Lead exposure is associated with functional and microstructural changes in the healthy human brain

AbstractLead is a toxin known to harm many organs in the body, particularly the central nervous system, across an individual’s lifespan. To date, no study has yet investigated the associations between body lead level and the microstructural properties of gray matter areas, and brain activity during attention-demanding tasks. Here, utilizing data of diffusion tensor imaging, functional magnetic resonance imaging and cognitive measures among 920 typically developing young adults, we show greater hair lead levels are weakly but significantly associated with (a) increased working memory-related activity in the right premotor and pre-supplemental motor areas, (b) lower fractional anisotropy (FA) in white matter areas near the internal capsule, (c) lower mean diffusivity (MD) in the dopaminergic system in the left hemisphere and other widespread contingent areas, and (d) greater MD in the white matter area adjacent to the right fusiform gyrus. Higher lead levels were also weakly but significantly associated with lower performance in tests of high-order cognitive functions, such as the psychometric intelligence test, greater impulsivity measures, and higher novelty seeking and extraversion. These findings reflect the weak effect of daily lead level on the excitability and microstructural properties of the brain, particularly in the dopaminergic system.

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

Neurology ◽

10.1212/01.wnl.0000580864.41102.8d ◽

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

Cephalalgia ◽

10.1177/0333102415573513 ◽

2015 ◽

Vol 35 (13) ◽

pp. 1162-1171 ◽

Cited By ~ 26

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.

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Correlation between DTI effect and white matter structural integrity, working memory in leukoaraiosis patients

ROMANIAN BIOTECHNOLOGICAL LETTERS ◽

10.25083/rbl/26.3/2714-2721 ◽

2021 ◽

Vol 26 (3) ◽

pp. 2714-2721

Author(s):

XIAOFENG YANG ◽

◽

WANMENG XIE ◽

Keyword(s):

Working Memory ◽

White Matter ◽

Structural Integrity ◽

Color Word ◽

Diffusion Tensor ◽

Mean Diffusivity ◽

Lesion Group ◽

Cingulum Bundle ◽

The Right ◽

White Matter Area

Our objective was to study the correlation between Diffusion tensor MR imaging (DTI) effect and white matter structural integrity, working memory in leukoaraiosis patients. 100 leukoaraiosis patients referring to the First Affiliated Hospital of Beijing Medical University from December 2018 to December 2019, were selected as study subjects and divided into four groups according to disease severity: lesion-free group, mild lesion group, moderate lesion group, and severe lesion group. All patients underwent magnetic resonance diffusion tensor imaging to collect DWI images and analyze Fractional anisotropy (FA), mean diffusivity (MD), ReHo values of white matter area under different grading. The patients’ working memory was tested via auditory verb learning test and Stroop color word test, so that correlation between white matter structural integrity and working memory can be analyzed. Results: There are statistically significant differences in FA values of the right posterior thalamic radiation, the right sagittal layer and the right superior longitudinal fasciculus, MD values of the right sagittal layer, the right cingulum bundle, the left cingulum bundle, the right inferior fasciculus fronto-occipitalis and the left inferior fasciculus frontooccipitalis, as well as instant recall, delayed recall, delayed recognition, card A (dot), card B (character), card C (color word) and SIE value (P<0.01). Correlation is shown between white matter structural integrity and working memory, gender, age, grading, disease course, recurrence interval, white matter area, and testing methods. There was a correlation between DTI effect and white matter structural integrity, working memory in leukoaraiosis patients, and leukoaraiosis patients have memory impairment.

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

10.21203/rs.3.rs-1168282/v1 ◽

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.

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T48. DEVIATIONS IN MICRO AND MACRO WHITE MATTER STRUCTURES IN PSYCHOSIS PRONENESS

Schizophrenia Bulletin ◽

10.1093/schbul/sbaa029.608 ◽

2020 ◽

Vol 46 (Supplement_1) ◽

pp. S249-S250

Author(s):

Seda Arslan ◽

Tuba Şahin ◽

Didenur Şahin ◽

Timothea Toulopoulou

Keyword(s):

