scholarly journals Brain white matter structure and language ability in preschool-aged children

2017 ◽  
Author(s):  
Matthew Walton ◽  
Deborah Dewey ◽  
Catherine Lebel
Keyword(s):  
White Matter ◽  
Language Processing ◽  
Phonological Processing ◽  
Right Hemisphere ◽  
Diffusion Tensor ◽  
Mean Diffusivity ◽  
Older Children ◽  
Brain White Matter ◽  
Preschool Period ◽  
Language Difficulties

AbstractBrain alterations are associated with reading and language difficulties in older children, but little research has investigated relationships between early language skills and brain white matter structure during the preschool period. We studied 68 children aged 3.0-5.6 years who underwent diffusion tensor imaging and participated in assessments of Phonological Processing and Speeded Naming. Tract-based spatial statistics and tractography revealed relationships between Phonological Processing and fractional anisotropy and mean diffusivity in bilateral ventral white matter pathways, the corpus callosum, and corticospinal tracts. The relationships observed in left ventral pathways are consistent with studies in older children, and demonstrate that structural markers for language difficulties are apparent as young as 3 years of age. Our findings in right hemisphere areas that are not as commonly found in adult studies suggest that young children rely on a widespread network for language processing that becomes more specialized with age.

scholarly journals A Diffusion Tensor Imaging Study on the Phonology-related Pathways in Cantonese-mandarin Bilinguals.

2021 ◽  
Author(s):  
Xiaoyu Xu ◽  
Yuying Jin ◽  
Ning Pan ◽  
Muqing Cao ◽  
Jin Jing ◽  
...  
Keyword(s):  
White Matter ◽  
Phonological Processing ◽  
Diffusion Tensor ◽  
Mean Diffusivity ◽  
Imaging Study ◽  
Brain White Matter ◽  
The Mean ◽  
The Right ◽  
Long Term Experience

Abstract Cantonese and Mandarin are logographic languages, and the phonology is the main difference between the two languages. It is unclear whether long-term experience of Cantonese-Mandarin bilingualism will shape different brain white matter structures of pathways related to phonological processing. 30 Cantonese-Mandarin bilinguals and 30 Mandarin monolinguals completed diffusion-weighted imaging (DWI) scans and phonological processing tasks. The tractography and TBSS were used to investigate the structural differences in the bilateral superior longitudinal fasciculus (SLF), inferior longitudinal fasciculus (ILF) and inferior fronto-occipital fasciculus (IFOF) between Cantonese-Mandarin bilinguals and Mandarin monolinguals. Post-hoc correlation analysis was conducted to investigate the relationship between the different structures with phonological processing skills. Compared to the Mandarin monolinguals, the Cantonese-Mandarin bilinguals had higher fractional anisotropy (FA) along the left ILF, higher mean diffusivity (MD) in the clusters along the temporoparietal segment of SLF (tSLF), as well as higher axial diffusivity (AD) in the right tSLF, IFOF, bilateral ILF. The mean AD of the different voxels in the right IFOF and the mean FA of the different voxels in the left ILF were positively correlated with the inverse efficiency score (IES) of the Cantonese auditory and Mandarin visual rhyming judgment tasks respectively within the bilingual group. Long-term experience of Cantonese-Mandarin bilinguals shape different brain white matter structures including right tSLF, IFOF, bilateral ILF. The bilinguals’ white matter showed higher diffusivity, especially in the axonal direction, than the monolinguals. These changes were related to bilinguals’ phonological processing.

scholarly journals White Matter Integrity Predicts Delay Discounting Behavior in 9- to 23-Year-Olds: A Diffusion Tensor Imaging Study

2009 ◽  
Vol 21 (7) ◽  
pp. 1406-1421 ◽  
Author(s):  
Elizabeth A. Olson ◽  
Paul F. Collins ◽  
Catalina J. Hooper ◽  
Ryan Muetzel ◽  
Kelvin O. Lim ◽  
...  
Keyword(s):  
Diffusion Tensor Imaging ◽  
White Matter ◽  
Delay Discounting ◽  
Diffusion Tensor ◽  
Mean Diffusivity ◽  
Imaging Study ◽  
Temporal Lobes ◽  
Brain White Matter ◽  
Independent Effects ◽  
Age Range

