb]) and oxidised cytochrome-c-oxidase ([oxCCO]) during a high +Gz acceleration, induced by a human centrifuge, on two healthy experienced volunteers (2 male, 34 and 37 years). We performed a sequence of several +Gz exposures that were terminated at the onset of visual symptoms (loss of peripheral vision). Systemic parameters were recorded (i.e. heart rate, blood pressure and arterial saturation), and brain tissue blood volume changes ([HbT] = [HbO2] + [HHb]) and oxygen delivery ([HbDiff] = [HbO2] - [HHb]) were calculated. Volunteer 1 demonstrated a decrease in [HbT] of −3.49 ± 0.02 μMol and [HbDiff] of −3.23 ± 0.44 μMol, and an increase of [oxCCO] of 0.42 ± 0.01μMol. Volunteer 2 demonstrated a decrease in [HbDiff] of −4.37 ± 0.23 μMol, and no significant change in [HbT] (0.53 ± 0.06 μMol) and [oxCCO] (0.09 ± 0.06 μMol). The variability of the brain metabolic response was related to the level of ischaemia, suggesting that suppression of metabolism was due to lack of glucose substrate delivery rather than oxygen availability.
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25
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Changes in Brain Tissue Oxygenation and Metabolism During Rewarming After Neonatal Encephalopathy are Related to Electrical Abnormality. ADVANCES IN EXPERIMENTAL MEDICINE AND BIOLOGY 2020; 1232:25-31. [PMID: 31893390 DOI: 10.1007/978-3-030-34461-0_4] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/03/2022]
Abstract
Hypoxic ischemic encephalopathy (HIE) leads to significant mortality and morbidity, and therapeutic hypothermia (TH) has become a standard of care following HIE. After TH, the body temperature is brought back to 37 °C. Early electroencephalography (EEG) is a reliable outcome biomarker following HIE. We hypothesized that changes in cerebral oxidative metabolism, measured as Δ[oxCCO], in relation to changes in brain tissue oxygenation (measured as Δ[HbD]) during rewarming will correlate with injury severity as evidenced on amplitude integrated EEG/EEG at initial presentation. Broadband near-infrared spectroscopy (NIRS) and systemic data were collected during rewarming from 14 infants following HIE over a mean period of 12.5 h. All infants were monitored with video EEG telemetry using a standard neonatal montage. aEEG and EEG background was classified into mild, moderate and severely abnormal groups based on the background pattern. Two infants had mild, 6 infants had moderate and another 6 infants had severe abnormality at presentation. The relationship between [oxCCO] and [HbD] was evaluated between two groups of infants with abnormal electrical activity (mild vs moderate to severe). A significant difference was noted between the groups in the relationship between [oxCCO] and [HbD] (as r2) (p = 0.02). This result indicates that the mitochondrial injury and deranged oxidative metabolism persists in the moderate to severely abnormal group during rewarming.
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Lingam I, Meehan C, Avdic-Belltheus A, Martinello K, Hristova M, Kaynezhad P, Bauer C, Tachtsidis I, Golay X, Robertson NJ. Short-term effects of early initiation of magnesium infusion combined with cooling after hypoxia-ischemia in term piglets. Pediatr Res 2019; 86:699-708. [PMID: 31357208 DOI: 10.1038/s41390-019-0511-8] [Citation(s) in RCA: 18] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/04/2019] [Revised: 07/12/2019] [Accepted: 07/16/2019] [Indexed: 11/10/2022]
Abstract
BACKGROUND Neuroprotection from therapeutic hypothermia (HT) is incomplete, therefore additional strategies are necessary to improve long-term outcomes. We assessed the neuroprotective efficacy of magnesium sulfate (MgSO4) bolus and infusion over 48 h plus HT in a piglet model of term neonatal encephalopathy (NE). METHODS Fifteen newborn piglets were randomized following hypoxia-ischemia (HI) to: (i) MgSO4 180 mg/kg bolus and 8 mg/kg/h infusion with HT (Mg+HT) or (ii) HT and saline 0.5 ml/h (HT). Treatments were initiated 1 h post-HI; HT administered for 12 h (33.5 °C). HI was performed by transient carotid occlusion and inhalation of 6% O2 for 20-25 min. Primary outcomes included aEEG, magnetic resonance spectroscopy (MRS) at 24, and 48 h, and immunohistochemistry. RESULTS MgSO4 bolus and infusion was well tolerated (no hypotension) and doubled serum magnesium (0.72 vs 1.52 mmol/L) with modest (16%) rise in CSF. In Mg+HT compared to HT, there was overall reduced cell death (p = 0.01) and increased oligodendrocytes (p = 0.002). No improvement was seen on aEEG recovery (p = 0.084) or MRS (Lac/NAA; PCr/Pi; NTP/epp) (p > 0.05) at 48 h. CONCLUSION Doubling serum magnesium with HT was safe; however, the small incremental benefit of Mg+HT compared to HT is unlikely to translate into substantive long-term improvement. Such an incremental effect might justify further study of MgSO4 in combination with multiple therapies.
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Affiliation(s)
- Ingran Lingam
- Neonatology, Institute for Women's Health, University College London, London, UK.
| | - Chris Meehan
- Neonatology, Institute for Women's Health, University College London, London, UK
| | | | - Kathryn Martinello
- Neonatology, Institute for Women's Health, University College London, London, UK
| | - Mariya Hristova
- Neonatology, Institute for Women's Health, University College London, London, UK
| | - Pardis Kaynezhad
- Department of Medical Physics and Biomedical Engineering, University College London, London, UK
| | - Cornelius Bauer
- Department of Medical Physics and Biomedical Engineering, University College London, London, UK
| | - Ilias Tachtsidis
- Department of Medical Physics and Biomedical Engineering, University College London, London, UK
| | - Xavier Golay
- Department of Medical Physics and Biomedical Engineering, University College London, London, UK.,Institute of Neurology, University College London, London, UK
| | - Nicola J Robertson
- Neonatology, Institute for Women's Health, University College London, London, UK.,Neonatology, Sidra Medicine, Al Luqta Street, Education City, North Campus, Qatar Foundation, PO Box 26999, Doha, Qatar
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Kaynezhad P, Mitra S, Bale G, Bauer C, Lingam I, Meehan C, Avdic-Belltheus A, Martinello KA, Bainbridge A, Robertson NJ, Tachtsidis I. Quantification of the severity of hypoxic-ischemic brain injury in a neonatal preclinical model using measurements of cytochrome-c-oxidase from a miniature broadband-near-infrared spectroscopy system. NEUROPHOTONICS 2019; 6:045009. [PMID: 31737744 PMCID: PMC6855218 DOI: 10.1117/1.nph.6.4.045009] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/12/2019] [Accepted: 10/14/2019] [Indexed: 05/05/2023]
Abstract
We describe the development of a miniaturized broadband near-infrared spectroscopy system (bNIRS), which measures changes in cerebral tissue oxyhemoglobin ( [ HbO 2 ] ) and deoxyhemoglobin ([HHb]) plus tissue metabolism via changes in the oxidation state of cytochrome-c-oxidase ([oxCCO]). The system is based on a small light source and a customized mini-spectrometer. We assessed the instrument in a preclinical study in 27 newborn piglets undergoing transient cerebral hypoxia-ischemia (HI). We aimed to quantify the recovery of the HI insult and estimate the severity of the injury. The recovery in brain oxygenation ( Δ [ HbDiff ] = Δ [ HbO 2 ] - Δ [ HHb ] ), blood volume ( Δ [ HbT ] = Δ [ HbO 2 ] + Δ [ HHb ] ), and metabolism ( Δ [ oxCCO ] ) for up to 30 min after the end of HI were quantified in percentages using the recovery fraction (RF) algorithm, which quantifies the recovery of a signal with respect to baseline. The receiver operating characteristic analysis was performed on bNIRS-RF measurements compared to proton ( H 1 ) magnetic resonance spectroscopic (MRS)-derived thalamic lactate/N-acetylaspartate (Lac/NAA) measured at 24-h post HI insult; Lac/NAA peak area ratio is an accurate surrogate marker of neurodevelopmental outcome in babies with neonatal HI encephalopathy. The Δ [ oxCCO ] -RF cut-off threshold of 79% within 30 min of HI predicted injury severity based on Lac/NAA with high sensitivity (100%) and specificity (93%). A significant difference in thalamic Lac/NAA was noticed ( p < 0.0001 ) between the two groups based on this cut-off threshold of 79% Δ [ oxCCO ] -RF. The severe injury group ( n = 13 ) had ∼ 30 % smaller recovery in Δ [ HbDiff ] -RF ( p = 0.0001 ) and no significant difference was observed in Δ [ HbT ] -RF between groups. At 48 h post HI, significantly higher P 31 -MRS-measured inorganic phosphate/exchangeable phosphate pool (epp) ( p = 0.01 ) and reduced phosphocreatine/epp ( p = 0.003 ) were observed in the severe injury group indicating persistent cerebral energy depletion. Based on these results, the bNIRS measurement of the oxCCO recovery fraction offers a noninvasive real-time biomarker of brain injury severity within 30 min following HI insult.