White Matter ◽

High Risk ◽

Diffusion Tensor ◽

Mean Diffusivity ◽

Structured Interview ◽

Anterior Cingulate ◽

White Matter Integrity ◽

Psychosis Proneness ◽

Brodmann Areas ◽

The Right

Abstract Background Psychotic disorders are characterized by neurobiological deviations, including in the macro and microstructure of white matter. White matter alterations are also seen in psychosis-proneness and in individuals who have a high risk of psychosis. For example, studies have indicated decreases in white matter integrity in the genu/forceps minor of corpus callosum (CC) in the latter populations. Anterior corona radiata (ACR) is one crucial white-matter tract connecting the anterior cingulate cortex to the striatum. Indeed, reductions in the white matter structure of anterior genu of CC significantly predict the transition from ultra-high risk to psychosis. However, there is a gap in the literature related to observing the psychosis-proneness by applying both micro and macrostructural brain analyses, and most of the microstructural white matter studies in psychosis focus on fractional anisotropy (FA) and not include mean diffusivity (MD). Thus, the current study aims to assess whether white matter deviations in CG, ACR, and CC, are associated with psychosis proneness by combining both tract-based spatial statistics (TBSS) and voxel-based morphometry (VBM) analyses in a sample of participants with psychosis proneness (PP) and without psychosis proneness (NPP). Methods The study included 53 participants (29 PP vs. 24 NPP) whose ages were between 17 and 24 years. Participants were split into two groups based on their scores on Structured Interview for Schizotypy assessment, a well-validated instrument of psychosis proneness. White matter integrity was analyzed via diffusion tensor imaging (DTI) and white matter volume (WMV) via VBM. Two sample t-test was used in GLM for both DTI and VBM analyses. FA, MD, and VMV were compared between two groups to observe micro and macro white matter structure alterations in the region of interest. Results DTI analysis revealed decreased FA values in the right ACR and right genu of the CC in the psychosis-proneness group (F(1,52)= 7.37, p= 0.009). Moreover, VBM showed a significant WMV decreases in the right CG, Brodmann areas 8, 9, and 32 in the PP group (F(1,52)= 50.85, uncorrected p<0.01). However, MD did not differ between the two groups (F(1,51)= 3.65, p=0.06) Discussion These findings suggest that PP associated with decreased white matter integrity in ACR, genu of CC, and also reduced white matter volumes in the right CG, Brodmann areas 8, 9, and 32. Significant FA decreases might result from alterations in radial or axial diffusivity since we did not observe significant MD differences between two groups. The current findings suggested that participants with PP had both macro and micro white matter structure disruptions, mostly in frontal parts of the right cerebrum, compared to no PP group.

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White Matter Abnormalities in Body Integrity Dysphoria

10.1101/2021.08.18.21262224 ◽

2021 ◽

Author(s):

Gianluca Saetta ◽

Kathy Ruddy ◽

Laura Zapparoli ◽

Martina Gandola ◽

Gerardo Salvato ◽

...

Keyword(s):

White Matter ◽

Diffusion Tensor ◽

Inferior Frontal Gyrus ◽

Structural Connectivity ◽

The Body ◽

Limb Amputation ◽

Middle Temporal Gyrus ◽

Imaging Data ◽

Severe Condition ◽

The Right

Body integrity dysphoria (BID) is a severe condition affecting non-psychotic individuals where a limb may be experienced as non-belonging, despite normal anatomical development and intact sensorimotor functions. Limb amputation is desired for restoring their own identity. We previously demonstrated altered brain structural (gray matter) and functional connectivity in 16 men with a long-lasting and exclusive desire for left leg amputation. Here we aimed to identify in the same sample altered patterns of white matter structural connectivity. Fractional anisotropy (FA), derived from Diffusion Tensor Imaging data, was considered as a measure of structural connectivity. Results showed reduced structural connectivity of: i) the right superior parietal lobule (rSPL) with the right cuneus, superior occipital and posterior cingulate gyri, and cuneus, ii) the pars orbitalis of the right middle frontal gyrus (rMFGOrb) with the putamen iii) the left middle temporal gyrus (lMTG) with the pars triangularis of the left inferior frontal gyrus. Increased connectivity was observed between the right paracentral lobule (rPLC) and the right caudate nucleus. By using a complementary method of investigation, we confirmed and extended previous results showing alterations in areas tuned to the processing of the sensorimotor representations of the affected leg (rPCL), and to higher-order components of bodily representation such as the body image (rSPL). Alongside this network for bodily awareness, other networks such as the limbic (rMFGOrb) and the mirror (lMTG) systems showed structural alterations as well. These findings consolidate current understanding of the neural correlates of BID, which might in turn guide diagnostics and rehabilitative treatments.

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Sensory processing sensitivity and axonal microarchitecture: Identifying brain structural characteristics for behavior

10.1101/2021.11.13.468491 ◽

2021 ◽

Author(s):

Szabolcs David ◽

Lucy L Brown ◽

Anneriet M Heemskerk ◽

Elaine Aron ◽

Alexander Leemans ◽

...

Keyword(s):

