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Auteur Siddhant SAWARDEKAR |
Documents disponibles écrits par cet auteur (3)



Brain tissue microstructure in a prospective, longitudinal, population-based cohort of preterm and term-born young adults / Sahar DELAVARI ; Jonathan SADIK ; Lars ERSLAND ; Irene B. ELGEN ; Siddhant SAWARDEKAR ; Ravi BANSAL ; Stein Magnus AUKLAND in Journal of Child Psychology and Psychiatry, 66-5 (May 2025)
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[article]
Titre : Brain tissue microstructure in a prospective, longitudinal, population-based cohort of preterm and term-born young adults Type de document : Texte imprimé et/ou numérique Auteurs : Sahar DELAVARI, Auteur ; Jonathan SADIK, Auteur ; Lars ERSLAND, Auteur ; Irene B. ELGEN, Auteur ; Siddhant SAWARDEKAR, Auteur ; Ravi BANSAL, Auteur ; Stein Magnus AUKLAND, Auteur Article en page(s) : p.635-649 Langues : Anglais (eng) Mots-clés : Premature birth preterm birth magnetic resonance imaging diffusion tensor imaging Index. décimale : PER Périodiques Résumé : Background Fifteen million infants annually are born prematurely, placing them at high risk for life-long adverse neurodevelopmental outcomes. Whether brain tissue abnormalities that accompany preterm birth persist into young adulthood and are associated with long-term cognitive or psychiatric outcomes is not known. Methods From infancy into young adulthood, we followed a population-based sample of consecutively identified preterm infants and their matched term controls. The preterm group was born at an average gestational age of 31.5?+?2.6?weeks. We obtained Diffusion Tensor Imaging scans and assessed cognitive and psychiatric outcomes in young adulthood, at a mean age of 19 (range 17.6?20.8) years. Usable data were acquired from 180 participants (89 preterm, 91 term). Results Preterm birth was associated with lower fractional anisotropy (FA) and higher average diffusion coefficient (ADC) values in deep white matter tracts of the internal capsule, cerebral peduncles, inferior frontal-occipital fasciculus, sagittal stratum and splenium of the corpus callosum, as well as in grey matter of the caudate, putamen and thalamus. A younger gestational age at birth accentuated these tissue abnormalities. Perinatal characteristics, including lower 5-min APGAR score, history of bronchopulmonary dysplasia, more days of oxygen supplementation and multiple births all increased ADC values in deep white matter tracts and grey matter throughout the brain. Preterm individuals had significantly lower full-scale IQ and more frequent lifetime psychiatric disorders. Those with psychiatric illnesses had significantly higher ADC and lower FA values throughout the deep posterior white matter. Conclusions Abnormalities in brain tissue microstructure associated with preterm birth persist into young adulthood and likely represent disordered myelination and accompanying axonal pathology. These disturbances are associated with a higher likelihood of developing a psychiatric disorder by young adulthood. Brain tissue disturbances were accentuated in those born at younger gestational ages and in those with a history of perinatal complications associated with infection and inflammation. En ligne : https://doi.org/10.1111/jcpp.14069 Permalink : https://www.cra-rhone-alpes.org/cid/opac_css/index.php?lvl=notice_display&id=554
in Journal of Child Psychology and Psychiatry > 66-5 (May 2025) . - p.635-649[article] Brain tissue microstructure in a prospective, longitudinal, population-based cohort of preterm and term-born young adults [Texte imprimé et/ou numérique] / Sahar DELAVARI, Auteur ; Jonathan SADIK, Auteur ; Lars ERSLAND, Auteur ; Irene B. ELGEN, Auteur ; Siddhant SAWARDEKAR, Auteur ; Ravi BANSAL, Auteur ; Stein Magnus AUKLAND, Auteur . - p.635-649.
