scholarly journals No Evidence for Systematic White Matter Correlates of Dyslexia: An Activation Likelihood Estimation Meta-Analysis

2018 ◽  
Author(s):  
David Moreau ◽  
Josephine E. Stonyer ◽  
Nicole S. McKay ◽  
Karen E. Waldie
Keyword(s):  
White Matter ◽  
Reading Ability ◽  
Diffusion Tensor ◽  
Meta Analysis ◽  
Neurodevelopmental Disorder ◽  
Likelihood Estimation ◽  
White Matter Integrity ◽  
Current View ◽  
Indirect Measure ◽  
Structural Differences

AbstractDyslexia is a prevalent neurodevelopmental disorder, characterized by reading and spelling difficulties. Beyond the behavioral and functional correlates of this condition, a growing number of studies have explored structural differences between individuals with dyslexia and typically developing individuals. To date, findings remain disparate – some studies suggest differences in fractional anisotropy (FA), an indirect measure of white matter integrity, whereas others do not identify significant disparities. Here, we synthesized the existing literature on this topic by conducting a meta-analysis of Diffusion Tensor Imaging (DTI) studies investigating white matter correlates of dyslexia via voxel-based analyses (VBA) of FA. Our results showed no reliable clusters underlying differences between dyslexics and typical individuals, after correcting for multiple comparisons (false discovery rate correction). Because group comparisons might be too coarse to yield subtle differences, we further explored differences in FA as a function of reading ability, measured on a continuous scale. Consistent with our initial findings, reading ability was not associated with reliable differences in white matter integrity. These findings nuance the current view of profound, structural differences underlying reading ability and its associated disorders, and suggest that their neural correlates might be more subtle than previously thought.

scholarly journals No Evidence for Systematic White Matter Correlates of Dyslexia and Dyscalculia

2018 ◽  
Author(s):  
David Moreau ◽  
Anna J. Wilson ◽  
Nicole S. McKay ◽  
Kasey Nihill ◽  
Karen E. Waldie
Keyword(s):  
Learning Disabilities ◽  
White Matter ◽  
Diffusion Tensor ◽  
Null Model ◽  
White Matter Integrity ◽  
Current View ◽  
Arcuate Fasciculus ◽  
Bayesian Hypothesis Testing ◽  
Structural Differences ◽  
And Mathematics

AbstractLearning disabilities such as dyslexia, dyscalculia and their comorbid manifestation are prevalent, affecting as much as fifteen percent of the population. Structural neuroimaging studies have indicated that these disorders can be related to differences in white matter integrity, although findings remain disparate. In this study, we used a unique design composed of individuals with dyslexia, dyscalculia, both disorders and controls, to systematically explore differences in fractional anisotropy across groups using diffusion tensor imaging. Specifically, we focused on the corona radiata and the arcuate fasciculus, two tracts associated with reading and mathematics in a number of previous studies. Using Bayesian hypothesis testing, we show that the present data favor the null model of no differences between groups for these particular tracts—a finding that seems to go against the current view but might be representative of the disparities within this field of research. Together, these findings suggest that structural differences associated with dyslexia and dyscalculia might not be as reliable as previously thought, with potential ramifications in terms of remediation.

scholarly journals Regional differences in white matter integrity in stimulant use disorders: A meta-analysis of diffusion tensor imaging studies

2019 ◽  
Vol 201 ◽  
pp. 29-37 ◽  
Author(s):  
Charlotte L. Beard ◽  
Joy M. Schmitz ◽  
Heather E. Soder ◽  
Robert Suchting ◽  
Jin H. Yoon ◽  
...  
Keyword(s):  
Diffusion Tensor Imaging ◽  
White Matter ◽  
Regional Differences ◽  
Diffusion Tensor ◽  
Meta Analysis ◽  
White Matter Integrity ◽  
Imaging Studies ◽  
Stimulant Use

scholarly journals A coordinate-based meta-analysis of white matter alterations in patients with alcohol use disorder

2021 ◽  
Author(s):  
Carolin Spindler ◽  
Louisa Mallien ◽  
Sebastian Trautmann ◽  
Nina Alexander ◽  
Markus Muehlhan
Keyword(s):  
White Matter ◽  
Alcohol Use ◽  
Alcohol Use Disorder ◽  
Diffusion Tensor ◽  
Meta Analysis ◽  
Internal Capsule ◽  
Likelihood Estimation ◽  
Posterior Limb ◽  
Reference Space ◽  
The Right

