Corpus Callosum Microstructural Alterations In Children With Memory Related Learning Disability: A Diffusion Tensor Imaging Study

QJM ◽  
2021 ◽  
Vol 114 (Supplement_1) ◽  
Author(s):  
Abeer Maghawry Abd elhameed ◽  
Shaimaa Abdelsattar Mohammad ◽  
Neveen Hassan Nashaat ◽  
Amgad Samy Abdel-Rahman ◽  
Ehab Ragaa Abdol Raouf
Keyword(s):  
Learning Disabilities ◽  
White Matter ◽  
Corpus Callosum ◽  
Learning Disability ◽  
Diffusion Tensor ◽  
Digit Span ◽  
Clinical Test ◽  
Control Subjects ◽  
Healthy Control ◽  
With Memory

Abstract Purpose The purpose of this study is to assess the corpus callosum microstructural changes in children with memory related learning disability. Methods DTI was performed in 20 patients with memory related learning disabilities (MRLD +) and 22 matched healthy control subjects (MRLD -) aged 7– 13 years. Fractional anisotropy (FA), axial diffusivity, radial diffusivity (RD) and trace were calculated for corpus callosum. Comparison between patients with memory related learning disabilities (MRLD +) and healthy control subjects (MRLD -) was performed. DTI metrics were correlated to clinical digit span backward scores in (MRLD +) group. A pvalue less than .05 was considered significant. Results The corpus callosum showed a highly significant higher FA and lower diffusivity indices in (MRLD +) group compared to the (MRLD -) group (p < 0.001). No significant correlation between the clinical test “digit span backward” scores and DTI metrics of the corpus callosum was found. Conclusion Changes in DTI metrics of corpus callosum in patients with memory related learning disabilities reflects white matter micro-structural changes. Higher FA values and lower diffusivity indices do not necessarily indicate healthier white matter but, can indicate pathology.

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 White matter abnormalities in the corpus callosum with cognitive impairment in Parkinson disease

Neurology ◽  
2018 ◽  
Vol 91 (24) ◽  
pp. e2244-e2255 ◽  
Author(s):  
Ian O. Bledsoe ◽  
Glenn T. Stebbins ◽  
Doug Merkitch ◽  
Jennifer G. Goldman
Keyword(s):  
Cognitive Impairment ◽  
White Matter ◽  
Corpus Callosum ◽  
Parkinson Disease ◽  
Information Transfer ◽  
Diffusion Tensor ◽  
Anterior Segment ◽  
Mean Diffusivity ◽  
Cognitive Domain ◽  
White Matter Abnormalities

ObjectiveTo evaluate microstructural characteristics of the corpus callosum using diffusion tensor imaging (DTI) and their relationships to cognitive impairment in Parkinson disease (PD).MethodsSeventy-five participants with PD and 24 healthy control (HC) participants underwent structural MRI brain scans including DTI sequences and clinical and neuropsychological evaluations. Using Movement Disorder Society criteria, PD participants were classified as having normal cognition (PD-NC, n = 23), mild cognitive impairment (PD-MCI, n = 35), or dementia (PDD, n = 17). Cognitive domain (attention/working memory, executive function, language, memory, visuospatial function) z scores were calculated. DTI scalar values, including fractional anisotropy (FA), mean diffusivity (MD), axial diffusivity (AD), and radial diffusivity (RD), were established for 5 callosal segments on a midsagittal plane, single slice using a topographically derived parcellation method. Scalar values were compared among participant groups. Regression analyses were performed on cognitive domain z scores and DTI metrics.ResultsParticipants with PD showed increased AD values in the anterior 3 callosal segments compared to healthy controls. Participants with PDD had significantly increased AD, MD, and RD in the anterior 2 segments compared to participants with PD-NC and most anterior segment compared to participants with PD-MCI. FA values did not differ significantly between participants with PD and participants with HC or among PD cognitive groups. The strongest associations for the DTI metrics and cognitive performance occurred in the most anterior and most posterior callosal segments, and also reflected fronto-striatal and posterior cortical type cognitive deficits, respectively.ConclusionsMicrostructural white matter abnormalities of the corpus callosum, as measured by DTI, may contribute to PD cognitive impairment by disrupting information transfer across interhemispheric and callosal–cortical projections.

