scholarly journals Relation Between Reading Performance and White-Matter Alteration and Reorganization in Neurosurgical Patients

2020 ◽  
Vol 11 ◽  
Author(s):  
Elisa Cargnelutti ◽  
Marta Maieron ◽  
Tamara Ius ◽  
Miran Skrap ◽  
Barbara Tomasino
Keyword(s):  
White Matter ◽  
Diffusion Tensor ◽  
Clinical Importance ◽  
Reading Performance ◽  
Low Grade ◽  
Reading Impairment ◽  
Reading Abilities ◽  
Neurosurgical Patients ◽  
The Right

Reading abilities and diffusion tensor imaging (DTI) parameters were retrospectively analyzed in a group of neurosurgical patients to investigate (Study 1) the role of white matter—in particular the arcuate fasciculus (AF)—in preserved vs. impaired reading; 4 months after surgery, we explored the plasticity processes (Study 2). Study 1 involved 40 patients with brain glioma (23 low-grade and 17 high-grade gliomas). We compared preoperative DTI parameters of language-related fascicles between patients who developed a reading impairment after surgery (n = 23) and patients with preserved reading (n = 17). Besides lower fractional anisotropy (FA), patients with impaired reading also displayed lower number and density of streamlines of a direct (i.e., directly connecting temporal and frontal lobes) AF segment. In Study 2, we longitudinally tested at follow-up-when reading performance had generally improved-13 patients diagnosed with low-grade glioma. The most relevant finding was a significant increase in length of streamlines of the direct AF segments in both hemispheres. From a neurosurgical perspective, our preliminary findings suggest the clinical importance of sparing direct AF segments for the involvement they showed in reading; however, the results also suggest the reorganization potential of these segments, possibly compensating of the right homologs as well.

scholarly journals A Preliminary Diffusion Tensor Imaging Study: Analysis of Whole Brain according to the Affected Side in Tinnitus

2017 ◽  
Vol 5 (1-2) ◽  
pp. 1-12
Author(s):  
L. Shrestha
Keyword(s):  
White Matter ◽  
Diffusion Tensor ◽  
Mean Diffusivity ◽  
Imaging Study ◽  
Healthy Controls ◽  
White Matter Changes ◽  
Whole Brain ◽  
Affected Side ◽  
The Right

Aim: To investigate the role of white matter integrity in the pathophysiology of tinnitus, and also to analyze the whole brain for white matter changes quantitatively by comparing tinnitus patients with healthy controls based on the affected side of the tinnitus using Tract Based Spatial Statistics (TBSS).Methods: Total of 41 right-handed tinnitus patients and 35 age-matched right-handed healthy controls were initially examined non-invasively in resting-state using the 3.0T MRI scanner. We obtained the estimated Fractional anisotropy (FA), mean diffusivity (MD), Axial Diffusivity (AD), Radial Diffusivity (RD), and Mode of Anisotropy (MO) data for each subject. TBSS was used to perform group statistical analysis of DTI data from each group.Results: Compared to controls in right-sided tinnitus patients, FA and MO were decreased, and MD was normal with decreased AD and increased RD. FA and AD showed similar decreased values (t>1.5, FWEcorrected P<0.05) in the right corticospinal tract, right superior longitudinal fasciculus, and right inferior fronto-occipital fasciculus. Compared to controls with left-sided tinnitus patients, FA and MO were decreased, and MD was also increased with decreased AD with increased RD in patients. MO showed significantly decreased values (t>1.5, FWEcorrected P<0.05) of MO in Forceps major, bilateral cingulum (especially the left), and bilateral anterior thalamic radiation. Bilaterally affected tinnitus patients showed no difference when compared to controls.Conclusion: After analyzing the whole brain for white matter changes quantitatively using TBSS, changes were observed in unilaterally affected tinnitus patients compared to controls. Our findings indicated cross-modal plasticity could have caused changes in somatosensory, audio-visual, limbic, and attention pathways.Nepal Journal of Radiology Vol.5(1-2) 2015: 1-12

White Matter Alteration Following SWAT Explosive Breaching Training and the Moderating Effect of a Neck Collar Device: A DTI and NODDI Study

