scholarly journals Regions of white matter abnormalities in the arcuate fasciculus in veterans with anger and aggression problems

2019 ◽  
Vol 225 (4) ◽  
pp. 1401-1411 ◽  
Author(s):  
Szabolcs David ◽  
Lieke Heesink ◽  
Elbert Geuze ◽  
Thomas Gladwin ◽  
Jack van Honk ◽  
...  
Keyword(s):  
White Matter ◽  
Diffusion Tensor ◽  
Military Veterans ◽  
Self Regulation ◽  
Brain Regions ◽  
Microstructural Properties ◽  
Uncinate Fasciculus ◽  
Arcuate Fasciculus ◽  
White Matter Connectivity ◽  
Diffusion Tensor Imaging Tractography

AbstractAggression after military deployment is a common occurrence in veterans. Neurobiological research has shown that aggression is associated with a dysfunction in a network connecting brain regions implicated in threat processing and emotion regulation. However, aggression may also be related to deficits in networks underlying communication and social cognition. The uncinate and arcuate fasciculi are integral to these networks, thus studying potential abnormalities in these white matter connections can further our understanding of anger and aggression problems in military veterans. Here, we use diffusion tensor imaging tractography to investigate white matter microstructural properties of the uncinate fasciculus and the arcuate fasciculus in veterans with and without anger and aggression problems. A control tract, the parahippocampal cingulum was also included in the analyses. More specifically, fractional anisotropy (FA) estimates are derived along the trajectory from all fiber pathways and compared between both groups. No between-group FA differences are observed for the uncinate fasciculus and the cingulum, however parts of the arcuate fasciculus show a significantly lower FA in the group of veterans with aggression and anger problems. Our data suggest that abnormalities in arcuate fasciculus white matter connectivity that are related to self-regulation may play an important role in the etiology of anger and aggression in military veterans.

scholarly journals Retrospective analysis of hemispheric structural network change as a function of location and size of glioma

2020 ◽  
Author(s):  
Shawn D’Souza ◽  
Lisa Hirt ◽  
David R Ormond ◽  
John A Thompson
Keyword(s):  
Diffusion Tensor Imaging ◽  
White Matter ◽  
Temporal Lobe ◽  
Diffusion Tensor ◽  
Brain Regions ◽  
Structural Network ◽  
Tumour Location ◽  
The Impact ◽  
Tractography Data ◽  
Diffusion Tensor Imaging Tractography

Abstract Gliomas are neoplasms that arise from glial cell origin and represent the largest fraction of primary malignant brain tumours (77%). These highly infiltrative malignant cell clusters modify brain structure and function through expansion, invasion and intratumoral modification. Depending on the growth rate of the tumour, location and degree of expansion, functional reorganization may not lead to overt changes in behaviour despite significant cerebral adaptation. Studies in simulated lesion models and in patients with stroke reveal both local and distal functional disturbances, using measures of anatomical brain networks. Investigations over the last two decades have sought to use diffusion tensor imaging tractography data in the context of intracranial tumours to improve surgical planning, intraoperative functional localization, and post-operative interpretation of functional change. In this study, we used diffusion tensor imaging tractography to assess the impact of tumour location on the white matter structural network. To better understand how various lobe localized gliomas impact the topology underlying efficiency of information transfer between brain regions, we identified the major alterations in brain network connectivity patterns between the ipsilesional versus contralesional hemispheres in patients with gliomas localized to the frontal, parietal or temporal lobe. Results were indicative of altered network efficiency and the role of specific brain regions unique to different lobe localized gliomas. This work draws attention to connections and brain regions which have shared structural susceptibility in frontal, parietal and temporal lobe glioma cases. This study also provides a preliminary anatomical basis for understanding which affected white matter pathways may contribute to preoperative patient symptomology.

scholarly journals Structural disconnectivity in schizophrenia: a diffusion tensor magnetic resonance imaging study

