scholarly journals Positive relation between arcuate fasciculus white matter fiber structure and severity of auditory hallucinations: A DTI tractography study

2019 ◽  
Author(s):  
Liv E. Falkenberg ◽  
René Westerhausen ◽  
Erik Johnsen ◽  
Rune Kroken ◽  
Else-Marie Løberg ◽  
...  
Keyword(s):  
White Matter ◽  
Diffusion Tensor ◽  
Control Group ◽  
Arcuate Fasciculus ◽  
Auditory Verbal Hallucinations ◽  
Syndrome Scale ◽  
Healthy Control ◽  
Dti Tractography ◽  
Positive Correlations ◽  
Language Areas

AbstractThe arcuate fasciculus (AF) has been implicated in the pathology behind schizophrenia and auditory verbal hallucinations (AVHs). White matter tracts forming the arcuate fasciculus can be quantified and visualized using diffusion tensor imaging (DTI) tractography. Although there have been a number of studies on this topic, the results have been conflicting. Studying the underlying white matter structure of the AF could shed light on functional connectivity between temporal and frontal language areas in AVHs. The participants were 66 patients with a schizophrenia diagnosis, where AVHs were defined from the Positive and Negative Syndrome Scale (PANSS), and compared with a healthy control group. DTI was performed on a 3T MR scanner, and tensor estimation was done using deterministic streamline tractography. Statistical analysis of the data showed significantly longer tracts along the AF in patients with severe and frequent AVHs, as well as an overall significant asymmetry with longer fibers on the left side. In addition, there were significant positive correlations between PANSS scores and tract length, tract volume, and number of streamlines for the posterior AF segment on the left side. It is concluded that the present structural results complement previous functional findings of fronto-temporal connectivity in AVH patients.

Impairment and Plasticity of Language-Related White Matter in Patients With Brain Arteriovenous Malformations

Stroke ◽  
2021 ◽  
Author(s):  
Xiaofeng Deng ◽  
Hu Yin ◽  
Yan Zhang ◽  
Dong Zhang ◽  
Shuo Wang ◽  
...  
Keyword(s):  
White Matter ◽  
Diffusion Tensor ◽  
Disease Model ◽  
Control Group ◽  
Language Functions ◽  
Traditional Language ◽  
The Difference ◽  
Uncinate Fascicle ◽  
Myelin Deficits ◽  
Language Areas

Background and Purpose: Language dysfunction is rarely seen in patients with unruptured brain arteriovenous malformation (AVM) albeit the AVM nidus involving language areas, which provides a unique disease model to study language reorganization. The objective of this study was to investigate the impairment and reorganization patterns and characteristics of language-related white matter in AVMs located at different brain areas. Methods: Thirty-three patients with AVMs involving language areas were prospectively enrolled. Patients were categorized into 3 groups according to the lesion locations: the frontal (14 patients), temporal (15 patients), and parietal groups (4 patients). Thirty age- and sex-matched healthy controls were enrolled as comparison. All participants underwent diffusion tensor imaging scans, and automated fiber quantification method was applied to quantitatively study the difference of segmented language-related white matter connectivity between 3 AVM groups and control group. Results: Language functions were normal in all subjects according to Western Aphasia Battery test. In the frontal group, fractional anisotropy (FA) value decreased in the left arcuate fascicle and increased in left superior longitudinal fasciculus and uncinate fascicle; in the temporal group, FA values decreased in left inferior fronto-occipital fascicle and inferior longitudinal fascicle and increased in right anterior thalamic radiation and uncinate fascicle; in the parietal group, FA values decreased in left arcuate fascicle and inferior longitudinal fascicle and increased in bilateral anterior thalamic radiations and uncinate fascicles and right inferior fronto-occipital fascicle. In fascicles with decreased FA values, the increase of radial diffusivity was common, and fascicles with increased FA values usually presented along with increased axial diffusivity values. Conclusions: Remodeling of language-related white matter occurs when traditional language areas are involved by AVM nidus, and its reorganization patterns vary with locations of AVM nidus. Fascicle impairment is mainly caused by the myelin deficits, and its plasticity may be dominated by the axon remodeling procedure.