Introduction: Besides the commonly described grey matter (GM) deficits, there is growing evidence of significant white matter (WM) alterations in patients with alcohol use disorder (AUD). WM changes can be assessed using volumetric and diffusive magnetic resonance imaging methods, such as voxel-based morphometry (VBM) and diffusion tensor imaging (DTI). The aim of the present meta-analysis is to investigate the spatial convergence of the reported findings on WM alterations in AUD. Methods: Systematic literature search on PubMed and further databases revealed 18 studies eligible for inclusion, entailing a total of 462 AUD patients and 416 healthy controls (up to January 18, 2021). All studies that had used either VBM or DTI whole-brain analyzing methods and reported results as peak-coordinates in standard reference space were considered for inclusion. We excluded studies using approaches nonconcordant with recent guidelines for neuroimaging meta-analyses and studies investigating patient groups with Korsakoff syndrome or other comorbid substance use disorders (except tobacco). Results: Anatomical Likelihood Estimation (ALE) revealed four significant clusters of convergent macro- and microstructural WM alterations in AUD patients that were assigned to the genu and body of the corpus callosum, anterior and posterior cingulum, fornix, and the right posterior limb of the internal capsule. Discussion: The changes in WM could to some extent explain the deteriorations in motor, cognitive, affective, and perceptual functions seen in AUD. Future studies are needed to clarify how WM alterations vary over the course of the disorder and to what extent they are reversible with prolonged abstinence.

White Matter Integrity Differences in Obesity: A Meta-Analysis of Diffusion Tensor Imaging Studies

2021 ◽  
Author(s):  
Justine Daoust ◽  
Joelle Schaffer ◽  
Yashar Zeighami ◽  
Alain Dagher ◽  
Isabel García-García ◽  
...  
Keyword(s):  
Diffusion Tensor Imaging ◽  
White Matter ◽  
Diffusion Tensor ◽  
Meta Analysis ◽  
White Matter Integrity ◽  
Imaging Studies

scholarly journals Is migraine associated to brain anatomical alterations? New data and an ALE meta-analysis

2020 ◽  
Author(s):  
Rémy Masson ◽  
Geneviève Demarquay ◽  
David Meunier ◽  
Yohana Lévêque ◽  
Salem Hannoun ◽  
...  
Keyword(s):  
White Matter ◽  
Cortical Thickness ◽  
Diffusion Tensor ◽  
Meta Analysis ◽  
Imaging Study ◽  
Likelihood Estimation ◽  
Brain Anatomy ◽  
White Matter Tract ◽  
Volume Data ◽  
Surface Based Morphometry

AbstractA growing number of studies investigate brain anatomy in migraine using voxel- (VBM) and surface-based morphometry (SBM), as well as diffusion tensor imaging (DTI). The purpose of this article is to identify consistent patterns of anatomical alterations associated with migraine. First, 19 migraineurs without aura and 19 healthy participants were included in a brain imaging study. T1-weighted MRIs and DTI sequences were acquired and analyzed using VBM, SBM and tract-based spatial statistics. No significant alterations of gray matter (GM) volume, cortical thickness, cortical gyrification, sulcus depth and white-matter tract integrity could be observed. However, migraineurs displayed decreased white matter (WM) volume in the left superior longitudinal fasciculus. Second, a systematic review of the literature employing VBM, SBM and DTI was conducted to investigate brain anatomy in migraine. Meta-analysis was performed using Activation Likelihood Estimation (ALE) on GM volume data. Alterations of GM volume, WM volume, cortical thickness or white-matter tract integrity were reported in 72%, 50%, 56% and 33% of published studies respectively. Spatial distribution and direction of the disclosed effects were highly inconsistent across studies. The ALE analysis revealed no significant decrease of GM volume in migraine. A significant increase of GM volume in the left superior temporal and angular gyri was detected in migraine, a result however based on a small number of studies. Overall there is to this day no strong evidence of specific brain anatomical alterations reliably associated to migraine. Possible explanations of this conflicting literature are discussed.

Arterial Stiffness Is Associated with White Matter Disruption and Cognitive Impairment: A Community-Based Cohort Study

2021 ◽  
Vol 80 (2) ◽  
pp. 567-576
Author(s):  
Fei Han ◽  
Fei-Fei Zhai ◽  
Ming-Li Li ◽  
Li-Xin Zhou ◽  
Jun Ni ◽  
...  
Keyword(s):  
Cognitive Function ◽  
White Matter ◽  
Arterial Stiffness ◽  
Cognitive Decline ◽  
Sex Education ◽  
Diffusion Tensor ◽  
Mean Diffusivity ◽  
White Matter Injury ◽  
White Matter Integrity ◽  
Cross Sectional

