scholarly journals Diffusion Tensor Tractography Characteristics of White Matter Tracts are Associated with Post-Stroke Depression

2021 ◽  
Vol Volume 17 ◽  
pp. 167-181
Author(s):  
Lijun Deng ◽  
Rubo Sui ◽  
Lei Zhang
Keyword(s):  
White Matter ◽  
Diffusion Tensor ◽  
Diffusion Tensor Tractography ◽  
White Matter Tracts ◽  
Post Stroke ◽  
Post Stroke Depression

Diffusion tensor tractography of the temporal stem on the inferior limiting sulcus

2008 ◽  
Vol 108 (4) ◽  
pp. 775-781 ◽  
Author(s):  
Feng Wang ◽  
Tao Sun ◽  
Xing-Gang Li ◽  
Na-Jia Liu
Keyword(s):  
White Matter ◽  
Diffusion Tensor ◽  
Anterior Commissure ◽  
Region Of Interest ◽  
Diffusion Tensor Tractography ◽  
Optic Radiation ◽  
Uncinate Fasciculus ◽  
White Matter Tracts ◽  
Temporal Horn ◽  
Temporal Stem

Object The aim of this study was to use diffusion tensor tractography (DTT) to define the 3D relationships of the uncinate fasciculus, anterior commissure, inferior occipitofrontal fasciculus, inferior thalamic peduncle, and optic radiation and to determine the positioning landmarks of these white matter tracts. Methods The anatomy was studied in 10 adult human brain specimens. Brain DTT was performed in 10 healthy volunteers. Diffusion tensor tractography images of the white matter tracts in the temporal stem were obtained using the simple single region of interest (ROI) and multi-ROIs based on the anatomical knowledge. Results The posteroinferior insular point is the anterior extremity of intersection of the Heschl gyrus and the inferior limiting sulcus. On the inferior limiting sulcus, this point is the posterior limit of the optic radiation, and the temporal stem begins at the limen insulae and ends at the posteroinferior insular point. The distance from the limen insulae to the tip of the temporal horn is just one third the length of the temporal stem. The uncinate fasciculus comprises the core of the anterior temporal stem, behind which the anterior commissure and the inferior thalamic peduncle are located, and they occupy the anterior third of the temporal stem. The inferior occipitofrontal fasciculus passes through the entire temporal stem. The most anterior extent of the Meyer loop is located between the anterior tip of the temporal horn and the limen insulae. Most of the optic radiation crosses the postmedian two thirds of the temporal stem. Conclusions On the inferior limiting sulcus, the posteroinferior insular point is a reliable landmark of the posterior limit of the optic radiations. The limen insulae, anterior tip of the temporal horn, and posteroinferior insular point may be used to localize the white matter fibers of the temporal stem in analyzing magnetic resonance imaging or during surgery.

scholarly journals The Role of the Right Hemisphere White Matter Tracts in Chronic Aphasic Patients After Damage of the Language Tracts in the Left Hemisphere

2021 ◽  
Vol 15 ◽  
Author(s):  
Evie Kourtidou ◽  
Dimitrios Kasselimis ◽  
Georgia Angelopoulou ◽  
Efstratios Karavasilis ◽  
Georgios Velonakis ◽  
...  
Keyword(s):  
White Matter ◽  
Left Hemisphere ◽  
Right Hemisphere ◽  
Diffusion Tensor ◽  
Inferior Frontal Gyrus ◽  
Language Performance ◽  
White Matter Tracts ◽  
Post Stroke ◽  
Language Functions ◽  
The Right

The involvement of the right hemisphere (RH) in language, and especially after aphasia resulting from left hemisphere (LH) lesions, has been recently highlighted. The present study investigates white matter structure in the right hemisphere of 25 chronic post-stroke aphasic patients after LH lesions in comparison with 24 healthy controls, focusing on the four cortico-cortical tracts that link posterior parietal and temporal language-related areas with Broca’s region in the inferior frontal gyrus of the LH: the Superior Longitudinal Fasciculi II and III (SLF II and SLF III), the Arcuate Fasciculus (AF), and the Temporo-Frontal extreme capsule Fasciculus (TFexcF). Additionally, the relationship of these RH white matter tracts to language performance was examined. The patients with post-stroke aphasia in the chronic phase and the healthy control participants underwent diffusion tensor imaging (DTI) examination. The aphasic patients were assessed with standard aphasia tests. The results demonstrated increased axial diffusivity in the RH tracts of the aphasic patients. Patients were then divided according to the extent of the left hemisphere white matter loss. Correlations of language performance with radial diffusivity (RD) in the right hemisphere homologs of the tracts examined were demonstrated for the TFexcF, SLF III, and AF in the subgroup with limited damage to the LH language networks and only with the TFexcF in the subgroup with extensive damage. The results argue in favor of compensatory roles of the right hemisphere tracts in language functions when the LH networks are disrupted.