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 In utero diffusion tensor imaging of the fetal brain: a reproducibility study

2017 ◽  
Author(s):  
András Jakab ◽  
Ruth O`Gorman Tuura ◽  
Christian Kellenberger ◽  
Ianina Scheer
Keyword(s):  
Diffusion Tensor Imaging ◽  
White Matter ◽  
Corpus Callosum ◽  
Coefficient Of Variation ◽  
Motion Correction ◽  
Diffusion Tensor ◽  
Structural Similarity ◽  
Image Correlation ◽  
Normal Brain ◽  
Slice Thickness

AbstractOur purpose was to evaluate the within-subject reproducibility of in utero diffusion tensor imaging (DTI) metrics and the visibility of major white matter structures.Images for 30 fetuses (20-33. postmenstrual weeks, normal neurodevelopment: 6 cases, cerebral pathology: 24 cases) were acquired on 1.5T or 3.0T MRI. DTI with 15 diffusion-weighting directions was repeated three times for each case, TR/TE: 2200/63 ms, voxel size: 1*1 mm, slice thickness: 3-5 mm, b-factor: 700 s/mm2. Reproducibility was evaluated from structure detectability, variability of DTI measures using the coefficient of variation (CV), image correlation and structural similarity across repeated scans for six selected structures. The effect of age, scanner type, presence of pathology was determined using Wilcoxon rank sum test.White matter structures were detectable in the following percentage of fetuses in at least two of the three repeated scans: corpus callosum genu 76%, splenium 64%, internal capsule, posterior limb 60%, brainstem fibers 40% and temporooccipital association pathways 60%. The mean CV of DTI metrics ranged between 3% and 14.6% and we measured higher reproducibility in fetuses with normal brain development. Head motion was negatively correlated with reproducibility, this effect was partially ameliorated by motion-correction algorithm using image registration. Structures on 3.0 T had higher variability both with- and without motion correction.Fetal DTI is reproducible for projection and commissural bundles during mid-gestation, however, in 16-30% of the cases, data were corrupted by artifacts, resulting in impaired detection of white matter structures. To achieve robust results for the quantitative analysis of diffusivity and anisotropy values, fetal-specific image processing is recommended and repeated DTI is needed to ensure the detectability of fiber pathways.AbbreviationsADaxial diffusivity;CCAcorpus callosum agenesis;CVcoefficient of variation,DTIdiffusion tensor imaging;FAfractional anisotropy;GWgestational week;MDmean diffusivity;RDradial diffusivity;ROIregion of interest;SSIMstructural similarity index

scholarly journals Characteristics of the corpus callosum in chronic schizophrenia treated with clozapine or risperidone and those never-treated

2021 ◽  
Vol 21 (1) ◽  
Author(s):  
Bo Tao ◽  
Yuan Xiao ◽  
Hengyi Cao ◽  
Wenjing Zhang ◽  
Chengmin Yang ◽  
...  
Keyword(s):  
White Matter ◽  
Corpus Callosum ◽  
Clinical Symptoms ◽  
Diffusion Tensor ◽  
Structural Characteristics ◽  
Chronic Schizophrenia ◽  
Cross Sectional Study ◽  
Antipsychotic Treatment ◽  
Cross Sectional

Abstract Background The corpus callosum (CC) deficits have been well documented in chronic schizophrenia. However, the long-term impacts of antipsychotic monotherapies on callosal anatomy remain unclear. This cross-sectional study sought to explore micro- and macro-structural characteristics of the CC in never-treated patients and those with long-term mono-antipsychotic treatment. Methods The study included 23 clozapine-treated schizophrenia patients (CT-SCZ), 19 risperidone-treated schizophrenia patients (RT-SCZ), 23 never-treated schizophrenia patients (NT-SCZ), and 35 healthy controls (HCs). High resolution structural images and diffusion tensor imaging (DTI) data for each participant were obtained via a 3.0 T MR scanner. FreeSurfer was used to examine the volumes and fractional anisotropy (FA) values of the CC for each participant. Results There were significant deficits in the total and sub-regional CC volume and white matter integrity in NT-SCZ in comparison with healthy subjects. Compared with NT-SCZ, both CT-SCZ and RT-SCZ showed significantly increased FA values in the anterior CC region, while only RT-SCZ showed significantly increased volume in the mid-anterior CC region. Moreover, the volume of the mid-anterior CC region was significantly smaller in CT-SCZ compared to HCs. No correlations of clinical symptoms with callosal metrics were observed in schizophrenia patients. Conclusions Our findings provide insight into micro- and macro-structural characteristics of the CC in chronic schizophrenia patients with or without antipsychotics. These results suggest that the pathology itself is responsible for cerebral abnormalities in schizophrenia and that chronic exposure to antipsychotics may have an impact on white matter structure of schizophrenia patients, especially in those with risperidone treatment.

Diffusion tensor imaging of cerebral white matter in patients with myotonic dystrophy

2005 ◽  
Vol 46 (1) ◽  
pp. 104-109 ◽  
Author(s):  
H. Fukuda ◽  
J. Horiguchi ◽  
C. Ono ◽  
T. Ohshita ◽  
J. Takaba ◽  
...  
Keyword(s):  
Diffusion Tensor Imaging ◽  
White Matter ◽  
Myotonic Dystrophy ◽  
Normal Control ◽  
Diffusion Tensor ◽  
Age At Onset ◽  
Mean Diffusivity ◽  
Magnetic Resonance Images ◽  
Microstructural Changes ◽  
Control Subjects