2003 ◽  
Vol 182 (5) ◽  
pp. 439-443 ◽  
Author(s):  
J. Burns ◽  
D. Job ◽  
M. E. Bastin ◽  
H. Whalley ◽  
T. Macgillivray ◽  
...  
Keyword(s):  
Magnetic Resonance Imaging ◽  
White Matter ◽  
Magnetic Resonance ◽  
Fractional Anisotropy ◽  
Structural Integrity ◽  
Diffusion Tensor ◽  
Uncinate Fasciculus ◽  
Arcuate Fasciculus ◽  
Resonance Imaging ◽  
White Matter Tracts

BackgroundThere is growing evidence that schizophrenia is a disorder of cortical connectivity Specifically, frontotemporal and frontoparietal connections are thought to be functionally impaired. Diffusion tensor magnetic resonance imaging (DT–MRI) is a technique that has the potential to demonstrate structural disconnectivity in schizophrenia.AimsTo investigate the structural integrity of frontotemporal and frontoparietal white matter tracts in schizophrenia.MethodThirty patients with DSM–IV schizophrenia and thirty matched control subjects underwent DT–MRI and structural MRI. Fractional anisotropy – an index of the integrity of white matter tracts – was determined in the uncinate fasciculus, the anterior cingulum and the arcuate fasciculus and analysed using voxel-based morphometry.ResultsThere was reduced fractional anisotropy in the left uncinate fasciculus and left arcuate fasciculus in patients with schizophrenia compared with controls.ConclusionsThe findings of reduced white matter tract integrity in the left uncinate fasciculus and left arcuate fasciculus suggest that there is frontotemporal and frontoparietal structural disconnectivity in schizophrenia.

scholarly journals Aberrant White Matter Networks Mediate Cognitive Impairment in Patients with Silent Lacunar Infarcts in Basal Ganglia Territory

2015 ◽  
Vol 35 (9) ◽  
pp. 1426-1434 ◽  
Author(s):  
Jinfu Tang ◽  
Suyu Zhong ◽  
Yaojing Chen ◽  
Kewei Chen ◽  
Junying Zhang ◽  
...  
Keyword(s):  
White Matter ◽  
Basal Ganglia ◽  
Cognitive Deficits ◽  
Large Scale ◽  
Diffusion Tensor ◽  
Brain Regions ◽  
Lacunar Infarcts ◽  
Healthy Elderly ◽  
Brain White Matter ◽  
Diffusion Tensor Imaging Tractography

Silent lacunar infarcts, which are present in over 20% of healthy elderly individuals, are associated with subtle deficits in cognitive functions. However, it remains largely unclear how these silent brain infarcts lead to cognitive deficits and even dementia. Here, we used diffusion tensor imaging tractography and graph theory to examine the topological organization of white matter networks in 27 patients with silent lacunar infarcts in the basal ganglia territory and 30 healthy controls. A whole-brain white matter network was constructed for each subject, where the graph nodes represented brain regions and the edges represented interregional white matter tracts. Compared with the controls, the patients exhibited a significant reduction in local efficiency and global efficiency. In addition, a total of eighteen brain regions showed significantly reduced nodal efficiency in patients. Intriguingly, nodal efficiency–behavior associations were significantly different between the two groups. The present findings provide new aspects into our understanding of silent infarcts that even small lesions in subcortical brain regions may affect large-scale cortical white matter network, as such may be the link between subcortical silent infarcts and the associated cognitive impairments. Our findings highlight the need for network-level neuroimaging assessment and more medical care for individuals with silent subcortical infarcts.

scholarly journals Cerebral White Matter Sex Dimorphism in Alcoholism: A Diffusion Tensor Imaging Study

