5 recherche sur le mot-clé 'White Matter/diagnostic imaging'

Connecting the dots: social networks in the classroom and white matter connections in the brain / Rosa H. MULDER in Journal of Child Psychology and Psychiatry, 63-12 (December 2022)  

Public ISBD [article]  inJournal of Child Psychology and Psychiatry > 63-12 (December 2022) . - p.1622-1630 Titre : Connecting the dots: social networks in the classroom and white matter connections in the brain Type de document : Texte imprimé et/ou numérique Auteurs : Rosa H. MULDER, Auteur ; Monica LOPEZ-VICENTE, Auteur ; Andrea P. CORTES HIDALGO, Auteur ; Lisa R. STEENKAMP, Auteur ; Berna GUROÄŽLU, Auteur ; Henning TIEMEIER, Auteur ; Ryan L. MUETZEL, Auteur Article en page(s) : p.1622-1630 Langues : Anglais (eng) Mots-clés : Child  Humans  White Matter/diagnostic imaging  Diffusion Tensor Imaging  Cross-Sectional Studies  Brain/diagnostic imaging  Social Networking  Bullying behavior  Generation R Study  brain imaging  peer acceptance  peer rejection  peer victimization  white matter microstructure Index. décimale : PER Périodiques Résumé : BACKGROUND: Peer connections in school classrooms play an important role in social-emotional development and mental health. However, research on the association between children's peer relationships and white matter connections in the brain is scarce. We studied associations between peer relationships in the classroom and white matter structural connectivity in a pediatric population-based sample. METHODS: Bullying and victimization, as well as rejection and acceptance, were assessed in classrooms in 634 children at age 7. White matter microstructure (fractional anisotropy (FA), mean diffusivity (MD)) was measured with diffusion tensor imaging at age 10. We examined global metrics of white matter microstructure and used Tract-Based Spatial Statistics (TBSS) for voxel-wise associations. RESULTS: Peer victimization was associated with higher global FA and lower global MD and peer rejection was associated with lower global MD; however, these associations did not remain after multiple testing correction. Voxel-wise TBSS results for peer victimization and rejection were in line with global metrics both in terms of direction and spatial extent of the associations, with associated voxels (p(FWE) <.05) observed throughout the brain (including corpus callosum, corona radiata, sagittal stratum and superior longitudinal fasciculi). CONCLUSIONS: Although based only on cross-sectional data, the findings could indicate accelerated white matter microstructure maturation in certain brain areas of children who are victimized or rejected more often. However, repeated measurements are essential to unravel this complex interplay of peer connections, maturation and brain development over time. En ligne : http://dx.doi.org/10.1111/jcpp.13647 Permalink : https://www.cra-rhone-alpes.org/cid/opac_css/index.php?lvl=notice_display&id=490 [article] Connecting the dots: social networks in the classroom and white matter connections in the brain [Texte imprimé et/ou numérique] / Rosa H. MULDER, Auteur ; Monica LOPEZ-VICENTE, Auteur ; Andrea P. CORTES HIDALGO, Auteur ; Lisa R. STEENKAMP, Auteur ; Berna GUROÄŽLU, Auteur ; Henning TIEMEIER, Auteur ; Ryan L. MUETZEL, Auteur . - p.1622-1630. Langues : Anglais (eng) in Journal of Child Psychology and Psychiatry > 63-12 (December 2022) . - p.1622-1630 Mots-clés : Child  Humans  White Matter/diagnostic imaging  Diffusion Tensor Imaging  Cross-Sectional Studies  Brain/diagnostic imaging  Social Networking  Bullying behavior  Generation R Study  brain imaging  peer acceptance  peer rejection  peer victimization  white matter microstructure Index. décimale : PER Périodiques Résumé : BACKGROUND: Peer connections in school classrooms play an important role in social-emotional development and mental health. However, research on the association between children's peer relationships and white matter connections in the brain is scarce. We studied associations between peer relationships in the classroom and white matter structural connectivity in a pediatric population-based sample. METHODS: Bullying and victimization, as well as rejection and acceptance, were assessed in classrooms in 634 children at age 7. White matter microstructure (fractional anisotropy (FA), mean