scholarly journals Imaging functional neuroplasticity in human white matter tracts

2021 ◽  
Author(s):  
Tory O. Frizzell ◽  
Elisha Phull ◽  
Mishaa Khan ◽  
Xiaowei Song ◽  
Lukas A. Grajauskas ◽  
...  
Keyword(s):  
White Matter ◽  
Corpus Callosum ◽  
Structural Changes ◽  
Diffusion Tensor ◽  
Low Frequency ◽  
Internal Capsule ◽  
Underlying Mechanism ◽  
Dominant Hand ◽  
Magnetic Resonance Imaging Mri ◽  
Functional Neuroplasticity

AbstractMagnetic resonance imaging (MRI) studies are sensitive to biological mechanisms of neuroplasticity in white matter (WM). In particular, diffusion tensor imaging (DTI) has been used to investigate structural changes. Historically, functional MRI (fMRI) neuroplasticity studies have been restricted to gray matter, as fMRI studies have only recently expanded to WM. The current study evaluated WM neuroplasticity pre–post motor training in healthy adults, focusing on motor learning in the non-dominant hand. Neuroplasticity changes were evaluated in two established WM regions-of-interest: the internal capsule and the corpus callosum. Behavioral improvements following training were greater for the non-dominant hand, which corresponded with MRI-based neuroplasticity changes in the internal capsule for DTI fractional anisotropy, fMRI hemodynamic response functions, and low-frequency oscillations (LFOs). In the corpus callosum, MRI-based neuroplasticity changes were detected in LFOs, DTI, and functional correlation tensors (FCT). Taken together, the LFO results converged as significant amplitude reductions, implicating a common underlying mechanism of optimized transmission through altered myelination. The structural and functional neuroplasticity findings open new avenues for direct WM investigations into mapping connectomes and advancing MRI clinical applications.

White matter microstructural abnormalities in families multiply affected with bipolar I disorder: a diffusion tensor tractography study

2013 ◽  
Vol 44 (10) ◽  
pp. 2139-2150 ◽  
Author(s):  
L. Emsell ◽  
C. Chaddock ◽  
N. Forde ◽  
W. Van Hecke ◽  
G. J. Barker ◽  
...  
Keyword(s):  
White Matter ◽  
Diffusion Tensor ◽  
Internal Capsule ◽  
Type I ◽  
Genetic Liability ◽  
Inferior Longitudinal Fasciculus ◽  
Participant Group ◽  
Dti Tractography ◽  
Magnetic Resonance Imaging Mri ◽  
Diffusion Tensor Imaging Dti

BackgroundWhite matter (WM) abnormalities are proposed as potential endophenotypic markers of bipolar disorder (BD). In a diffusion tensor imaging (DTI) voxel-based analysis (VBA) study of families multiply affected with BD, we previously reported that widespread abnormalities of fractional anisotropy (FA) are associated with both BD and genetic liability for illness. In the present study, we further investigated the endophenotypic potential of WM abnormalities by applying DTI tractography to specifically investigate tracts implicated in the pathophysiology of BD.MethodDiffusion magnetic resonance imaging (MRI) data were acquired from 19 patients with BD type I from multiply affected families, 21 of their unaffected first-degree relatives and 18 healthy volunteers. DTI tractography was used to identify the cingulum, uncinate fasciculus (UF), arcuate portion of the superior longitudinal fasciculus (SLF), inferior longitudinal fasciculus (ILF), corpus callosum, and the anterior limb of the internal capsule (ALIC). Regression analyses were conducted to investigate the effect of participant group and genetic liability on FA and radial diffusivity (RD) in each tract.ResultsWe detected a significant effect of group on both FA and RD in the cingulum, SLF, callosal splenium and ILF driven by reduced FA and increased RD in patients compared to controls and relatives. Increasing genetic liability was associated with decreased FA and increased RD in the UF, and decreased FA in the SLF, among patients.ConclusionsWM microstructural abnormalities in limbic, temporal and callosal pathways represent microstructural abnormalities associated with BD whereas alterations in the SLF and UF may represent potential markers of endophenotypic risk.

