5 recherche sur le mot-clé 'Tractography'

White Matter and Visuospatial Processing in Autism: A Constrained Spherical Deconvolution Tractography Study / Jane MCGRATH in Autism Research, 6-5 (October 2013)  

Public ISBD [article]  inAutism Research > 6-5 (October 2013) . - p.307-319 Titre : White Matter and Visuospatial Processing in Autism: A Constrained Spherical Deconvolution Tractography Study Type de document : Texte imprimé et/ou numérique Auteurs : Jane MCGRATH, Auteur ; Katherine JOHNSON, Auteur ; Erik O'HANLON, Auteur ; Hugh GARAVAN, Auteur ; Louise GALLAGHER, Auteur ; Alexander LEEMANS, Auteur Article en page(s) : p.307-319 Langues : Anglais (eng) Mots-clés : diffusion MRI  constrained spherical deconvolution  tractography  autism  visuospatial processing  inferior fronto-occipital fasciculus Index. décimale : PER Périodiques Résumé : Autism spectrum disorders (ASDs) are associated with a marked disturbance of neural functional connectivity, which may arise from disrupted organization of white matter. The aim of this study was to use constrained spherical deconvolution (CSD)-based tractography to isolate and characterize major intrahemispheric white matter tracts that are important in visuospatial processing. CSD-based tractography avoids a number of critical confounds that are associated with diffusion tensor tractography, and to our knowledge, this is the first time that this advanced diffusion tractography method has been used in autism research. Twenty-five participants with ASD and aged 25, intelligence quotient-matched controls completed a high angular resolution diffusion imaging scan. The inferior fronto-occipital fasciculus (IFOF) and arcuate fasciculus were isolated using CSD-based tractography. Quantitative diffusion measures of white matter microstructural organization were compared between groups and associated with visuospatial processing performance. Significant alteration of white matter organization was present in the right IFOF in individuals with ASD. In addition, poorer visuospatial processing was associated in individuals with ASD with disrupted white matter in the right IFOF. Using a novel, advanced tractography method to isolate major intrahemispheric white matter tracts in autism, this research has demonstrated that there are significant alterations in the microstructural organization of white matter in the right IFOF in ASD. This alteration was associated with poorer visuospatial processing performance in the ASD group. This study provides an insight into structural brain abnormalities that may influence atypical visuospatial processing in autism. En ligne : http://dx.doi.org/10.1002/aur.1290 Permalink : https://www.cra-rhone-alpes.org/cid/opac_css/index.php?lvl=notice_display&id=218 [article] White Matter and Visuospatial Processing in Autism: A Constrained Spherical Deconvolution Tractography Study [Texte imprimé et/ou numérique] / Jane MCGRATH, Auteur ; Katherine JOHNSON, Auteur ; Erik O'HANLON, Auteur ; Hugh GARAVAN, Auteur ; Louise GALLAGHER, Auteur ; Alexander LEEMANS, Auteur . - p.307-319. Langues : Anglais (eng) in Autism Research > 6-5 (October 2013) . - p.307-319 Mots-clés : diffusion MRI  constrained spherical deconvolution  tractography  autism  visuospatial processing  inferior fronto-occipital fasciculus Index. décimale : PER Périodiques Résumé : Autism spectrum disorders (ASDs) are associated with a marked disturbance of neural functional connectivity, which may arise from disrupted organization of white matter. The aim of this study was to use constrained spherical deconvolution (CSD)-based tractography to isolate and characterize major intrahemispheric white matter tracts that are important in visuospatial processing. CSD-based tractography avoids a number of critical confounds that are associated with diffusion tensor tractography, and to our knowledge, this is the first time that this advanced diffusion tractography method has been used in autism research. Twenty-five participants with ASD and aged 25, intelligence quotient-matched controls completed a high angular resolution diffusion imaging scan. The inferior fronto-occipital fasciculus (IFOF) and arcuate fasciculus were isolated using CSD-based tractography. Quantitative