2017 ◽  
Author(s):  
Kayle S. Sawyer ◽  
Nasim Maleki ◽  
George Papadimitriou ◽  
Nikos Makris ◽  
Marlene Oscar-Berman ◽  
...  
Keyword(s):  
Sex Differences ◽  
White Matter ◽  
Corpus Callosum ◽  
Diffusion Tensor ◽  
Imaging Study ◽  
Brain Regions ◽  
Cerebral White Matter ◽  
Excessive Alcohol Consumption ◽  
White Matter Microstructure ◽  
White Matter Connectivity

AbstractBackgroundExcessive alcohol consumption is associated with widespread brain damage, including abnormalities in frontal and limbic brain regions. In a prior study of neuronal circuitry connecting the frontal lobes and limbic system structures in abstinent alcoholic men, we demonstrated decreases in white matter fractional anisotropy (FA) on diffusion tensor magnetic resonance imaging (dMRI). In the present study, we examined sex differences in alcoholism-related abnormalities of white matter connectivity.MethodsdMRI scans were acquired from 49 abstinent alcoholic individuals (26 women) and 41 nonalcoholic controls (22 women). Tract-based spatial statistical tools were used to estimate regional FA of white matter tracts and to determine sex differences and their relation to measures of alcoholism history.ResultsSex-related differences in white matter connectivity were observed in association with alcoholism: Compared to nonalcoholic men, alcoholic men had diminished FA in portions of the corpus callosum, the superior longitudinal fasciculi II and III, and the arcuate fasciculus and extreme capsule. In contrast, alcoholic women had higher FA in these regions. Sex differences also were observed for correlations between corpus callosum FA and length of sobriety.ConclusionsSexual dimorphism in white matter microstructure in abstinent alcoholics may implicate underlying differences in the neurobehavioral liabilities for developing alcohol abuse disorders, or for sequelae following abuse.

Disrupted thalamo-orbitofrontal but not fronto-temporal white matter connectivity in people with schizotypal personality disorder

2016 ◽  
Vol 33 (S1) ◽  
pp. S103-S103
Author(s):  
T.Y. Lee ◽  
S.N. Kim ◽  
J.S. Kwon
Keyword(s):  
White Matter ◽  
Personality Disorder ◽  
Negative Symptoms ◽  
Diffusion Tensor ◽  
Brain Regions ◽  
Schizotypal Personality Disorder ◽  
Cross Sectional ◽  
Schizotypal Personality ◽  
Competing Interest ◽  
White Matter Connectivity

IntroductionDespite patients with schizophrenia showed the deficits in the fronto-temporal and thalamo-frontal connectivity, the white matter connectivity in patients with schizotypal personality disorder had not been systemically investigated.MethodsThis study involved 40 neuroleptic-naïve patients with schizotypal personality disorder (SPD), 60 patients with schizophrenia (SCZ), and 100 healthy controls (HC), and scanned on the 3T MRI scanner. Probablistic tractography was performed using the FATCAT software in AFNI. The target brain regions (bilateral lateral frontal, medial frontal, orbitofrontal, temporal and thalamus) were extracted from the automated segmentation and cortical parcellation. Cross-sectional comparisons in mean fractional anisotropy (FA) performed on the thalamo-lateral frontal, thalamo-medial frontal, thalamo-orbitofrontal, lateral frontal-temporal and orbitofrontal-temporal pathway. We also analyzed the relationship between the white matter pathway and the Positive and Negative Syndrome Scale and GAF.ResultsThe diffusion tensor imaging showed that SCZ and SPD had decreased FA in the left thalamo-orbitofrontal pathway. However, SPD showed no alteration in the fronto-temporal pathway, despite SCZ showed decreased FA in the left temporo-orbitofrontal pathway. In SCZ, there were significant correlations between FA value in the left temporo-orbitofrontal pathway and negative symptoms score in PANSS and GAF score. However, SPD showed the trend level relationship between the GAF score and FA value in the left temporo-orbitofrontal pathway.ConclusionThese results suggest that the deficits in thalamo-frontal connectivity may be a trait marker of schizophrenia spectrum disorder, and the deficits in fronto-temporal connectivity may play a key role towards the vulnerability of psychosis.Disclosure of interestThe authors have not supplied their declaration of competing interest.