Background: Mechanisms through which arterial stiffness impacts cognitive function are crucial for devising better strategies to prevent cognitive decline. Objective: To examine the associations of arterial stiffness with white matter integrity and cognition in community dwellings, and to investigate whether white matter injury was the intermediate of the associations between arterial stiffness and cognition. Methods: This study was a cross-sectional analysis on 952 subjects (aged 55.5±9.1 years) who underwent diffusion tensor imaging and measurement of brachial-ankle pulse wave velocity (baPWV). Both linear regression and tract-based spatial statistics were used to investigate the association between baPWV and white matter integrity. The association between baPWV and global cognitive function, measured as the mini-mental state examination (MMSE) was evaluated. Mediation analysis was performed to assess the influence of white matter integrity on the association of baPWV with MMSE. Results: Increased baPWV was significantly associated with lower mean global fractional anisotropy (β= –0.118, p < 0.001), higher mean diffusivity (β= 0.161, p < 0.001), axial diffusivity (β= 0.160, p < 0.001), and radial diffusivity (β= 0.147, p < 0.001) after adjustment of age, sex, and hypertension, which were measures having a direct effect on arterial stiffness and white matter integrity. After adjustment of age, sex, education, apolipoprotein E ɛ4, cardiovascular risk factors, and brain atrophy, we found an association of increased baPWV with worse performance on MMSE (β= –0.093, p = 0.011). White matter disruption partially mediated the effect of baPWV on MMSE. Conclusion: Arterial stiffness is associated with white matter disruption and cognitive decline. Reduced white matter integrity partially explained the effect of arterial stiffness on cognition.

Diffusion tensor imaging analysis in scrub typhus meningoencephalitis to determine the alteration of microstructural subcortical white-matter integrity

2020 ◽  
pp. 197140092098031
Author(s):  
Pranjal Phukan ◽  
Kalyan Sarma ◽  
Aman Yusuf Khan ◽  
Bhupen Barman ◽  
Md Jamil ◽  
...  
Keyword(s):  
Diffusion Tensor Imaging ◽  
White Matter ◽  
Scrub Typhus ◽  
Diffusion Tensor ◽  
Neuronal Degeneration ◽  
Central Nervous System Involvement ◽  
Subcortical White Matter ◽  
White Matter Integrity ◽  
Conventional Mri ◽  
Significant Difference

Background and purpose Magnetic resonance imaging (MRI) of the brain in scrub typhus meningoencephalitis is non-specific, and in the majority of the cases, conventional MRI fails to detect any abnormality. However, autopsy reports depict central nervous system involvement in almost all patients. There is therefore a need for research on the quantitative assessment of brain parenchyma that can detect microstructural abnormalities. The study aimed to assess the microstructural integrity changes of scrub typhus meningoencephalitis by using different diffusion tensor imaging (DTI) parameters. Methods This was a retrospective analysis of scrub typhus meningoencephalitis. Seven patients and seven age- and sex-matched healthy controls were included. Different DTI parameters such as apparent diffusion coefficient (ADC), fractional anisotropy (FA), relative anisotropy (RA), trace, volume ratio (VR) and geodesic anisotropy (GA) were obtained from six different regions of subcortical white matter at the level of the centrum semiovale. Intergroup significant difference was determined by one-way analysis of variance followed by Tukey’s post hoc test. Receiver operating characteristic curves were constructed to determine the accuracy of the DTI matrices. Results There was a significant decrease in FA, RA and GA as well as an increase in ADC and VR in the subcortical white matter in patients with scrub typhus meningoencephalitis compared to controls ( p < 0.001). The maximum sensitivity of the DTI parameters was 85.7%, and the maximum specificity was 81%. Conclusion There was an alteration of subcortical white-matter integrity in scrub typhus meningoencephalitis that represents the axonal degeneration, myelin breakdown and neuronal degeneration. DTI may be a useful tool to detect white-matter abnormalities in scrub typhus meningoencephalitis in clinical practice, particularly in patients with negative conventional MRI.

Age-related changes in white matter integrity: A diffusion tensor imaging study

NeuroImage ◽  
2009 ◽  
Vol 47 ◽  
pp. S128
Author(s):  
H Lemaitre ◽  
S Marenco ◽  
M Emery ◽  
T Alam ◽  
M Geramita ◽  
...  
Keyword(s):  
Diffusion Tensor Imaging ◽  
White Matter ◽  
Diffusion Tensor ◽  
Imaging Study ◽  
White Matter Integrity ◽  
Age Related ◽  
Diffusion Tensor Imaging Study ◽  
Age Related Changes
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