Langues : Anglais (eng)
in Journal of Child Psychology and Psychiatry > 66-5 (May 2025) . - p.635-649
Mots-clés : Premature birth preterm birth magnetic resonance imaging diffusion tensor imaging Index. décimale : PER Périodiques Résumé : Background Fifteen million infants annually are born prematurely, placing them at high risk for life-long adverse neurodevelopmental outcomes. Whether brain tissue abnormalities that accompany preterm birth persist into young adulthood and are associated with long-term cognitive or psychiatric outcomes is not known. Methods From infancy into young adulthood, we followed a population-based sample of consecutively identified preterm infants and their matched term controls. The preterm group was born at an average gestational age of 31.5?+?2.6?weeks. We obtained Diffusion Tensor Imaging scans and assessed cognitive and psychiatric outcomes in young adulthood, at a mean age of 19 (range 17.6?20.8) years. Usable data were acquired from 180 participants (89 preterm, 91 term). Results Preterm birth was associated with lower fractional anisotropy (FA) and higher average diffusion coefficient (ADC) values in deep white matter tracts of the internal capsule, cerebral peduncles, inferior frontal-occipital fasciculus, sagittal stratum and splenium of the corpus callosum, as well as in grey matter of the caudate, putamen and thalamus. A younger gestational age at birth accentuated these tissue abnormalities. Perinatal characteristics, including lower 5-min APGAR score, history of bronchopulmonary dysplasia, more days of oxygen supplementation and multiple births all increased ADC values in deep white matter tracts and grey matter throughout the brain. Preterm individuals had significantly lower full-scale IQ and more frequent lifetime psychiatric disorders. Those with psychiatric illnesses had significantly higher ADC and lower FA values throughout the deep posterior white matter. Conclusions Abnormalities in brain tissue microstructure associated with preterm birth persist into young adulthood and likely represent disordered myelination and accompanying axonal pathology. These disturbances are associated with a higher likelihood of developing a psychiatric disorder by young adulthood. Brain tissue disturbances were accentuated in those born at younger gestational ages and in those with a history of perinatal complications associated with infection and inflammation. En ligne : https://doi.org/10.1111/jcpp.14069 Permalink : https://www.cra-rhone-alpes.org/cid/opac_css/index.php?lvl=notice_display&id=554 Prenatal exposure to air pollution is associated with altered brain structure, function, and metabolism in childhood / Bradley S. PETERSON in Journal of Child Psychology and Psychiatry, 63-11 (November 2022)
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Titre : Prenatal exposure to air pollution is associated with altered brain structure, function, and metabolism in childhood Type de document : Texte imprimé et/ou numérique Auteurs : Bradley S. PETERSON, Auteur ; Ravi BANSAL, Auteur ; Siddhant SAWARDEKAR, Auteur ; Carlo NATI, Auteur ; Eman R. ELGABALAWY, Auteur ; Lori A. HOEPNER, Auteur ; Wanda GARCIA, Auteur ; Xuejun HAO, Auteur ; Amy MARGOLIS, Auteur ; Frederica PERERA, Auteur ; Virginia RAUH, Auteur Article en page(s) : p.1316-1331 Langues : Anglais (eng) Mots-clés : Male Adolescent Pregnancy Female Humans Child Prenatal Exposure Delayed Effects/metabolism Prospective Studies Air Pollution/adverse effects Brain Particulate Matter/adverse effects/analysis/metabolism Polycyclic Aromatic Hydrocarbons Air Pollutants Air pollution arterial spin labeling diffusion tensor imaging magnetic resonance imaging magnetic resonance spectroscopy particulate matter polycyclic aromatic hydrocarbons Index. décimale : PER Périodiques Résumé : BACKGROUND: Prenatal exposure to air pollution disrupts cognitive, emotional, and behavioral development. The brain disturbances associated with prenatal air pollution are largely unknown. METHODS: In this prospective cohort study, we estimated prenatal exposures to fine particulate matter (PM(2.5) ) and polycyclic aromatic hydrocarbons (PAH), and then assessed their associations with measures of brain anatomy, tissue microstructure, neurometabolites, and blood flow in 332 youth, 6-14 years old. We then assessed how those brain disturbances were associated with measures of intelligence, ADHD and anxiety symptoms, and socialization. RESULTS: Both exposures were associated with thinning of dorsal parietal cortices and thickening of postero-inferior and mesial wall cortices. They were associated with smaller white matter volumes, reduced organization in white matter of the internal capsule and frontal lobe, higher metabolite concentrations in frontal cortex, reduced cortical blood flow, and greater microstructural organization in subcortical gray matter nuclei. Associations were stronger for PM(2.5) in boys and PAH in girls. Youth with low exposure accounted for most significant associations of ADHD, anxiety, socialization, and intelligence measures with cortical thickness and white matter volumes, whereas it appears that high exposures generally disrupted these neurotypical brain-behavior associations, likely because strong exposure-related effects increased the variances of these brain measures. CONCLUSIONS: The commonality of effects across exposures suggests PM(2.5) and PAH disrupt brain development through one or more common molecular pathways, such as inflammation or oxidative stress. Progressively higher exposures were associated with greater disruptions in local volumes, tissue organization, metabolite concentrations, and blood flow throughout cortical and subcortical brain regions and the white matter pathways interconnecting them. Together these affected regions comprise cortico-striato-thalamo-cortical circuits, which support the regulation of thought, emotion, and behavior. En ligne : http://dx.doi.org/10.1111/jcpp.13578 Permalink : https://www.cra-rhone-alpes.org/cid/opac_css/index.php?lvl=notice_display&id=490
in Journal of Child Psychology and Psychiatry > 63-11 (November 2022) . - p.1316-1331[article] Prenatal exposure to air pollution is associated with altered brain structure, function, and metabolism in childhood [Texte imprimé et/ou numérique] / Bradley S. PETERSON, Auteur ; Ravi BANSAL, Auteur ; Siddhant SAWARDEKAR, Auteur ; Carlo NATI, Auteur ; Eman R. ELGABALAWY, Auteur ; Lori A. HOEPNER, Auteur ; Wanda GARCIA, Auteur ; Xuejun HAO, Auteur ; Amy MARGOLIS, Auteur ; Frederica PERERA, Auteur ; Virginia RAUH, Auteur . - p.1316-1331.