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Affiliation(s)
- Pardis Kaynezhad
- University College London, Department of Medical Physics and Biomedical Engineering, London, United Kingdom
- Address all correspondence to Ilias Tachtsidis, E-mail:
| | - Subhabrata Mitra
- University College London, Institute for Women’s Health, London, United Kingdom
| | - Gemma Bale
- University College London, Department of Medical Physics and Biomedical Engineering, London, United Kingdom
| | - Cornelius Bauer
- University College London, Department of Medical Physics and Biomedical Engineering, London, United Kingdom
| | - Ingran Lingam
- University College London, Institute for Women’s Health, London, United Kingdom
| | - Christopher Meehan
- University College London, Institute for Women’s Health, London, United Kingdom
| | | | | | - Alan Bainbridge
- University College London Hospital, Department of Medical Physics and Biomedical Engineering, London, United Kingdom
| | - Nicola J. Robertson
- University College London, Institute for Women’s Health, London, United Kingdom
| | - Ilias Tachtsidis
- University College London, Department of Medical Physics and Biomedical Engineering, London, United Kingdom
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Bale G, Mitra S, de Roever I, Sokolska M, Price D, Bainbridge A, Gunny R, Uria-Avellanal C, Kendall GS, Meek J, Robertson NJ, Tachtsidis I. Oxygen dependency of mitochondrial metabolism indicates outcome of newborn brain injury. J Cereb Blood Flow Metab 2019; 39:2035-2047. [PMID: 29775114 PMCID: PMC6775592 DOI: 10.1177/0271678x18777928] [Citation(s) in RCA: 35] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/15/2022]
Abstract
There is a need for a method of real-time assessment of brain metabolism during neonatal hypoxic-ischaemic encephalopathy (HIE). We have used broadband near-infrared spectroscopy (NIRS) to monitor cerebral oxygenation and metabolic changes in 50 neonates with HIE undergoing therapeutic hypothermia treatment. In 24 neonates, 54 episodes of spontaneous decreases in peripheral oxygen saturation (desaturations) were recorded between 6 and 81 h after birth. We observed differences in the cerebral metabolic responses to these episodes that were related to the predicted outcome of the injury, as determined by subsequent magnetic resonance spectroscopy derived lactate/N-acetyl-aspartate. We demonstrated that a strong relationship between cerebral metabolism (broadband NIRS-measured cytochrome-c-oxidase (CCO)) and cerebral oxygenation was associated with unfavourable outcome; this is likely to be due to a lower cerebral metabolic rate and mitochondrial dysfunction in severe encephalopathy. Specifically, a decrease in the brain tissue oxidation state of CCO greater than 0.06 µM per 1 µM brain haemoglobin oxygenation drop was able to predict the outcome with 64% sensitivity and 79% specificity (receiver operating characteristic area under the curve = 0.73). With further work on the implementation of this methodology, broadband NIRS has the potential to provide an early, cotside, non-invasive, clinically relevant metabolic marker of perinatal hypoxic-ischaemic injury.
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Affiliation(s)
- Gemma Bale
- Department of Medical Physics and Biomedical Engineering, University College London, London, UK
| | - Subhabrata Mitra
- Institute of Women's Health, University College London, London, UK
| | - Isabel de Roever
- Department of Medical Physics and Biomedical Engineering, University College London, London, UK
| | - Magdalena Sokolska
- Department of Medical Physics and Biomedical Engineering, University College London Hospital, London, UK
| | - David Price
- Department of Medical Physics and Biomedical Engineering, University College London Hospital, London, UK
| | - Alan Bainbridge
- Department of Medical Physics and Biomedical Engineering, University College London Hospital, London, UK
| | - Roxana Gunny
- Paediatric Neuroradiology, Great Ormond Street Hospital for Children, London, UK
| | | | - Giles S Kendall
- Neonatal Unit, University College London Hospital, London, UK
| | - Judith Meek
- Institute of Women's Health, University College London, London, UK
| | | | - Ilias Tachtsidis
- Department of Medical Physics and Biomedical Engineering, University College London, London, UK
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29
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Holper L, Lan MJ, Brown PJ, Sublette ME, Burke A, Mann JJ. Brain cytochrome-c-oxidase as a marker of mitochondrial function: A pilot study in major depression using NIRS. Depress Anxiety 2019; 36:766-779. [PMID: 31111623 PMCID: PMC6716511 DOI: 10.1002/da.22913] [Citation(s) in RCA: 21] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/27/2018] [Revised: 03/12/2019] [Accepted: 04/22/2019] [Indexed: 12/16/2022] Open
Abstract
BACKGROUND Brain mitochondrial dysfunction is implicated in the pathophysiology of mood disorders. Brain cytochrome-c-oxidase (COX) activity is associated with the mitochondrial function. Near-infrared spectroscopy (NIRS) noninvasively measures oxidized COX (oxCOX) and tissue oxygenation index (TOI) reflecting cerebral blood flow and oxygenation. METHODS oxCOX and TOI were assessed in prefrontal cortex (Fp1/2, Brodmann area 10) in patients in a major depressive episode (N = 13) with major depressive disorder (MDD; N = 7) and bipolar disorder (BD; N = 6) compared with the controls (N = 10). One patient with MDD and all the patients with BD were taking medications. Computational modeling estimated oxCOX and TOI related indices of mitochondrial function and cerebral blood flow, respectively. RESULTS oxCOX was lower in patients than controls (p = .014) correlating inversely with depression severity (r = -.72; p = .006), driven primarily by lower oxCOX in BD compared with the controls. Computationally modeled mitochondrial parameters of the electron transport chain, such as the nicotinamide adenine dinucleotide ratio (NAD+ /NADH; p = .001) and the proton leak rate across the inner mitochondrial membrane (klk2 ; p = .008), were also lower in patients and correlated inversely with depression severity. No such effects were found for TOI. CONCLUSIONS In this pilot study, oxCOX and related mitochondrial parameters assessed by NIRS indicate an abnormal cerebral metabolic state in mood disorders proportional to depression severity, potentially providing a biomarker of antidepressant effect. Because the effect was driven by the medicated BD group, findings need to be evaluated in a larger, medication-free population.
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Affiliation(s)
- L Holper
- Division of Molecular Imaging and Neuropathology, Columbia University and New York State Psychiatric Institute, New York, NY,Department of Psychiatry, Psychotherapy, and Psychosomatics, University Hospital of Psychiatry Zurich, 8032 Zurich, Switzerland
| | - MJ Lan
- Division of Molecular Imaging and Neuropathology, Columbia University and New York State Psychiatric Institute, New York, NY
| | - PJ Brown
- Geriatric Psychiatry, Columbia University College of Physicians and Surgeons and New York State Psychiatric Institute, New York, NY
| | - ME Sublette
- Division of Molecular Imaging and Neuropathology, Columbia University and New York State Psychiatric Institute, New York, NY
| | - A Burke
- Division of Molecular Imaging and Neuropathology, Columbia University and New York State Psychiatric Institute, New York, NY
| | - JJ Mann
- Division of Molecular Imaging and Neuropathology, Columbia University and New York State Psychiatric Institute, New York, NY,Department of Radiology, Columbia University, New York, NY
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30
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Martinello KA, Meehan C, Avdic-Belltheus A, Lingam I, Ragab S, Hristova M, Tann CJ, Peebles D, Hagberg H, Wolfs TGAM, Klein N, Tachtsidis I, Golay X, Kramer BW, Fleiss B, Gressens P, Robertson NJ. Acute LPS sensitization and continuous infusion exacerbates hypoxic brain injury in a piglet model of neonatal encephalopathy. Sci Rep 2019; 9:10184. [PMID: 31308390 PMCID: PMC6629658 DOI: 10.1038/s41598-019-46488-y] [Citation(s) in RCA: 32] [Impact Index Per Article: 6.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/20/2018] [Accepted: 06/29/2019] [Indexed: 12/12/2022] Open
Abstract
Co-existing infection/inflammation and birth asphyxia potentiate the risk of developing neonatal encephalopathy (NE) and adverse outcome. In a newborn piglet model we assessed the effect of E. coli lipopolysaccharide (LPS) infusion started 4 h prior to and continued for 48 h after hypoxia on brain cell death and systemic haematological changes compared to LPS and hypoxia alone. LPS sensitized hypoxia resulted in an increase in mortality and in brain cell death (TUNEL positive cells) throughout the whole brain, and in the internal capsule, periventricular white matter and sensorimotor cortex. LPS alone did not increase brain cell death at 48 h, despite evidence of neuroinflammation, including the greatest increases in microglial proliferation, reactive astrocytosis and cleavage of caspase-3. LPS exposure caused splenic hypertrophy and platelet count suppression. The combination of LPS and hypoxia resulted in the highest and most sustained systemic white cell count increase. These findings highlight the significant contribution of acute inflammation sensitization prior to an asphyxial insult on NE illness severity.