Abstract 9: Diffusion Tensor Tractography Correlates of Post-Stroke Spasticity & Its Mitigation

Stroke ◽  
2017 ◽  
Vol 48 (suppl_1) ◽  
Author(s):  
Svetlana Pundik ◽  
Margaret Skelly ◽  
Jessica McCabe ◽  
Heba Akbari ◽  
Janis J Daly
Keyword(s):  
White Matter ◽  
Limbic System ◽  
Corticospinal Tract ◽  
Diffusion Tensor ◽  
Rank Test ◽  
White Matter Tracts ◽  
Post Stroke ◽  
Anatomical Localization ◽  
Sign Rank Test ◽  
The Relationship

Purpose: Anatomical localization of brain networks controlling post-stroke spasticity are not fully understood. The purpose of this study was to determine the relationship between the integrity of white matter tracts and severity of spasticity and how this relationship changes with mitigation of spasticity in response to motor learning therapy. Methods: Eleven stroke survivors (>6 months post-stroke) with arm sensorimotor deficits had 12-week (5 d/week, 5 hr/day) motor learning therapy. Outcome measures included modified Ashworth Scale (mAS), Fugl-Meyer Upper limb (FM) and Diffusion Tensor Imaging (DTI). mAS was scored for 9 arm muscles and summated. Using Freesurfer software, DTI was analyzed via longitudinal processing stream and white matter tracts were reconstructed according to a global probabilistic tractography algorithm. Fractional anisotropy (FA), axial diffusivity (AD), and radial diffusivity (RD) were averaged along the center of the 8 bilateral and 2 interhemispheric white matter tracts. We performed partial Spearman correlation (Bonferonni correction for multiple comparisons) to evaluate the relationship between mAS and DTI measures while controlling for change in Fugl-Meyer. Wilcoxon paired sign rank test was used to compare pre vs post rehab scores for mAS and FM. Results: Subjects were 59±8.3 years old, 46±30 months after stroke and 54% were female. mAS improved from 5.95±3 to 3.95±2.6 (p=0.002, paired sign rank test) and FM improved from 25.9±12.4 to 37.6±13.9 (p=0.00097). At baseline, lower spasticity correlated with higher AD in the ipsilesional cingulum angular bundle (rho=.86; p=0.0007). Greater improvement in spasticity correlated with lower AD in the contralesional uncinate fasciculus (rho=.79;p=0.004) at baseline. Both tracts are part of limbic system. Furthermore, lower spasticity at baseline correlated with lower FA in the contralesional corticospinal tract (rho=.81; p=0.004) at baseline. Conclusion: The results show the complex nature of anatomical localization for spasticity and its mitigation. Structural integrity of the contralesional corticospinal tract as well as bi-hemispheric limbic system tracts may be involved in post-stroke spasticity.

Atlas-based segmentation of white matter tracts of the human brain using diffusion tensor tractography and comparison with classical dissection

NeuroImage ◽  
2008 ◽  
Vol 39 (1) ◽  
pp. 62-79 ◽  
Author(s):  
I. Nigel C. Lawes ◽  
Thomas R. Barrick ◽  
Vengadasalam Murugam ◽  
Natalia Spierings ◽  
David R. Evans ◽  
...  
Keyword(s):  
White Matter ◽  
Human Brain ◽  
Diffusion Tensor ◽  
Diffusion Tensor Tractography ◽  
White Matter Tracts

scholarly journals Assessing the effects of age on long white matter tracts using diffusion tensor tractography

NeuroImage ◽  
2009 ◽  
Vol 46 (2) ◽  
pp. 530-541 ◽  
Author(s):  
Simon W. Davis ◽  
Nancy A. Dennis ◽  
Norbou G. Buchler ◽  
Leonard E. White ◽  
David J. Madden ◽  
...  
Keyword(s):  
White Matter ◽  
Diffusion Tensor ◽  
Diffusion Tensor Tractography ◽  
White Matter Tracts

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.

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