Langues : Anglais (eng)
in Journal of Child Psychology and Psychiatry > 63-11 (November 2022) . - p.1316-1331
Mots-clés : Male Adolescent Pregnancy Female Humans Child Prenatal Exposure Delayed Effects/metabolism Prospective Studies Air Pollution/adverse effects Brain Particulate Matter/adverse effects/analysis/metabolism Polycyclic Aromatic Hydrocarbons Air Pollutants Air pollution arterial spin labeling diffusion tensor imaging magnetic resonance imaging magnetic resonance spectroscopy particulate matter polycyclic aromatic hydrocarbons Index. décimale : PER Périodiques Résumé : BACKGROUND: Prenatal exposure to air pollution disrupts cognitive, emotional, and behavioral development. The brain disturbances associated with prenatal air pollution are largely unknown. METHODS: In this prospective cohort study, we estimated prenatal exposures to fine particulate matter (PM(2.5) ) and polycyclic aromatic hydrocarbons (PAH), and then assessed their associations with measures of brain anatomy, tissue microstructure, neurometabolites, and blood flow in 332 youth, 6-14 years old. We then assessed how those brain disturbances were associated with measures of intelligence, ADHD and anxiety symptoms, and socialization. RESULTS: Both exposures were associated with thinning of dorsal parietal cortices and thickening of postero-inferior and mesial wall cortices. They were associated with smaller white matter volumes, reduced organization in white matter of the internal capsule and frontal lobe, higher metabolite concentrations in frontal cortex, reduced cortical blood flow, and greater microstructural organization in subcortical gray matter nuclei. Associations were stronger for PM(2.5) in boys and PAH in girls. Youth with low exposure accounted for most significant associations of ADHD, anxiety, socialization, and intelligence measures with cortical thickness and white matter volumes, whereas it appears that high exposures generally disrupted these neurotypical brain-behavior associations, likely because strong exposure-related effects increased the variances of these brain measures. CONCLUSIONS: The commonality of effects across exposures suggests PM(2.5) and PAH disrupt brain development through one or more common molecular pathways, such as inflammation or oxidative stress. Progressively higher exposures were associated with greater disruptions in local volumes, tissue organization, metabolite concentrations, and blood flow throughout cortical and subcortical brain regions and the white matter pathways interconnecting them. Together these affected regions comprise cortico-striato-thalamo-cortical circuits, which support the regulation of thought, emotion, and behavior. En ligne : http://dx.doi.org/10.1111/jcpp.13578 Permalink : https://www.cra-rhone-alpes.org/cid/opac_css/index.php?lvl=notice_display&id=490 Using tissue microstructure and multimodal MRI to parse the phenotypic heterogeneity and cellular basis of autism spectrum disorder / Bradley S. PETERSON in Journal of Child Psychology and Psychiatry, 63-8 (August 2022)
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Titre : Using tissue microstructure and multimodal MRI to parse the phenotypic heterogeneity and cellular basis of autism spectrum disorder Type de document : Texte imprimé et/ou numérique Auteurs : Bradley S. PETERSON, Auteur ; Jiaqi LIU, Auteur ; Louis DANTEC, Auteur ; Courtney NEWMAN, Auteur ; Siddhant SAWARDEKAR, Auteur ; Suzanne GOH, Auteur ; Ravi BANSAL, Auteur Article en page(s) : p.855-870 Langues : Anglais (eng) Mots-clés : Autism Spectrum Disorder/metabolism Brain/metabolism Diffusion Tensor Imaging Humans Magnetic Resonance Imaging White Matter/diagnostic imaging/pathology Autism white matter interest. Index. décimale : PER Périodiques Résumé : BACKGROUND: Identifying the brain bases for phenotypic heterogeneity in Autism Spectrum Disorder (ASD) will advance understanding of its pathogenesis and improve its clinical management. METHODS: We compared Diffusion Tensor Imaging (DTI) indices and connectome measures between 77 ASD and 88 Typically