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Affiliation(s)
- Kathryn A Martinello
- Institute for Women's Health, University College London, London, United Kingdom
- Robinson Research Institute, University of Adelaide, Adelaide, Australia
| | - Christopher Meehan
- Institute for Women's Health, University College London, London, United Kingdom
| | | | - Ingran Lingam
- Institute for Women's Health, University College London, London, United Kingdom
| | - Sara Ragab
- Institute for Women's Health, University College London, London, United Kingdom
| | - Mariya Hristova
- Institute for Women's Health, University College London, London, United Kingdom
| | - Cally J Tann
- Institute for Women's Health, University College London, London, United Kingdom
- Maternal, Adolescent, Reproductive and Child Health Centre, Department of Infectious Disease Epidemiology, London School of Hygiene and Tropical Medicine, London, United Kingdom
| | - Donald Peebles
- Institute for Women's Health, University College London, London, United Kingdom
| | - Henrik Hagberg
- Centre of Perinatal Medicine & Health, Department of Clinical Sciences, Sahlgrenska Academy, Gothenburg University, Gothenburg, Sweden
- Centre for the Developing Brain, Department of Imaging Sciences and Biomedical Engineering, King's College London, King's Health Partners, St. Thomas' Hospital, London, United Kingdom
| | - Tim G A M Wolfs
- Department of Paediatrics, University of Maastricht, Maastricht, Netherlands
| | - Nigel Klein
- Infection, Inflammation and Rheumatology, UCL Great Ormond Street Institute of Child Health, London, United Kingdom
| | - Ilias Tachtsidis
- Medical Physics and Biomedical Engineering, University College London, London, United Kingdom
| | - Xavier Golay
- Institute of Neurology, University College London, London, United Kingdom
| | - Boris W Kramer
- Department of Paediatrics, University of Maastricht, Maastricht, Netherlands
| | - Bobbi Fleiss
- Centre for the Developing Brain, Department of Imaging Sciences and Biomedical Engineering, King's College London, King's Health Partners, St. Thomas' Hospital, London, United Kingdom
- PROTECT, INSERM, Université Paris Diderot, Sorbonne Paris Cité, Paris, France
| | - Pierre Gressens
- Centre for the Developing Brain, Department of Imaging Sciences and Biomedical Engineering, King's College London, King's Health Partners, St. Thomas' Hospital, London, United Kingdom
- PROTECT, INSERM, Université Paris Diderot, Sorbonne Paris Cité, Paris, France
| | - Nicola J Robertson
- Institute for Women's Health, University College London, London, United Kingdom.
- Division of Neonatology, Sidra Medicine, Doha, Qatar.
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31
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Skowno JJ. Hemodynamic monitoring in children with heart disease: Overview of newer technologies. Paediatr Anaesth 2019; 29:467-474. [PMID: 30667124 DOI: 10.1111/pan.13590] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/30/2018] [Revised: 12/26/2018] [Accepted: 01/14/2019] [Indexed: 12/21/2022]
Affiliation(s)
- Justin J Skowno
- Department of Anaesthesia, The Children's Hospital at Westmead, Sydney, NSW, Australia.,Discipline of Child and Adolescent Health, Faculty of Medicine and Health, The University of Sydney, NSW, Australia
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32
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Zhou KQ, Green CR, Bennet L, Gunn AJ, Davidson JO. The Role of Connexin and Pannexin Channels in Perinatal Brain Injury and Inflammation. Front Physiol 2019; 10:141. [PMID: 30873043 PMCID: PMC6400979 DOI: 10.3389/fphys.2019.00141] [Citation(s) in RCA: 35] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/12/2018] [Accepted: 02/07/2019] [Indexed: 12/21/2022] Open
Abstract
Perinatal brain injury remains a major cause of death and life-long disability. Perinatal brain injury is typically associated with hypoxia-ischemia and/or infection/inflammation. Both hypoxia-ischemia and infection trigger an inflammatory response in the brain. The inflammatory response can contribute to brain cell loss and chronic neuroinflammation leading to neurological impairments. It is now well-established that brain injury evolves over time, and shows a striking spread from injured to previously uninjured regions of the brain. There is increasing evidence that this spread is related to opening of connexin hemichannels and pannexin channels, both of which are large conductance membrane channels found in almost all cell types in the brain. Blocking connexin hemichannels within the first 3 h after hypoxia-ischemia has been shown to improve outcomes in term equivalent fetal sheep but it is important to also understand the downstream pathways linking membrane channel opening with the development of injury in order to identify new therapeutic targets. Open membrane channels release adenosine triphosphate (ATP), and other neuroactive molecules, into the extracellular space. ATP has an important physiological role, but has also been reported to act as a damage-associated molecular pattern (DAMP) signal mediated through specific purinergic receptors and so act as a primary signal 1 in the innate immune system inflammasome pathway. More crucially, extracellular ATP is a key inflammasome signal 2 activator, with purinergic receptor binding triggering the assembly of the multi-protein inflammasome complex. The inflammasome pathway and complex formation contribute to activation of inflammatory caspases, and the release of inflammatory cytokines, including interleukin (IL)-1β, tumor necrosis factor (TNF)-α, IL-18, and vascular endothelial growth factor (VEGF). We propose that the NOD-like receptor protein-3 (NLRP3) inflammasome, which has been linked to inflammatory responses in models of ischemic stroke and various inflammatory diseases, may be one mechanism by which connexin hemichannel opening especially mediates perinatal brain injury.
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Affiliation(s)
- Kelly Q Zhou
- Department of Physiology, The University of Auckland, Auckland, New Zealand
| | - Colin R Green
- Department of Ophthalmology, The University of Auckland, Auckland, New Zealand
| | - Laura Bennet
- Department of Physiology, The University of Auckland, Auckland, New Zealand
| | - Alistair J Gunn
- Department of Physiology, The University of Auckland, Auckland, New Zealand
| | - Joanne O Davidson
- Department of Physiology, The University of Auckland, Auckland, New Zealand.,Department of Ophthalmology, The University of Auckland, Auckland, New Zealand
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Changes in Cytochrome-C-Oxidase Account for Changes in Attenuation of Near-Infrared Light in the Healthy Infant Brain. ADVANCES IN EXPERIMENTAL MEDICINE AND BIOLOGY 2019; 1072:7-12. [PMID: 30178316 PMCID: PMC6821534 DOI: 10.1007/978-3-319-91287-5_2] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Indexed: 04/07/2023]
Abstract
A novel multi-wavelength broadband near infrared spectroscopy (NIRS) system has been employed to simultaneously measure haemodynamic changes alongside changes in cellular oxygen utilization by measurement of oxidation state of mitochondrial enzyme cytochrome-c-oxidase (oxCCO). The aim of this study was to investigate the role of oxCCO in neural responses to functional activation in infants. Studies were performed using a NIRS broadband system in 33 typically developing infants aged between 4 and 6 months. Responses were recorded over the right temporal lobe while infants were presented with engaging videos containing social and non-social content. Changes in the concentration of oxyhaemoglobin (Δ[HbO2]), deoxyhaemoglobin (Δ[HHb]) and Δ[oxCCO] were calculated using changes in attenuation of light at 120 wavelengths between 780 and 900 nm using the UCLn algorithm. The algorithm was also used to fit (a) HbO2 and HHb spectra (2 component fit) and (b) HbO2, HHb and oxCCO (3 component fit) to the change in attenuation occurring within an experimental block in different participants. Residuals resulting from these two fits were compared with oxidized-minus reduced CCO spectrum, calculated using the CCO specific extinction coefficient. A significant increase in oxCCO was found in response to the social stimuli (maximum increase 0.238 ± 0.13 μM). Residuals analysis showed that the best fits were achieved when oxCCO was included as a tissue chromophore. These results are the first reported significant change in oxCCO to stimulus-evoked activation in infants and may reveal vital information about oxygen metabolism during functional activation in the developing human brain.