diffusion measures of white matter microstructural organization were compared between groups and associated with visuospatial processing performance. Significant alteration of white matter organization was present in the right IFOF in individuals with ASD. In addition, poorer visuospatial processing was associated in individuals with ASD with disrupted white matter in the right IFOF. Using a novel, advanced tractography method to isolate major intrahemispheric white matter tracts in autism, this research has demonstrated that there are significant alterations in the microstructural organization of white matter in the right IFOF in ASD. This alteration was associated with poorer visuospatial processing performance in the ASD group. This study provides an insight into structural brain abnormalities that may influence atypical visuospatial processing in autism. En ligne : http://dx.doi.org/10.1002/aur.1290 Permalink : https://www.cra-rhone-alpes.org/cid/opac_css/index.php?lvl=notice_display&id=218

Abnormal Corpus Callosum Connectivity, Socio-communicative Deficits, and Motor Deficits in Children with Autism Spectrum Disorder: A Diffusion Tensor Imaging Study / Ryuzo HANAIE in Journal of Autism and Developmental Disorders, 44-9 (September 2014)  

Public ISBD [article]  inJournal of Autism and Developmental Disorders > 44-9 (September 2014) . - p.2209-2220 Titre : Abnormal Corpus Callosum Connectivity, Socio-communicative Deficits, and Motor Deficits in Children with Autism Spectrum Disorder: A Diffusion Tensor Imaging Study Type de document : Texte imprimé et/ou numérique Auteurs : Ryuzo HANAIE, Auteur ; Ikuko MOHRI, Auteur ; Kuriko KAGITANI-SHIMONO, Auteur ; Masaya TACHIBANA, Auteur ; Junko MATSUZAKI, Auteur ; Yoshiyuki WATANABE, Auteur ; Norihiko FUJITA, Auteur ; Masako TANIIKE, Auteur Article en page(s) : p.2209-2220 Langues : Anglais (eng) Mots-clés : Diffusion tensor imaging  Tractography  Corpus callosum  Autism spectrum disorder  Motor function Index. décimale : PER Périodiques Résumé : In addition to social and communicative deficits, many studies have reported motor deficits in autism spectrum disorder (ASD). This study investigated the macro and microstructural properties of the corpus callosum (CC) of 18 children with ASD and 12 typically developing controls using diffusion tensor imaging tractography. We aimed to explore whether abnormalities of the CC were related to motor deficits, as well as social and communication deficits in children with ASD. The ASD group displayed abnormal macro and microstructure of the total CC and its subdivisions and its structural properties were related to socio-communicative deficits, but not to motor deficits in ASD. These findings advance our understanding of the contributions of the CC to ASD symptoms. En ligne : http://dx.doi.org/10.1007/s10803-014-2096-8 Permalink : https://www.cra-rhone-alpes.org/cid/opac_css/index.php?lvl=notice_display&id=238 [article] Abnormal Corpus Callosum Connectivity, Socio-communicative Deficits, and Motor Deficits in Children with Autism Spectrum Disorder: A Diffusion Tensor Imaging Study [Texte imprimé et/ou numérique] / Ryuzo HANAIE, Auteur ; Ikuko MOHRI, Auteur ; Kuriko KAGITANI-SHIMONO, Auteur ; Masaya TACHIBANA, Auteur ; Junko MATSUZAKI, Auteur ; Yoshiyuki WATANABE, Auteur ; Norihiko FUJITA, Auteur ; Masako TANIIKE, Auteur . - p.2209-2220. Langues : Anglais (eng) in Journal of Autism and Developmental Disorders > 44-9 (September 2014) . - p.2209-2220 Mots-clés : Diffusion tensor imaging  Tractography  Corpus callosum  Autism spectrum disorder  Motor function Index. décimale : PER Périodiques Résumé : In addition to social and communicative deficits, many studies have reported motor deficits in autism spectrum disorder (ASD). This study investigated the macro and microstructural properties of the corpus callosum (CC) of 18 children with ASD and 12 typically developing controls using diffusion tensor imaging tractography. We aimed to explore whether abnormalities of the CC were related to motor deficits, as well as social and communication deficits in children with ASD. The ASD group displayed abnormal macro and microstructure of the total CC and its subdivisions and its structural properties were related to socio-communicative deficits, but not to motor deficits in ASD. These findings advance our understanding of the contributions of the CC to ASD symptoms. En ligne : http://dx.doi.org/10.1007/s10803-014-2096-8 Permalink : https://www.cra-rhone-alpes.org/cid/opac_css/index.php?lvl=notice_display&id=238