Healthy participants (n = 79), ages 9–23, completed a delay discounting task assessing the extent to which the value of a monetary reward declines as the delay to its receipt increases. Diffusion tensor imaging (DTI) was used to evaluate how individual differences in delay discounting relate to variation in fractional anisotropy (FA) and mean diffusivity (MD) within whole-brain white matter using voxel-based regressions. Given that rapid prefrontal lobe development is occurring during this age range and that functional imaging studies have implicated the prefrontal cortex in discounting behavior, we hypothesized that differences in FA and MD would be associated with alterations in the discounting rate. The analyses revealed a number of clusters where less impulsive performance on the delay discounting task was associated with higher FA and lower MD. The clusters were located primarily in bilateral frontal and temporal lobes and were localized within white matter tracts, including portions of the inferior and superior longitudinal fasciculi, anterior thalamic radiation, uncinate fasciculus, inferior fronto-occipital fasciculus, corticospinal tract, and splenium of the corpus callosum. FA increased and MD decreased with age in the majority of these regions. Some, but not all, of the discounting/DTI associations remained significant after controlling for age. Findings are discussed in terms of both developmental and age-independent effects of white matter organization on discounting behavior.

scholarly journals Spatial Gradient of Microstructural Changes in Normal-Appearing White Matter in Tracts Affected by White Matter Hyperintensities in Older Age

2018 ◽  
Author(s):  
Susana Muñoz Maniega ◽  
Rozanna Meijboom ◽  
Francesca M. Chappell ◽  
Maria C. Valdés Hernández ◽  
John M. Starr ◽  
...  
Keyword(s):  
White Matter ◽  
White Matter Hyperintensities ◽  
Diffusion Tensor ◽  
Mean Diffusivity ◽  
Pathological Process ◽  
Spatial Gradient ◽  
Microstructural Changes ◽  
Normal Appearing White Matter ◽  
Brain White Matter ◽  
Lothian Birth Cohort

AbstractBrain white matter hyperintensities (WMH), common in older adults, may contribute to cortical disconnection and cognitive dysfunction. The presence of WMH within white matter (WM) tracts indicates underlying microstructural WM changes that may also affect the normal-appearing WM (NAWM) of a tract. We performed an exploratory study using diffusion magnetic resonance imaging of 52 healthy participants from the Lothian Birth Cohort 1936 (age 72.2 ± 0.7 years) selected to include a range of WMH burden, to quantify microstructural changes of tracts intersecting WMH. We reconstructed tracts using automated tractography and identified intersections with WMH. Tissue volumes and water diffusion tensor parameters (mean diffusivity (MD) and fractional anisotropy (FA)) were established for tract-WMH and tract-NAWM. MD and FA were also measured for tract-NAWM at 2 mm incremental distances from the tract-WMH edge, and from the edge of nearby, non-intersecting, WMH. We observed microstructural changes in tract-WMH suggestive of tissue damage. Tract-NAWM also showed a spatial gradient of FA and MD abnormalities, which diminished with distance from the tract-WMH. Nearby WMH lesions, not directly crossed by the tract, also affected tract microstructure with a similar pattern. Additionally, both FA and MD changes in tract-NAWM were predicted by FA and MD changes respectively in tract-WMH. FA was also predicted by tract-WMH overlap volume, whereas MD was better predicted by whole-brain WMH load. These results suggest that tract-NAWM microstructure is affected by the pathological process underlying WMH, when WMH are either within or near to the tract. The changes in NAWM tract tissue may indicate future lesion progression and may play an important role in cognitive ageing.

scholarly journals Age-Related Variations in Regional White Matter Volumetry and Microstructure During the Post-adolescence Period: A Cross-Sectional Study of a Cohort of 1,713 University Students

2021 ◽  
Vol 15 ◽  
Author(s):  
Ami Tsuchida ◽  
Alexandre Laurent ◽  
Fabrice Crivello ◽  
Laurent Petit ◽  
Antonietta Pepe ◽  
...  
Keyword(s):  
White Matter ◽  
University Students ◽  
Diffusion Tensor ◽  
Brain Mri ◽  
Mean Diffusivity ◽  
High Angular Resolution ◽  
White Matter Volume ◽  
Matter Volume ◽  
Brain White Matter ◽  
Age Related