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Mitra S, Bale G, Highton D, Gunny R, Uria-Avellanal C, Bainbridge A, Sokolska M, Price D, Huertas-Ceballos A, Kendall GS, Meek J, Tachtsidis I, Robertson NJ. Pressure passivity of cerebral mitochondrial metabolism is associated with poor outcome following perinatal hypoxic ischemic brain injury. J Cereb Blood Flow Metab 2019; 39:118-130. [PMID: 28949271 PMCID: PMC6311664 DOI: 10.1177/0271678x17733639] [Citation(s) in RCA: 23] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
Hypoxic ischemic encephalopathy (HIE) leads to significant morbidity and mortality. Impaired autoregulation after hypoxia-ischaemia has been suggested to contribute further to injury. Thalamic lactate/N-Acetylasperate (Lac/NAA) peak area ratio of > 0.3 on proton (1H) magnetic resonance spectroscopy (MRS) is associated with poor neurodevelopment outcome following HIE. Cytochrome-c-oxidase (CCO) plays a central role in mitochondrial oxidative metabolism and ATP synthesis. Using a novel broadband NIRS system, we investigated the impact of pressure passivity of cerebral metabolism (CCO), oxygenation (haemoglobin difference (HbD)) and cerebral blood volume (total haemoglobin (HbT)) in 23 term infants following HIE during therapeutic hypothermia (HT). Sixty-minute epochs of data from each infant were studied using wavelet analysis at a mean age of 48 h. Wavelet semblance (a measure of phase difference) was calculated to compare reactivity between mean arterial blood pressure (MABP) with oxCCO, HbD and HbT. OxCCO-MABP semblance correlated with thalamic Lac/NAA ( r = 0.48, p = 0.02). OxCCO-MABP semblance also differed between groups of infants with mild to moderate and severe injury measured using brain MRI score ( p = 0.04), thalamic Lac/NAA ( p = 0.04) and neurodevelopmental outcome at one year ( p = 0.04). Pressure passive changes in cerebral metabolism were associated with injury severity indicated by thalamic Lac/NAA, MRI scores and neurodevelopmental assessment at one year of age.
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Affiliation(s)
- Subhabrata Mitra
- 1 Institute for Women's Health, University College London, London, UK
| | - Gemma Bale
- 2 Department of Medical Physics and Biomedical Engineering, University College London, London, UK
| | - David Highton
- 3 Neurocritical Care, National Hospital for Neurology & Neurosurgery, University College London, London, UK
| | - Roxanna Gunny
- 4 Paediatric Neuroradiology, Great Ormond Street Hospital for Children, London, UK
| | | | - Alan Bainbridge
- 5 Department of Medical Physics and Biomedical Engineering, University College London Hospital, London, UK
| | - Magdalena Sokolska
- 5 Department of Medical Physics and Biomedical Engineering, University College London Hospital, London, UK
| | - David Price
- 5 Department of Medical Physics and Biomedical Engineering, University College London Hospital, London, UK
| | | | - Giles S Kendall
- 6 Neonatal Unit, University College London Hospital, London, UK
| | - Judith Meek
- 1 Institute for Women's Health, University College London, London, UK
| | - Ilias Tachtsidis
- 2 Department of Medical Physics and Biomedical Engineering, University College London, London, UK
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35
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Counsell SJ, Arichi T, Arulkumaran S, Rutherford MA. Fetal and neonatal neuroimaging. HANDBOOK OF CLINICAL NEUROLOGY 2019; 162:67-103. [PMID: 31324329 DOI: 10.1016/b978-0-444-64029-1.00004-7] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/03/2023]
Abstract
Magnetic resonance imaging (MRI) can provide detail of the soft tissues of the fetal and neonatal brain that cannot be obtained by any other imaging modality. Conventional T1 and T2 weighted sequences provide anatomic detail of the normally developing brain and can demonstrate lesions, including those associated with preterm birth, hypoxic ischemic encephalopathy, perinatal arterial stroke, infections, and congenital malformations. Specialized imaging techniques can be used to assess cerebral vasculature (magnetic resonance angiography and venography), cerebral metabolism (magnetic resonance spectroscopy), cerebral perfusion (arterial spin labeling), and function (functional MRI). A wealth of quantitative tools, most of which were originally developed for the adult brain, can be applied to study the developing brain in utero and postnatally including measures of tissue microstructure obtained from diffusion MRI, morphometric studies to measure whole brain and regional tissue volumes, and automated approaches to study cortical folding. In this chapter, we aim to describe different imaging approaches for the fetal and neonatal brain, and to discuss their use in a range of clinical applications.
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Affiliation(s)
- Serena J Counsell
- Centre for the Developing Brain, School of Biomedical Engineering and Imaging Sciences, King's College London, London, United Kingdom.
| | - Tomoki Arichi
- Centre for the Developing Brain, School of Biomedical Engineering and Imaging Sciences, King's College London, London, United Kingdom
| | - Sophie Arulkumaran
- Centre for the Developing Brain, School of Biomedical Engineering and Imaging Sciences, King's College London, London, United Kingdom
| | - Mary A Rutherford
- Centre for the Developing Brain, School of Biomedical Engineering and Imaging Sciences, King's College London, London, United Kingdom
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Davies A, Wassink G, Bennet L, Gunn AJ, Davidson JO. Can we further optimize therapeutic hypothermia for hypoxic-ischemic encephalopathy? Neural Regen Res 2019; 14:1678-1683. [PMID: 31169174 PMCID: PMC6585539 DOI: 10.4103/1673-5374.257512] [Citation(s) in RCA: 22] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022] Open
Abstract
Perinatal hypoxic-ischemic encephalopathy is a leading cause of neonatal death and disability. Therapeutic hypothermia significantly reduces death and major disability associated with hypoxic-ischemic encephalopathy; however, many infants still experience lifelong disabilities to movement, sensation and cognition. Clinical guidelines, based on strong clinical and preclinical evidence, recommend therapeutic hypothermia should be started within 6 hours of birth and continued for a period of 72 hours, with a target brain temperature of 33.5 ± 0.5°C for infants with moderate to severe hypoxic-ischemic encephalopathy. The clinical guidelines also recommend that infants be rewarmed at a rate of 0.5°C per hour, but this is not based on strong evidence. There are no randomized controlled trials investigating the optimal rate of rewarming after therapeutic hypothermia for infants with hypoxic-ischemic encephalopathy. Preclinical studies of rewarming are conflicting and results were confounded by treatment with sub-optimal durations of hypothermia. In this review, we evaluate the evidence for the optimal start time, duration and depth of hypothermia, and whether the rate of rewarming after treatment affects brain injury and neurological outcomes.
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Affiliation(s)
- Anthony Davies
- Department of Physiology, The University of Auckland, Auckland, New Zealand
| | - Guido Wassink
- Department of Physiology, The University of Auckland, Auckland, New Zealand
| | - Laura Bennet
- Department of Physiology, The University of Auckland, Auckland, New Zealand
| | - Alistair J Gunn
- Department of Physiology, The University of Auckland, Auckland, New Zealand
| | - Joanne O Davidson
- Department of Physiology, The University of Auckland, Auckland, New Zealand
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Keil VC, Eichhorn L, Mutsaerts HJMM, Träber F, Block W, Mädler B, van de Ven K, Siero JCW, MacIntosh BJ, Petr J, Fimmers R, Schild HH, Hattingen E. Cerebrovascular Reactivity during Prolonged Breath-Hold in Experienced Freedivers. AJNR Am J Neuroradiol 2018; 39:1839-1847. [PMID: 30237299 DOI: 10.3174/ajnr.a5790] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/29/2017] [Accepted: 07/19/2018] [Indexed: 12/26/2022]
Abstract
BACKGROUND AND PURPOSE Experienced freedivers can endure prolonged breath-holds despite severe hypoxemia and are therefore ideal subjects to study apnea-induced cerebrovascular reactivity. This multiparametric study investigated CBF, the spatial coefficient of variation as a correlate of arterial transit time and brain metabolism, dynamics during prolonged apnea. MATERIALS AND METHODS Fifteen male freedivers (age range, 20-64 years; cumulative previous prolonged breath-holds >2 minutes and 30 seconds: 4-79,200) underwent repetitive 3T pseudocontinuous arterial spin-labeling and 31P-/1H-MR spectroscopy before, during, and after a 5-minute breath-hold (split into early and late phases) and gave temporally matching venous blood gas samples. Correlation of temporal and regional cerebrovascular reactivity to blood gases and cumulative previous breath-holds of >2 minutes and 30 seconds in a lifetime was assessed. RESULTS The spatial coefficient of variation of CBF (by arterial spin-labeling) decreased during the early breath-hold phase (-30.0%, P = .002), whereas CBF remained almost stable during this phase and increased in the late phase (+51.8%, P = .001). CBF differed between the anterior and the posterior circulation during all phases (eg, during late breath-hold: MCA, 57.3 ± 14.2 versus posterior cerebral artery, 42.7 ± 10.8 mL/100 g/min; P = .001). There was an association between breath-hold experience and lower CBF (1000 previous breath-holds reduced WM CBF by 0.6 mL/100 g/min; 95% CI, 0.15-1.1 mL/100 g/min; P = .01). While breath-hold caused peripheral lactate rise (+18.5%) and hypoxemia (oxygen saturation, -24.0%), cerebral lactate and adenosine diphosphate remained within physiologic ranges despite early signs of oxidative stress [-6.4% phosphocreatine / (adenosine triphosphate + adenosine diphosphate); P = .02]. CONCLUSIONS This study revealed that the cerebral energy metabolism of trained freedivers withstands severe hypoxic hypercarbia in prolonged breath-hold due to a complex cerebrovascular hemodynamic response.