diffusivity (MD)) was measured with diffusion tensor imaging at age 10. We examined global metrics of white matter microstructure and used Tract-Based Spatial Statistics (TBSS) for voxel-wise associations. RESULTS: Peer victimization was associated with higher global FA and lower global MD and peer rejection was associated with lower global MD; however, these associations did not remain after multiple testing correction. Voxel-wise TBSS results for peer victimization and rejection were in line with global metrics both in terms of direction and spatial extent of the associations, with associated voxels (p(FWE) <.05) observed throughout the brain (including corpus callosum, corona radiata, sagittal stratum and superior longitudinal fasciculi). CONCLUSIONS: Although based only on cross-sectional data, the findings could indicate accelerated white matter microstructure maturation in certain brain areas of children who are victimized or rejected more often. However, repeated measurements are essential to unravel this complex interplay of peer connections, maturation and brain development over time. En ligne : http://dx.doi.org/10.1111/jcpp.13647 Permalink : https://www.cra-rhone-alpes.org/cid/opac_css/index.php?lvl=notice_display&id=490

Cortico-basal ganglia white matter microstructure is linked to restricted repetitive behavior in autism spectrum disorder / Bradley J. WILKES in Molecular Autism, 15 (2024)  

Public ISBD [article]  inMolecular Autism > 15 (2024) . - 6p. Titre : Cortico-basal ganglia white matter microstructure is linked to restricted repetitive behavior in autism spectrum disorder Type de document : Texte imprimé et/ou numérique Auteurs : Bradley J. WILKES, Auteur ; Derek B. ARCHER, Auteur ; Anna L. FARMER, Auteur ; Carly BASS, Auteur ; Hannah KORAH, Auteur ; David E. VAILLANCOURT, Auteur ; Mark H. LEWIS, Auteur Article en page(s) : 6p. Langues : Anglais (eng) Mots-clés : United States  Adolescent  Child  Humans  White Matter/diagnostic imaging  Autism Spectrum Disorder/diagnostic imaging  Basal Ganglia/diagnostic imaging  Brain  Water  Autism spectrum disorder  Basal ganglia  Cerebellum  Cortico-basal ganglia  Diffusion tensor imaging  Free-water  Gray matter  Restricted repetitive behavior  White matter Index. décimale : PER Périodiques Résumé : BACKGROUND: Restricted repetitive behavior (RRB) is one of two behavioral domains required for the diagnosis of autism spectrum disorder (ASD). Neuroimaging is widely used to study brain alterations associated with ASD and the domain of social and communication deficits, but there has been less work regarding brain alterations linked to RRB. METHODS: We utilized neuroimaging data from the National Institute of Mental Health Data Archive to assess basal ganglia and cerebellum structure in a cohort of children and adolescents with ASD compared to typically developing (TD) controls. We evaluated regional gray matter volumes from T1-weighted anatomical scans and assessed diffusion-weighted scans to quantify white matter microstructure with free-water imaging. We also investigated the interaction of biological sex and ASD diagnosis on these measures, and their correlation with clinical scales of RRB. RESULTS: Individuals with ASD had significantly lower free-water corrected fractional anisotropy (FA(T)) and higher free-water (FW) in cortico-basal ganglia white matter tracts. These microstructural differences did not interact with biological sex. Moreover, both FA(T) and FW in basal ganglia white matter tracts significantly correlated with measures of RRB. In contrast, we found no significant difference in basal ganglia or cerebellar gray matter volumes. LIMITATIONS: The basal ganglia and cerebellar regions in this study were selected due to their hypothesized relevance to RRB. Differences between ASD and TD individuals that may occur outside the basal ganglia and cerebellum, and their potential relationship to RRB, were not evaluated. CONCLUSIONS: These new findings demonstrate that cortico-basal ganglia white matter microstructure is altered in ASD and linked to RRB. FW in cortico-basal ganglia and intra-basal ganglia white matter was more sensitive to group differences in ASD, whereas cortico-basal ganglia FA(T) was more closely linked to RRB. In contrast, basal ganglia and cerebellar volumes