White matter architecture of the language network

2014 ◽  
Vol 5 (4) ◽  
Author(s):  
Vanja Kljajevic
Keyword(s):  
White Matter ◽  
Diffusion Imaging ◽  
Awake Surgery ◽  
Neural Basis ◽  
Functional Interpretation ◽  
Inferior Longitudinal Fasciculus ◽  
The Subject ◽  
The 19Th Century ◽  
And Diffusion ◽  
Language Network

AbstractThe relevance of anatomical connectivity for understanding of the neural basis of language was recognized in the 19th century, and yet this topic has only recently become the subject of wider research interest. In this paper, I review recent findings on white matter tracts implicated in language: the arcuate fasciculus, superior longitudinal fasciculus, extreme capsule, uncinate fasciculus, middle longitudinal fasciculus, inferior longitudinal fasciculus, and inferior fronto-occipital fasciculus. The reviewed findings on these tracts were reported in studies that used a variety of methods, from post-mortem dissection and diffusion imaging to intraoperative electrostimulation with awake surgery patients. The emerging picture suggests that there is currently no consensus with regard to the exact number and identity of the tracts supporting language, their origins, trajectories, and terminations, as well as their functional interpretation.

scholarly journals Altered White Matter Organization in the TUBB3 E410K Syndrome

2018 ◽  
Vol 29 (8) ◽  
pp. 3561-3576 ◽  
Author(s):  
P Ellen Grant ◽  
Kiho Im ◽  
Banu Ahtam ◽  
Cynthia T Laurentys ◽  
Wai-Man Chan ◽  
...  
Keyword(s):  
White Matter ◽  
De Novo ◽  
Neuropsychological Testing ◽  
Network Efficiency ◽  
Age Related ◽  
Bilateral Absence ◽  
Cortical Parcellation ◽  
Social Disabilities ◽  
And Diffusion ◽  
Language Network

Abstract Seven unrelated individuals (four pediatric, three adults) with the TUBB3 E410K syndrome, harboring identical de novo heterozygous TUBB3 c.1228 G>A mutations, underwent neuropsychological testing and neuroimaging. Despite the absence of cortical malformations, they have intellectual and social disabilities. To search for potential etiologies for these deficits, we compared their brain's structural and white matter organization to 22 controls using structural and diffusion magnetic resonance imaging. Diffusion images were processed to calculate fractional anisotropy (FA) and perform tract reconstructions. Cortical parcellation-based network analysis and gyral topology-based FA analyses were performed. Major interhemispheric, projection and intrahemispheric tracts were manually segmented. Subjects had decreased corpus callosum volume and decreased network efficiency. While only pediatric subjects had diffuse decreases in FA predominantly affecting mid- and long-range tracts, only adult subjects had white matter volume loss associated with decreased cortical surface area. All subjects showed aberrant corticospinal tract trajectory and bilateral absence of the dorsal language network long segment. Furthermore, pediatric subjects had more tracts with decreased FA compared with controls than did adult subjects. These findings define a TUBB3 E410K neuroimaging endophenotype and lead to the hypothesis that the age-related changes are due to microscopic intrahemispheric misguided axons that are pruned during maturation.

scholarly journals Effects of tDCS on Language Recovery in Post-Stroke Aphasia: A Pilot Study Investigating Clinical Parameters and White Matter Change with Diffusion Imaging

2021 ◽  
Vol 11 (10) ◽  
pp. 1277
Author(s):  
Radwa K. Soliman ◽  
Chantal M. W. Tax ◽  
Noha Abo-Elfetoh ◽  
Ahmed A. Karim ◽  
Ayda Youssef ◽  
...  
Keyword(s):  
White Matter ◽  
Diffusion Imaging ◽  
Uncinate Fasciculus ◽  
Post Stroke ◽  
Clinical Recovery ◽  
Language Recovery ◽  
Before And After ◽  
Frontal Aslant Tract ◽  
The Right ◽  
And Diffusion