Altered Cortical Thickness and Tract Integrity of the Mirror Neuron System and Associated Social Communication in Autism Spectrum Disorder / Hsiang-Yun CHIEN in Autism Research, 8-6 (December 2015)  

Public ISBD [article]  inAutism Research > 8-6 (December 2015) . - p.694-708 Titre : Altered Cortical Thickness and Tract Integrity of the Mirror Neuron System and Associated Social Communication in Autism Spectrum Disorder Type de document : Texte imprimé et/ou numérique Auteurs : Hsiang-Yun CHIEN, Auteur ; Susan Shur-Fen GAU, Auteur ; Yung-Chin HSU, Auteur ; Yu-Jen CHEN, Auteur ; Yu-Chun LO, Auteur ; Yao-Chia SHIH, Auteur ; Wen-Yih Isaac TSENG, Auteur Article en page(s) : p.694-708 Langues : Anglais (eng) Mots-clés : autism spectrum disorder  mirror neuron system  diffusion spectrum imaging  cortical thickness  white matter integrity  tractography  social communication Index. décimale : PER Périodiques Résumé : Previous studies using neural activity recording and neuroimaging techniques have reported functional deficits in the mirror neuron system (MNS) for individuals with autism spectrum disorder (ASD). However, a few studies focusing on gray and white matter structures of the MNS have yielded inconsistent results. The current study recruited adolescents and young adults with ASD (aged 15–26 years) and age-matched typically developing (TD) controls (aged 14–25 years). The cortical thickness (CT) and microstructural integrity of the tracts connecting the regions forming the classical MNS were investigated. High-resolution T1-weighted imaging and diffusion spectrum imaging were performed to quantify the CT and tract integrity, respectively. The structural covariance of the CT of the MNS regions revealed a weaker coordination of the MNS network in ASD. A strong correlation was found between the integrity of the right frontoparietal tracts and the social communication subscores measured by the Chinese version of the Social Communication Questionnaire. The results showed that there were no significant mean differences in the CTs and tract integrity between the ASD and TD groups, but revealed a moderate or even reverse age effect on the frontal MNS structures in ASD. In conclusion, aberrant structural coordination may be an underlying factor affecting the function of the MNS in ASD patients. The association between the right frontoparietal tracts and social communication performance implies a neural correlate of communication processing in the autistic brain. This study provides evidence of abnormal MNS structures and their influence on social communication in individuals with ASD. Autism Res 2015, 8: 694–708. © 2015 International Society for Autism Research, Wiley Periodicals, Inc. En ligne : http://dx.doi.org/10.1002/aur.1484 Permalink : https://www.cra-rhone-alpes.org/cid/opac_css/index.php?lvl=notice_display&id=278 [article] Altered Cortical Thickness and Tract Integrity of the Mirror Neuron System and Associated Social Communication in Autism Spectrum Disorder [Texte imprimé et/ou numérique] / Hsiang-Yun CHIEN, Auteur ; Susan Shur-Fen GAU, Auteur ; Yung-Chin HSU, Auteur ; Yu-Jen CHEN, Auteur ; Yu-Chun LO, Auteur ; Yao-Chia SHIH, Auteur ; Wen-Yih Isaac TSENG, Auteur . - p.694-708. Langues : Anglais (eng) in Autism Research > 8-6 (December 2015) . - p.694-708 Mots-clés : autism spectrum disorder  mirror neuron system  diffusion spectrum imaging  cortical thickness  white matter integrity  tractography  social communication Index. décimale : PER Périodiques Résumé : Previous studies using neural activity recording and neuroimaging techniques have reported functional deficits in the mirror neuron system (MNS) for individuals with autism spectrum disorder (ASD). However, a few studies focusing on gray and white matter structures of the MNS have yielded inconsistent results. The current study recruited adolescents and young adults with ASD (aged 15–26 years) and age-matched typically