Structural alterations in white-matter tracts connecting (para-)limbic and prefrontal brain regions in borderline personality disorder

2015 ◽  
Vol 45 (15) ◽  
pp. 3171-3180 ◽  
Author(s):  
A. Lischke ◽  
M. Domin ◽  
H. J. Freyberger ◽  
H. J. Grabe ◽  
R. Mentel ◽  
...  
Keyword(s):  
Borderline Personality Disorder ◽  
White Matter ◽  
Personality Disorder ◽  
Diffusion Tensor ◽  
Brain Regions ◽  
Borderline Personality ◽  
Anterior Cingulate ◽  
Uncinate Fasciculus ◽  
White Matter Tracts ◽  
Structural Alterations

BackgroundA dysfunctional network of prefrontal and (para-)limbic brain region has been suggested to underlie emotional dysregulation in borderline personality disorder (BPD). Abnormal activity in this network may be due to structural alterations in white-matter tracts connecting prefrontal and (para-)limbic brain regions. To test this hypothesis, we investigated the structural integrity of major white-matter tracts connecting these regions in BPD.MethodUsing diffusion tensor imaging, we investigated fractional anisotropy (FA), axonal anisotropy (AD) and radial diffusivity (RD) in the uncinate fasciculus, the major white-matter tract connecting (para-)limbic and prefrontal brain regions, in 26 healthy controls (HC) and 26 BPD participants. To clarify the specificity of possible white-matter alterations among HC and BPD participants, FA, AD and RD were also investigated in the cingulum.ResultsWe found distinct structural alterations in the uncinate fasciculus but not in the cingulum of BPD participants. Compared to HC participants, BPD participants showed lower FA and higher RD in the uncinate fasciculus. By contrast, AD did not differ in the uncinate fasciculus of HC and BPD participants.ConclusionsOur finding of abnormal FA and RD in the uncinate fasciculus indicates distinct white-matter alterations in BPD, presumably due to stress-induced myelin degeneration in the aftermath of stressful life events. Although these alterations may account for abnormal activity in brain regions implicated in emotion dysregulation, such as the amygdala, anterior cingulate cortex and prefrontal cortex, it remains to be determined whether these alterations are specific for BPD.

scholarly journals Shared white-matter dysconnectivity in schizophrenia and bipolar disorder with psychosis

2014 ◽  
Vol 45 (4) ◽  
pp. 759-770 ◽  
Author(s):  
J. Kumar ◽  
S. Iwabuchi ◽  
S. Oowise ◽  
V. Balain ◽  
L. Palaniyappan ◽  
...  
Keyword(s):  
Bipolar Disorder ◽  
White Matter ◽  
Psychotic Disorders ◽  
Diffusion Tensor ◽  
Stable State ◽  
Brain Regions ◽  
Clinical Spectrum ◽  
Stable Phase ◽  
Healthy Controls ◽  
White Matter Connectivity

BackgroundThere is an appreciable overlap in the clinical presentation, epidemiology and treatment response of the two major psychotic disorders – schizophrenia and bipolar disorder. Nevertheless, the shared neurobiological correlates of these two disorders are still elusive. Using diffusion tensor imaging (DTI), we sought to identify brain regions which share altered white-matter connectivity across a clinical spectrum of psychotic disorders.MethodA sample of 41 healthy controls, 62 patients in a clinically stable state of an established psychotic disorder (40 with schizophrenia, 22 with bipolar disorder) were studied using DTI. Tract-based spatial statistics (TBSS) was used in order to study group differences between patients with psychosis and healthy controls using fractional anisotropy (FA). Probabilistic tractography was used in order to visualize the clusters that showed significant differences between these two groups.ResultsThe TBSS analysis revealed five clusters (callosal, posterior thalamic/optic, paralimbic, fronto-occipital) with reduced FA in psychosis. This reduction in FA was associated with an increase in radial diffusivity and a decrease in mode of anisotropy. Factor analysis revealed a single white-matter integrity factor that predicted social and occupational functioning scores in patients irrespective of the diagnostic categorization.ConclusionsOur results show that a shared white-matter dysconnectivity links the two major psychotic disorders. These microstructural abnormalities predict functional outcome better than symptom-based diagnostic boundaries during a clinically stable phase of illness, highlighting the importance of seeking shared neurobiological factors that underlie the clinical spectrum of psychosis.