did not differ in ASD. There was no interaction between ASD diagnosis and sex-related differences in brain structure. Future diffusion imaging investigations in ASD may benefit from free-water estimation and correction in order to better understand how white matter is affected in ASD, and how such measures are linked to RRB. En ligne : https://dx.doi.org/10.1186/s13229-023-00581-2 Permalink : https://www.cra-rhone-alpes.org/cid/opac_css/index.php?lvl=notice_display&id=538 [article] Cortico-basal ganglia white matter microstructure is linked to restricted repetitive behavior in autism spectrum disorder [Texte imprimé et/ou numérique] / Bradley J. WILKES, Auteur ; Derek B. ARCHER, Auteur ; Anna L. FARMER, Auteur ; Carly BASS, Auteur ; Hannah KORAH, Auteur ; David E. VAILLANCOURT, Auteur ; Mark H. LEWIS, Auteur . - 6p. Langues : Anglais (eng) in Molecular Autism > 15 (2024) . - 6p. Mots-clés : United States  Adolescent  Child  Humans  White Matter/diagnostic imaging  Autism Spectrum Disorder/diagnostic imaging  Basal Ganglia/diagnostic imaging  Brain  Water  Autism spectrum disorder  Basal ganglia  Cerebellum  Cortico-basal ganglia  Diffusion tensor imaging  Free-water  Gray matter  Restricted repetitive behavior  White matter Index. décimale : PER Périodiques Résumé : BACKGROUND: Restricted repetitive behavior (RRB) is one of two behavioral domains required for the diagnosis of autism spectrum disorder (ASD). Neuroimaging is widely used to study brain alterations associated with ASD and the domain of social and communication deficits, but there has been less work regarding brain alterations linked to RRB. METHODS: We utilized neuroimaging data from the National Institute of Mental Health Data Archive to assess basal ganglia and cerebellum structure in a cohort of children and adolescents with ASD compared to typically developing (TD) controls. We evaluated regional gray matter volumes from T1-weighted anatomical scans and assessed diffusion-weighted scans to quantify white matter microstructure with free-water imaging. We also investigated the interaction of biological sex and ASD diagnosis on these measures, and their correlation with clinical scales of RRB. RESULTS: Individuals with ASD had significantly lower free-water corrected fractional anisotropy (FA(T)) and higher free-water (FW) in cortico-basal ganglia white matter tracts. These microstructural differences did not interact with biological sex. Moreover, both FA(T) and FW in basal ganglia white matter tracts significantly correlated with measures of RRB. In contrast, we found no significant difference in basal ganglia or cerebellar gray matter volumes. LIMITATIONS: The basal ganglia and cerebellar regions in this study were selected due to their hypothesized relevance to RRB. Differences between ASD and TD individuals that may occur outside the basal ganglia and cerebellum, and their potential relationship to RRB, were not evaluated. CONCLUSIONS: These new findings demonstrate that cortico-basal ganglia white matter microstructure is altered in ASD and linked to RRB. FW in cortico-basal ganglia and intra-basal ganglia white matter was more sensitive to group differences in ASD, whereas cortico-basal ganglia FA(T) was more closely linked to RRB. In contrast, basal ganglia and cerebellar volumes did not differ in ASD. There was no interaction between ASD diagnosis and sex-related differences in brain structure. Future diffusion imaging investigations in ASD may benefit from free-water estimation and correction in order to better understand how white matter is affected in ASD, and how such measures are linked to RRB. En ligne : https://dx.doi.org/10.1186/s13229-023-00581-2 Permalink : https://www.cra-rhone-alpes.org/cid/opac_css/index.php?lvl=notice_display&id=538

Individual differences in white matter of the uncinate fasciculus and inferior fronto-occipital fasciculus: possible early biomarkers for callous-unemotional behaviors in young children with disruptive behavior problems / P. A. GRAZIANO in Journal of Child Psychology and Psychiatry, 63-1 (January 2022)  