Diffusion Tensor Imaging ◽

White Matter ◽

Sensory Processing ◽

Diffusion Tensor ◽

Structural Characteristics ◽

Inferior Frontal Gyrus ◽

Mean Diffusivity ◽

Human Connectome Project ◽

Sensory Processing Sensitivity ◽

The Right

Previously, researchers used functional MRI to identify regional brain activations associated with sensory processing sensitivity (SPS), a proposed normal phenotype trait. To further validate SPS as a behavioral entity, to characterize it anatomically, and to test the usefulness in psychology of methodologies that assess axonal properties, the present study correlated SPS proxy questionnaire scores (adjusted for neuroticism) with diffusion tensor imaging measures. Participants (n=408) from the Young Adult Human Connectome Project that are free of neurologic and psychiatric disorders were investigated. We computed mean diffusivity (MD), radial diffusivity (RD), axial diffusivity (AD) and fractional anisotropy (FA). A voxelwise, exploratory analysis showed that MD and RD correlated positively with SPS proxy scores in the right and left subcallosal and anterior ventral cingulum bundle, and the right forceps minor of the corpus callosum (peak Cohens D effect size = 0.269). Further analyses showed correlations throughout the entire right and left ventromedial prefrontal cortex, including the superior longitudinal fasciculus, inferior fronto-occipital fasciculus, uncinate and arcuate fasciculus. These prefrontal regions are generally involved in emotion, reward and social processing. FA was negatively correlated with SPS proxy scores in white matter of the right premotor/motor/somatosensory/supramarginal gyrus regions, which are associated with empathy, theory of mind, primary and secondary somatosensory processing. Region of interest (ROI) analysis, based-on previous fMRI results and Freesurfer atlas-defined areas, showed small effect sizes, (+0.151 to -0.165) in white matter of the precuneus and inferior frontal gyrus. Other ROI effects were found in regions of the dorsal and ventral visual pathways and primary auditory cortex. The results reveal that in a large, diverse group of participants axonal microarchitectural differences can be identified with SPS traits that are subtle and in the range of typical behavior. The results suggest that the heightened sensory processing in people who show SPS may be influenced by the microstructure of white matter in specific neocortical regions. Although previous fMRI studies had identified most of these general neocortical regions, the DTI results put a new focus on brain areas related to attention and cognitive flexibility, empathy, emotion and low-level sensory processing, as in the primary sensory cortex. Psychological trait characterization may benefit from diffusion tensor imaging methodology by identifying influential brain systems for traits.

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Age-related Differences in White Matter Integrity in Healthy Human Brain: Evidence from Structural Mri and Diffusion Tensor Imaging

Magnetic Resonance Insights ◽

10.4137/mri.s39666 ◽

2016 ◽

Vol 9 ◽

pp. MRI.S39666 ◽

Cited By ~ 7

Author(s):

Rishu Rathee ◽

V.P. Subramanyam Rallabandi ◽

Prasun K. Roy

Keyword(s):

Diffusion Tensor Imaging ◽

White Matter ◽

Spatial Statistics ◽

Diffusion Tensor ◽

Mean Diffusivity ◽

Middle Aged ◽

Healthy Human ◽

Aged Group ◽

Age Related ◽

Tract Based Spatial Statistics

The aim is to investigate the relationship between microstructural white matter (WM) diffusivity indices and macrostructural WM volume (WMV) among healthy individuals (20–85 years). Whole-brain diffusion measures were calculated from diffusion tensor imaging using FMRIB software library while WMV was estimated through voxel-based morphometry, and voxel-based analysis was carried out using tract-based spatial statistics. Our results revealed that mean diffusivity, axial diffusivity, and radial diffusivity had shown good correlation with WMV but not for fractional anisotropy (FA). Voxel-wise tract-based spatial statistics analysis for FA showed a significant decrease in four regions for middle-aged group compared to young-aged group, in 22 regions for old-aged group compared to middle-aged group, and in 26 regions for old-aged group compared to young-aged group ( P < 0.05). We found significantly lower WMV, FA, and mean diffusivity values in females than males and inverted-U trend for FA in males. We conclude differential age- and gender-related changes for structural WMV and WM diffusion indices.

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

Acta Neuropsychiatrica ◽

10.1017/neu.2015.35 ◽

2015 ◽

Vol 27 (4) ◽

pp. 197-205 ◽

Cited By ~ 17

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.

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White Matter Integrity Correlates of the Reading Span

10.20944/preprints202101.0254.v2 ◽

2021 ◽

Author(s):

Ekaterina V. Pechenkova ◽

Yana R. Panikratova ◽

Maria A. Fomina ◽

Elena A. Mershina ◽

Daria A. Bazhenova ◽

...

Keyword(s):

Working Memory ◽

White Matter ◽

Right Hemisphere ◽

Diffusion Tensor ◽

Structural Connectivity ◽

Verbal Working Memory ◽

The Body ◽

White Matter Integrity ◽

Reading Span ◽

The Right

Although working memory (WM) is crucial for intellectual abilities, not much is known about its brain underpinnings, especially the structural connectivity. We used diffusion tensor imaging (DTI) to look across the whole brain for the white matter integrity correlates of the individual differences in the reading span (verbal WM capacity during reading) in healthy adults. Right-handed healthy native Russian speakers (N = 67) underwent DTI on a 3T Philips Ingenia scanner. Verbal WM was assessed with the Daneman-Carpenter reading span test (Russian version). Fractional anisotropy maps from each participant were entered into the group tract-based spatial statistics analysis with the reading span as a covariate; the results were TFCE-corrected. After taking into account effects of age, sex, education and handedness, reading span positively correlated with the white matter integrity in multiple sites: the body, the genu and the splenium of corpus callosum; bilateral corona radiata (anterior, posterior, and superior); bilateral superior longitudinal fasciculus; several tracts in the right hemisphere only, including the internal and external capsule; bilateral superior parietal and frontal white matter. Although the left hemisphere is central for verbal processing, we revealed the important role of the right hemisphere white matter for the verbal WM capacity. Our finding indicates that larger verbal working memory span may originate from additional processing resources of the right hemisphere.

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