Neocortex (Frontal and Temporal Lobe) Discirculatory Lesions of the Chernobyl Accident Liquidators at the Remote Period (Based on Diffusion Tensor MRI Data)

2020 ◽  
Vol 65 (4) ◽  
pp. 43-47
Author(s):  
S. Aleksanin ◽  
S. Serebryakova ◽  
I. Levashkina
Keyword(s):  
White Matter ◽  
Temporal Lobe ◽  
Chernobyl Accident ◽  
Structural Changes ◽  
Diffusion Tensor ◽  
Internal Capsule ◽  
Brain Structures ◽  
Structure Changes ◽  
Average Fraction ◽  
High Level

Purpose: To find the distinctive features of the white matter tracts’ structural changes for Chernobyl accident liquidators with ebcephalopathy at the remote period using DT-MRI methods. Material and methods: Chernobyl accident liquidators group (41 subjects) and group of control (49 subjects), all subjects with stage II of encephalopathy, mean age of liquidators’ group 68.3 ± 6.9 years, gropup of control — 68.6 ± 5.8 years. All subjects were clinically examined to confirm encephalopathy stage, hypertension, diabetes (and prove patients of both groups have comparable level of damage of those deseases), as well as with routine MRI and DT-MRI protocols. According routine MRI results, all subjects of both groups had high level of discirculatory damages: multifocal lesions of white matter and periventricular leukoaraiosis, mixed replacement hydrocephalus. Results: Liquidator’s group average fraction anisotropy coefficient (CFA) had shown statistically significant reduction in four frontal and temporal lobe tracts of neocortex if compare with average CFA in the group of control: superior longitudinal fasciculi (р < 0.02); front sections of corona radiata (р < 0.02); anterior horn of internal capsule (р < 0.01), inferior longitudinal fasciculi (р < 0.01). Conclusion: Frontal and temporal lobe tracts of neocortex, responsible for cognitive processes, are the most sensible to accident liquidation negative factors. Cerebral structure changes, found for group of liquidators, are similar to elder people with encephalopathy, but are clnically more strongly marked, what proves hyoptesis of early aging of liquidators’ brain structures.

Diffusion tensor imaging in hyperthyroidism: assessment of microstructural white matter abnormality with a tract-based spatial statistical analysis

2020 ◽  
Vol 61 (12) ◽  
pp. 1677-1683 ◽  
Author(s):  
Kerim Aslan ◽  
Hediye Pinar Gunbey ◽  
Sumeyra Cortcu ◽  
Onur Ozyurt ◽  
Ugur Avci ◽  
...  
Keyword(s):  
Diffusion Tensor Imaging ◽  
White Matter ◽  
Corpus Callosum ◽  
Diffusion Tensor ◽  
Mean Diffusivity ◽  
Imaging Study ◽  
Internal Capsule ◽  
Control Group ◽  
Corona Radiata ◽  
Microstructural Alterations

Background Metabolic, morphological, and functional brain changes associated with a neurological deficit in hyperthyroidism have been observed. However, changes in microstructural white matter (WM), which can explain the underlying pathophysiology of brain dysfunctions, have not been researched. Purpose To assess microstructural WM abnormality in patients with untreated or newly diagnosed hyperthyroidism using tract-based spatial statistics (TBSS). Material and Methods Eighteen patients with hyperthyroidism and 14 age- and sex-matched healthy controls were included in this study. TBSS were used in this diffusion tensor imaging study for a whole-brain voxel-wise analysis of fractional anisotropy, mean diffusivity, axial diffusivity (AD), and radial diffusivity (RD) of WM. Results When compared to the control group, TBSS showed a significant increase in the RD of the corpus callosum, anterior and posterior corona radiata, posterior thalamic radiation, cingulum, superior longitudinal fasciculus, and the retrolenticular region of the internal capsule in patients with hyperthyroidism ( P < 0.05), as well as a significant decrease in AD in the anterior corona radiata and the genu of corpus callosum ( P < 0.05). Conclusion This study showed that more regions are affected by the RD increase than the AD decrease in the WM tracts of patients with hyperthyroidism. These preliminary results suggest that demyelination is the main mechanism of microstructural alterations in the WM of hyperthyroid patients.