Developing (TD) control participants. We also assessed voxel-wise associations of DTI indices with measures of regional cerebral blood flow (rCBF) and N-acetylaspartate (NAA) to understand how tissue microstructure associates with cellular metabolism and neuronal density, respectively. RESULTS: Autism Spectrum Disorder participants had significantly lower fractional anisotropy (FA) and higher diffusivity values in deep white matter tracts, likely representing ether reduced myelination by oligodendrocytes or a reduced density of myelinated axons. Greater abnormalities in these measures and regions were associated with higher ASD symptom scores. Participant age, sex and IQ significantly moderated these group differences. Path analyses showed that reduced NAA levels accounted significantly for higher diffusivity and higher rCBF values in ASD compared with TD participants. CONCLUSIONS: Reduced neuronal density (reduced NAA) likely underlies abnormalities in DTI indices of white matter microstructure in ASD, which in turn are major determinants of elevated blood flow. Together, these findings suggest the presence of reduced axonal density and axonal pathology in ASD white matter. Greater pathology in turn accounts for more severe symptoms, lower intellectual ability, and reduced global efficiency for measures of white matter connectivity in ASD. En ligne : http://dx.doi.org/10.1111/jcpp.13531 Permalink : https://www.cra-rhone-alpes.org/cid/opac_css/index.php?lvl=notice_display&id=486
in Journal of Child Psychology and Psychiatry > 63-8 (August 2022) . - p.855-870[article] Using tissue microstructure and multimodal MRI to parse the phenotypic heterogeneity and cellular basis of autism spectrum disorder [Texte imprimé et/ou numérique] / Bradley S. PETERSON, Auteur ; Jiaqi LIU, Auteur ; Louis DANTEC, Auteur ; Courtney NEWMAN, Auteur ; Siddhant SAWARDEKAR, Auteur ; Suzanne GOH, Auteur ; Ravi BANSAL, Auteur . - p.855-870.
Langues : Anglais (eng)
in Journal of Child Psychology and Psychiatry > 63-8 (August 2022) . - p.855-870
Mots-clés : Autism Spectrum Disorder/metabolism Brain/metabolism Diffusion Tensor Imaging Humans Magnetic Resonance Imaging White Matter/diagnostic imaging/pathology Autism white matter interest. Index. décimale : PER Périodiques Résumé : BACKGROUND: Identifying the brain bases for phenotypic heterogeneity in Autism Spectrum Disorder (ASD) will advance understanding of its pathogenesis and improve its clinical management. METHODS: We compared Diffusion Tensor Imaging (DTI) indices and connectome measures between 77 ASD and 88 Typically Developing (TD) control participants. We also assessed voxel-wise associations of DTI indices with measures of regional cerebral blood flow (rCBF) and N-acetylaspartate (NAA) to understand how tissue microstructure associates with cellular metabolism and neuronal density, respectively. RESULTS: Autism Spectrum Disorder participants had significantly lower fractional anisotropy (FA) and higher diffusivity values in deep white matter tracts, likely representing ether reduced myelination by oligodendrocytes or a reduced density of myelinated axons. Greater abnormalities in these measures and regions were associated with higher ASD symptom scores. Participant age, sex and IQ significantly moderated these group differences. Path analyses showed that reduced NAA levels accounted significantly for higher diffusivity and higher rCBF values in ASD compared with TD participants. CONCLUSIONS: Reduced neuronal density (reduced NAA) likely underlies abnormalities in DTI indices of white matter microstructure in ASD, which in turn are major determinants of elevated blood flow. Together, these findings suggest the presence of reduced axonal density and axonal pathology in ASD white matter. Greater pathology in turn accounts for more severe symptoms, lower intellectual ability, and reduced global efficiency for measures of white matter connectivity in ASD. En ligne : http://dx.doi.org/10.1111/jcpp.13531 Permalink : https://www.cra-rhone-alpes.org/cid/opac_css/index.php?lvl=notice_display&id=486