developing (TD) controls (aged 14–25 years). The cortical thickness (CT) and microstructural integrity of the tracts connecting the regions forming the classical MNS were investigated. High-resolution T1-weighted imaging and diffusion spectrum imaging were performed to quantify the CT and tract integrity, respectively. The structural covariance of the CT of the MNS regions revealed a weaker coordination of the MNS network in ASD. A strong correlation was found between the integrity of the right frontoparietal tracts and the social communication subscores measured by the Chinese version of the Social Communication Questionnaire. The results showed that there were no significant mean differences in the CTs and tract integrity between the ASD and TD groups, but revealed a moderate or even reverse age effect on the frontal MNS structures in ASD. In conclusion, aberrant structural coordination may be an underlying factor affecting the function of the MNS in ASD patients. The association between the right frontoparietal tracts and social communication performance implies a neural correlate of communication processing in the autistic brain. This study provides evidence of abnormal MNS structures and their influence on social communication in individuals with ASD. Autism Res 2015, 8: 694–708. © 2015 International Society for Autism Research, Wiley Periodicals, Inc. En ligne : http://dx.doi.org/10.1002/aur.1484 Permalink : https://www.cra-rhone-alpes.org/cid/opac_css/index.php?lvl=notice_display&id=278

Altered Structure–Function Relations of Semantic Processing in Youths with High-Functioning Autism: A Combined Diffusion and Functional MRI Study / Yu-Chun LO in Autism Research, 6-6 (December 2013)  

Public ISBD [article]  inAutism Research > 6-6 (December 2013) . - p.561-570 Titre : Altered Structure–Function Relations of Semantic Processing in Youths with High-Functioning Autism: A Combined Diffusion and Functional MRI Study Type de document : Texte imprimé et/ou numérique Auteurs : Yu-Chun LO, Auteur ; Tai-Li CHOU, Auteur ; Li-Ying FAN, Auteur ; Susan Shur-Fen GAU, Auteur ; Yen-Nan CHIU, Auteur ; Wen-Yih Isaac TSENG, Auteur Année de publication : 2013 Article en page(s) : p.561-570 Langues : Anglais (eng) Mots-clés : autism  dual stream model  diffusion spectrum imaging  functional MRI  tractography Index. décimale : PER Périodiques Résumé : Deficits in language and communication are among the core symptoms of autism, a common neurodevelopmental disorder with long-term impairment. Despite the striking nature of the autistic language impairment, knowledge about its corresponding alterations in the brain is still evolving. We hypothesized that the dual stream language network is altered in autism, and that this alteration could be revealed by changes in the relationships between microstructural integrity and functional activation. The study recruited 20 right-handed male youths with autism and 20 carefully matched individually, typically developing (TD) youths. Microstructural integrity of the left dorsal and left ventral pathways responsible for language processing and the functional activation of the connected brain regions were investigated by using diffusion spectrum imaging and functional magnetic resonance imaging of a semantic task, respectively. Youths with autism had significantly poorer language function, and lower functional activation in left dorsal and left ventral regions of the language network, compared with TD youths. The TD group showed a significant correlation of the functional activation of the left dorsal region with microstructural integrity of the left ventral pathway, whereas the autism group showed a significant correlation of the functional activation of the left ventral region with microstructural integrity of the left dorsal pathway, and moreover verbal comprehension index was correlated with microstructural integrity of the left ventral pathway. These altered structure–function relationships in autism suggest possible involvement of the dual pathways in supporting deficient semantic processing. En ligne : http://dx.doi.org/10.1002/aur.1315 Permalink : https://www.cra-rhone-alpes.org/cid/opac_css/index.php?lvl=notice_display&id=221 [article] Altered Structure–Function