P02 - 361 White matter microstructural abnormalities in antisocial personality disorder: A pilot diffusion tensor imaging study

2011 ◽  
Vol 26 (S2) ◽  
pp. 957-957
Author(s):  
F. Sundram ◽  
Q. Deeley ◽  
S. Sarkar ◽  
E. Daly ◽  
R. Latham ◽  
...  
Keyword(s):  
Diffusion Tensor Imaging ◽  
White Matter ◽  
Personality Disorder ◽  
Corpus Callosum ◽  
Antisocial Personality Disorder ◽  
Diffusion Tensor ◽  
Internal Capsule ◽  
Uncinate Fasciculus ◽  
Antisocial Personality ◽  
The Right

IntroductionAntisocial personality disorder (ASPD) and psychopathy involve significant interpersonal and behavioural impairments. However, little is known about white matter (WM) abnormalities in tracts linking grey matter regions. A previous diffusion tensor imaging (DT-MRI) tractography study in ASPD and psychopathy revealed abnormalities in the right uncinate fasciculus, indicating fronto-limbic disconnectivity.ObjectivesIt is not clear whether WM abnormalities are restricted to only this tract or are more widespread. Therefore, we planned to use whole brain DT-MRI voxel-based analyses.AimsTo clarify if WM abnormalities extend beyond the frontal lobe.MethodsWe used whole brain DT-MRI to compare WM fractional anisotropy (FA) of 15 adults with ASPD and healthy age, handedness and IQ-matched controls. Also, within ASPD subjects, we related differences in FA to severity of psychopathy measures.ResultsSignificant WM FA reductions were found in ASPD subjects relative to controls. These were found bilaterally in the anterior corpus callosum. Right hemisphere FA reduction was found in the anterior corona radiata, uncinate fasciculus, inferior fronto-occipital fasciculus and internal capsule. Left hemisphere, FA deficits encompassed the inferior longitudinal fasciculus, inferior fronto-occipital fasciculus and internal capsule. There was a significant negative correlation between WM FA in the right uncinate fasciculus and corpus callosum and measures of psychopathy.ConclusionsWe report FA reduction in the uncinate fasciculus and anterior corpus callosum which may be associated with frontal and inter-hemispheric disconnectivity in ASPD, in addition to abnormalities in other tracts which directly or indirectly connect to prefrontal regions.

Altered functional synchrony between gray and white matter as a novel indicator of brain system dysconnectivity in schizophrenia

2021 ◽  
pp. 1-9
Author(s):  
Naici Liu ◽  
Rebekka Lencer ◽  
Zhipeng Yang ◽  
Wenjing Zhang ◽  
Chengmin Yang ◽  
...  
Keyword(s):  
White Matter ◽  
Corpus Callosum ◽  
Symptom Severity ◽  
Functional Activity ◽  
Diffusion Tensor ◽  
Low Frequency ◽  
Blood Oxygenation ◽  
Future Research ◽  
Functional Magnetic Resonance ◽  
Oxygenation Level

Abstract Background There is increasing evidence that blood oxygenation level-dependent signaling in white matter (WM) reflects WM functional activity. Whether this activity is altered in schizophrenia remains uncertain, as does whether it is related to established alterations of gray matter (GM) or the microstructure of WM tracts. Methods A total of 153 antipsychotic-naïve schizophrenia patients and 153 healthy comparison subjects were assessed by resting-state functional magnetic resonance imaging, diffusion tensor imaging, and high-resolution T1-weighted imaging. We tested for case–control differences in the functional activity of WM, and examined their relation to the functional activity of GM and WM microstructure. The relations between fractional anisotropy (FA) in WM and GM–WM functional synchrony were investigated as well. Then, we examined the associations of identified abnormalities to age, duration of untreated psychosis (DUP), and symptom severity. Results Schizophrenia patients displayed reductions of the amplitude of low-frequency fluctuations (ALFF), GM–WM functional synchrony, and FA in widespread regions. Specifically, the genu of corpus callosum not only had weakening in the synchrony of functional activity but also had reduced ALFF and FA. Positive associations were found between FA and functional synchrony in the genu of corpus callosum as well. No significant association was found between identified abnormalities and DUP, and symptom severity. Conclusions The widespread weakening in the synchrony of functional activity of GM and WM provided novel evidence for functional alterations in schizophrenia. Regarding the WM function as a component of brain systems and investigating its alternation represent a promising direction for future research.