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Affiliation(s)
- V C Keil
- From the Departments of Radiology (V.C.K., F.T., W.B., H.H.S., E.H.)
| | - L Eichhorn
- Anesthesiology and Intensive Care Medicine (L.E.)
| | - H J M M Mutsaerts
- Department of Radiology (H.J.M.M.M.), Academic Medical Center, Amsterdam, the Netherlands.,Sunnybrook Research Institute (H.J.M.M.M., B.J.M.), University of Toronto, Toronto, Ontario, Canada.,Department of Radiology (H.J.M.M.M., J.C.W.S.), University Medical Center Utrecht, Utrecht, the Netherlands
| | - F Träber
- From the Departments of Radiology (V.C.K., F.T., W.B., H.H.S., E.H.)
| | - W Block
- From the Departments of Radiology (V.C.K., F.T., W.B., H.H.S., E.H.)
| | - B Mädler
- Philips GmbH (B.M), Bonn, Germany
| | - K van de Ven
- Philips Healthcare (K.v.d.V.), Best, the Netherlands
| | - J C W Siero
- Department of Radiology (H.J.M.M.M., J.C.W.S.), University Medical Center Utrecht, Utrecht, the Netherlands.,Spinoza Centre for Neuroimaging (J.C.W.S.), Amsterdam, the Netherlands
| | - B J MacIntosh
- Sunnybrook Research Institute (H.J.M.M.M., B.J.M.), University of Toronto, Toronto, Ontario, Canada
| | - J Petr
- Helmholtz Center Dresden-Rossendorf, Institute for Radiopharmaceutic Cancer Research (J.P.), PET Center, Dresden-Rossendorf, Germany
| | - R Fimmers
- Institut für Medizinische Biometrie, Informatik und Epidemiologie (R.F.), University Hospital Bonn, Bonn, Germany
| | - H H Schild
- From the Departments of Radiology (V.C.K., F.T., W.B., H.H.S., E.H.)
| | - E Hattingen
- From the Departments of Radiology (V.C.K., F.T., W.B., H.H.S., E.H.)
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38
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Rajaram A, Bale G, Kewin M, Morrison LB, Tachtsidis I, St. Lawrence K, Diop M. Simultaneous monitoring of cerebral perfusion and cytochrome c oxidase by combining broadband near-infrared spectroscopy and diffuse correlation spectroscopy. BIOMEDICAL OPTICS EXPRESS 2018; 9:2588-2603. [PMID: 30258675 PMCID: PMC6154190 DOI: 10.1364/boe.9.002588] [Citation(s) in RCA: 30] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/01/2018] [Revised: 05/04/2018] [Accepted: 05/07/2018] [Indexed: 05/23/2023]
Abstract
Preterm infants born with very low birth weights are at a high risk of brain injury, in part because the premature brain is believed to be prone to periods of low cerebral blood flow (CBF). Tissue damage is likely to occur if reduction in CBF is sufficient to impair cerebral energy metabolism for extended periods. Therefore, a neuromonitoring method that can detect reductions in CBF, large enough to affect metabolism, could alert the neonatal intensive care team before injury occurs. In this report, we present the development of an optical system that combines diffuse correlation spectroscopy (DCS) for monitoring CBF and broadband near-infrared spectroscopy (B-NIRS) for monitoring the oxidation state of cytochrome c oxidase (oxCCO) - a key biomarker of oxidative metabolism. The hybrid instrument includes a multiplexing system to enable concomitant DCS and B-NIRS measurements while avoiding crosstalk between the two subsystems. The ability of the instrument to monitor dynamic changes in CBF and oxCCO was demonstrated in a piglet model of neonatal hypoxia-ischemia (HI). Experiments conducted in eight animals, including two controls, showed that oxCCO exhibited a delayed response to ischemia while CBF and tissue oxygenation (StO2) responses were instantaneous. These findings suggest that simultaneous neuromonitoring of perfusion and metabolism could provide critical information regarding clinically significant hemodynamic events prior to the onset of brain injury.
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Affiliation(s)
- Ajay Rajaram
- Imaging Program, Lawson Health Research Institute, 268 Grosvenor St., London, ON, N6A 4V2, Canada
- Department of Medical Biophysics, Western University, 1151 Richmond St., London, ON, N6A 3K7, Canada
| | - Gemma Bale
- Medical Physics & Biomedical Engineering, University College London, Gower St., Bloomsbury, London, WC1E 6BT, United Kingdom
| | - Matthew Kewin
- Imaging Program, Lawson Health Research Institute, 268 Grosvenor St., London, ON, N6A 4V2, Canada
- Department of Medical Biophysics, Western University, 1151 Richmond St., London, ON, N6A 3K7, Canada
| | - Laura B. Morrison
- Imaging Program, Lawson Health Research Institute, 268 Grosvenor St., London, ON, N6A 4V2, Canada
| | - Ilias Tachtsidis
- Medical Physics & Biomedical Engineering, University College London, Gower St., Bloomsbury, London, WC1E 6BT, United Kingdom
| | - Keith St. Lawrence
- Imaging Program, Lawson Health Research Institute, 268 Grosvenor St., London, ON, N6A 4V2, Canada
- Department of Medical Biophysics, Western University, 1151 Richmond St., London, ON, N6A 3K7, Canada
| | - Mamadou Diop
- Imaging Program, Lawson Health Research Institute, 268 Grosvenor St., London, ON, N6A 4V2, Canada
- Department of Medical Biophysics, Western University, 1151 Richmond St., London, ON, N6A 3K7, Canada
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Giannoni L, Lange F, Tachtsidis I. Hyperspectral imaging solutions for brain tissue metabolic and hemodynamic monitoring: past, current and future developments. JOURNAL OF OPTICS (2010) 2018; 20:044009. [PMID: 29854375 PMCID: PMC5964611 DOI: 10.1088/2040-8986/aab3a6] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/29/2017] [Revised: 01/29/2018] [Accepted: 03/02/2018] [Indexed: 05/21/2023]
Abstract
Hyperspectral imaging (HSI) technologies have been used extensively in medical research, targeting various biological phenomena and multiple tissue types. Their high spectral resolution over a wide range of wavelengths enables acquisition of spatial information corresponding to different light-interacting biological compounds. This review focuses on the application of HSI to monitor brain tissue metabolism and hemodynamics in life sciences. Different approaches involving HSI have been investigated to assess and quantify cerebral activity, mainly focusing on: (1) mapping tissue oxygen delivery through measurement of changes in oxygenated (HbO2) and deoxygenated (HHb) hemoglobin; and (2) the assessment of the cerebral metabolic rate of oxygen (CMRO2) to estimate oxygen consumption by brain tissue. Finally, we introduce future perspectives of HSI of brain metabolism, including its potential use for imaging optical signals from molecules directly involved in cellular energy production. HSI solutions can provide remarkable insight in understanding cerebral tissue metabolism and oxygenation, aiding investigation on brain tissue physiological processes.