Public ISBD [article]  inJournal of Child Psychology and Psychiatry > 63-1 (January 2022) . - p.19-33 Titre : Individual differences in white matter of the uncinate fasciculus and inferior fronto-occipital fasciculus: possible early biomarkers for callous-unemotional behaviors in young children with disruptive behavior problems Type de document : Texte imprimé et/ou numérique Auteurs : P. A. GRAZIANO, Auteur ; D. GARIC, Auteur ; A. S. DICK, Auteur Article en page(s) : p.19-33 Langues : Anglais (eng) Mots-clés : Biomarkers  Child  Child, Preschool  Diffusion Tensor Imaging  Female  Humans  Individuality  Male  Problem Behavior  Uncinate Fasciculus  White Matter/diagnostic imaging  Callous-unemotional behaviors  Dti  conduct problems  imaging  preschool  uncinate fasciculus Index. décimale : PER Périodiques Résumé : BACKGROUND: Callous-unemotional (CU) behaviors are important for identifying severe patterns of conduct problems (CP). One major fiber tract implicated in the development of CP is the uncinate fasciculus (UF), which connects amygdala and orbitofrontal cortex (OFC). The goals of the current study were to (a) explore differences in the white matter microstructure in the UF and other major fiber tracks between young typically developing (TD) children and those with a disruptive behavior disorder (DBD) and (b) explore, within the DBD group, whether individual differences in these white matter tracts relate to co-occurring CP and CU behaviors. METHODS: Participants included 198 young children (69% boys, M(age) ?=?5.66?years; 80% Latinx; 48.5% TD). CU behaviors and CP were measured via a combination of teacher/parent ratings. Non-invasive diffusion-weighted imaging (DWI) was used to measure fractional anisotropy (FA), an indirect indicator of white matter properties. RESULTS: Relative to TD children, children in the DBD group had reduced FA on four out of the five fiber tracks we examined (except for cingulum and right ILF), even after accounting for whole brain FA, sex, movement, parental income, and IQ. Within the DBD group, no associations were found between CP and reduced white matter integrity across any of the fiber tracks examined. However, we found that even after accounting for CP, ADHD symptomology, and a host of covariates (whole brain FA, sex, movement, parental income, and IQ), CU behaviors were independently related to reduced FA in bilateral UF and left inferior fronto-occipital fasciculus (IFOF) in the DBD group, but this was not the case for TD children. CONCLUSIONS: Alterations in the white matter microstructure within bilateral UF and left IFOF may be biomarkers of CU behaviors, even in very young children. En ligne : http://dx.doi.org/10.1111/jcpp.13444 Permalink : https://www.cra-rhone-alpes.org/cid/opac_css/index.php?lvl=notice_display&id=456 [article] Individual differences in white matter of the uncinate fasciculus and inferior fronto-occipital fasciculus: possible early biomarkers for callous-unemotional behaviors in young children with disruptive behavior problems [Texte imprimé et/ou numérique] / P. A. GRAZIANO, Auteur ; D. GARIC, Auteur ; A. S. DICK, Auteur . - p.19-33. Langues : Anglais (eng) in Journal of Child Psychology and Psychiatry > 63-1 (January 2022) . - p.19-33 Mots-clés : Biomarkers  Child  Child, Preschool  Diffusion Tensor Imaging  Female  Humans  Individuality  Male  Problem Behavior  Uncinate Fasciculus  White Matter/diagnostic imaging  Callous-unemotional behaviors  Dti  conduct problems  imaging  preschool  uncinate fasciculus Index. décimale : PER Périodiques Résumé : BACKGROUND: Callous-unemotional (CU) behaviors are important for identifying severe patterns of conduct problems (CP). One major fiber tract implicated in the development of CP is the uncinate fasciculus (UF), which connects amygdala and orbitofrontal cortex (OFC). The goals of the current study were to (a) explore differences in the white matter microstructure in the UF and other major fiber tracks between young typically developing (TD) children and those with a disruptive behavior disorder (DBD) and (b) explore, within the DBD group, whether individual differences in these white matter tracts relate to co-occurring CP and CU behaviors. METHODS: Participants included 198 young children (69% boys, M(age) ?