Objectives: In this pilot study we investigated the effects of transcranial direct current stimulation (tDCS) on language recovery in the subacute stage of post-stroke aphasia using clinical parameters and diffusion imaging with constrained spherical deconvolution-based tractography. Methods: The study included 21 patients with subacute post-stroke aphasia. Patients were randomly classified into two groups with a ratio of 2:1 to receive real tDCS or sham tDCS as placebo control. Patients received 10 sessions (5/week) bi-hemispheric tDCS treatments over the left affected Broca’s area (anodal electrode) and over the right unaffected Broca’s area (cathodal stimulation). Aphasia score was assessed clinically using the language section of the Hemispheric Stroke Scale (HSS) before and after treatment sessions. Diffusion imaging and tractography were performed for seven patients of the real group, both before and after the 10th session. Dissection of language-related white matter tracts was achieved, and diffusion measures were extracted. A paired Student’s t-test was used to compare the clinical recovery and diffusion measures of the dissected tracts both pre- and post- treatment. The partial correlation between changes in diffusion measures and the language improvements was calculated. Results: At baseline assessment, there were no significant differences between groups in demographic and clinical HSS language score. No significant clinical recovery in HSS was evident in the sham group. However, significant improvements in the different components of HSS were only observed in patients receiving real tDCS. Associated significant increase in the fractional anisotropy of the right uncinate fasciculus and a significant reduction in the mean diffusivity of the right frontal aslant tract were reported. A significant positive correlation was found between the changes in the right uncinate fasciculus and fluency improvement. Conclusions: Aphasia recovery after bi-hemispheric transcranial direct current stimulation was associated with contralesional right-sided white matter changes at the subacute stage. These changes probably reflect neuroplasticity that could contribute to the recovery. Both the right uncinate fasciculus and right frontal aslant tract seem to be involved in aphasia recovery.

scholarly journals Analyses of regional radiosensitivity of white matter structures along tract axes using novel white matter segmentation and diffusion imaging biomarkers

2018 ◽  
Vol 6 ◽  
pp. 39-46 ◽  
Author(s):  
Jordan Houri ◽  
Roshan Karunamuni ◽  
Michael Connor ◽  
Niclas Pettersson ◽  
Carrie McDonald ◽  
...  
Keyword(s):  
White Matter ◽  
Diffusion Imaging ◽  
Imaging Biomarkers ◽  
And Diffusion

Altered white matter integrity and development in children with autism: A combined voxel-based morphometry and diffusion imaging study

2011 ◽  
Vol 84 (2) ◽  
pp. 189-195 ◽  
Author(s):  
Paola Mengotti ◽  
Serena D’Agostini ◽  
Robert Terlevic ◽  
Cristina De Colle ◽  
Elsa Biasizzo ◽  
...  
Keyword(s):  
White Matter ◽  
Diffusion Imaging ◽  
Imaging Study ◽  
Children With Autism ◽  
White Matter Integrity ◽  
Voxel Based Morphometry ◽  
And Diffusion

scholarly journals A Quantitative Tractography Study into the Connectivity, Segmentation and Laterality of the Human Inferior Longitudinal Fasciculus

2018 ◽  
Author(s):  
Sandip S Panesar ◽  
Yeh Fang-Cheng ◽  
Timothée Jacquesson ◽  
William Hula ◽  
C Fernandez-Miranda Juan
Keyword(s):  
White Matter ◽  
Volume Diffusion ◽  
Cadaveric Specimen ◽  
Close Proximity ◽  
Inferior Longitudinal Fasciculus ◽  
Connectivity Patterns ◽  
Resolution Imaging ◽  
The Subject ◽  
Connectivity Strength

AbstractThe human inferior longitudinal fasciculus (ILF) is a ventral, temporo-occipital association tract. Though described in early neuroanatomical works, its existence was later questioned. Application of in vivo tractography to the neuroanatomical study of the ILF has generally confirmed its existence, however consensus is lacking regarding its subdivision, laterality and connectivity. Further, there is a paucity of detailed neuroanatomic data pertaining to the exact anatomy of the ILF. Generalized Q-Sampling imaging (GQI) is a non-tensor tractographic modality permitting high resolution imaging of white-matter structures. As it is a non-tensor modality, it permits visualization of crossing fibers and accurate delineation of close-proximity fiber-systems. We applied deterministic GQI tractography to data from 30 healthy subjects and a large-volume diffusion atlas, to delineate ILF anatomy. Post-mortem white matter dissection was also carried out in a cadaveric specimen for further validation. The ILF was found in all 60 hemispheres. At its occipital extremity, it demonstrated a trifurcated termination pattern which was used to separate the ILF into 3 distinct sub-fascicles: Dorsolateral, ventrolateral and ventromedial. These divisions were consistent across the subject set and within the atlas. We applied quantitative techniques to study connectivity strength of the ILF at its anterior and posterior extremities. Overall, the 3 sub-fascicles, and the whole ILF, demonstrated strong leftward-lateralized connectivity patterns. Leftward-lateralization was also found for ILF volumes across the subject set. Due to connective and volumetric leftward-dominance and ventral location, we postulate the ILFs role in the semantic system. Further, our results are in agreement with functional and lesion-based postulations pertaining to the ILFs role in facial recognition.

