Lesser suppression of response to bright visual stimuli and visual abnormality in children with autism spectrum disorder: a magnetoencephalographic study / S. AOKI in Journal of Neurodevelopmental Disorders, 11-1 (December 2019)  

Public ISBD [article]  inJournal of Neurodevelopmental Disorders > 11-1 (December 2019) . - 9 p. Titre : Lesser suppression of response to bright visual stimuli and visual abnormality in children with autism spectrum disorder: a magnetoencephalographic study Type de document : Texte imprimé et/ou numérique Auteurs : S. AOKI, Auteur ; Kuriko KAGITANI-SHIMONO, Auteur ; J. MATSUZAKI, Auteur ; R. HANAIE, Auteur ; M. NAKANISHI, Auteur ; K. TOMINAGA, Auteur ; Y. NAGAI, Auteur ; I. MOHRI, Auteur ; M. TANIIKE, Auteur Article en page(s) : 9 p. Langues : Anglais (eng) Mots-clés : Autism spectrum disorders (ASD)  Bright visual stimuli  Magnetoencephalography (MEG)  Neural suppression  Supramarginal gyrus (SMG)  Visual abnormality Index. décimale : PER Périodiques Résumé : BACKGROUND: Visual abnormality is a common sensory impairment in autism spectrum disorder (ASD), which may cause behavioral problems. However, only a few studies exist on the neural features corresponding to the visual symptoms in ASD. The purpose of this study was to investigate the relationship between cortical responses to visual stimuli and visual abnormality to examine the neurophysiological mechanisms of the visual abnormality in ASD. METHODS: Twenty-two high-functioning children with ASD (10.95 +/- 2.01 years old) and 23 age-matched typically developing (TD) children (10.13 +/- 2.80 years old) participated in this study. We measured the cortical responses (i.e., activated intensity and attenuation ratio) elicited by the Original visual image and other two types of bright images (the Dot noise or Blind image, which includes overlapped particles onto the Original image or the enhanced-brightness version of the Original image, respectively) using magnetoencephalography. RESULTS: The severity of visual abnormalities was significantly associated with behavioral problems in children with ASD. In addition, we found the increased cortical activation in response to the Original image in the left supramarginal gyrus (SMG) and middle temporal gyrus in children with ASD. However, there were no inter-group differences in the primary visual and medial orbitofrontal cortices. Furthermore, when we compared cortical responses according to the type of images, children with ASD showed lesser attenuation of the activated intensities than children with TD in response to the bright images compared with the Original image in the right SMG. These attenuation ratios (Dot noise/Original and Blind/Original) were also associated with the severity of visual abnormalities. CONCLUSIONS: Our results show that dysfunction of stimulus-driven neural suppression plays a crucial role in the neural mechanism of visual abnormality in children with ASD. To the best of our knowledge, this is the first magnetoencephalography study to demonstrate the association between the severity of visual abnormality and lower attenuation ratios in children with ASD. Our results contribute to the knowledge of the mechanisms underlying visual abnormality in children with ASD, and may therefore lead to more effective diagnosis and earlier intervention. En ligne : https://dx.doi.org/10.1186/s11689-019-9266-0 Permalink : https://www.cra-rhone-alpes.org/cid/opac_css/index.php?lvl=notice_display&id=409 [article] Lesser suppression of response to bright visual stimuli and visual abnormality in children with autism spectrum disorder: a magnetoencephalographic study [Texte imprimé et/ou numérique] / S. AOKI, Auteur ; Kuriko KAGITANI-SHIMONO, Auteur ; J. MATSUZAKI, Auteur ; R. HANAIE, Auteur ; M. NAKANISHI, Auteur ; K. TOMINAGA, Auteur ; Y. NAGAI, Auteur ; I. MOHRI, Auteur ; M. TANIIKE, Auteur . - 9 p. Langues : Anglais (eng) in Journal of Neurodevelopmental Disorders > 11-1 (December 2019) . - 9 p. Mots-clés : Autism spectrum disorders (ASD)  Bright visual stimuli  Magnetoencephalography (MEG)  Neural suppression  Supramarginal gyrus (SMG)  Visual abnormality Index. décimale : PER Périodiques Résumé : BACKGROUND: Visual abnormality is a common sensory impairment in autism spectrum disorder (ASD), which may cause behavioral problems. However, only a few studies exist