scholarly journals Cognitive deficits and white matter abnormalities in never-treated first-episode schizophrenia

2020 ◽  
Vol 10 (1) ◽  
Author(s):  
Mi Yang ◽  
Shan Gao ◽  
Xiangyang Zhang
Keyword(s):  
Cognitive Impairment ◽  
White Matter ◽  
Diffusion Tensor ◽  
Internal Capsule ◽  
First Episode ◽  
Control Group ◽  
Pathophysiological Mechanism ◽  
Healthy Controls ◽  
Healthy Control ◽  
First Episode Schizophrenia

Abstract Cognitive impairment is viewed as a core symptom of schizophrenia (SCZ), but its pathophysiological mechanism remains unclear. White matter (WM) disruption is considered to be a central abnormality that may contribute to cognitive impairment in SCZ patients. However, few studies have addressed the association between cognition and WM integrity in never-treated first-episode (NTFE) patients with SCZ. In this study, we used the MATRICS Consensus Cognitive Battery (MCCB) to evaluate cognitive function in NTFE patients (n = 39) and healthy controls (n = 30), and associated it with whole-brain fractional anisotropy (FA) values obtained via voxel-based diffusion tensor imaging. We found that FA was lower in five brain areas of SCZ patients, including the cingulate gyrus, internal capsule, corpus callosum, cerebellum, and brainstem. Compared with the healthy control group, the MCCB’s total score and 8 out of 10 subscores were significantly lower in NTFE patients (all p < 0.001). Moreover, in patients but not healthy controls, the performance in the Trail Making Test was negatively correlated with the FA value in the left cingulate. Our findings provide evidence that WM disconnection is involved in some cognitive impairment in the early course of SCZ.

scholarly journals Perspectives on (A)symmetry of Arcuate Fasciculus. A Short Review About Anatomy, Tractography and TMS for Arcuate Fasciculus Reconstruction in Planning Surgery for Gliomas in Language Areas

2021 ◽  
Vol 12 ◽  
Author(s):  
Andrea Di Cristofori ◽  
Gianpaolo Basso ◽  
Camilla de Laurentis ◽  
Ilaria Mauri ◽  
Martina Andrea Sirtori ◽  
...  
Keyword(s):  
Diffusion Tensor ◽  
Preoperative Evaluation ◽  
Brain Magnetic Resonance Imaging ◽  
Connectionist Model ◽  
Arcuate Fasciculus ◽  
Human Beings ◽  
Dominant Hemisphere ◽  
Language Functions ◽  
Dti Tractography ◽  
Language Areas

Gliomas are brain tumors that are treated with surgical resection. Prognosis is influenced by the extent of resection and postoperative neurological status. As consequence, given the extreme interindividual and interhemispheric variability of subcortical white matter (WM) surgical planning requires to be patient's tailored. According to the “connectionist model,” there is a huge variability among both cortical areas and subcortical WM in all human beings, and it is known that brain is able to reorganize itself and to adapt to WM lesions. Brain magnetic resonance imaging diffusion tensor imaging (DTI) tractography allows visualization of WM bundles. Nowadays DTI tractography is widely available in the clinical setting for presurgical planning. Arcuate fasciculus (AF) is a long WM bundle that connects the Broca's and Wernicke's regions with a complex anatomical architecture and important role in language functions. Thus, its preservation is important for the postoperative outcome, and DTI tractography is usually performed for planning surgery within the language-dominant hemisphere. High variability among individuals and an asymmetrical pattern has been reported for this WM bundle. However, the functional relevance of AF in the contralateral non-dominant hemisphere in case of tumoral or surgical lesion of the language-dominant AF is unclear. This review focuses on AF anatomy with special attention to its asymmetry in both normal and pathological conditions and how it may be explored with preoperative tools for planning surgery on gliomas in language areas. Based on the findings available in literature, we finally speculate about the potential role of preoperative evaluation of the WM contralateral to the surgical site.