=?5.66?years; 80% Latinx; 48.5% TD). CU behaviors and CP were measured via a combination of teacher/parent ratings. Non-invasive diffusion-weighted imaging (DWI) was used to measure fractional anisotropy (FA), an indirect indicator of white matter properties. RESULTS: Relative to TD children, children in the DBD group had reduced FA on four out of the five fiber tracks we examined (except for cingulum and right ILF), even after accounting for whole brain FA, sex, movement, parental income, and IQ. Within the DBD group, no associations were found between CP and reduced white matter integrity across any of the fiber tracks examined. However, we found that even after accounting for CP, ADHD symptomology, and a host of covariates (whole brain FA, sex, movement, parental income, and IQ), CU behaviors were independently related to reduced FA in bilateral UF and left inferior fronto-occipital fasciculus (IFOF) in the DBD group, but this was not the case for TD children. CONCLUSIONS: Alterations in the white matter microstructure within bilateral UF and left IFOF may be biomarkers of CU behaviors, even in very young children. En ligne : http://dx.doi.org/10.1111/jcpp.13444 Permalink : https://www.cra-rhone-alpes.org/cid/opac_css/index.php?lvl=notice_display&id=456

Atypical structural connectivity of language networks in autism spectrum disorder: A meta-analysis of diffusion tensor imaging studies / Min LI in Autism Research, 15-9 (September 2022)  

Public ISBD [article]  inAutism Research > 15-9 (September 2022) . - p.1585-1602 Titre : Atypical structural connectivity of language networks in autism spectrum disorder: A meta-analysis of diffusion tensor imaging studies Type de document : Texte imprimé et/ou numérique Auteurs : Min LI, Auteur ; Yide WANG, Auteur ; Masaya TACHIBANA, Auteur ; Shafiur RAHMAN, Auteur ; Kuriko KAGITANI-SHIMONO, Auteur Article en page(s) : p.1585-1602 Langues : Anglais (eng) Mots-clés : Adult  Autism Spectrum Disorder/diagnostic imaging  Brain/diagnostic imaging  Child  Child Development Disorders, Pervasive/diagnosis  Diffusion Tensor Imaging  Humans  White Matter/diagnostic imaging  autism spectrum disorder  language networks  meta-analysis  white matter connectivity Index. décimale : PER Périodiques Résumé : Patients with autism spectrum disorder (ASD) often show pervasive and complex language impairments that are closely associated with aberrant structural connectivity of language networks. However, the characteristics of white matter connectivity in ASD have remained inconclusive in previous diffusion tensor imaging (DTI) studies. The current meta-analysis aimed to comprehensively elucidate the abnormality in language-related white matter connectivity in individuals with ASD. We searched PubMed, Web of Science, Scopus, and Medline databases to identify relevant studies. The standardized mean difference was calculated to measure the pooled difference in DTI metrics in each tract between the ASD and typically developing (TD) groups. The moderating effects of age, sex, language ability, and symptom severity were investigated using subgroup and meta-regression analysis. Thirty-three DTI studies involving 831 individuals with ASD and 836 TD controls were included in the meta-analysis. ASD subjects showed significantly lower fractional anisotropy or higher mean diffusivity across language-associated tracts than TD controls. These abnormalities tended to be more prominent in the left language networks than in the right. In addition, children with ASD exhibit more pronounced and pervasive disturbances in white matter connectivity than adults. These results support the under-connectivity hypothesis and demonstrate the widespread abnormal microstructure of language-related tracts in patients with ASD. Otherwise, white matter abnormalities in the autistic brain could vary depending on the developmental stage and hemisphere. LAY SUMMARY: This meta-analysis explored abnormalities in white matter connectivity in language networks of individuals with ASD. Significantly reduced white matter integrity was found in all language-associated tracts in subjects with ASD compared with TD controls. In addition, structural disturbances of language networks in the autistic brain exhibit a leftward tendency, and more prominent abnormalities are observed in younger people with ASD than in adults. En ligne : http://dx.doi.org/10.1002/aur.2789 Permalink : https://www.cra-rhone-alpes.org/cid/opac_css/index.php?lvl=notice_display&id=483 [article] Atypical structural connectivity of language networks in autism spectrum