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Affiliation(s)
- Luca Giannoni
- Department of Medical Physics and Biomedical Engineering, University College London, London WC1E 6BT, United Kingdom
| | - Frédéric Lange
- Department of Medical Physics and Biomedical Engineering, University College London, London WC1E 6BT, United Kingdom
| | - Ilias Tachtsidis
- Department of Medical Physics and Biomedical Engineering, University College London, London WC1E 6BT, United Kingdom
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40
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Demetriou E, Tachrount M, Zaiss M, Shmueli K, Golay X. PRO-QUEST: a rapid assessment method based on progressive saturation for quantifying exchange rates using saturation times in CEST. Magn Reson Med 2018; 80:1638-1654. [PMID: 29504144 DOI: 10.1002/mrm.27155] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/11/2017] [Revised: 02/05/2018] [Accepted: 02/06/2018] [Indexed: 11/10/2022]
Abstract
PURPOSE To develop a new MRI technique to rapidly measure exchange rates in CEST MRI. METHODS A novel pulse sequence for measuring chemical exchange rates through a progressive saturation recovery process, called PRO-QUEST (progressive saturation for quantifying exchange rates using saturation times), has been developed. Using this method, the water magnetization is sampled under non-steady-state conditions, and off-resonance saturation is interleaved with the acquisition of images obtained through a Look-Locker type of acquisition. A complete theoretical framework has been set up, and simple equations to obtain the exchange rates have been derived. RESULTS A reduction of scan time from 58 to 16 minutes has been obtained using PRO-QUEST versus the standard QUEST. Maps of both T1 of water and B1 can simply be obtained by repetition of the sequence without off-resonance saturation pulses. Simulations and calculated exchange rates from experimental data using amino acids such as glutamate, glutamine, taurine, and alanine were compared and found to be in good agreement. The PRO-QUEST sequence was also applied on healthy and infarcted rats after 24 hours, and revealed that imaging specificity to ischemic acidification during stroke was substantially increased relative to standard amide proton transfer-weighted imaging. CONCLUSION Because of the reduced scan time and insensitivity to nonchemical exchange factors such as direct water saturation, PRO-QUEST can serve as an excellent alternative for researchers and clinicians interested to map pH changes in vivo.
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Affiliation(s)
- Eleni Demetriou
- Brain Repair & Rehabilitation, Institute of Neurology, University College London, United Kingdom
| | - Mohamed Tachrount
- Brain Repair & Rehabilitation, Institute of Neurology, University College London, United Kingdom
| | - Moritz Zaiss
- High Field Magnetic Resonance, Max Planck Institute for Biological Cybernetics, Tübingen, Germany
| | - Karin Shmueli
- Department of Medical Physics and Biomedical Engineering, University College London, United Kingdom
| | - Xavier Golay
- Brain Repair & Rehabilitation, Institute of Neurology, University College London, United Kingdom
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41
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Liu Y, Gu Y, Yu X. Assessing tissue metabolism by phosphorous-31 magnetic resonance spectroscopy and imaging: a methodology review. Quant Imaging Med Surg 2017; 7:707-726. [PMID: 29312876 PMCID: PMC5756783 DOI: 10.21037/qims.2017.11.03] [Citation(s) in RCA: 50] [Impact Index Per Article: 7.1] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/03/2017] [Accepted: 11/11/2017] [Indexed: 01/11/2023]
Abstract
Many human diseases are caused by an imbalance between energy production and demand. Magnetic resonance spectroscopy (MRS) and magnetic resonance imaging (MRI) provide the unique opportunity for in vivo assessment of several fundamental events in tissue metabolism without the use of ionizing radiation. Of particular interest, phosphate metabolites that are involved in ATP generation and utilization can be quantified noninvasively by phosphorous-31 (31P) MRS/MRI. Furthermore, 31P magnetization transfer (MT) techniques allow in vivo measurement of metabolic fluxes via creatine kinase (CK) and ATP synthase. However, a major impediment for the clinical applications of 31P-MRS/MRI is the prohibitively long acquisition time and/or the low spatial resolution that are necessary to achieve adequate signal-to-noise ratio. In this review, current 31P-MRS/MRI techniques used in basic science and clinical research are presented. Recent advances in the development of fast 31P-MRS/MRI methods are also discussed.
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Affiliation(s)
- Yuchi Liu
- Department of Biomedical Engineering, Case Western Reserve University, Cleveland, OH, USA
| | - Yuning Gu
- Department of Biomedical Engineering, Case Western Reserve University, Cleveland, OH, USA
| | - Xin Yu
- Department of Biomedical Engineering, Case Western Reserve University, Cleveland, OH, USA
- Department of Radiology, Case Western Reserve University, Cleveland, OH, USA
- Department of Physiology and Biophysics, Case Western Reserve University, Cleveland, OH, USA
- Case Center for Imaging Research, Case Western Reserve University, Cleveland, OH, USA
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42
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Ghosh A, Highton D, Kolyva C, Tachtsidis I, Elwell CE, Smith M. Hyperoxia results in increased aerobic metabolism following acute brain injury. J Cereb Blood Flow Metab 2017; 37:2910-2920. [PMID: 27837190 PMCID: PMC5536254 DOI: 10.1177/0271678x16679171] [Citation(s) in RCA: 24] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/30/2022]
Abstract
Acute brain injury is associated with depressed aerobic metabolism. Below a critical mitochondrial pO2 cytochrome c oxidase, the terminal electron acceptor in the mitochondrial respiratory chain, fails to sustain oxidative phosphorylation. After acute brain injury, this ischaemic threshold might be shifted into apparently normal levels of tissue oxygenation. We investigated the oxygen dependency of aerobic metabolism in 16 acutely brain-injured patients using a 120-min normobaric hyperoxia challenge in the acute phase (24-72 h) post-injury and multimodal neuromonitoring, including transcranial Doppler ultrasound-measured cerebral blood flow velocity, cerebral microdialysis-derived lactate-pyruvate ratio (LPR), brain tissue pO2 (pbrO2), and tissue oxygenation index and cytochrome c oxidase oxidation state (oxCCO) measured using broadband spectroscopy. Increased inspired oxygen resulted in increased pbrO2 [ΔpbrO2 30.9 mmHg p < 0.001], reduced LPR [ΔLPR -3.07 p = 0.015], and increased cytochrome c oxidase (CCO) oxidation (Δ[oxCCO] + 0.32 µM p < 0.001) which persisted on return-to-baseline (Δ[oxCCO] + 0.22 µM, p < 0.01), accompanied by a 7.5% increase in estimated cerebral metabolic rate for oxygen ( p = 0.038). Our results are consistent with an improvement in cellular redox state, suggesting oxygen-limited metabolism above recognised ischaemic pbrO2 thresholds. Diffusion limitation or mitochondrial inhibition might explain these findings. Further investigation is warranted to establish optimal oxygenation to sustain aerobic metabolism after acute brain injury.
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Affiliation(s)
- Arnab Ghosh
- 1 Neurocritical Care, University College London Hospitals, National Hospital for Neurology & Neurosurgery, London, UK
| | - David Highton
- 1 Neurocritical Care, University College London Hospitals, National Hospital for Neurology & Neurosurgery, London, UK
| | - Christina Kolyva
- 2 Department of Medical Physics and Biomedical Engineering, University College London, London, UK
| | - Ilias Tachtsidis
- 2 Department of Medical Physics and Biomedical Engineering, University College London, London, UK
| | - Clare E Elwell
- 2 Department of Medical Physics and Biomedical Engineering, University College London, London, UK
| | - Martin Smith
- 1 Neurocritical Care, University College London Hospitals, National Hospital for Neurology & Neurosurgery, London, UK.,2 Department of Medical Physics and Biomedical Engineering, University College London, London, UK.,3 University College London Hospitals National Institute for Health Research Biomedical Research Centre, London, UK
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43
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Niu FN, Meng HL, Chang LL, Wu HY, Li WP, Liu RY, Wang HT, Zhang B, Xu Y. Mitochondrial dysfunction and cerebral metabolic abnormalities in patients with mitochondrial encephalomyopathy subtypes: Evidence from proton MR spectroscopy and muscle biopsy. CNS Neurosci Ther 2017; 23:686-697. [PMID: 28695670 DOI: 10.1111/cns.12714] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/12/2017] [Revised: 06/01/2017] [Accepted: 06/06/2017] [Indexed: 11/27/2022] Open
Abstract
AIMS Accumulated evidence indicates that cerebral metabolic features, evaluated by proton magnetic resonance spectroscopy (1 H-MRS), are sensitive to early mitochondrion dysfunction associated with mitochondrial encephalomyopathy (ME). The metabolite ratios of lactate (lac)/Cr, N-acetyl aspartate (NAA)/creatine (Cr), total choline (tCho)/Cr, and myoinositol (mI)/Cr are measured in the infarct-like lesions by 1 H-MRS and may reveal metabolic changes associated with ME. However, the application of this molecular imaging technique in the investigation of the pathology of ME subtypes is unknown. METHODS In this study, cerebral metabolic features of pathologically diagnosed ME cases, that is, 19 mitochondrial encephalomyopathy, lactic acidosis, and stroke-like episodes (MELAS); nine chronic progressive external ophthalmoplegia (CPEO); and 23 healthy controls, were investigated using 1 H-MRS. Receiver operating characteristics (ROC) analysis was used to evaluate the diagnostic power of the cerebral metabolites. Histochemical evaluation was carried out on muscle tissues derived from biopsy to assess the abnormal mitochondrial proliferation. The association between cerebral metabolic and mitochondrial cytopathy was examined by correlation analysis. RESULTS Patients with MELAS or CPEO exhibited a significantly higher Lac/Cr ratio and a lower NAA/Cr ratio compared with controls. The ROC curve of Lac/Cr ratio indicated prominent discrimination between MELAS or CPEO and healthy control subjects, whereas the NAA/Cr ratio may present diagnostic power in the distinction of MELAS from CPEO. Lower NAA/Cr ratio was associated with higher Lac/Cr in MELAS, but not in CPEO. Furthermore, higher ragged-red fibers (RRFs) percentages were associated with elevated Lac/Cr and reduced NAA/Cr ratios, notably in MELAS. This association was not noted in the case of mI/Cr ratio. CONCLUSIONS Mitochondrial cytopathy (lactic acidosis and RRFs on muscle biopsy) was associated with neuronal viability but not glial proliferation, notably in MELAS. Mitochondrial neuronopathy and neuronal vulnerability are considered significant causes in the pathogenesis of MELAS, particularly with regard to stroke-like episodes.
