2 recherche sur le mot-clé 'MR spectroscopy'

Biochemistry of the cingulate cortex in autism: An MR spectroscopy study / Lauren E. LIBERO in Autism Research, 9-6 (June 2016)  

Public ISBD [article]  inAutism Research > 9-6 (June 2016) . - p.643-657 Titre : Biochemistry of the cingulate cortex in autism: An MR spectroscopy study Type de document : Texte imprimé et/ou numérique Auteurs : Lauren E. LIBERO, Auteur ; Meredith A. REID, Auteur ; David M. WHITE, Auteur ; Nouha SALIBI, Auteur ; Adrienne C. LAHTI, Auteur ; Rajesh K. KANA, Auteur Article en page(s) : p.643-657 Langues : Anglais (eng) Mots-clés : autism spectrum disorder  cingulate cortex  1H-MRS  MR spectroscopy  neurochemicals  biochemistry Index. décimale : PER Périodiques Résumé : Neuroimaging studies have uncovered structural and functional alterations in the cingulate cortex in individuals with autism spectrum disorders (ASD). Such abnormalities may underlie neurochemical imbalance. In order to characterize the neurochemical profile, the current study examined the concentration of brain metabolites in dorsal ACC (dACC) and posterior cingulate cortex (PCC) in high-functioning adults with ASD. Twenty high-functioning adults with ASD and 20 age-and-IQ-matched typically developing (TD) peers participated in this Proton magnetic resonance spectroscopy (1H-MRS) study. LCModel was used in analyzing the spectra to measure the levels of N-Acetyl aspartate (NAA), choline (Cho), creatine (Cr), and glutamate/glutamine (Glx) in dACC and PCC. Groups were compared using means for the ratio of each metabolite to their respective Cr levels as well as on absolute internal-water-referenced measures of each metabolite. There was a significant increase in Cho in PCC for ASD adults, with a marginal increase in dACC. A reduction in NAA/Cr in dACC was found in ASD participants, compared to their TD peers. No significant differences in Glx/Cr or Cho/Cr were found in dACC. There were no statistically significant group differences in the absolute concentration of NAA, Cr, Glx, or NAA/Cr, Cho/Cr, and Glx/Cr in the PCC. Differences in the metabolic properties of dACC compared to PCC were also found. Results of this study provide evidence for possible cellular and metabolic differences in the dACC and PCC in adults with ASD. This may suggest neuronal dysfunction in these regions and may contribute to the neuropathology of ASD. Autism Res 2016, 9: 643–657. © 2015 International Society for Autism Research, Wiley Periodicals, Inc. En ligne : http://dx.doi.org/10.1002/aur.1562 Permalink : https://www.cra-rhone-alpes.org/cid/opac_css/index.php?lvl=notice_display&id=290 [article] Biochemistry of the cingulate cortex in autism: An MR spectroscopy study [Texte imprimé et/ou numérique] / Lauren E. LIBERO, Auteur ; Meredith A. REID, Auteur ; David M. WHITE, Auteur ; Nouha SALIBI, Auteur ; Adrienne C. LAHTI, Auteur ; Rajesh K. KANA, Auteur . - p.643-657. Langues : Anglais (eng) in Autism Research > 9-6 (June 2016) . - p.643-657 Mots-clés : autism spectrum disorder  cingulate cortex  1H-MRS  MR spectroscopy  neurochemicals  biochemistry Index. décimale : PER Périodiques Résumé : Neuroimaging studies have uncovered structural and functional alterations in the cingulate cortex in individuals with autism spectrum disorders (ASD). Such abnormalities may underlie neurochemical imbalance. In order to characterize the neurochemical profile, the current study examined the concentration of brain metabolites in dorsal ACC (dACC) and posterior cingulate cortex (PCC) in high-functioning adults with ASD. Twenty high-functioning adults with ASD and 20 age-and-IQ-matched typically developing (TD) peers participated in this Proton magnetic resonance spectroscopy (1H-MRS) study. LCModel was used in analyzing the spectra to measure the levels of N-Acetyl aspartate (NAA), choline (Cho), creatine (Cr), and glutamate/glutamine (Glx) in dACC and PCC. Groups were compared using means for the ratio of each metabolite to their respective Cr levels as well as on absolute internal-water-referenced measures of each metabolite. There was a significant increase in Cho in PCC for ASD adults, with a marginal increase in dACC. A reduction in NAA/Cr in dACC was found in ASD participants, compared to their TD peers. No significant differences in Glx/Cr or Cho/Cr were found in dACC. There were no statistically significant group differences in the absolute concentration of NAA, Cr, Glx, or NAA/Cr, Cho/Cr, and Glx/Cr in the PCC. Differences in the metabolic properties of dACC compared to PCC were also found. Results of this study provide evidence for possible cellular and metabolic differences in the dACC and PCC in adults with ASD. This may suggest neuronal dysfunction in these regions and may contribute to the neuropathology of ASD. Autism Res 2016, 9: 643–657. © 2015 International Society for Autism Research, Wiley Periodicals, Inc. En ligne : http://dx.doi.org/10.1002/aur.1562 Permalink : https://www.cra-rhone-alpes.org/cid/opac_css/index.php?lvl=notice_display&id=290

A Multimodal Study of the Contributions of Conduction Velocity to the Auditory Evoked Neuromagnetic Response: Anomalies in Autism Spectrum Disorder / Timothy P. L. ROBERTS in Autism Research, 13-10 (October 2020)  

