scholarly journals Mapping Remote Subcortical Ramifications of Injury after Ischemic Strokes

2014 ◽  
Vol 2014 ◽  
pp. 1-6 ◽  
Author(s):  
Leonardo Bonilha ◽  
Travis Nesland ◽  
Chris Rorden ◽  
Paul Fillmore ◽  
Ruwan P. Ratnayake ◽  
...  
Keyword(s):  
White Matter ◽  
Diffusion Mri ◽  
Chronic Stroke ◽  
Cortical Lesions ◽  
Tissue Necrosis ◽  
Stroke Patients ◽  
Fiber Density ◽  
Brain Connectome ◽  
Cortical Dysfunction ◽  
The Relationship

Background. The extent of brain damage in chronic stroke patients is traditionally defined as the necrotic tissue observed on magnetic resonance image (MRI). However, patients often exhibit symptoms suggesting that functional impairment may affect areas beyond the cortical necrotic lesion, for example, when cortical symptoms ensue after subcortical damage. This observation suggests that disconnection or diaschisis can lead to remote cortical dysfunction that can be functionally equivalent to direct cortical lesions.Objective. To directly measure subcortical disconnection after stroke.Methods. We describe a principled approach utilizing the whole brain connectome reconstructed from diffusion MRI to evaluate the reduction of apparent white matter fiber density in the hemisphere affected by the stroke compared with the spared hemisphere.Results. In eight chronic stroke patients, we observed subcortical disconnection extending beyond the location of tissue necrosis and affecting major white matter pathways underlying the necrotic area.Conclusions. We suggest that it is possible to detect and quantify previously unappreciated areas of subcortical and cortical disconnection. Specifically, this method can be used to evaluate the relationship between lesion location and symptoms, with emphasis on a connectivity-based approach.

Relationship Between Stroke’s Risk Factors with Daily Activities Using Modified Shah Barthel Index in Chronic Stroke Patient at RSCM

2018 ◽  
Vol 24 (8) ◽  
pp. 6225-6231
Author(s):  
S Rachmayanti ◽  
W Kusumaningsih
Keyword(s):  
Diabetes Mellitus ◽  
Risk Factors ◽  
Logistic Regression ◽  
Stroke Risk ◽  
Chronic Stroke ◽  
Medical Rehabilitation ◽  
Stroke Patients ◽  
Chi Square ◽  
Stroke Risk Factors ◽  
The Relationship

Hypertension and diabetes mellitus are the most common risk factors of stroke.The study aimed to determine the relationship between stroke risk factors, hypertension and diabetes mellitus, with dependency of chronic stroke patients in Department of Medical Rehabilitation RSCM. The study is conducted by using the analytical observational cross-sectional study. The samples used in this study were 44 respondents selected by quota sampling method. The relationship between variabels was analyzed by bivariate test Chi-Square and multivariate analysis: Logistic Regression. Based on Chi-Square test, relationship between MSBI scoring with hypertension and diabetes mellitus as stroke risk factors, sequentiallly p = 0,122 and p = 0,002. Furthermore, Logistic Regression test suggested that hypertension and diabetes mellitus as stroke risk factors related to MSBI scoring, respectively; hypertension p = 0,076 (OR 4,076; CI95 0,861–19,297) and diabetes mellitus p = 0,007 (OR 22,690; CI95 2,332–220,722). Discussion: Diabetes mellitus is the most prominent risk factor in severe dependecy of chronic stroke patients.

scholarly journals Visualizing orientation-specific relaxation-diffusion features mapped onto orientation distribution functions estimated via nonparametric Monte Carlo MRI signal inversion

2020 ◽  
Author(s):  
João P. de Almeida Martins ◽  
Chantal M. W. Tax ◽  
Alexis Reymbaut ◽  
Filip Szczepankiewicz ◽  
Derek K. Jones ◽  
...  
Keyword(s):  
Monte Carlo ◽  
White Matter ◽  
Diffusion Mri ◽  
Orientation Distribution ◽  
Distribution Functions ◽  
Volume Distribution ◽  
Relaxation Rates ◽  
Brain Connectome ◽  
And Diffusion ◽  
Signal Inversion