Relations of Semantic Processing in Youths with High-Functioning Autism: A Combined Diffusion and Functional MRI Study [Texte imprimé et/ou numérique] / Yu-Chun LO, Auteur ; Tai-Li CHOU, Auteur ; Li-Ying FAN, Auteur ; Susan Shur-Fen GAU, Auteur ; Yen-Nan CHIU, Auteur ; Wen-Yih Isaac TSENG, Auteur . - 2013 . - p.561-570. Langues : Anglais (eng) in Autism Research > 6-6 (December 2013) . - p.561-570 Mots-clés : autism  dual stream model  diffusion spectrum imaging  functional MRI  tractography Index. décimale : PER Périodiques Résumé : Deficits in language and communication are among the core symptoms of autism, a common neurodevelopmental disorder with long-term impairment. Despite the striking nature of the autistic language impairment, knowledge about its corresponding alterations in the brain is still evolving. We hypothesized that the dual stream language network is altered in autism, and that this alteration could be revealed by changes in the relationships between microstructural integrity and functional activation. The study recruited 20 right-handed male youths with autism and 20 carefully matched individually, typically developing (TD) youths. Microstructural integrity of the left dorsal and left ventral pathways responsible for language processing and the functional activation of the connected brain regions were investigated by using diffusion spectrum imaging and functional magnetic resonance imaging of a semantic task, respectively. Youths with autism had significantly poorer language function, and lower functional activation in left dorsal and left ventral regions of the language network, compared with TD youths. The TD group showed a significant correlation of the functional activation of the left dorsal region with microstructural integrity of the left ventral pathway, whereas the autism group showed a significant correlation of the functional activation of the left ventral region with microstructural integrity of the left dorsal pathway, and moreover verbal comprehension index was correlated with microstructural integrity of the left ventral pathway. These altered structure–function relationships in autism suggest possible involvement of the dual pathways in supporting deficient semantic processing. En ligne : http://dx.doi.org/10.1002/aur.1315 Permalink : https://www.cra-rhone-alpes.org/cid/opac_css/index.php?lvl=notice_display&id=221

Structural and functional connectivity in the default mode network in 22q11.2 deletion syndrome / M. C. PADULA in Journal of Neurodevelopmental Disorders, 7-1 (December 2015)  

Public ISBD [article]  inJournal of Neurodevelopmental Disorders > 7-1 (December 2015) . - p.23 Titre : Structural and functional connectivity in the default mode network in 22q11.2 deletion syndrome Type de document : Texte imprimé et/ou numérique Auteurs : M. C. PADULA, Auteur ; M. SCHAER, Auteur ; E. SCARIATI, Auteur ; M. SCHNEIDER, Auteur ; D. VAN DE VILLE, Auteur ; M. DEBBANE, Auteur ; S. ELIEZ, Auteur Article en page(s) : p.23 Langues : Anglais (eng) Mots-clés : Dti  Maturation  Positive symptoms  Resting-state fMRI  Schizophrenia  Tractography Index. décimale : PER Périodiques Résumé : BACKGROUND: The neural endophenotype associated with 22q11.2 deletion syndrome (22q11DS) includes deviant cortical development and alterations in brain connectivity. Resting-state functional magnetic resonance imaging (fMRI) findings also reported disconnectivity within the default mode network (DMN). In this study, we explored the relationship between functional and structural DMN connectivity and their changes with age in patients with 22q11DS in comparison to control participants. Given previous evidence of an association between DMN disconnectivity and the manifestation of psychotic symptoms, we further investigated this relationship in our group of patients with 22q11DS. METHODS: T1-weighted, diffusion, and resting-state fMRI scans were acquired from 41 patients with 22q11DS and 43 control participants aged 6 to 28 years. A data-driven approach based on independent component analysis (ICA) was used to identify the DMN and to define regions of interest for the structural and functional connectivity analysis. Prodromal psychotic symptoms were assessed in