Human brain white matter undergoes a protracted maturation that continues well into adulthood. Recent advances in diffusion-weighted imaging (DWI) methods allow detailed characterizations of the microstructural architecture of white matter, and they are increasingly utilized to study white matter changes during development and aging. However, relatively little is known about the late maturational changes in the microstructural architecture of white matter during post-adolescence. Here we report on regional changes in white matter volume and microstructure in young adults undergoing university-level education. As part of the MRi-Share multi-modal brain MRI database, multi-shell, high angular resolution DWI data were acquired in a unique sample of 1,713 university students aged 18–26. We assessed the age and sex dependence of diffusion metrics derived from diffusion tensor imaging (DTI) and neurite orientation dispersion and density imaging (NODDI) in the white matter regions as defined in the John Hopkins University (JHU) white matter labels atlas. We demonstrate that while regional white matter volume is relatively stable over the age range of our sample, the white matter microstructural properties show clear age-related variations. Globally, it is characterized by a robust increase in neurite density index (NDI), and to a lesser extent, orientation dispersion index (ODI). These changes are accompanied by a decrease in diffusivity. In contrast, there is minimal age-related variation in fractional anisotropy. There are regional variations in these microstructural changes: some tracts, most notably cingulum bundles, show a strong age-related increase in NDI coupled with decreases in radial and mean diffusivity, while others, mainly cortico-spinal projection tracts, primarily show an ODI increase and axial diffusivity decrease. These age-related variations are not different between males and females, but males show higher NDI and ODI and lower diffusivity than females across many tracts. These findings emphasize the complexity of changes in white matter structure occurring in this critical period of late maturation in early adulthood.

scholarly journals Evaluating the diagnostic utility of applying a machine learning algorithm to diffusion tensor MRI measures in individuals with major depressive disorder

2016 ◽  
Author(s):  
David M Schnyer ◽  
Peter C. Clasen ◽  
Christopher Gonzalez ◽  
Christopher G Beevers
Keyword(s):  
Major Depressive Disorder ◽  
White Matter ◽  
Depressive Disorder ◽  
Right Hemisphere ◽  
Diffusion Tensor ◽  
Support Vector ◽  
Healthy Controls ◽  
Major Depressive ◽  
Predictive Information ◽  
Brain White Matter

AbstractUsing MRI to diagnose mental disorders has been a long-term goal. Despite this, the vast majority of prior neuroimaging work has been descriptive rather than predictive. The current study applies support vector machine (SVM) learning to MRI measures of brain white matter to classify adults with Major Depressive Disorder (MDD) and healthy controls. In a precisely matched group of individuals with MDD (n = 25) and healthy controls (n = 25), SVM learning accurately (70%) classified patients and controls across a brain map of white matter fractional anisotropy values (FA). The study revealed three main findings: 1) SVM applied to DTI derived FA maps can accurately classify MDD vs. healthy controls; 2) prediction is strongest when only right hemisphere white matter is examined; and 3) removing FA values from a region identified by univariate contrast as significantly different between MDD and healthy controls does not change the SVM accuracy. These results indicate that SVM learning applied to neuroimaging data can classify the presence versus absence of MDD and that predictive information is distributed across brain networks rather than being highly localized. Finally, MDD group differences revealed through typical univariate contrasts do not necessarily reveal patterns that provide accurate predictive information.

scholarly journals A study of the effects of prenatal alcohol exposure on white matter microstructural integrity at birth

2015 ◽  
Vol 27 (4) ◽  
pp. 197-205 ◽  
Author(s):  
Kirsten Ann Donald ◽  
Annerine Roos ◽  
Jean-Paul Fouche ◽  
Nastassja Koen ◽  
Fleur M. Howells ◽  
...  
Keyword(s):  
White Matter ◽  
Diffusion Tensor ◽  
Prenatal Alcohol Exposure ◽  
Mean Diffusivity ◽  
Alcohol Exposure ◽  
Brain Regions ◽  
Older Children ◽  
Prenatal Alcohol ◽  
The Right ◽  
Microstructural Integrity