ABSTRACTDiffusion MRI techniques are widely used to study in vivo changes in the human brain connectome. However, to resolve and characterise white matter fibres in heterogeneous diffusion MRI voxels remains a challenging problem typically approached with signal models that rely on prior information and restrictive constraints. We have recently introduced a 5D relaxation-diffusion correlation framework wherein multidimensional diffusion encoding strategies are used to acquire data at multiple echo-times in order to increase the amount of information encoded into the signal and ease the constraints needed for signal inversion. Nonparametric Monte Carlo inversion of the resulting datasets yields 5D relaxation-diffusion distributions where contributions from different sub-voxel tissue environments are separated with minimal assumptions on their microscopic properties. Here, we build on the 5D correlation approach to derive fibre-specific metrics that can be mapped throughout the imaged brain volume. Distribution components ascribed to fibrous tissues are resolved, and subsequently mapped to a dense mesh of overlapping orientation bins in order to define a smooth orientation distribution function (ODF). Moreover, relaxation and diffusion measures are correlated to each independent ODF coordinate, thereby allowing the estimation of orientation-specific relaxation rates and diffusivities. The proposed method is tested on a healthy volunteer, where the estimated ODFs were observed to capture major WM tracts, resolve fibre crossings, and, more importantly, inform on the relaxation and diffusion features along distinct fibre bundles. If combined with fibre-tracking algorithms, the methodology presented in this work may be useful for investigating the microstructural properties along individual white matter pathways.

scholarly journals Modern Technology in Multi-Shell Diffusion MRI Reveals Diffuse White Matter Changes in Young Adults With Relapsing-Remitting Multiple Sclerosis

2021 ◽  
Vol 15 ◽  
Author(s):  
Ann-Marie Beaudoin ◽  
François Rheault ◽  
Guillaume Theaud ◽  
Frédéric Laberge ◽  
Kevin Whittingstall ◽  
...  
Keyword(s):  
Multiple Sclerosis ◽  
White Matter ◽  
Diffusion Mri ◽  
Free Water ◽  
Cerebral White Matter ◽  
Fiber Density ◽  
White Matter Changes ◽  
Relapsing Remitting ◽  
Remitting Multiple Sclerosis ◽  
Relapsing Remitting Multiple Sclerosis

ObjectiveTo characterize microstructural white matter changes related to relapsing-remitting multiple sclerosis using advanced diffusion MRI modeling and tractography. The association between imaging data and patient’s cognitive performance, fatigue severity and depressive symptoms is also explored.MethodsIn this cross-sectional study, 24 relapsing-remitting multiple sclerosis patients and 11 healthy controls were compared using high angular resolution diffusion imaging (HARDI). The imaging method includes a multi-shell scheme, free water correction to obtain tissue-specific measurements, probabilistic tracking algorithm robust to crossing fibers and white matter lesions, automatic streamlines and bundle dissection and tract-profiling with tractometry. The neuropsychological evaluation included the Symbol Digit Modalities Test, Paced Auditory Serial Addition Test, Modified Fatigue Impact Scale and Beck Depression Inventory-II.ResultsBundle-wise analysis by tractometry revealed a difference between patients and controls for 11 of the 14 preselected white matter bundles. In patients, free water corrected fractional anisotropy was significantly reduced while radial and mean diffusivities were increased, consistent with diffuse demyelination. The fornix and left inferior fronto-occipital fasciculus exhibited a higher free water fraction. Eight bundles showed an increase in total apparent fiber density and four bundles had a higher number of fiber orientations, suggesting axonal swelling and increased organization complexity, respectively. In the association study, depressive symptoms were associated with diffusion abnormalities in the right superior longitudinal fasciculus.ConclusionTissue-specific diffusion measures showed abnormalities along multiple cerebral white matter bundles in patients with relapsing-remitting multiple sclerosis. The proposed methodology combines free-water imaging, advanced bundle dissection and tractometry, which is a novel approach to investigate cerebral pathology in multiple sclerosis. It opens a new window of use for HARDI-derived measures and free water corrected diffusion measures. Advanced diffusion MRI provides a better insight into cerebral white matter changes in relapsing-remitting multiple sclerosis, namely diffuse demyelination, edema and increased fiber density and complexity.

scholarly journals Intensive therapy induces contralateral white matter changes in chronic stroke patients with Broca’s aphasia

2014 ◽  
Vol 136 ◽  
pp. 1-7 ◽  
Author(s):  
Catherine Y. Wan ◽  
Xin Zheng ◽  
Sarah Marchina ◽  
Andrea Norton ◽  
Gottfried Schlaug
Keyword(s):  
White Matter ◽  
Intensive Therapy ◽  
Chronic Stroke ◽  
Broca's Aphasia ◽  
Stroke Patients ◽  
White Matter Changes ◽  
Broca’S Aphasia

scholarly journals Left egocentric neglect in early subacute right-stroke patients is related to damage of the superior longitudinal fasciculus

2021 ◽  
Author(s):  
Barbara Spanò ◽  
Davide Nardo ◽  
Giovanni Giulietti ◽  
Alessandro Matano ◽  
Ilenia Salsano ◽  
...  
Keyword(s):  
White Matter ◽  
Right Hemisphere ◽  
Neural Substrates ◽  
Spatial Neglect ◽  
Stroke Patients ◽  
Superior Longitudinal Fasciculus ◽  
Unilateral Spatial Neglect ◽  
Object Based ◽  
The Right ◽  
The Relationship