scholarly journals White Matter Microstructural Differences between Hallucinating and Non-Hallucinating Schizophrenia Spectrum Patients

Diagnostics ◽  
2021 ◽  
Vol 11 (1) ◽  
pp. 139
Author(s):  
Justyna Beresniewicz ◽  
Alexander R. Craven ◽  
Kenneth Hugdahl ◽  
Else-Marie Løberg ◽  
Rune Andreas Kroken ◽  
...  
Keyword(s):  
White Matter ◽  
Negative Symptoms ◽  
Diffusion Tensor ◽  
Longitudinal Design ◽  
Qualitative Difference ◽  
Control Group ◽  
Auditory Verbal Hallucinations ◽  
Schizophrenia Spectrum ◽  
Significant Difference ◽  
Patient Groups

The relation between auditory verbal hallucinations (AVH) and white matter has been studied, but results are still inconsistent. This inconsistency may be related to having only a single time-point of AVH assessment in many studies, not capturing that AVH severity fluctuates over time. In the current study, AVH fluctuations were captured by utilizing a longitudinal design and using repeated (Positive and Negative Symptoms Scale) PANSS questionnaire interviews over a 12 month period. We used a Magnetic Resonance Diffusion Tensor Imaging (MR DTI) sequence and tract-based spatial statistics (TBSS) to explore white matter differences between two subtypes of schizophrenia patients; 44 hallucinating (AVH+) and 13 non-hallucinating (AVH-), compared to 13 AVH- matched controls and 44 AVH+ matched controls. Additionally, we tested for hemispheric fractional anisotropy (FA) asymmetry between the groups. Significant widespread FA-value reduction was found in the AVH+ group in comparison to the AVH- group. Although not significant, the extracted FA-values for the control group were in between the two patient groups, for all clusters. We also found a significant difference in FA-asymmetry between the AVH+ and AVH- groups in two clusters, with significantly higher leftward asymmetry in the AVH- group. The current findings suggest a possible qualitative difference in white matter integrity between AVH+ and AVH- patients. Strengths and limitations of the study are discussed.

scholarly journals Multiple sclerosis and depressive manifestations: can diffusion tensor MR imaging help in the detection of microstructural white matter changes?

2019 ◽  
Vol 50 (1) ◽  
Author(s):  
Talaat A. Hassan ◽  
Shaima Fattouh Elkholy ◽  
Bahaa Eldin Mahmoud ◽  
Mona ElSherbiny
Keyword(s):  
Multiple Sclerosis ◽  
Depressive Symptoms ◽  
White Matter ◽  
Limbic System ◽  
Diffusion Tensor ◽  
Control Group ◽  
Uncinate Fasciculus ◽  
White Matter Tracts ◽  
Significant Difference ◽  
The Right

Abstract Background Multiple sclerosis is one of the commonest causes of neurological disability in middle-aged and young adults. Depression in MS patients can compromise cognitive functions, lead to suicide attempts, impair relationships and reduce compliance with disease-modifying treatments. The aim of this study was to investigate and compare the microstructural changes in the white matter tracts of the limbic system in MS patients with and those without depressive manifestations using a diffusion tensor imaging (DTI) technique. Methods This study included 40 patients who were divided into three groups. Group 1 comprised of 20 patients with relapsing-remitting MS with depressive symptoms and group 2 comprised 10 MS patients without symptoms of depression. The third group is a control group that included 10 age-matched healthy individuals. All patients underwent conventional MRI examinations and DTI to compare the fractional anisotropy (FA) values in the white matter tracts of the limbic system. Results We compared the DTI findings in MS patients with and those without depressive symptoms. It was found that patients with depression and MS exhibited a significant reduction in the FA values of the cingulum (P < 0.0111 on the right and P < 0.0142 on the left), uncinate fasciculus (P < 0.0001 on the right and P < 0.0076 on the left) and the fornix (P < 0.0001 on both sides). No significant difference was found between the FA values of the anterior thalamic radiations in both groups. Conclusion Patients with depression and MS showed more pronounced microstructural damage in the major white matter connections of the limbic pathway, namely, the uncinate fasciculus, cingulum and fornix. These changes can be detected by DTI as decreased FA values in depressed MS patients compared to those in non-depressed patients.