Individual differences in white and grey matter structure associated with verbal habits of thought

2019 ◽  
Author(s):  
Justin C. Hayes ◽  
Katherine L Alfred ◽  
Rachel Pizzie ◽  
Joshua S. Cetron ◽  
David J. M. Kraemer
Keyword(s):  
Individual Differences ◽  
White Matter ◽  
Cognitive Processing ◽  
Grey Matter ◽  
Structural Changes ◽  
Structural Integrity ◽  
Diffusion Tensor ◽  
Self Report ◽  
White Matter Tracts

Modality specific encoding habits account for a significant portion of individual differences reflected in functional activation during cognitive processing. Yet, little is known about how these habits of thought influence long-term structural changes in the brain. Traditionally, habits of thought have been assessed using self-report questionnaires such as the visualizer-verbalizer questionnaire. Here, rather than relying on subjective reports, we measured habits of thought using a novel behavioral task assessing attentional biases toward picture and word stimuli. Hypothesizing that verbal habits of thought are reflected in the structural integrity of white matter tracts and cortical regions of interest, we used diffusion tensor imaging and volumetric analyses to assess this prediction. Using a whole-brain approach, we show that word bias is associated with increased volume in several bilateral language regions, in both white and grey matter parcels. Additionally, connectivity within white matter tracts within an a priori speech production network increased as a function of word bias. These results demonstrate long-term structural and morphological differences associated with verbal habits of thought.

Assessment of White Matter Lesions in Parkinson's Disease: Voxel-based Analysis and Tract-based Spatial Statistics Analysis of Parkinson's Disease with Mild Cognitive Impairment

2020 ◽  
Vol 17 (4) ◽  
pp. 480-486
Author(s):  
Wei Pu ◽  
Xudong Shen ◽  
Mingming Huang ◽  
Zhiqian Li ◽  
Xianchun Zeng ◽  
...  
Keyword(s):  
Parkinson’S Disease ◽  
Parkinson's Disease ◽  
Cognitive Impairment ◽  
Mild Cognitive Impairment ◽  
White Matter ◽  
Corpus Callosum ◽  
Fractional Anisotropy ◽  
Spatial Statistics ◽  
Diffusion Tensor ◽  
Tract Based Spatial Statistics

Objective: Application of diffusion tensor imaging (DTI) to explore the changes of FA value in patients with Parkinson's disease (PD) with mild cognitive impairment. Methods: 27 patients with PD were divided into PD with mild cognitive impairment (PD-MCI) group (n = 7) and PD group (n = 20). The original images were processed using voxel-based analysis (VBA) and tract-based spatial statistics (TBSS). Results: The average age of pd-mci group was longer than that of PD group, and the course of disease was longer than that of PD group. Compared with PD group, the voxel based analysis-fractional anisotropy (VBA-FA) values of PD-MCI group decreased in the following areas: bilateral frontal lobe, bilateral temporal lobe, bilateral parietal lobe, bilateral subthalamic nucleus, corpus callosum, and gyrus cingula. Tract-based spatial statistics-fractional anisotropy (TBSS-FA) values in PD-MCI group decreased in bilateral corticospinal tract, anterior cingulum, posterior cingulum, fornix tract, bilateral superior thalamic radiation, corpus callosum(genu, body and splenium), bilateral uncinate fasciculus, bilateral inferior longitudinal fasciculus, bilateral superior longitudinal fasciculus, bilateral superior fronto-occipital fasciculus, bilateral inferior fronto-occipital fasciculus, and bilateral parietal-occipital tracts. The mean age of onset in the PD-MCI group was greater than that in the PD group, and the disease course was longer than that in the PD group. Conclusion: DTI-based VBA and TBSS post-processing methods can detect abnormalities in multiple brain areas and white matter fiber tracts in PD-MCI patients. Impairment of multiple cerebral cortex and white matter fiber pathways may be an important causes of cognitive dysfunction in PD-MCI.

scholarly journals Structural brain signature of cognitive decline in Parkinson’s disease: DTI-based evidence from the LANDSCAPE study

