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.

Migraine affects white-matter tract integrity: A diffusion-tensor imaging study

Cephalalgia ◽  
2015 ◽  
Vol 35 (13) ◽  
pp. 1162-1171 ◽  
Author(s):  
Catherine D Chong ◽  
Todd J Schwedt
Keyword(s):  
Diffusion Tensor Imaging ◽  
White Matter ◽  
Corticospinal Tract ◽  
Diffusion Tensor ◽  
Mean Diffusivity ◽  
Imaging Study ◽  
White Matter Tract ◽  
Inferior Longitudinal Fasciculus ◽  
Left And Right ◽  
The Right

Background Specific white-matter tract alterations in migraine remain to be elucidated. Using diffusion tensor imaging (DTI), this study investigated whether the integrity of white-matter tracts that underlie regions of the “pain matrix” is altered in migraine and interrogated whether the number of years lived with migraine modifies fibertract structure. Methods Global probabilistic tractography was used to assess the anterior thalamic radiations, the corticospinal tracts and the inferior longitudinal fasciculi in 23 adults with migraine and 18 healthy controls. Results Migraine patients show greater mean diffusivity (MD) in the left and right anterior thalamic radiations, the left corticospinal tract, and the right inferior longitudinal fasciculus tract. Migraine patients also show greater radial diffusivity (RD) in the left anterior thalamic radiations, the left corticospinal tract as well as the left and right inferior longitudinal fasciculus tracts. No group fractional anisotropy (FA) differences were identified for any tracts. Migraineurs showed a positive correlation between years lived with migraine and MD in the right anterior thalamic radiations ( r = 0.517; p = 0.012) and the left corticospinal tract ( r = 0.468; p = 0.024). Conclusion Results indicate that white-matter integrity is altered in migraine and that longer migraine history is positively correlated with greater alterations in tract integrity.

Characterization of abnormal diffusion properties of supratentorial brain tumors: a preliminary diffusion tensor imaging study

2008 ◽  
Vol 1 (4) ◽  
pp. 263-269 ◽  
Author(s):  
Weihong Yuan ◽  
Scott K. Holland ◽  
Blaise V. Jones ◽  
Kerry Crone ◽  
Francesco T. Mangano
Keyword(s):  
Diffusion Tensor Imaging ◽  
White Matter ◽  
Diffusion Tensor ◽  
Mean Diffusivity ◽  
Imaging Study ◽  
Low Grade ◽  
High Grade ◽  
The Mean ◽  
Supratentorial Tumors ◽  
Diffusion Properties

Object Diffusion tensor (DT) imaging was used in children with supratentorial tumors to evaluate the anisotropic diffusion properties between different tumor grades and between tumors and adjacent and contralateral white matter. Methods In this retrospective review, the authors review the cases of 16 children (age range 1–18 years) who presented to their institution with supratentorial tumors and were treated between 2004 and 2007. Eleven patients had low-grade and 5 had high-grade tumors. Fractional anisotropy (FA), mean diffusivity, and axial (λ∥) and radial (λ⊥) eigenvalues within selected regions were studied. Mitotic index, necrosis, and vascularity of the tumors were compared with DT imaging parameters. Results The mean diffusivity was significantly higher in low-grade than in high-grade tumors (p = 0.04); the 2 tumor grades also significantly differed for both λ∥ (p < 0.05) and λ⊥ (p < 0.05). Mean diffusivity values in low-grade tumors were significantly higher than in adjacent normal-appearing white matter (NAWM; p = 0.0004) and contralateral NAWM (p = 0.0001). In both low- and high-grade tumors, the FA was significantly lower than in NAWM (p < 0.0001 and p < 0.03, respectively) and contralateral NAWM (p < 0.0001 and p < 0.003, respectively). Tumor cellularity highly correlated with mean diffusivity and λ∥and λ⊥. Conclusions Diffusion tensor imaging is a useful tool in the evaluation of supratentorial tumors in children. The mean diffusivity appears to be a significant marker in differentiating tumors grades. Findings related to λ∥ and λ⊥ within tumor groups and between tumors and NAWM may be an indirect manifestation of the combined effects of axonal injury, demyelination, and tumor mass within the cranial compartment.