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Affiliation(s)
- Feng-Nan Niu
- Department of Pathology, Drum Tower Hospital, Medical School of Nanjing University, Nanjing, Jiangsu, China
| | - Hai-Lan Meng
- Department of Neurology, Drum Tower Hospital, Medical School of Nanjing University, Nanjing, Jiangsu, China
| | - Lei-Lei Chang
- Department of Neurology, Drum Tower Hospital, Medical School of Nanjing University, Nanjing, Jiangsu, China
| | - Hong-Yan Wu
- Department of Pathology, Drum Tower Hospital, Medical School of Nanjing University, Nanjing, Jiangsu, China
| | - Wei-Ping Li
- Department of Radiology, Drum Tower Hospital, Medical School of Nanjing University, Nanjing, Jiangsu, China
| | - Ren-Yuan Liu
- Department of Neurology, Drum Tower Hospital, Medical School of Nanjing University, Nanjing, Jiangsu, China
| | - Hui-Ting Wang
- Department of Radiology, Drum Tower Hospital, Medical School of Nanjing University, Nanjing, Jiangsu, China
| | - Bing Zhang
- Department of Radiology, Drum Tower Hospital, Medical School of Nanjing University, Nanjing, Jiangsu, China
| | - Yun Xu
- Department of Neurology, Drum Tower Hospital, Medical School of Nanjing University, Nanjing, Jiangsu, China
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Martinello K, Hart AR, Yap S, Mitra S, Robertson NJ. Management and investigation of neonatal encephalopathy: 2017 update. Arch Dis Child Fetal Neonatal Ed 2017; 102:F346-F358. [PMID: 28389438 PMCID: PMC5537522 DOI: 10.1136/archdischild-2015-309639] [Citation(s) in RCA: 110] [Impact Index Per Article: 15.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/09/2016] [Accepted: 02/15/2017] [Indexed: 12/26/2022]
Abstract
This review discusses an approach to determining the cause of neonatal encephalopathy, as well as current evidence on resuscitation and subsequent management of hypoxic-ischaemic encephalopathy (HIE). Encephalopathy in neonates can be due to varied aetiologies in addition to hypoxic-ischaemia. A combination of careful history, examination and the judicious use of investigations can help determine the cause. Over the last 7 years, infants with moderate to severe HIE have benefited from the introduction of routine therapeutic hypothermia; the number needed to treat for an additional beneficial outcome is 7 (95% CI 5 to 10). More recent research has focused on optimal resuscitation practices for babies with cardiorespiratory depression, such as delayed cord clamping after establishment of ventilation and resuscitation in air. Around a quarter of infants with asystole at 10 min after birth who are subsequently cooled have normal outcomes, suggesting that individualised decision making on stopping resuscitation is needed, based on access to intensive treatment unit and early cooling. The full benefit of cooling appears to have been exploited in our current treatment protocols of 72 hours at 33.5°C; deeper and longer cooling showed adverse outcome. The challenge over the next 5-10 years will be to assess which adjunct therapies are safe and optimise hypothermic brain protection in phase I and phase II trials. Optimal care may require tailoring treatments according to gender, genetic risk, injury severity and inflammatory status.
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Affiliation(s)
- Kathryn Martinello
- Department of Neonatology, Institute for Women's Health, University College London, UK
| | - Anthony R Hart
- Department of Neonatal and Paediatric Neurology, Sheffield Children's Hospital NHS Foundation Trust, Sheffield, UK
| | - Sufin Yap
- Department of Inherited Metabolic Diseases, Sheffield Children's Hospital NHS Foundation Trust, Sheffield, UK
| | - Subhabrata Mitra
- Department of Neonatology, Institute for Women's Health, University College London, UK
| | - Nicola J Robertson
- Department of Neonatology, Institute for Women's Health, University College London, UK
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Non-invasive measurement of a metabolic marker of infant brain function. Sci Rep 2017; 7:1330. [PMID: 28465584 PMCID: PMC5430960 DOI: 10.1038/s41598-017-01394-z] [Citation(s) in RCA: 23] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/11/2017] [Accepted: 03/29/2017] [Indexed: 01/01/2023] Open
Abstract
While near-infrared spectroscopy (NIRS) haemodynamic measures have proven to be vastly useful in investigating human brain development, the haemodynamic response function (HRF) in infants is not yet fully understood. NIRS measurements of the oxidation state of mitochondrial enzyme cytochrome-c-oxidase (oxCCO) have the potential to yield key information about cellular oxygen utilisation and therefore energy metabolism. We used a broadband NIRS system to measure changes in oxCCO, in addition to haemodynamic changes, during functional activation in a group of 33 typically developing infants aged between 4 and 6 months. The responses were recorded over the right temporal lobe while the infants were presented with engaging videos containing social content. A significant increase in oxCCO was found in response to the social stimuli, with maximum increase of 0.238 ± 0.13 μM. These results are the first reported significant change in oxCCO in response to stimulus-evoked activation in human infants and open new vistas for investigating human infant brain function and its energy metabolism.
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Holper L, Mitra S, Bale G, Robertson N, Tachtsidis I. Prediction of brain tissue temperature using near-infrared spectroscopy. NEUROPHOTONICS 2017; 4:021106. [PMID: 28630878 PMCID: PMC5469395 DOI: 10.1117/1.nph.4.2.021106] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/24/2017] [Accepted: 05/15/2017] [Indexed: 08/17/2023]
Abstract
Broadband near-infrared spectroscopy (NIRS) can provide an endogenous indicator of tissue temperature based on the temperature dependence of the water absorption spectrum. We describe a first evaluation of the calibration and prediction of brain tissue temperature obtained during hypothermia in newborn piglets (animal dataset) and rewarming in newborn infants (human dataset) based on measured body (rectal) temperature. The calibration using partial least squares regression proved to be a reliable method to predict brain tissue temperature with respect to core body temperature in the wavelength interval of 720 to 880 nm with a strong mean predictive power of [Formula: see text] (animal dataset) and [Formula: see text] (human dataset). In addition, we applied regression receiver operating characteristic curves for the first time to evaluate the temperature prediction, which provided an overall mean error bias between NIRS predicted brain temperature and body temperature of [Formula: see text] (animal dataset) and [Formula: see text] (human dataset). We discuss main methodological aspects, particularly the well-known aspect of over- versus underestimation between brain and body temperature, which is relevant for potential clinical applications.