disorder: A meta-analysis of diffusion tensor imaging studies [Texte imprimé et/ou numérique] / Min LI, Auteur ; Yide WANG, Auteur ; Masaya TACHIBANA, Auteur ; Shafiur RAHMAN, Auteur ; Kuriko KAGITANI-SHIMONO, Auteur . - p.1585-1602. Langues : Anglais (eng) in Autism Research > 15-9 (September 2022) . - p.1585-1602 Mots-clés : Adult  Autism Spectrum Disorder/diagnostic imaging  Brain/diagnostic imaging  Child  Child Development Disorders, Pervasive/diagnosis  Diffusion Tensor Imaging  Humans  White Matter/diagnostic imaging  autism spectrum disorder  language networks  meta-analysis  white matter connectivity Index. décimale : PER Périodiques Résumé : Patients with autism spectrum disorder (ASD) often show pervasive and complex language impairments that are closely associated with aberrant structural connectivity of language networks. However, the characteristics of white matter connectivity in ASD have remained inconclusive in previous diffusion tensor imaging (DTI) studies. The current meta-analysis aimed to comprehensively elucidate the abnormality in language-related white matter connectivity in individuals with ASD. We searched PubMed, Web of Science, Scopus, and Medline databases to identify relevant studies. The standardized mean difference was calculated to measure the pooled difference in DTI metrics in each tract between the ASD and typically developing (TD) groups. The moderating effects of age, sex, language ability, and symptom severity were investigated using subgroup and meta-regression analysis. Thirty-three DTI studies involving 831 individuals with ASD and 836 TD controls were included in the meta-analysis. ASD subjects showed significantly lower fractional anisotropy or higher mean diffusivity across language-associated tracts than TD controls. These abnormalities tended to be more prominent in the left language networks than in the right. In addition, children with ASD exhibit more pronounced and pervasive disturbances in white matter connectivity than adults. These results support the under-connectivity hypothesis and demonstrate the widespread abnormal microstructure of language-related tracts in patients with ASD. Otherwise, white matter abnormalities in the autistic brain could vary depending on the developmental stage and hemisphere. LAY SUMMARY: This meta-analysis explored abnormalities in white matter connectivity in language networks of individuals with ASD. Significantly reduced white matter integrity was found in all language-associated tracts in subjects with ASD compared with TD controls. In addition, structural disturbances of language networks in the autistic brain exhibit a leftward tendency, and more prominent abnormalities are observed in younger people with ASD than in adults. En ligne : http://dx.doi.org/10.1002/aur.2789 Permalink : https://www.cra-rhone-alpes.org/cid/opac_css/index.php?lvl=notice_display&id=483

Diffusional kurtosis imaging of the corpus callosum in autism / Y. V. SUI in Molecular Autism, 9 (2018)  

Public ISBD [article]  inMolecular Autism > 9 (2018) . - 62 p. Titre : Diffusional kurtosis imaging of the corpus callosum in autism Type de document : Texte imprimé et/ou numérique Auteurs : Y. V. SUI, Auteur ; J. DONALDSON, Auteur ; L. MILES, Auteur ; James S. BABB, Auteur ; Francisco Xavier CASTELLANOS, Auteur ; M. LAZAR, Auteur Article en page(s) : 62 p. Langues : Anglais (eng) Mots-clés : Adolescent  Adult  Autistic Disorder/*diagnostic imaging/physiopathology  Case-Control Studies  Corpus Callosum/*diagnostic imaging  Humans  Magnetic Resonance Imaging  Wechsler Scales  White Matter/diagnostic imaging  *Autism  *Corpus callosum  *Diffusional kurtosis imaging  *Interhemispheric connectivity  *Processing speed  Medicine. All participants provided informed consent at the time of their  visit.The authors give consent for this manuscript to be published.The authors  declare that they have no competing interests.Springer Nature remains neutral  with regard to jurisdictional claims in published maps and institutional  affiliations. Index. décimale : PER Périodiques Résumé : Background: The corpus callosum is implicated in the pathophysiology of autism spectrum disorder (ASD). However, specific structural deficits and underlying mechanisms are yet to be well defined. Methods: We employed diffusional