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 Preliminary Diffusion Tensor Imaging Study: Analysis of Whole Brain according to the Affected Side in Tinnitus

2017 ◽  
Vol 5 (1-2) ◽  
pp. 1-12
Author(s):  
L. Shrestha
Keyword(s):  
White Matter ◽  
Diffusion Tensor ◽  
Mean Diffusivity ◽  
Imaging Study ◽  
Healthy Controls ◽  
White Matter Changes ◽  
Whole Brain ◽  
Affected Side ◽  
The Right

Aim: To investigate the role of white matter integrity in the pathophysiology of tinnitus, and also to analyze the whole brain for white matter changes quantitatively by comparing tinnitus patients with healthy controls based on the affected side of the tinnitus using Tract Based Spatial Statistics (TBSS).Methods: Total of 41 right-handed tinnitus patients and 35 age-matched right-handed healthy controls were initially examined non-invasively in resting-state using the 3.0T MRI scanner. We obtained the estimated Fractional anisotropy (FA), mean diffusivity (MD), Axial Diffusivity (AD), Radial Diffusivity (RD), and Mode of Anisotropy (MO) data for each subject. TBSS was used to perform group statistical analysis of DTI data from each group.Results: Compared to controls in right-sided tinnitus patients, FA and MO were decreased, and MD was normal with decreased AD and increased RD. FA and AD showed similar decreased values (t>1.5, FWEcorrected P<0.05) in the right corticospinal tract, right superior longitudinal fasciculus, and right inferior fronto-occipital fasciculus. Compared to controls with left-sided tinnitus patients, FA and MO were decreased, and MD was also increased with decreased AD with increased RD in patients. MO showed significantly decreased values (t>1.5, FWEcorrected P<0.05) of MO in Forceps major, bilateral cingulum (especially the left), and bilateral anterior thalamic radiation. Bilaterally affected tinnitus patients showed no difference when compared to controls.Conclusion: After analyzing the whole brain for white matter changes quantitatively using TBSS, changes were observed in unilaterally affected tinnitus patients compared to controls. Our findings indicated cross-modal plasticity could have caused changes in somatosensory, audio-visual, limbic, and attention pathways.Nepal Journal of Radiology Vol.5(1-2) 2015: 1-12

scholarly journals QOL-09. WHOLE-BRAIN WHITE MATTER NETWORK CONNECTIVITY IS DISRUPTED BY PEDIATRIC BRAIN TUMOR TREATMENT

2020 ◽  
Vol 22 (Supplement_3) ◽  
pp. iii432-iii432
Author(s):  
Adeoye Oyefiade ◽  
Kiran Beera ◽  
Iska Moxon-Emre ◽  
Jovanka Skocic ◽  
Ute Bartels ◽  
...  
Keyword(s):  
White Matter ◽  
Pediatric Brain Tumor ◽  
Pediatric Brain Tumors ◽  
Magnetic Resonance Images ◽  
Long Term Effects ◽  
Brain White Matter ◽  
The Right ◽  
Pediatric Brain ◽  
Betweeness Centrality

Abstract INTRODUCTION Treatments for pediatric brain tumors (PBT) are neurotoxic and lead to long-term deficits that are driven by the perturbation of underlying white matter (WM). It is unclear if and how treatment may impair WM connectivity across the entire brain. METHODS Magnetic resonance images from 41 PBT survivors (mean age: 13.19 years, 53% M) and 41 typically developing (TD) children (mean age: 13.32 years, 51% M) were analyzed. Image reconstruction, segmentation, and node parcellation were completed in FreeSurfer. DTI maps and probabilistic streamline generation were completed in MRtrix3. Connectivity matrices were based on the number of streamlines connecting two nodes and the mean DTI (FA) index across streamlines. We used graph theoretical analyses to define structural differences between groups, and random forest (RF) analyses to identify hubs that reliably classify PBT and TD children. RESULTS For survivors treated with radiation, betweeness centrality was greater in the left insular (p &lt; 0.000) but smaller in the right pallidum (p &lt; 0.05). For survivors treated without radiation (surgery-only), betweeness centrality was smaller in the right interparietal sulcus (p &lt; 0.05). RF analyses showed that differences in WM connectivity from the right pallidum to other parts of the brain reliably classified PBT survivors from TD children (classification accuracy = 77%). CONCLUSIONS The left insular, right pallidum, and right inter-parietal sulcus are structurally perturbed hubs in PBT survivors. WM connectivity from the right pallidum is vulnerable to the long-term effects of treatment for PBT.