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Affiliation(s)
- Lisa Holper
- University of Zurich, Hospital of Psychiatry, Department of Psychiatry, Psychotherapy, and Psychosomatics, Zurich, Switzerland
| | - Subhabrata Mitra
- University College London and Neonatal Unit, University College London Hospitals Trust, Institute for Women’s Health, London, United Kingdom
| | - Gemma Bale
- University College London, Biomedical Optics Research Laboratory, Department of Medical Physics and Biomedical Engineering, London, United Kingdom
| | - Nicola Robertson
- University College London and Neonatal Unit, University College London Hospitals Trust, Institute for Women’s Health, London, United Kingdom
| | - Ilias Tachtsidis
- University College London, Biomedical Optics Research Laboratory, Department of Medical Physics and Biomedical Engineering, London, United Kingdom
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Brigadoi S, Phan P, Highton D, Powell S, Cooper RJ, Hebden J, Smith M, Tachtsidis I, Elwell CE, Gibson AP. Image reconstruction of oxidized cerebral cytochrome C oxidase changes from broadband near-infrared spectroscopy data. NEUROPHOTONICS 2017; 4:021105. [PMID: 28560239 PMCID: PMC5443419 DOI: 10.1117/1.nph.4.2.021105] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/03/2017] [Accepted: 05/01/2017] [Indexed: 05/23/2023]
Abstract
In diffuse optical tomography (DOT), overlapping and multidistance measurements are required to reconstruct depth-resolved images of oxy- ([Formula: see text]) and deoxy- (HHb) hemoglobin concentration changes occurring in the brain. These can be considered an indirect measure of brain activity, under the assumption of intact neurovascular coupling. Broadband systems also allow changes in the redox state of cytochrome c oxidase (oxCCO) to be measured, which can be an important biomarker when neurovascular coupling is impaired. We used DOT to reconstruct images of [Formula: see text], [Formula: see text], and [Formula: see text] from data acquired with a broadband system. Four healthy volunteers were measured while performing a visual stimulation task (4-Hz inverting checkerboard). The broadband system was configured to allow multidistance and overlapping measurements of the participants' visual cortex with 32 channels. A multispectral approach was employed to reconstruct changes in concentration of the three chromophores during the visual stimulation. A clear and focused activation was reconstructed in the left occipital cortex of all participants. The difference between the residuals of the three-chromophore model and of the two-chromophore model (recovering only [Formula: see text] and [Formula: see text]) exhibits a spectrum similar to that of oxCCO. These results form a basis for further studies aimed to further optimize image reconstruction of [Formula: see text].
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Affiliation(s)
- Sabrina Brigadoi
- University College London, Department of Medical Physics and Biomedical Engineering, Biomedical Optics Research Laboratory, London, United Kingdom
- University of Padova, Department of Developmental and Social Psychology, Padova, Italy
| | - Phong Phan
- University College London, Department of Medical Physics and Biomedical Engineering, Biomedical Optics Research Laboratory, London, United Kingdom
| | - David Highton
- National Hospital for Neurology and Neurosurgery, Neurocritical Care, London, United Kingdom
| | - Samuel Powell
- University College London, Department of Medical Physics and Biomedical Engineering, Biomedical Optics Research Laboratory, London, United Kingdom
- University College London, Department of Computer Science, London, United Kingdom
| | - Robert J. Cooper
- University College London, Department of Medical Physics and Biomedical Engineering, Biomedical Optics Research Laboratory, London, United Kingdom
| | - Jeremy Hebden
- University College London, Department of Medical Physics and Biomedical Engineering, Biomedical Optics Research Laboratory, London, United Kingdom
| | - Martin Smith
- University College London, Department of Medical Physics and Biomedical Engineering, Biomedical Optics Research Laboratory, London, United Kingdom
- National Hospital for Neurology and Neurosurgery, Neurocritical Care, London, United Kingdom
- NIHR University College London Hospitals Biomedical Research Centre, London, United Kingdom
| | - Ilias Tachtsidis
- University College London, Department of Medical Physics and Biomedical Engineering, Biomedical Optics Research Laboratory, London, United Kingdom
| | - Clare E. Elwell
- University College London, Department of Medical Physics and Biomedical Engineering, Biomedical Optics Research Laboratory, London, United Kingdom
| | - Adam P. Gibson
- University College London, Department of Medical Physics and Biomedical Engineering, Biomedical Optics Research Laboratory, London, United Kingdom
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Functional NIRS Measurement of Cytochrome-C-Oxidase Demonstrates a More Brain-Specific Marker of Frontal Lobe Activation Compared to the Haemoglobins. ADVANCES IN EXPERIMENTAL MEDICINE AND BIOLOGY 2017; 977:141-147. [PMID: 28685438 PMCID: PMC6126217 DOI: 10.1007/978-3-319-55231-6_19] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Abstract
Functional near-infrared spectroscopy (fNIRS) is an increasingly common neuromonitoring technique used to observe evoked haemodynamic changes in the brain in response to a stimulus. The measurement is typically in terms of concentration changes of oxy- (∆HbO2) and deoxy- (∆HHb) haemoglobin. However, noise from systemic fluctuations in the concentration of these chromophores can contaminate stimulus-evoked haemodynamic responses, leading to misinterpretation of results. Short-separation channels can be used to regress out extracerebral haemodynamics to better reveal cerebral changes, significantly improving the reliability of fNIRS. Broadband NIRS can be used to additionally monitor concentration changes of the oxidation state of cytochrome-c-oxidase (∆oxCCO). Recent studies have shown ∆oxCCO to be a depth-dependent and hence brain-specific signal. This study aims to investigate whether ∆oxCCO can produce a more robust marker of functional activation. Continuous frontal lobe NIRS measurements were collected from 17 healthy adult volunteers. Short 1 cm source-detector separation channels were regressed from longer separation channels in order to minimise the extracerebral contribution to standard fNIRS channels. Significant changes in ∆HbO2 and ∆HHb were seen at 1 cm channels but were not observed in ∆oxCCO. An improvement in the haemodynamic signals was achieved with regression of the 1 cm channel. Broadband NIRS-measured concentration changes of the oxidation state of cytochrome-c-oxidase has the potential to be an alternative and more brain-specific marker of functional activation.
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Nosrati R, Lin S, Ramadeen A, Monjazebi D, Dorian P, Toronov V. Cerebral Hemodynamics and Metabolism During Cardiac Arrest and Cardiopulmonary Resuscitation Using Hyperspectral Near Infrared Spectroscopy. Circ J 2017; 81:879-887. [PMID: 28302943 DOI: 10.1253/circj.cj-16-1225] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Abstract
BACKGROUND Maintaining cerebral oxygen delivery and metabolism during cardiac arrest (CA) through resuscitation is essential to improve the survival rate while avoiding brain injury. The effect of CA and cardiopulmonary resuscitation (CPR) on cerebral and muscle oxygen delivery and metabolism is not clearly quantified.Methods and Results:A novel hyperspectral near-infrared spectroscopy (hNIRS) technique was developed and evaluated to measure cerebral oxygen delivery and aerobic metabolism during ventricular fibrillation (VF) CA and CPR in 14 pigs. The hNIRS parameters were measured simultaneously on the dura and skull to investigate the validity of non-invasive hNIRS measurements. In addition, we compared the hNIRS data collected simultaneously on the brain and muscle. Following VF induction, oxygenated hemoglobin (HbO2) declined with a 9.9 s delay and then cytochrome-c-oxidase (Cyt-ox) decreased on average 4.4 s later (P<0.05). CPR improved cerebral metabolism, which was reflected by an average 0.4 μmol/L increase in Cyt-ox, but had no significant effect on HbO2, deoxygenated hemoglobin (HHb) and tissue oxygen saturation (tSO2). Cyt-ox had greater correlation with HHb than HbO2. Muscle metabolism during VF and CPR was significantly different from that of the brain. The total hemoglobin concentration (in the brain only) increased after ~200 s of untreated CA, which is most likely driven by cerebral autoregulation through vasodilation. CONCLUSIONS Overall, hNIRS showed consistent measurements of hemodynamics and metabolism during CA and CPR.
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Affiliation(s)
- Reyhaneh Nosrati
- Department of Physics, Ryerson University.,Medical Physics, Sunnybrook Health Sciences Centre
| | - Steve Lin
- Keenan Research Centre, Li Ka Shing Knowledge Institute, St. Michael's Hospital.,Department of Medicine, University of Toronto
| | - Andrew Ramadeen
- Keenan Research Centre, Li Ka Shing Knowledge Institute, St. Michael's Hospital
| | | | - Paul Dorian
- Keenan Research Centre, Li Ka Shing Knowledge Institute, St. Michael's Hospital.,Department of Medicine, University of Toronto
| | - Vladislav Toronov
- Department of Physics, Ryerson University.,Keenan Research Centre, Li Ka Shing Knowledge Institute, St. Michael's Hospital
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