Segmentation of the inferior longitudinal fasciculus in the human brain: A white matter dissection and diffusion tensor tractography study

2017 ◽  
Vol 1675 ◽  
pp. 102-115 ◽  
Author(s):  
Francesco Latini ◽  
Johanna Mårtensson ◽  
Elna-Marie Larsson ◽  
Mats Fredrikson ◽  
Fredrik Åhs ◽  
...  
Keyword(s):  
White Matter ◽  
Human Brain ◽  
Diffusion Tensor ◽  
Diffusion Tensor Tractography ◽  
Inferior Longitudinal Fasciculus ◽  
And Diffusion

Diffusion Tensor MRI Methods: Historical Perspective and New Directions

CNS Spectrums ◽  
2002 ◽  
Vol 7 (7) ◽  
pp. 505-509 ◽  
Author(s):  
Timothy L. Davis ◽  
David S. Tuch
Keyword(s):  
Diffusion Tensor Imaging ◽  
Diffusion Tensor ◽  
Diffusion Imaging ◽  
Diffusion Tensor Mri ◽  
Basic Principles ◽  
New Directions ◽  
History Of ◽  
The 19Th Century ◽  
And Diffusion

ABSTRACTThis article will briefly review the history of diffusion physics and diffusion imaging beginning with Brown's initial observations of the diffusion phenomenon in the early part of the 19th century, through the development of diffusion-weighted imaging, and diffusion tensor imaging. The basic principles and limitations of diffusion tensor imaging are discussed. We conclude by reflecting on some of the open interpretative questions in diffusion imaging.

Immigrant Arab Women in Chile during the Renaissance (Nahda), 1910s-1920s

1970 ◽  
pp. 47-55
Author(s):  
Sarah Limorté
Keyword(s):  
20Th Century ◽  
19Th Century ◽  
Thematic Analysis ◽  
New World ◽  
Arab Women ◽  
Arab Woman ◽  
The Subject ◽  
The 19Th Century

Levantine immigration to Chile started during the last quarter of the 19th century. This immigration, almost exclusively male at the outset, changed at the beginning of the 20th century when women started following their fathers, brothers, and husbands to the New World. Defining the role and status of the Arab woman within her community in Chile has never before been tackled in a detailed study. This article attempts to broach the subject by looking at Arabic newspapers published in Chile between 1912 and the end of the 1920s. A thematic analysis of articles dealing with the question of women or written by women, appearing in publications such as Al-Murshid, Asch-Schabibat, Al-Watan, and Oriente, will be discussed.

Museum Preserves in the Sphere of “Cultural Tourism”: Through the Example of the Cultural Preserves of Tatarstan

2019 ◽  
Vol 9 (4) ◽  
pp. 193-198
Author(s):  
Lyudmila S. Timofeeva ◽  
Albina R. Akhmetova ◽  
Liliya R. Galimzyanova ◽  
Roman R. Nizaev ◽  
Svetlana E. Nikitina
Keyword(s):  
19Th Century ◽  
Art Museum ◽  
Medium Size ◽  
Business Elite ◽  
Wide Range ◽  
The Subject ◽  
Tourist Center ◽  
Regional Authorities ◽  
The 19Th Century ◽  
The City

Abstract The article studies the existence experience of historical cities as centers of tourism development as in the case of Elabuga. The city of Elabuga is among the historical cities of Russia. The major role in the development of the city as a tourist center is played by the Elabuga State Historical-Architectural and Art Museum-Reserve. The object of the research in the article is Elabuga as a medium-size historical city. The subject of the research is the activity of the museum-reserve which contributes to the preservation and development of the historical look of Elabuga and increases its attractiveness to tourists. The tourism attractiveness of Elabuga is obtained primarily through the presence of the perfectly preserved historical center of the city with the blocks of integral buildings of the 19th century. The Elabuga State Historical-Architectural and Art Museum-Reserve, which emerged in 1989, is currently an object of historical and cultural heritage of federal importance. Museum-reserves with their significant territories and rich historical, cultural and natural heritage have unique resources for the implementation of large partnership projects. Such projects are not only aimed at attracting a wide range of tourists, but also stimulate interest in the reserve from the business elite, municipal and regional authorities. The most famous example is the Spasskaya Fair which revived in 2008 in Elabuga. It was held in the city since the second half of the 19th century, and was widely known throughout Russia. The process of the revival and successful development of the fair can be viewed as the creation of a special tourist event contributing to the formation of new and currently important tourism products.

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