Abstract P58: Motor Recovery After Chronic Stroke Correlates With Diffusion Tensor Measures of Ipsilesional Cerebral and Cerebellar White Matter Integrity

Stroke ◽  
2021 ◽  
Vol 52 (Suppl_1) ◽  
Author(s):  
Sarah N Chiang ◽  
Siddharth Rana ◽  
Joseph B Humphries ◽  
Eric C Leuthardt

Introduction: We aimed to determine whether white matter (WM) tract integrity improved after a brain-computer interface (BCI) rehabilitation program for chronic stroke patients with upper extremity weakness. Mean diffusivity (MD) was calculated from diffusion tensor imaging (DTI) and is an indication of the integrity of axons and myelination in WM. MD is a biomarker in subacute stroke for post-stroke motor deficits and recovery. Methods: DTI scans were performed with 9 chronic hemiplegic stroke patients within 2 weeks of initiation and completion of a 12-week BCI rehabilitation program. All patients were a minimum of 6 months post-stroke. MD was then calculated using DSI-Studio for WM tracts in each patient at both pre- and post-therapy time points. Motor function was evaluated at these time points using the upper extremity portion of the Fugl-Meyer Assessment (UEFM). Voxelwise statistical analysis comparing pre- and post-intervention MD values was carried out using tract-based spatial statistics (TBSS). Relationships between MD measures in regions of interest and changes in motor function were estimated with Spearman correlations. Results: Voxelwise analysis using TBSS showed no significant group-level change in MD of WM tracts throughout the brain after completing BCI rehabilitation. However, the change in MD in ipsilesional cerebral WM was positively correlated with UEFM change (Spearman’s rho = 0.75, p = 0.02) as was the pre-BCI MD in the ipsilesional cerebellar WM (rho = 0.78, p = 0.01). The correlations between contralesional MD measures and UEFM change were not statistically significant. Conclusion: Correlation between changes in mean diffusivity of ipsilesional cerebral white matter and motor improvement in chronic stroke supports the literature that recovery may be mediated by axonal remyelination and regeneration. Furthermore, we find that pre-therapy, ipsilesional cerebellar white matter MD correlates with motor recovery and as such may serve as a predictive measure of the effectiveness of BCI therapy for patients.

QJM ◽  
2021 ◽  
Vol 114 (Supplement_1) ◽  
Author(s):  
Dalia Maher Samy ◽  
Mohamed Mahmoud Mostafa ◽  
Eman Mahmoud ◽  
Ahmed Mohamed Hazzou ◽  
Mohamed Khaled Ahmed Elewa ◽  
...  

Abstract Background Ischemic cerebrovascular stroke is defined as an acute neurological dysfunction caused by focal cerebral infarction after decrease in the blood supply of the brain either by stenosis or occlusion leading to gross physical impairment or disability lasting more than 24 hours. Objective To assess correlation between site of infarction and upper extremity ( UE) function in chronic stroke patients. Methodology A cross sectional study with (30) Patients with chronic ischemic stroke ( >3 months) suffering from persistent UE motor function impairment, MRI brain done to assess the site of infarction. UE motor function assessment using the Fugl Meyer Assessment (FMA-UE) Scale. Results The current study found that no significant correlation between the site of infarction and UE motor function. Conclusion We concluded that the site of infarction not correlated with UE motor function in chronic stroke patients.


2018 ◽  
Vol 20 (1) ◽  
pp. 49-57 ◽  
Author(s):  
Yifei Zhu ◽  
Yana He ◽  
Karen M. von Deneen ◽  
Ming Zhang

Background/Study Concept: Acute lacunar stroke (Als) plays a role in death/disability worldwide. Aphasia refers to chronic difficulty with communication in >20% of patients post stroke. We describe pathophysiological features of white matter (WM) abnormalities and their relationship between WM changes and aphasia quotient (AQ) scores in Als.Methods: Diffusion tensor imaging data were acquired in 37 Als patients and 28 healthy controls. Tract-based spatial statistics (TBSS) and correlation analyses were used.Results: Consistent with the hypothesis, Als had decreased fractional anisotropy (FA) and increased mean diffusivity, axial diffusivity and radial diffusivity in the genu, body and splenium of the corpus callosum (CC), superior longitudinal fasciculus (SLF) and corona radiata in the bilateral hemisphere. Reduced FA of SLF was correlated with AQ scores in Als patients.Conclusion: It is hoped that TBSS could shed new insights into aphasia mechanisms in Als to help promote aging-related disease studies.