2021 ◽  
Author(s):  
Weihong Yuan ◽  
Jonathan Dudley ◽  
Alexis B Slutsky-Ganesh ◽  
James Leach ◽  
Pete Scheifele ◽  
...  
Keyword(s):  
Diffusion Tensor Imaging ◽  
White Matter ◽  
Diffusion Tensor ◽  
Moderating Effect ◽  
Significant Group ◽  
Blast Exposure ◽  
Diffusion Weighted ◽  
Weighted Data ◽  
The Right ◽  
The Impact

ABSTRACT Introduction Special Weapons and Tactics (SWAT) personnel who practice breaching with blast exposure are at risk for blast-related head trauma. We aimed to investigate the impact of low-level blast exposure on underlying white matter (WM) microstructure based on diffusion tensor imaging (DTI) and neurite orientation and density imaging (NODDI) in SWAT personnel before and after breacher training. Diffusion tensor imaging is an advanced MRI technique sensitive to underlying WM alterations. NODDI is a novel MRI technique emerged recently that acquires diffusion weighted data from multiple shells modeling for different compartments in the microstructural environment in the brain. We also aimed to evaluate the effect of a jugular vein compression collar device in mitigating the alteration of the diffusion properties in the WM as well as its role as a moderator on the association between the diffusion property changes and the blast exposure. Materials and Methods Twenty-one SWAT personnel (10 non-collar and 11 collar) completed the breacher training and underwent MRI at both baseline and after blast exposure. Diffusion weighted data were acquired with two shells (b = 1,000, 2,000 s/mm2) on 3T Phillips scanners. Diffusion tensor imaging metrices, including fractional anisotropy, mean, axial, and radial diffusivity, and NODDI metrics, including neurite density index (NDI), isotropic volume fraction (fiso), and orientation dispersion index, were calculated. Tract-based spatial statistics was used in the voxel-wise statistical analysis. Post hoc analyses were performed for the quantification of the pre- to post-blast exposure diffusion percentage change in the WM regions with significant group difference and for the assessment of the interaction of the relationship between blast exposure and diffusion alteration. Results The non-collar group exhibited significant pre- to post-blast increase in NDI (corrected P &lt; .05) in the WM involving the right internal capsule, the right posterior corona radiation, the right posterior thalamic radiation, and the right sagittal stratum. A subset of these regions showed significantly greater alteration in NDI and fiso in the non-collar group when compared with those in the collar group (corrected P &lt; .05). In addition, collar wearing exhibited a significant moderating effect for the alteration of fiso for its association with average peak pulse pressure. Conclusions Our data provided initial evidence of the impact of blast exposure on WM diffusion alteration based on both DTI and NODDI. The mitigating effect of WM diffusivity changes and the moderating effect of collar wearing suggest that the device may serve as a promising solution to protect WM against blast exposure.

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.

Changes in mild cognitive impairment and its subtypes as seen on diffusion tensor imaging

2012 ◽  
Vol 24 (9) ◽  
pp. 1483-1493 ◽  
Author(s):  
Senthil Thillainadesan ◽  
Wei Wen ◽  
Lin Zhuang ◽  
John Crawford ◽  
Nicole Kochan ◽  
...  
Keyword(s):  
Cognitive Impairment ◽  
White Matter ◽  
Multiple Testing ◽  
Diffusion Tensor ◽  
Internal Capsule ◽  
Anterior Cingulate ◽  
Corona Radiata ◽  
Amnestic Mci ◽  
Subcortical Regions ◽  
The Right

ABSTRACTBackground: Previous studies using diffusion tensor imaging (DTI) have observed microstructural abnormalities in white matter regions in both Alzheimer's disease and mild cognitive impairment (MCI). The aim of this work was to examine the abnormalities in white matter and subcortical regions of MCI and its subtypes in a large, community-dwelling older aged cohortMethods: A community-based sample of 396 individuals without dementia underwent medical assessment, neuropsychiatric testing, and neuroimaging. Of these, 158 subjects were classified as MCI and 238 as cognitively normal (controls) based on international MCI consensus criteria. Regional fractional anisotropy (FA) and mean diffusivity (MD) measures were calculated from the DTI and compared between groups. The false discovery rate correction was applied for multiple testing.Results: Subjects with MCI did not have significant differences in FA compared with controls after correction for multiple testing, but had increased MD in the right putamen, right anterior limb of the internal capsule, genu and splenium of the corpus callosum, right posterior cingulate gyrus, left superior frontal gyrus, and right and left corona radiata. When compared with controls, changes in left anterior cingulate, left superior frontal gyrus, and right corona radiata were associated with amnestic MCI (aMCI), whereas changes in the right putamen, right anterior limb of the internal capsule, and the right corona radiata were associated with non-amnestic MCI (naMCI). On logistic regression, the FA values in the left superior gyrus and MD values in the anterior cingulate distinguished aMCI from naMCI.Conclusions: MCI is associated with changes in white matter and subcortical regions as seen on DTI. Changes in some anterior brain regions distinguish aMCI from naMCI.