Abstract TMP56: Differential Effect of Left versus Right White Matter Hyperintensity Burden on Functional Decline: The Northern Manhattan Study

Stroke ◽  
2017 ◽  
Vol 48 (suppl_1) ◽  
Author(s):  
Mandip S Dhamoon ◽  
Ying-Kuen Cheung ◽  
Ahmet M Bagci ◽  
Dalila Varela ◽  
Noam Alperin ◽  
...  
Keyword(s):  
White Matter ◽  
Large Population ◽  
Functional Decline ◽  
Frontal Lobes ◽  
White Matter Hyperintensity ◽  
Periventricular White Matter ◽  
Parietal Lobes ◽  
Brain White Matter ◽  
The Right

Background: We previously showed that overall brain white matter hyperintensity volume (WMHV) was associated with accelerated long-term functional decline. Asymmetry of brain dysfunction may disrupt brain network efficiency. We hypothesized that greater left-right WMHV asymmetry was associated with functional trajectories. Methods: In the Northern Manhattan MRI study, participants had brain MRI with axial T1, T2, and fluid attenuated inversion recovery sequences, with baseline interview and examination. Volumetric WMHV distribution across 14 brain regions (brainstem, cerebellum, and bilateral frontal, occipital, temporal, and parietal lobes, and bilateral anterior and posterior periventricular white matter) was determined separately by combining bimodal image intensity distribution and atlas based methods.. Participants had annual functional assessments with the Barthel index (BI, range 0-100) over a mean of 7.3 years. Generalized estimating equations models estimated associations of regional WMHV and regional left-right asymmetry with baseline BI and change over time, adjusted for baseline medical risk factors, sociodemographics, and cognition, and stroke and myocardial infarction during follow-up. Results: Among 1195 participants, mean age was 71 (SD 9) years, 39% were male, 67% had hypertension and 19% diabetes. Greater WMHV asymmetry in the frontal lobes (-3.53 BI points per unit greater WMHV on the right compared to left, 95% CI -0.18, -6.88) and whole brain (-7.23 BI points, 95% CI 0.07, -14.54) was associated with lower overall function. Greater WMHV asymmetry in the frontal lobes (-0.74 additional BI points per year per unit greater WMHV on the right compared to left, 95% CI 0.05, -1.54) and parietal lobes (1.11 additional BI points per year, 95% CI 0.30, 1.93) was independently associated with accelerated functional decline. Periventricular WMHV asymmetry was not associated with function. Conclusions: In this large population-based study with long-term repeated measures of function, greater regional WMHV asymmetry was associated with lower function and functional decline, especially with greater WMHV on the right. In addition to global WMHV, WHMV asymmetry may be an important predictor of long-term functional decline.

scholarly journals Thalamic and thalamic projection abnormalities on DTI and NODDI analysis following acute concussion

Neurology ◽  
2019 ◽  
Vol 93 (14 Supplement 1) ◽  
pp. S4.2-S5
Author(s):  
James Houston ◽  
Frank Skidmore ◽  
William Monroe ◽  
Jon Amburgy ◽  
Mitchell Self
Keyword(s):  
White Matter ◽  
Diffusion Tensor ◽  
Mean Diffusivity ◽  
Oculomotor System ◽  
White Matter Injury ◽  
Football Players ◽  
Cortical Regions ◽  
The Right ◽  
Collegiate Football ◽  
Concussive Injury

ObjectiveTo compare preseason and post-concussive MRI in a cohort of collegiate football players utilizing Diffusion Tensor Imaging (DTI) and Neurite Orientation Dispersion and Density Imaging (NODDI) post processing.BackgroundAcute post-concussive symptoms can vary in clinical characteristics and severity. However, vestibular and ocular dysfunction in particular, has been associated with poor clinical outcomes. The vestibular system comprises a complex network of projections from peripheral vestibular organs to thalamic relay systems and numerous cortical regions. The visual/oculomotor system is also complex, involving brainstem, subcortical-cortical and thalamo-cortical connections. Oculomotor deficits are thought to involve the midbrain and the visual and parietal association cortices, both of which have thalamic projections.Design/MethodsWe gathered pre-season MR diffusion weighted imaging on a cohort of 30 collegiate football players. We performed repeat imaging within 36 hours of any diagnosed concussion in the same subject cohort. DTI metrics: mean diffusivity (MD), axial diffusivity (AD), fractional anisotropy (FA), and radial diffusivity (RD) along with NODDI metric: orientation dispersion index (ODI), were analyzed for statistical comparisons between groups.Results4 subjects with pre-season MRI underwent repeat MRI within 36 hours of concussive injury. A paired t-test between these two groups using DTI and NODDI metrics showed significant (p < 0.05) decreases in: AD and MD in the left posterior thalamic radiations, FA in the column and body of the fornix, and MD in the right anterior corona radiata and superior fronto-occipital fasciculus, and a significant decrease in ODI in the anterior thalamus.ConclusionsDisruptions in the thalamus and its white matter projections may play a role in the vestibular/ocular dysfunction associated with acute concussive injury. While our numbers are small, the findings suggest that DTI and NODDI processing techniques have the capability to locate and measure grey and white matter injury patterns after concussive injury.

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