on the neural features corresponding to the visual symptoms in ASD. The purpose of this study was to investigate the relationship between cortical responses to visual stimuli and visual abnormality to examine the neurophysiological mechanisms of the visual abnormality in ASD. METHODS: Twenty-two high-functioning children with ASD (10.95 +/- 2.01 years old) and 23 age-matched typically developing (TD) children (10.13 +/- 2.80 years old) participated in this study. We measured the cortical responses (i.e., activated intensity and attenuation ratio) elicited by the Original visual image and other two types of bright images (the Dot noise or Blind image, which includes overlapped particles onto the Original image or the enhanced-brightness version of the Original image, respectively) using magnetoencephalography. RESULTS: The severity of visual abnormalities was significantly associated with behavioral problems in children with ASD. In addition, we found the increased cortical activation in response to the Original image in the left supramarginal gyrus (SMG) and middle temporal gyrus in children with ASD. However, there were no inter-group differences in the primary visual and medial orbitofrontal cortices. Furthermore, when we compared cortical responses according to the type of images, children with ASD showed lesser attenuation of the activated intensities than children with TD in response to the bright images compared with the Original image in the right SMG. These attenuation ratios (Dot noise/Original and Blind/Original) were also associated with the severity of visual abnormalities. CONCLUSIONS: Our results show that dysfunction of stimulus-driven neural suppression plays a crucial role in the neural mechanism of visual abnormality in children with ASD. To the best of our knowledge, this is the first magnetoencephalography study to demonstrate the association between the severity of visual abnormality and lower attenuation ratios in children with ASD. Our results contribute to the knowledge of the mechanisms underlying visual abnormality in children with ASD, and may therefore lead to more effective diagnosis and earlier intervention. En ligne : https://dx.doi.org/10.1186/s11689-019-9266-0 Permalink : https://www.cra-rhone-alpes.org/cid/opac_css/index.php?lvl=notice_display&id=409

Neurite orientation dispersion and density imaging reveals white matter microstructural alterations in adults with autism / C. ANDICA in Molecular Autism, 12 (2021)  

Public ISBD [article]  inMolecular Autism > 12 (2021) . - 48 p. Titre : Neurite orientation dispersion and density imaging reveals white matter microstructural alterations in adults with autism Type de document : Texte imprimé et/ou numérique Auteurs : C. ANDICA, Auteur ; K. KAMAGATA, Auteur ; E. KIRINO, Auteur ; W. UCHIDA, Auteur ; R. IRIE, Auteur ; S. MURATA, Auteur ; S. AOKI, Auteur Article en page(s) : 48 p. Langues : Anglais (eng) Mots-clés : Autism  Diffusion tensor imaging  Linear discriminant analysis  Neurite orientation dispersion and density imaging  Neuroinflammation  Neuronal loss  Region-of-interest  Tract-based spatial statistics  White matter microstructure Index. décimale : PER Périodiques Résumé : BACKGROUND: Evidences suggesting the association between behavioral anomalies in autism and white matter (WM) microstructural alterations are increasing. Diffusion tensor imaging (DTI) is widely used to infer tissue microstructure. However, due to its lack of specificity, the underlying pathology of reported differences in DTI measures in autism remains poorly understood. Herein, we applied neurite orientation dispersion and density imaging (NODDI) to quantify and define more specific causes of WM microstructural changes associated with autism in adults. METHODS: NODDI (neurite density index [NDI], orientation dispersion index, and isotropic volume fraction [ISOVF]) and DTI (fractional anisotropy [FA], mean diffusivity [MD], axial diffusivity, and radial diffusivity [RD]) measures were compared between autism (N?=?26; 19 males and 7 females; 32.93?±?9.24 years old) and age- and sex-matched typically developing (TD; N?=?25; 17 males and 8 females; 34.43?