Purpose: To determine whether myotonic dystrophy (MyD) patients have diffusion tensor abnormalities suggestive of microstructural changes in normal‐appearing white matter (NAWM). Material and Methods: Conventional and diffusion tensor magnetic resonance images of the brain were obtained in 19 MyD patients and 19 age‐matched normal control subjects. Fractional anisotropy (FA) and mean diffusivity (MD) values were calculated in white matter lesions (WMLs) and NAWM in MyD patients and in the white matter of normal control subjects. Differences between WML and NAWM values and between MyD patient and control subject values were analyzed statistically. Results: Significantly lower FA and higher MD values were found in all regions of interest in the NAWM of MyD patients than in the white matter of control subjects ( P<0.01), as well as significantly lower FA and higher MD values in WMLs than in NAWM of MyD patients ( P<0.05). There was no significant correlation of mean FA or MD values in NAWM with patient age, age at onset, or duration of illness ( P>0.1). Conclusion: Diffusion tensor imaging analysis suggests the presence of diffuse microstructural changes in NAWM of MyD patients that may play an important role in the development of disability.

scholarly journals Novel strain analysis informs about injury susceptibility of the corpus callosum to repeated impacts

2019 ◽  
Vol 1 (1) ◽  
Author(s):  
Allen A Champagne ◽  
Emile Peponoulas ◽  
Itamar Terem ◽  
Andrew Ross ◽  
Maryam Tayebi ◽  
...  
Keyword(s):  
Magnetic Resonance Imaging ◽  
White Matter ◽  
Magnetic Resonance ◽  
Corpus Callosum ◽  
Diffusion Tensor ◽  
White Matter Integrity ◽  
White Matter Tract ◽  
Exposure Group ◽  
Resonance Imaging ◽  
High Exposure

Abstract Increasing evidence for the cumulative effects of head trauma on structural integrity of the brain has emphasized the need to understand the relationship between tissue mechanic properties and injury susceptibility. Here, diffusion tensor imaging, helmet accelerometers and amplified magnetic resonance imaging were combined to gather insight about the region-specific vulnerability of the corpus callosum to microstructural changes in white-matter integrity upon exposure to sub-concussive impacts. A total of 33 male Canadian football players (meanage = 20.3 ± 1.4 years) were assessed at three time points during a football season (baseline pre-season, mid-season and post-season). The athletes were split into a LOW (N = 16) and HIGH (N = 17) exposure group based on the frequency of sub-concussive impacts sustained on a per-session basis, measured using the helmet-mounted accelerometers. Longitudinal decreases in fractional anisotropy were observed in anterior and posterior regions of the corpus callosum (average cluster size = 40.0 ± 4.4 voxels; P &lt; 0.05, corrected) for athletes from the HIGH exposure group. These results suggest that the white-matter tract may be vulnerable to repetitive sub-concussive collisions sustained over the course of a football season. Using these findings as a basis for further investigation, a novel exploratory analysis of strain derived from sub-voxel motion of brain tissues in response to cardiac impulses was developed using amplified magnetic resonance imaging. This approach revealed specific differences in strain (and thus possibly stiffness) along the white-matter tract (P &lt; 0.0001) suggesting a possible signature relationship between changes in white-matter integrity and tissue mechanical properties. In light of these findings, additional information about the viscoelastic behaviour of white-matter tissues may be imperative in elucidating the mechanisms responsible for region-specific differences in injury susceptibility observed, for instance, through changes in microstructural integrity following exposure to sub-concussive head impacts.

scholarly journals White matter abnormalities of corpus callosum in patients with bipolar disorder and suicidal ideation

2019 ◽  
Vol 18 (1) ◽  
Author(s):  
Ran Zhang ◽  
Xiaowei Jiang ◽  
Miao Chang ◽  
Shengnan Wei ◽  
Yanqing Tang ◽  
...  
Keyword(s):  
Bipolar Disorder ◽  
White Matter ◽  
Suicidal Ideation ◽  
Corpus Callosum ◽  
Diffusion Tensor ◽  
The Body ◽  
Pathophysiological Mechanism ◽  
The Relationship ◽  
Diffusion Tensor Imaging Dti

Abstract Objective Although many studies have shown that the corpus callosum (CC) may play an important role in bipolar disorder (BD) and suicide, the pathophysiological mechanism of BD underlying suicidal behavior is still unclear. This study aimed to explore the relationship between the CC, and BD and suicidal ideation using diffusion tensor imaging (DTI). Method A total of 203 participants (47 BD patients with suicidal ideation, 59 with BD without suicidal ideation, and 97 healthy controls [HC]) underwent DTI scanning at a single site. We examined the white matter integrity of the CC in the three groups. Results A comparison among groups showed that BD patients with suicidal ideation had significant lower fractional anisotropy (FA) values than those of BD without suicidal ideation and HCs in the body and genu of the CC, and FA values of BD without suicidal ideation were significantly lower than those of HCs. However, in the splenium of corpus callosum, no difference was found between BD without suicidal ideation and HCs. Conclusions Our findings add to the evidence suggesting that the CC plays a key role in BD with suicidal ideation, especially with respect to the role of the genu and body of the CC subserving emotion regulation.

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