scholarly journals Tractography Alterations in the Arcuate and Uncinate Fasciculi in Post-Stroke Aphasia

2021 ◽  
Vol 11 (1) ◽  
pp. 53
Author(s):  
Sara Kierońska ◽  
Milena Świtońska ◽  
Grzegorz Meder ◽  
Magdalena Piotrowska ◽  
Paweł Sokal
Keyword(s):  
White Matter ◽  
Brain Connectivity ◽  
Three Dimensional ◽  
Cerebral White Matter ◽  
Neural Pathways ◽  
Uncinate Fasciculus ◽  
Arcuate Fasciculus ◽  
Fiber Tractography ◽  
Post Stroke

Fiber tractography based on diffuse tensor imaging (DTI) can reveal three-dimensional white matter connectivity of the human brain. Tractography is a non-invasive method of visualizing cerebral white matter structures in vivo, including neural pathways surrounding the ischemic area. DTI may be useful for elucidating alterations in brain connectivity resulting from neuroplasticity after stroke. We present a case of a male patient who developed significant mixed aphasia following ischemic stroke. The patient had been treated by mechanical thrombectomy followed by an early rehabilitation, in conjunction with transcranial direct current stimulation (tDCS). DTI was used to examine the arcuate fasciculus and uncinate fasciculus upon admission and again at three months post-stroke. Results showed an improvement in the patient’s symptoms of aphasia, which was associated with changes in the volume and numbers of tracts in the uncinate fasciculus and the arcuate fasciculus.

scholarly journals White matter network damage mediates association between cerebrovascular disease and cognition

2021 ◽  
pp. 0271678X2199098
Author(s):  
Saima Hilal ◽  
Siwei Liu ◽  
Tien Yin Wong ◽  
Henri Vrooman ◽  
Ching-Yu Cheng ◽  
...  
Keyword(s):  
White Matter ◽  
Cerebrovascular Disease ◽  
Verbal Memory ◽  
Visual Memory ◽  
Diffusion Tensor ◽  
Mean Diffusivity ◽  
Domain Specific ◽  
Epidemiology Of Dementia ◽  
Z Scores ◽  
White Matter Connectivity

To determine whether white matter network disruption mediates the association between MRI markers of cerebrovascular disease (CeVD) and cognitive impairment. Participants (n = 253, aged ≥60 years) from the Epidemiology of Dementia in Singapore study underwent neuropsychological assessments and MRI. CeVD markers were defined as lacunes, white matter hyperintensities (WMH), microbleeds, cortical microinfarcts, cortical infarcts and intracranial stenosis (ICS). White matter microstructure damage was measured as fractional anisotropy and mean diffusivity by tract based spatial statistics from diffusion tensor imaging. Cognitive function was summarized as domain-specific Z-scores. Lacunar counts, WMH volume and ICS were associated with worse performance in executive function, attention, language, verbal and visual memory. These three CeVD markers were also associated with white matter microstructural damage in the projection, commissural, association, and limbic fibers. Path analyses showed that lacunar counts, higher WMH volume and ICS were associated with executive and verbal memory impairment via white matter disruption in commissural fibers whereas impairment in the attention, visual memory and language were mediated through projection fibers. Our study shows that the abnormalities in white matter connectivity may underlie the relationship between CeVD and cognition. Further longitudinal studies are needed to understand the cause-effect relationship between CeVD, white matter damage and cognition.

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