scholarly journals A preliminary study of the clinical application of optic pathway diffusion tensor tractography in suprasellar tumor surgery: preoperative, intraoperative, and postoperative assessment

2016 ◽  
Vol 125 (3) ◽  
pp. 759-765 ◽  
Author(s):  
Mohamadreza Hajiabadi ◽  
Madjid Samii ◽  
Rudolf Fahlbusch
Keyword(s):  
Visual Acuity ◽  
Visual Field ◽  
Diffusion Tensor ◽  
Tumor Resection ◽  
Visual Pathway ◽  
Optic Chiasm ◽  
Control Group ◽  
Optic Pathway ◽  
Dti Tractography ◽  
Mass Lesions

OBJECT Visual impairments are the most common objective manifestations of suprasellar lesions. Diffusion tensor imaging (DTI) is a noninvasive MRI modality that depicts the subcortical white matter tracts in vivo. In this study the authors tested the value of visual pathway tractography in comparison with visual field and visual acuity analyses. METHODS This prospective study consisted of 25 patients with progressive visual impairment due to suprasellar mass lesions and 6 control patients with normal vision without such lesions. Visual acuity, visual field, and the optic fundus were examined preoperatively and repeated 1 week and 3 months after surgery. Visual pathway DTI tractography was performed preoperatively, intraoperatively immediately after tumor resection, and 1 week and 3 months after surgery. RESULTS In the control group, pre- and postoperative visual status were normal and visual pathway tractography revealed fibers crossing the optic chiasm without any alteration. In patients with suprasellar lesions, vision improved in 24 of 25. The mean distance between optic tracts in tractography decreased after tumor resection and detectable fibers crossing the optic chiasm increased from 12% preoperatively to 72% postoperatively 3 months after tumor resection, and undetectable fibers crossing the optic chiasm decreased from 88% preoperatively to 27% postoperatively 3 months after tumor resection. Visual improvement after tumor removal 1 week and 3 months after surgery was significantly correlated with the distance between optic tracts in intraoperative tractography (p < 0.01). CONCLUSIONS Visual pathway DTI tractography appears to be a promising adjunct to the standard clinical and paraclinical visual examinations in patients with suprasellar mass lesions. The intraoperative findings, in particular the distance between optic tract fibers, can predict visual outcome after tumor resection. Furthermore, postoperative application of this technique may be useful in following anterior optic pathway recovery.

scholarly journals Galectin-3 as a Novel Multifaceted and Not Only Cardiovascular Biomarker in Patients with Psoriasis with Regard to Systemic Treatment—Preliminary Data

Biology ◽  
2022 ◽  
Vol 11 (1) ◽  
pp. 88
Author(s):  
Anna Baran ◽  
Paulina Kiluk ◽  
Julia Nowowiejska ◽  
Tomasz W. Kaminski ◽  
Magdalena Maciaszek ◽  
...  
Keyword(s):  
Protective Role ◽  
Control Group ◽  
Plaque Type ◽  
Before And After ◽  
Diagnostic Role ◽  
Galectin 3 ◽  
Healthy Control ◽  
History Of ◽  
Cardiovascular Biomarker ◽  
Positive Correlations