scholarly journals The Surgical White Matter Chassis: A Practical 3-Dimensional Atlas for Planning Subcortical Surgical Trajectories

2017 ◽  
Vol 14 (5) ◽  
pp. 469-482 ◽  
Author(s):  
Jonathan E Jennings ◽  
Amin B Kassam ◽  
Melanie B Fukui ◽  
Alejandro Monroy-Sosa ◽  
Srikant Chakravarthi ◽  
...  
Keyword(s):  
White Matter ◽  
Surgical Planning ◽  
Diffusion Tensor ◽  
Magnetic Resonance Images ◽  
Practical Implementation ◽  
Fiber Types ◽  
3.0 Tesla ◽  
3 Dimensional ◽  
White Matter Anatomy

AbstractBACKGROUNDThe imperative role of white matter preservation in improving surgical functional outcomes is now recognized. Understanding the fundamental white matter framework is essential for translating the anatomic and functional literature into practical strategies for surgical planning and neuronavigation.OBJECTIVETo present a 3-dimensional (3-D) atlas of the structural and functional scaffolding of human white matter—ie, a “Surgical White Matter Chassis (SWMC)”—that can be used as an organizational tool in designing precise and individualized trajectory-based neurosurgical corridors.METHODSPreoperative diffusion tensor imaging magnetic resonance images were obtained prior to each of our last 100 awake subcortical resections, using a clinically available 3.0 Tesla system. Tractography was generated using a semiautomated deterministic global seeding algorithm. Tract data were conceptualized as a 3-D modular chassis based on the 3 major fiber types, organized along median and paramedian planes, with special attention to limbic and neocortical association tracts and their interconnections.RESULTSWe discuss practical implementation of the SWMC concept, and highlight its use in planning select illustrative cases. Emphasis has been given to developing practical understanding of the arcuate fasciculus, uncinate fasciculus, and vertical rami of the superior longitudinal fasciculus, which are often-neglected fibers in surgical planning.CONCLUSIONA working knowledge of white matter anatomy, as embodied in the SWMC, is of paramount importance to the planning of parafascicular surgical trajectories, and can serve as a basis for developing reliable safe corridors, or modules, toward the goal of “zero-footprint” transsulcal access to the subcortical space.

Disrupting the right pars opercularis with electrical stimulation frees the song: case report

2015 ◽  
Vol 123 (6) ◽  
pp. 1401-1404 ◽  
Author(s):  
Guillaume Herbet ◽  
Gilles Lafargue ◽  
Fabien Almairac ◽  
Sylvie Moritz-Gasser ◽  
François Bonnetblanc ◽  
...  
Keyword(s):  
Language Production ◽  
Inferior Frontal Gyrus ◽  
Awake Surgery ◽  
Low Grade ◽  
Speech Impairment ◽  
First Case ◽  
Pars Opercularis ◽  
The Right

The authors report the first case of a strikingly unusual speech impairment evoked by intraoperative electrostimulation in a 36-year-old right-handed patient, a well-trained singer, who underwent awake surgery for a right fronto-temporo-insular low-grade glioma. Functionally disrupting the pars opercularis of the right inferior frontal gyrus led the patient to automatically switch from a speaking to a singing mode of language production. Given the central role of the right pars opercularis in the inhibitory control network, the authors propose that this finding may be interpreted as possible evidence for a competitive and independent neurocognitive subnetwork devoted to the melodically intoned articulation of words (normal language-based vs singing-based) in subjects with high expertise. From a more clinical perspective, such data may have implications for awake neurosurgery, especially to preserve the quality of life for singers.

scholarly journals Changes in language white matter tract microarchitecture associated with cognitive deficits in patients with presumed low-grade glioma