kurtosis imaging (DKI) metrics to characterize white matter properties within five discrete segments of the corpus callosum in 17 typically developing (TD) adults and 16 age-matched participants with ASD without co-occurring intellectual disability (ID). The DKI metrics included axonal water fraction (f axon) and intra-axonal diffusivity (D axon), which reflect axonal density and caliber, and extra-axonal radial (RDextra) and axial (ADextra) diffusivities, which reflect myelination and microstructural organization of the extracellular space. The relationships between DKI metrics and processing speed, a cognitive feature known to be impaired in ASD, were also examined. Results: ASD group had significantly decreased callosal f axon and D axon (p = .01 and p = .045), particularly in the midbody, isthmus, and splenium. Regression analysis showed that variation in DKI metrics, primarily in the mid and posterior callosal regions explained up to 70.7% of the variance in processing speed scores for TD (p = .001) but not for ASD (p > .05). Conclusion: Decreased DKI metrics suggested that ASD may be associated with axonal deficits such as reduced axonal caliber and density in the corpus callosum, especially in the mid and posterior callosal areas. These data suggest that impaired interhemispheric connectivity may contribute to decreased processing speed in ASD participants. En ligne : https://dx.doi.org/10.1186/s13229-018-0245-1 Permalink : https://www.cra-rhone-alpes.org/cid/opac_css/index.php?lvl=notice_display&id=389 [article] Diffusional kurtosis imaging of the corpus callosum in autism [Texte imprimé et/ou numérique] / Y. V. SUI, Auteur ; J. DONALDSON, Auteur ; L. MILES, Auteur ; James S. BABB, Auteur ; Francisco Xavier CASTELLANOS, Auteur ; M. LAZAR, Auteur . - 62 p. Langues : Anglais (eng) in Molecular Autism > 9 (2018) . - 62 p. Mots-clés : Adolescent  Adult  Autistic Disorder/*diagnostic imaging/physiopathology  Case-Control Studies  Corpus Callosum/*diagnostic imaging  Humans  Magnetic Resonance Imaging  Wechsler Scales  White Matter/diagnostic imaging  *Autism  *Corpus callosum  *Diffusional kurtosis imaging  *Interhemispheric connectivity  *Processing speed  Medicine. All participants provided informed consent at the time of their  visit.The authors give consent for this manuscript to be published.The authors  declare that they have no competing interests.Springer Nature remains neutral  with regard to jurisdictional claims in published maps and institutional  affiliations. Index. décimale : PER Périodiques Résumé : Background: The corpus callosum is implicated in the pathophysiology of autism spectrum disorder (ASD). However, specific structural deficits and underlying mechanisms are yet to be well defined. Methods: We employed diffusional kurtosis imaging (DKI) metrics to characterize white matter properties within five discrete segments of the corpus callosum in 17 typically developing (TD) adults and 16 age-matched participants with ASD without co-occurring intellectual disability (ID). The DKI metrics included axonal water fraction (f axon) and intra-axonal diffusivity (D axon), which reflect axonal density and caliber, and extra-axonal radial (RDextra) and axial (ADextra) diffusivities, which reflect myelination and microstructural organization of the extracellular space. The relationships between DKI metrics and processing speed, a cognitive feature known to be impaired in ASD, were also examined. Results: ASD group had significantly decreased callosal f axon and D axon (p = .01 and p = .045), particularly in the midbody, isthmus, and splenium. Regression analysis showed that variation in DKI metrics, primarily in the mid and posterior callosal regions explained up to 70.7% of the variance in processing speed scores for TD (p = .001) but not for ASD (p > .05). Conclusion: Decreased DKI metrics suggested that ASD may be associated with axonal deficits such as reduced axonal caliber and density in the corpus callosum, especially in the mid and posterior callosal areas. These data suggest that impaired interhemispheric connectivity may contribute to decreased processing speed in ASD participants. En ligne : https://dx.doi.org/10.1186/s13229-018-0245-1 Permalink : https://www.cra-rhone-alpes.org/cid/opac_css/index.php?lvl=notice_display&id=389