BackgroundNeuroimaging studies have indicated that prenatal alcohol exposure is associated with alterations in the structure of specific brain regions in children. However, the temporal and regional specificity of such changes and their behavioural consequences are less known. Here we explore the integrity of regional white matter microstructure in infants with in utero exposure to alcohol, shortly after birth.MethodsTwenty-eight alcohol-exposed and 28 healthy unexposed infants were imaged using diffusion tensor imaging sequences to evaluate white matter integrity using validated tract-based spatial statistics analysis methods. Second, diffusion values were extracted for group comparisons by regions of interest. Differences in fractional anisotropy (FA), mean diffusivity (MD), axial diffusivity (AD) and radial diffusivity were compared between groups and associations with measures from the Dubowitz neonatal neurobehavioural assessment were examined.ResultsLower AD values (p<0.05) were observed in alcohol-exposed infants in the right superior longitudinal fasciculus compared with non-exposed infants. Altered FA and MD values in alcohol-exposed neonates in the right inferior cerebellar were associated with abnormal neonatal neurobehaviour.ConclusionThese exploratory data suggest that prenatal alcohol exposure is associated with reduced white matter microstructural integrity even early in the neonatal period. The association with clinical measures reinforces the likely clinical significance of this finding. The location of the findings is remarkably consistent with previously reported studies of white matter structural deficits in older children with a diagnosis of foetal alcohol spectrum disorders.

scholarly journals Transient changes in white matter microstructure during general anesthesia

PLoS ONE ◽  
2021 ◽  
Vol 16 (3) ◽  
pp. e0247678
Author(s):  
Cheuk Y. Tang ◽  
Victoria X. Wang ◽  
Min Yin Lun ◽  
Joshua S. Mincer ◽  
Johnny C. Ng ◽  
...  
Keyword(s):  
White Matter ◽  
General Anesthesia ◽  
Diffusion Tensor ◽  
Mean Diffusivity ◽  
The Elderly ◽  
Volumetric Analysis ◽  
Sevoflurane Anesthesia ◽  
Transient Effects ◽  
Brain White Matter ◽  
White Matter Microstructure

Cognitive dysfunction after surgery under general anesthesia is a well-recognized clinical phenomenon in the elderly. Physiological effects of various anesthetic agents have been studied at length. Very little is known about potential effects of anesthesia on brain structure. In this study we used Diffusion Tensor Imaging to compare the white matter microstructure of healthy control subjects under sevoflurane anesthesia with their awake state. Fractional Anisotropy, a white mater integrity index, transiently decreases throughout the brain during sevoflurane anesthesia and then returns back to baseline. Other DTI metrics such as mean diffusivity, axial diffusivity and radial diffusivity were increased under sevoflurane anesthesia. Although DTI metrics are age dependent, the transient changes due to sevoflurane were independent of age and sex. Volumetric analysis shows various white matter volumes decreased whereas some gray matter volumes increased during sevoflurane anesthesia. These results suggest that sevoflurane anesthesia has a significant, but transient, effect on white matter microstructure. In spite of the transient effects of sevoflurane anesthesia there were no measurable effects on brain white matter as determined by the DTI metrics at 2 days and 7 days following anesthesia. The role of white matter in the loss of consciousness under anesthesia will need to be studied and MRI studies with subjects under anesthesia will need to take these results into account.

scholarly journals Evidence of Genetic Overlap Between Circadian Preference and Brain White Matter Microstructure

2021 ◽  
Vol 24 (1) ◽  
pp. 1-6
Author(s):  
Luis M. García-Marín ◽  
Sarael Alcauter ◽  
Adrian I. Campos ◽  
Aoibhe Mulcahy ◽  
Pik-Fang Kho ◽  
...  
Keyword(s):  
White Matter ◽  
Diffusion Tensor ◽  
Genetic Correlations ◽  
Mean Diffusivity ◽  
Causal Association ◽  
Posterior Limb ◽  
Brain White Matter ◽  
White Matter Microstructure ◽  
Genetic Overlap ◽  
Circadian Preference