±?9.02 years old) groups using tract-based spatial statistics and region-of-interest analyses. Linear discriminant analysis using leave-one-out cross-validation (LDA-LOOCV) was also performed to assess the discriminative power of diffusion measures in autism and TD. RESULTS: Significantly lower NDI and higher ISOVF, suggestive of decreased neurite density and increased extracellular free-water, respectively, were demonstrated in the autism group compared with the TD group, mainly in commissural and long-range association tracts, but with distinct predominant sides. Consistent with previous reports, the autism group showed lower FA and higher MD and RD when compared with TD group. Notably, LDA-LOOCV suggests that NDI and ISOVF have relatively higher accuracy (82%) and specificity (NDI, 84%; ISOVF, 88%) compared with that of FA, MD, and RD (accuracy, 67-73%; specificity, 68-80%). LIMITATIONS: The absence of histopathological confirmation limit the interpretation of our findings. CONCLUSIONS: Our results suggest that NODDI measures might be useful as imaging biomarkers to diagnose autism in adults and assess its behavioral characteristics. Furthermore, NODDI allows interpretation of previous findings on changes in WM diffusion tensor metrics in individuals with autism. En ligne : http://dx.doi.org/10.1186/s13229-021-00456-4 Permalink : https://www.cra-rhone-alpes.org/cid/opac_css/index.php?lvl=notice_display&id=459 [article] Neurite orientation dispersion and density imaging reveals white matter microstructural alterations in adults with autism [Texte imprimé et/ou numérique] / C. ANDICA, Auteur ; K. KAMAGATA, Auteur ; E. KIRINO, Auteur ; W. UCHIDA, Auteur ; R. IRIE, Auteur ; S. MURATA, Auteur ; S. AOKI, Auteur . - 48 p. Langues : Anglais (eng) in Molecular Autism > 12 (2021) . - 48 p. Mots-clés : Autism  Diffusion tensor imaging  Linear discriminant analysis  Neurite orientation dispersion and density imaging  Neuroinflammation  Neuronal loss  Region-of-interest  Tract-based spatial statistics  White matter microstructure Index. décimale : PER Périodiques Résumé : BACKGROUND: Evidences suggesting the association between behavioral anomalies in autism and white matter (WM) microstructural alterations are increasing. Diffusion tensor imaging (DTI) is widely used to infer tissue microstructure. However, due to its lack of specificity, the underlying pathology of reported differences in DTI measures in autism remains poorly understood. Herein, we applied neurite orientation dispersion and density imaging (NODDI) to quantify and define more specific causes of WM microstructural changes associated with autism in adults. METHODS: NODDI (neurite density index [NDI], orientation dispersion index, and isotropic volume fraction [ISOVF]) and DTI (fractional anisotropy [FA], mean diffusivity [MD], axial diffusivity, and radial diffusivity [RD]) measures were compared between autism (N?=?26; 19 males and 7 females; 32.93?±?9.24 years old) and age- and sex-matched typically developing (TD; N?=?25; 17 males and 8 females; 34.43?±?9.02 years old) groups using tract-based spatial statistics and region-of-interest analyses. Linear discriminant analysis using leave-one-out cross-validation (LDA-LOOCV) was also performed to assess the discriminative power of diffusion measures in autism and TD. RESULTS: Significantly lower NDI and higher ISOVF, suggestive of decreased neurite density and increased extracellular free-water, respectively, were demonstrated in the autism group compared with the TD group, mainly in commissural and long-range association tracts, but with distinct predominant sides. Consistent with previous reports, the autism group showed lower FA and higher MD and RD when compared with TD group. Notably, LDA-LOOCV suggests that NDI and ISOVF have relatively higher accuracy (82%) and specificity (NDI, 84%; ISOVF, 88%) compared with that of FA, MD, and RD (accuracy, 67-73%; specificity, 68-80%). LIMITATIONS: The absence of histopathological confirmation limit the interpretation of our findings. CONCLUSIONS: Our results suggest that NODDI measures might be useful as imaging biomarkers to diagnose autism in adults and assess its behavioral characteristics. Furthermore, NODDI allows interpretation of previous findings on changes in WM diffusion tensor metrics in individuals with autism. En ligne : http://dx.doi.org/10.1186/s13229-021-00456-4 Permalink : https://www.cra-rhone-alpes.org/cid/opac_css/index.php?lvl=notice_display&id=459

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