adolescents and adults using the positive symptom scores of the Structured Interview of Prodromal Syndromes (SIPS). Connectivity measures were compared between groups and correlated with age. Repeating the between-group analysis in three different age bins further assessed the presence of age-related alterations in DMN connectivity. Structural and functional connectivity measures were then correlated with the SIPS scores. RESULTS: A simultaneous reduction of functional and structural connectivity between core medial nodes of the DMN was observed. Furthermore, structural connectivity measures significantly increased with age in the control group but not in patients with 22q11DS, suggesting the presence of an age-related alteration of the DMN structural connections. No correlations were found between the DMN disconnectivity and expression of prodromal symptoms in 22q11DS. CONCLUSIONS: These findings indicate the presence of functional and structural DMN disconnectivity in 22q11DS and that patients with 22q11DS fail to develop normal structural connections between medial DMN nodes. This suggests the presence of altered neurodevelopmental trajectories in 22q11DS. En ligne : http://dx.doi.org/10.1186/s11689-015-9120-y Permalink : https://www.cra-rhone-alpes.org/cid/opac_css/index.php?lvl=notice_display&id=347 [article] Structural and functional connectivity in the default mode network in 22q11.2 deletion syndrome [Texte imprimé et/ou numérique] / M. C. PADULA, Auteur ; M. SCHAER, Auteur ; E. SCARIATI, Auteur ; M. SCHNEIDER, Auteur ; D. VAN DE VILLE, Auteur ; M. DEBBANE, Auteur ; S. ELIEZ, Auteur . - p.23. Langues : Anglais (eng) in Journal of Neurodevelopmental Disorders > 7-1 (December 2015) . - p.23 Mots-clés : Dti  Maturation  Positive symptoms  Resting-state fMRI  Schizophrenia  Tractography Index. décimale : PER Périodiques Résumé : BACKGROUND: The neural endophenotype associated with 22q11.2 deletion syndrome (22q11DS) includes deviant cortical development and alterations in brain connectivity. Resting-state functional magnetic resonance imaging (fMRI) findings also reported disconnectivity within the default mode network (DMN). In this study, we explored the relationship between functional and structural DMN connectivity and their changes with age in patients with 22q11DS in comparison to control participants. Given previous evidence of an association between DMN disconnectivity and the manifestation of psychotic symptoms, we further investigated this relationship in our group of patients with 22q11DS. METHODS: T1-weighted, diffusion, and resting-state fMRI scans were acquired from 41 patients with 22q11DS and 43 control participants aged 6 to 28 years. A data-driven approach based on independent component analysis (ICA) was used to identify the DMN and to define regions of interest for the structural and functional connectivity analysis. Prodromal psychotic symptoms were assessed in adolescents and adults using the positive symptom scores of the Structured Interview of Prodromal Syndromes (SIPS). Connectivity measures were compared between groups and correlated with age. Repeating the between-group analysis in three different age bins further assessed the presence of age-related alterations in DMN connectivity. Structural and functional connectivity measures were then correlated with the SIPS scores. RESULTS: A simultaneous reduction of functional and structural connectivity between core medial nodes of the DMN was observed. Furthermore, structural connectivity measures significantly increased with age in the control group but not in patients with 22q11DS, suggesting the presence of an age-related alteration of the DMN structural connections. No correlations were found between the DMN disconnectivity and expression of prodromal symptoms in 22q11DS. CONCLUSIONS: These findings indicate the presence of functional and structural DMN disconnectivity in 22q11DS and that patients with 22q11DS fail to develop normal structural connections between medial DMN nodes. This suggests the presence of altered neurodevelopmental trajectories in 22q11DS. En ligne : http://dx.doi.org/10.1186/s11689-015-9120-y Permalink : https://www.cra-rhone-alpes.org/cid/opac_css/index.php?lvl=notice_display&id=347