2019 ◽  
Vol 12 ◽  
pp. 175628641984344 ◽  
Author(s):  
Martin Gorges ◽  
Hans-Peter Müller ◽  
Inga Liepelt-Scarfone ◽  
Alexander Storch ◽  
Richard Dodel ◽  
...  
Keyword(s):  
Parkinson’S Disease ◽  
Parkinson's Disease ◽  
White Matter ◽  
Corpus Callosum ◽  
Cognitive Decline ◽  
Diffusion Tensor ◽  
Structural Connectivity ◽  
Structural Data ◽  
The Body ◽  
Normal Cognitive Function

Background: The nonmotor symptom spectrum of Parkinson’s disease (PD) includes progressive cognitive decline mainly in late stages of the disease. The aim of this study was to map the patterns of altered structural connectivity of patients with PD with different cognitive profiles ranging from cognitively unimpaired to PD-associated dementia. Methods: Diffusion tensor imaging and neuropsychological data from the observational multicentre LANDSCAPE study were analyzed. A total of 134 patients with PD with normal cognitive function (56 PD-N), mild cognitive impairment (67 PD-MCI), and dementia (11 PD-D) as well as 72 healthy controls were subjected to whole-brain-based fractional anisotropy mapping and covariance analysis with cognitive performance measures. Results: Structural data indicated subtle changes in the corpus callosum and thalamic radiation in PD-N, whereas severe white matter impairment was observed in both PD-MCI and PD-D patients including anterior and inferior fronto-occipital, uncinate, insular cortices, superior longitudinal fasciculi, corona radiata, and the body of the corpus callosum. These regional alterations were demonstrated for PD-MCI and were more pronounced in PD-D. The pattern of involved regions was significantly correlated with the Consortium to Establish a Registry for Alzheimer’s Disease (CERAD) total score. Conclusions: The findings in PD-N suggest impaired cross-hemispherical white matter connectivity that can apparently be compensated for. More pronounced involvement of the corpus callosum as demonstrated for PD-MCI together with affection of fronto-parieto-temporal structural connectivity seems to lead to gradual disruption of cognition-related cortico-cortical networks and to be associated with the onset of overt cognitive deficits. The increase of regional white matter damage appears to be associated with the development of PD-associated dementia.

scholarly journals Anatomy and white matter connections of the orbitofrontal gyrus

2018 ◽  
Vol 128 (6) ◽  
pp. 1865-1872 ◽  
Author(s):  
Joshua D. Burks ◽  
Andrew K. Conner ◽  
Phillip A. Bonney ◽  
Chad A. Glenn ◽  
Cordell M. Baker ◽  
...  
Keyword(s):  
White Matter ◽  
Diffusion Tensor ◽  
Diffusion Imaging ◽  
Internal Capsule ◽  
Ground Truth ◽  
Outcome Evaluation ◽  
Anterior Cingulate ◽  
Anatomical Dissection ◽  
Visual Spatial ◽  
Human Connectome Project

OBJECTIVEThe orbitofrontal cortex (OFC) is understood to have a role in outcome evaluation and risk assessment and is commonly involved with infiltrative tumors. A detailed understanding of the exact location and nature of associated white matter tracts could significantly improve postoperative morbidity related to declining capacity. Through diffusion tensor imaging–based fiber tracking validated by gross anatomical dissection as ground truth, the authors have characterized these connections based on relationships to other well-known structures.METHODSDiffusion imaging from the Human Connectome Project for 10 healthy adult controls was used for tractography analysis. The OFC was evaluated as a whole based on connectivity with other regions. All OFC tracts were mapped in both hemispheres, and a lateralization index was calculated with resultant tract volumes. Ten postmortem dissections were then performed using a modified Klingler technique to demonstrate the location of major tracts.RESULTSThe authors identified 3 major connections of the OFC: a bundle to the thalamus and anterior cingulate gyrus, passing inferior to the caudate and medial to the vertical fibers of the thalamic projections; a bundle to the brainstem, traveling lateral to the caudate and medial to the internal capsule; and radiations to the parietal and occipital lobes traveling with the inferior fronto-occipital fasciculus.CONCLUSIONSThe OFC is an important center for processing visual, spatial, and emotional information. Subtle differences in executive functioning following surgery for frontal lobe tumors may be better understood in the context of the fiber-bundle anatomy highlighted by this study.

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