2019 ◽  
Vol 130 (5) ◽  
pp. 1538-1546 ◽  
Author(s):  
Fatih Incekara ◽  
Djaina Satoer ◽  
Evy Visch-Brink ◽  
Arnaud Vincent ◽  
Marion Smits
Keyword(s):  
Executive Function ◽  
Diffusion Tensor Imaging ◽  
White Matter ◽  
Diffusion Tensor ◽  
Mean Diffusivity ◽  
Low Grade Glioma ◽  
Cognitive Domain ◽  
Awake Surgery ◽  
Low Grade ◽  
Linear Regression Models

OBJECTIVEThe authors conducted a study to determine whether cognitive functioning of patients with presumed low-grade glioma is associated with white matter (WM) tract changes.METHODSThe authors included 77 patients with presumed low-grade glioma who underwent awake surgery between 2005 and 2013. Diffusion tensor imaging with deterministic tractography was performed preoperatively to identify the arcuate, inferior frontooccipital, and uncinate fasciculi and to obtain the mean fractional anisotropy (FA) and mean diffusivity per tract. All patients were evaluated preoperatively using an extensive neuropsychological protocol that included assessments of the language, memory, and attention/executive function domains. Linear regression models were used to analyze each cognitive domain and each diffusion tensor imaging metric of the 3 WM tracts.RESULTSSignificant correlations (corrected for multiple testing) were found between FA of the arcuate fasciculus and results of the repetition test for the language domain (β = 0.59, p < 0.0001) and between FA of the inferior frontooccipital fasciculus and results of the imprinting test for the memory domain (β = −0.55, p = 0.002) and the attention test for the attention and executive function domain (β = −0.62, p = 0.006).CONCLUSIONSIn patients with glioma, language deficits in repetition of speech, imprinting, and attention deficits are associated with changes in the microarchitecture of the arcuate and inferior frontooccipital fasciculi.

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.

scholarly journals Thalamic and thalamic projection abnormalities on DTI and NODDI analysis following acute concussion

Neurology ◽  
2019 ◽  
Vol 93 (14 Supplement 1) ◽  
pp. S4.2-S5
Author(s):  
James Houston ◽  
Frank Skidmore ◽  
William Monroe ◽  
Jon Amburgy ◽  
Mitchell Self
Keyword(s):  
White Matter ◽  
Diffusion Tensor ◽  
Mean Diffusivity ◽  
Oculomotor System ◽  
White Matter Injury ◽  
Football Players ◽  
Cortical Regions ◽  
The Right ◽  
Collegiate Football ◽  
Concussive Injury

ObjectiveTo compare preseason and post-concussive MRI in a cohort of collegiate football players utilizing Diffusion Tensor Imaging (DTI) and Neurite Orientation Dispersion and Density Imaging (NODDI) post processing.BackgroundAcute post-concussive symptoms can vary in clinical characteristics and severity. However, vestibular and ocular dysfunction in particular, has been associated with poor clinical outcomes. The vestibular system comprises a complex network of projections from peripheral vestibular organs to thalamic relay systems and numerous cortical regions. The visual/oculomotor system is also complex, involving brainstem, subcortical-cortical and thalamo-cortical connections. Oculomotor deficits are thought to involve the midbrain and the visual and parietal association cortices, both of which have thalamic projections.Design/MethodsWe gathered pre-season MR diffusion weighted imaging on a cohort of 30 collegiate football players. We performed repeat imaging within 36 hours of any diagnosed concussion in the same subject cohort. DTI metrics: mean diffusivity (MD), axial diffusivity (AD), fractional anisotropy (FA), and radial diffusivity (RD) along with NODDI metric: orientation dispersion index (ODI), were analyzed for statistical comparisons between groups.Results4 subjects with pre-season MRI underwent repeat MRI within 36 hours of concussive injury. A paired t-test between these two groups using DTI and NODDI metrics showed significant (p < 0.05) decreases in: AD and MD in the left posterior thalamic radiations, FA in the column and body of the fornix, and MD in the right anterior corona radiata and superior fronto-occipital fasciculus, and a significant decrease in ODI in the anterior thalamus.ConclusionsDisruptions in the thalamus and its white matter projections may play a role in the vestibular/ocular dysfunction associated with acute concussive injury. While our numbers are small, the findings suggest that DTI and NODDI processing techniques have the capability to locate and measure grey and white matter injury patterns after concussive injury.

Sign in / Sign up

Export Citation Format

Share Document