Galectin-3 (gal-3) is a multifunctional regulator of various biological processes and diseases, which are common comorbidities in psoriasis. Data regarding potential diagnostic role of gal-3 in psoriasis are insufficient. Serum gal-3 levels were evaluated before and after twelve weeks of treatment with acitretin or methotrexate in 31 patients with plaque-type psoriasis and compared to 11 healthy control group. The mean serum galectin-3 level in patients with psoriasis was significantly higher compared to the control group (p < 0.01). In patients with obesity and long-lasting psoriasis (>20 years) positive relations of gal-3 and PASI were noted. In psoriatics with low gal-3 levels, positive correlations between the gal-3 and BMI, glucose level, and with the latter in short-lasting psoriasis (<20 years) were noted. In the long history of psoriasis, gal-3 was negatively correlated with lipids levels. The Gal-3 level might be a multifaceted modulator of the course of psoriasis and predictive factor of cardiometabolic comorbidities’ development, especially in patients with a long history of the disease or obesity. Patients with low serum gal-3 and short history of psoriasis are presumably at greater risk of diabetes. In patients with long-lasting psoriasis and concomitant obesity, gal-3 may exert a protective role against dyslipidemia or perhaps further CMD development.

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 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 Stereotactic diffusion tensor imaging tractography for Gamma Knife radiosurgery

2016 ◽  
Vol 125 (Supplement_1) ◽  
pp. 139-146 ◽  
Author(s):  
Cormac G. Gavin ◽  
H. Ian Sabin
Keyword(s):  
Diffusion Tensor Imaging ◽  
White Matter ◽  
Stereotactic Radiosurgery ◽  
Treatment Planning ◽  
Vestibular Schwannoma ◽  
Diffusion Tensor ◽  
Gamma Knife Radiosurgery ◽  
Optic Radiation ◽  
Arcuate Fasciculus ◽  
Stereotactic Frame

OBJECTIVEThe integration of modern neuroimaging into treatment planning has increased the therapeutic potential and safety of stereotactic radiosurgery. The authors report their method of integrating stereotactic diffusion tensor imaging (DTI) tractography into conventional treatment planning for Gamma Knife radiosurgery (GKRS). The aim of this study was to demonstrate the feasibility of this technique and to address some of the technical limitations of previously reported techniques.METHODSTwenty patients who underwent GKRS composed the study cohort. They consisted of 1 initial test case (a patient with a vestibular schwannoma), 5 patients with arteriovenous malformations, 9 patients with cerebral metastases, 1 patient with parasagittal meningioma, and 4 patients with vestibular schwannoma. DT images were obtained at the time of standard GKRS protocol MRI (T1 and T2 weighted) for treatment, with the patient's head secured by a Leksell stereotactic frame. All studies were performed using a 1.5-T magnet with a single-channel head coil. DTI was performed with diffusion gradients in 32 directions and coregistered with the volumetric T1-weighted study. DTI postprocessing by means of commercially available software allowed tensor computation and the creation of directionally encoded color–, apparent diffusion coefficient–, and fractional anisotropy–mapped sequences. In addition, the software allowed visualized critical tracts to be exported as a structural volume and integrated into GammaPlan as an “organ at risk” during shot planning. Combined images were transferred to GammaPlan and integrated into treatment planning.RESULTSStereotactic DT images were successfully acquired in all patients, with generation of correct directionally encoded color images. Tract generation with the software was straightforward and reproducible, particularly for axial tracts such as the optic radiation and the arcuate fasciculus. Corticospinal tract visualization was hampered by some artifacts from the base of the stereotactic frame, but this was overcome by a combination of frame/MRI volume adjustment and DTI seeding parameters. Coregistration of the DTI series with the T1-weighted treatment volume at the time of imaging was essential for the generation of correct tensor data. All patients with the exception of the vestibular schwannoma cases had treatment pathology in the vicinity of eloquent tracts and/or the cortex. No new neurological deficits due to radiation were recorded at the short-term follow-up.CONCLUSIONSRecent reports in the medical literature have suggested that white matter tracts (particularly the optic radiation and arcuate fasciculus) are more vulnerable to radiation during stereotactic radiosurgery than previously thought. Integration of stereotactic tractography into GKRS represents a promising tool for preventing GKRS complications by reduction in radiation doses to functional organs at risk, including critical cortical areas and subcortical white matter tracts.

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