AbstractA typical consequence of stroke in the right hemisphere is unilateral spatial neglect. Distinct forms of neglect have been described, such as space-based (egocentric) and object-based (allocentric) neglect. However, the relationship between these two forms of neglect is still far from being understood, as well as their neural substrates. Here, we further explore this issue by using voxel lesion symptoms mapping (VLSM) analyses on a large sample of early subacute right-stroke patients assessed with the Apples Cancellation Test. This is a sensitive test that simultaneously measures both egocentric and allocentric neglect. Behaviourally, we found no correlation between egocentric and allocentric performance, indicating independent mechanisms supporting the two forms of neglect. This was confirmed by the VLSM analysis that pointed out a link between a damage in the superior longitudinal fasciculus and left egocentric neglect. By contrast, no association was found between brain damage and left allocentric neglect. These results indicate a higher probability to observe egocentric neglect as a consequence of white matter damages in the superior longitudinal fasciculus, while allocentric neglect appears more “globally” related to the whole lesion map. Overall, these findings on early subacute right-stroke patients highlight the role played by white matter integrity in sustaining attention-related operations within an egocentric frame of reference.

scholarly journals The Effect of Psychological Factors on Cognitive Functions in Stroke Patients With Chronic Fatigue

2021 ◽  
Vol 15 (3) ◽  
pp. 185-192
Author(s):  
Lale Lajevardi ◽  
◽  
Ghorban Taghizade ◽  
Zahra Parnain ◽  
◽  
...  
Keyword(s):  
Cognitive Functions ◽  
Cognitive Assessment ◽  
Psychological Factors ◽  
Mini Mental State Examination ◽  
Chronic Fatigue ◽  
Chronic Stroke ◽  
Cognitive Factors ◽  
Stroke Patients ◽  
The Relationship ◽  
State Examination

Background and Objectives: Cognitive and psychological impairments are among the disabling consequences of chronic stroke. Despite the high prevalence of these impairments in patients with chronic stroke and the significant impact of psychological factors on cognitive factors in other neurological diseases, no study was found to investigate the relationship between psychological factors and cognitive factors in chronic stroke patients with chronic fatigue. Therefore, this study aimed to investigate the relationship between psychological factors and cognitive functions in chronic stroke patients with chronic fatigue Methods: A total of 85 chronic stroke patients with chronic fatigue visited the Rehabilitation Centers of Tehran, Iran, were selected through the simple non-probability sampling method and enrolled in this correlational study. The Fatigue Severity Scale, Beck Depression Inventory, and Beck Anxiety Inventory were used to measure the levels of the fatigue, depression, and anxiety of patients with strokes, respectively. Besides, the cognitive functions of the participants were assessed using the Mini-Mental State Examination, the Montreal Cognitive Assessment, and the Pain Visual Analog Scale. Results: Based on the regression models, the Mini-Mental State Examination and the Montreal Cognitive Assessment explained up to 24.2% and 39.6% of the variance of cognitive functions, respectively. In all step-by-step models, the variables of anxiety, education level, and depression were the strongest predictors of cognitive functions. Conclusion: According to the clinical findings, psychological impairments, such as anxiety can adversely affect cognitive factors in chronic stroke patients with chronic fatigue. Therefore, therapeutic interventions focused on psychological factors may considerably improve the cognitive skills of these patients.

The Use of Mesh Glove Neurostimulation for Motor Recovery in Chronic Stroke

2011 ◽  
pp. 307-311
Author(s):  
Katsuhiro Nishino ◽  
Suguru Yamaguchi ◽  
Kousuke Matsuzono ◽  
Hiroyuki Yamamoto
Keyword(s):  
Motor Control ◽  
Motor Cortex ◽  
Range Of Motion ◽  
Sensory Stimulation ◽  
Chronic Stroke ◽  
Motor Recovery ◽  
Neural Stimulation ◽  
Stroke Patients ◽  
Hand Control ◽  
The Relationship

The results showed that the range of motion (ROM) was improved in 6 out of 7 cases, while fine movement of the hand was also improved in 4 cases. These improvements were observed a few days after the initiation of whole-hand electrical neural stimulation. In one chronic stroke case, the treatment resulted in an almost full recovery of hand control during the first 30 minutes of sub-threshold sensory stimulation, including pinching and grasping. This dramatic recovery led the authors to hypothesize that the responder would show no lesioning of the motor cortex on CT or MRI images. While more cases are needed to test the limitations of this modality and to determine the relationship between the level of recovery and the topology of CNS lesioning, this work illustrates the utility of this approach for improving motor control of the hand in chronic stroke patients.

Sign in / Sign up

Export Citation Format

Share Document