AbstractSeveral neuroimaging studies have reported associations between brain white matter microstructure and chronotype. However, it is unclear whether those phenotypic relationships are causal or underlined by genetic factors. In the present study, we use genetic data to examine the genetic overlap and infer causal relationships between chronotype and diffusion tensor imaging (DTI) measures. We identify 29 significant pairwise genetic correlations, of which 13 also show evidence for a causal association. Genetic correlations were identified between chronotype and brain-wide mean, axial and radial diffusivities. When exploring individual tracts, 10 genetic correlations were observed with mean diffusivity, 10 with axial diffusivity, 4 with radial diffusivity and 2 with mode of anisotropy. We found evidence for a possible causal association of eveningness with white matter microstructure measures in individual tracts including the posterior limb and the retrolenticular part of the internal capsule; the genu and splenium of the corpus callosum and the posterior, superior and anterior regions of the corona radiata. Our findings contribute to the understanding of how genes influence circadian preference and brain white matter and provide a new avenue for investigating the role of chronotype in health and disease.

scholarly journals Rest-activity rhythms and white matter microstructure across the lifespan

SLEEP ◽  
2020 ◽  
Author(s):  
Megan McMahon ◽  
Yoshita Malneedi ◽  
Darrell A Worthy ◽  
David M Schnyer
Keyword(s):  
Older Adults ◽  
White Matter ◽  
Adult Development ◽  
Diffusion Tensor ◽  
Mean Diffusivity ◽  
Brain White Matter ◽  
White Matter Microstructure ◽  
Sleep Physiology ◽  
Rhythm Stability ◽  
Rest Activity

Abstract Study Objectives The purpose of this study was to examine how rest-activity (RA) rhythm stability may be associated with white matter microstructure across the lifespan in healthy adults free of significant cardiovascular risk. Methods We analyzed multi-shell diffusion tensor images from 103 healthy young and older adults using tract-based spatial statistics (TBSS) to examine relationships between white matter microstructure and RA rhythm stability. RA measures were computed using both cosinor and non-parametric methods derived from 7 days of actigraphy data. Fractional anisotropy (FA) and mean diffusivity (MD) were examined in this analysis. Because prior studies have suggested that the corpus callosum (CC) is sensitive to sleep physiology and RA rhythms, we also conducted a focused region of interest analysis on the CC. Results Greater rest-activity rhythm stability was associated with greater FA across both young and older adults, primarily in the CC and anterior corona radiata. This effect was not moderated by age group. While RA measures were associated with sleep metrics, RA rhythm measures uniquely accounted for the variance in white matter integrity. Conclusions This study strengthens existing evidence for a relationship between brain white matter structure and RA rhythm stability in the absence of health risk factors. While there are differences in RA stability between age groups, the relationship with brain white matter was present across both young and older adults. RA rhythms may be a useful biomarker of brain health across both periods of adult development.

scholarly journals The correlation between white matter integrity and pragmatic language processing in first episode schizophrenia

2020 ◽  
Author(s):  
Agnieszka Pawełczyk ◽  
Emila Łojek ◽  
Natalia Żurner ◽  
Marta Gawłowska-Sawosz ◽  
Piotr Gębski ◽  
...  
Keyword(s):  
White Matter ◽  
Fractional Anisotropy ◽  
Language Processing ◽  
Right Hemisphere ◽  
Diffusion Tensor ◽  
Pragmatic Language ◽  
First Episode ◽  
Arcuate Fasciculus ◽  
The Right ◽  
First Episode Schizophrenia

Abstract Objective: Higher-order language disturbances could be the result of white matter tract abnormalities. The study explores the relationship between white matter and pragmatic skills in first-episode schizophrenia. Methods: Thirty-four first-episode patients with schizophrenia and 32 healthy subjects participated in a pragmatic language and Diffusion Tensor Imaging study, where fractional anisotropy of the arcuate fasciculus, corpus callosum and cingulum was correlated with the Polish version of the Right Hemisphere Language Battery. Results: The patients showed reduced fractional anisotropy in the right arcuate fasciculus, left anterior cingulum bundle and left forceps minor. Among the first episode patients, reduced understanding of written metaphors correlated with reduced fractional anisotropy of left forceps minor, and greater explanation of written and picture metaphors correlated with reduced fractional anisotropy of the left anterior cingulum. Conclusions: The white matter dysfunctions may underlie the pragmatic language impairment in schizophrenia. Our results shed further light on the functional neuroanatomical basis of pragmatic language use by patients with schizophrenia.

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