Public ISBD [article]  inAutism Research > 13-10 (October 2020) . - p.1730-1745 Titre : A Multimodal Study of the Contributions of Conduction Velocity to the Auditory Evoked Neuromagnetic Response: Anomalies in Autism Spectrum Disorder Type de document : Texte imprimé et/ou numérique Auteurs : Timothy P. L. ROBERTS, Auteur ; Luke BLOY, Auteur ; Matt KU, Auteur ; Lisa BLASKEY, Auteur ; Carissa R. JACKEL, Auteur ; James Christopher EDGAR, Auteur ; Jeffrey I. BERMAN, Auteur Article en page(s) : p.1730-1745 Langues : Anglais (eng) Mots-clés : MR spectroscopy  autism spectrum disorder  conduction velocity  diffusion MRI  magnetoencephalography  multimodal imaging Index. décimale : PER Périodiques Résumé : This multimodal imaging study used magnetoencephalography, diffusion magnetic resonance imaging (MRI), and gamma-aminobutyric acid (GABA) magnetic resonance spectroscopy (MRS) to identify and contrast the multiple physiological mechanisms associated with auditory processing efficiency in typically developing (TD) children and children with autism spectrum disorder (ASD). Efficient transmission of auditory input between the ear and auditory cortex is necessary for rapid encoding of auditory sensory information. It was hypothesized that the M50 auditory evoked response latency would be modulated by white matter microstructure (indexed by diffusion MRI) and by tonic inhibition (indexed by GABA MRS). Participants were 77 children diagnosed with ASD and 40 TD controls aged 7-17?years. A model of M50 latency with auditory radiation fractional anisotropy and age as independent variables was able to predict 52% of M50 latency variance in TD children, but only 12% of variance in ASD. The ASD group exhibited altered patterns of M50 latency modulation characterized by both higher variance and deviation from the expected structure-function relationship established with the TD group. The TD M50 latency model was used to identify a subpopulation of ASD who are significant "outliers" to the TD model. The ASD outlier group exhibited unexpectedly long M50 latencies in conjunction with significantly lower GABA levels. These findings indicate the dependence of electrophysiologic sensory response latency on underlying microstructure (white matter) and neurochemistry (synaptic activity). This study demonstrates the use of biologically based measures to stratify ASD according to their brain-level "building blocks" as an alternative to their behavioral phenotype. LAY SUMMARY: Children with ASD often have a slower brain response when hearing sounds. This study used multiple brain imaging techniques to examine the structural and neurochemical factors which control the brain's response time to auditory tones in children with ASD and TD children. The relationship between brain imaging measures and brain response time was also used to identify ASD subgroups. Autism Res 2020, 13: 1730-1745. © 2020 International Society for Autism Research and Wiley Periodicals LLC. En ligne : http://dx.doi.org/10.1002/aur.2369 Permalink : https://www.cra-rhone-alpes.org/cid/opac_css/index.php?lvl=notice_display&id=431 [article] A Multimodal Study of the Contributions of Conduction Velocity to the Auditory Evoked Neuromagnetic Response: Anomalies in Autism Spectrum Disorder [Texte imprimé et/ou numérique] / Timothy P. L. ROBERTS, Auteur ; Luke BLOY, Auteur ; Matt KU, Auteur ; Lisa BLASKEY, Auteur ; Carissa R. JACKEL, Auteur ; James Christopher EDGAR, Auteur ; Jeffrey I. BERMAN, Auteur . - p.1730-1745. Langues : Anglais (eng) in Autism Research > 13-10 (October 2020) . - p.1730-1745 Mots-clés : MR spectroscopy  autism spectrum disorder  conduction velocity  diffusion MRI  magnetoencephalography  multimodal imaging Index. décimale : PER Périodiques Résumé : This multimodal imaging study used magnetoencephalography, diffusion magnetic resonance imaging (MRI), and gamma-aminobutyric acid (GABA) magnetic resonance spectroscopy (MRS) to identify and contrast the multiple physiological mechanisms associated with auditory processing efficiency in typically developing (TD) children and children with autism spectrum disorder (ASD). Efficient transmission of auditory input between the ear and auditory cortex is necessary for rapid encoding of auditory sensory information. It was hypothesized that the M50 auditory evoked response latency would be modulated by white matter microstructure (indexed by diffusion MRI) and by tonic inhibition (indexed by GABA MRS). Participants were 77 children diagnosed with ASD and 40 TD controls aged 7-17?years. A model of M50 latency with auditory radiation fractional anisotropy and age as independent variables was able to predict 52% of M50 latency variance in TD children, but only 12% of variance in ASD. The ASD group exhibited altered patterns of M50 latency modulation characterized by both higher variance and deviation from the expected structure-function relationship established with the TD group. The TD M50 latency model was used to identify a subpopulation of ASD who are significant "outliers" to the TD model. The ASD outlier group exhibited unexpectedly long M50 latencies in conjunction with significantly lower GABA levels. These findings indicate the dependence of electrophysiologic sensory response latency on underlying microstructure (white matter) and neurochemistry (synaptic activity). This study demonstrates the use of biologically based measures to stratify ASD according to their brain-level "building blocks" as an alternative to their behavioral phenotype. LAY SUMMARY: Children with ASD often have a slower brain response when hearing sounds. This study used multiple brain imaging techniques to examine the structural and neurochemical factors which control the brain's response time to auditory tones in children with ASD and TD children. The relationship between brain imaging measures and brain response time was also used to identify ASD subgroups. Autism Res 2020, 13: 1730-1745. © 2020 International Society for Autism Research and Wiley Periodicals LLC. En ligne : http://dx.doi.org/10.1002/aur.2369 Permalink : https://www.cra-rhone-alpes.org/cid/opac_css/index.php?lvl=notice_display&id=431