Healthcare ◽  
2021 ◽  
Vol 9 (5) ◽  
pp. 614
Author(s):  
Reem M. Alwhaibi ◽  
Noha F. Mahmoud ◽  
Hoda M. Zakaria ◽  
Walaa M. Ragab ◽  
Nisreen N. Al Awaji ◽  
...  

Inability to use the affected upper extremity (UE) in daily activities is a common complaint in stroke patients. The somatosensory system (central and peripheral) is essential for brain reorganization and plasticity. Neuromuscular electrical stimulation is considered an effective modality for improving UE function in stroke patients. The aim of the current study was to determine the therapeutic effects of transcutaneous electrical nerve stimulation (TENS) acupoints on cortical activity and the motor function of the affected UE in chronic stroke patients. Forty male and female patients diagnosed with stroke agreed to join the study. They were randomly assigned to group 1 (G1) and group 2 (G2). G1 received task-specific training (TST) and sham electrical stimulation while G2 received TST in addition to TENS acupoints. Session duration was 80 min. Both groups received 18 sessions for 6 successive weeks, 3 sessions per week. Evaluation was carried out before and after completion of the treatment program. Outcome measures used were the Fugl-Meyer Assessment of the upper extremity (FMA-UE) and the box and block test (BBT) as measures of the motor function of the affected UE. Brain activity of the motor area (C3) in the ipsilesional hemisphere was measured using a quantitative electroencephalogram (QEEG). The measured parameter was peak frequency. It was noted that the motor function of the affected UE improved significantly post-treatment in both groups, while no significant change was reported in the FMA-UE and BBT scores post-treatment in either G1 or G2. On the other hand, the activity of the motor area C3 improved significantly in G2 only, post-treatment, while G1 showed no significant improvement. There was also significant improvement in the activity of the motor area (C3) in G2 compared to G1 post-treatment. The results of the current study indicate that TST only or combined with TENS acupoints can be considered an effective method for improving motor function of the affected UE in chronic stroke patients, both being equally effective. However, TST combined with TENS acupoints proved better in improving brain plasticity in chronic stroke patients.


2021 ◽  
Vol 80 (2) ◽  
pp. 567-576
Author(s):  
Fei Han ◽  
Fei-Fei Zhai ◽  
Ming-Li Li ◽  
Li-Xin Zhou ◽  
Jun Ni ◽  
...  

Background: Mechanisms through which arterial stiffness impacts cognitive function are crucial for devising better strategies to prevent cognitive decline. Objective: To examine the associations of arterial stiffness with white matter integrity and cognition in community dwellings, and to investigate whether white matter injury was the intermediate of the associations between arterial stiffness and cognition. Methods: This study was a cross-sectional analysis on 952 subjects (aged 55.5±9.1 years) who underwent diffusion tensor imaging and measurement of brachial-ankle pulse wave velocity (baPWV). Both linear regression and tract-based spatial statistics were used to investigate the association between baPWV and white matter integrity. The association between baPWV and global cognitive function, measured as the mini-mental state examination (MMSE) was evaluated. Mediation analysis was performed to assess the influence of white matter integrity on the association of baPWV with MMSE. Results: Increased baPWV was significantly associated with lower mean global fractional anisotropy (β= –0.118, p < 0.001), higher mean diffusivity (β= 0.161, p < 0.001), axial diffusivity (β= 0.160, p < 0.001), and radial diffusivity (β= 0.147, p < 0.001) after adjustment of age, sex, and hypertension, which were measures having a direct effect on arterial stiffness and white matter integrity. After adjustment of age, sex, education, apolipoprotein E ɛ4, cardiovascular risk factors, and brain atrophy, we found an association of increased baPWV with worse performance on MMSE (β= –0.093, p = 0.011). White matter disruption partially mediated the effect of baPWV on MMSE. Conclusion: Arterial stiffness is associated with white matter disruption and cognitive decline. Reduced white matter integrity partially explained the effect of arterial stiffness on cognition.


2021 ◽  
pp. 0271678X2199098
Author(s):  
Saima Hilal ◽  
Siwei Liu ◽  
Tien Yin Wong ◽  
Henri Vrooman ◽  
Ching-Yu Cheng ◽  
...  

To determine whether white matter network disruption mediates the association between MRI markers of cerebrovascular disease (CeVD) and cognitive impairment. Participants (n = 253, aged ≥60 years) from the Epidemiology of Dementia in Singapore study underwent neuropsychological assessments and MRI. CeVD markers were defined as lacunes, white matter hyperintensities (WMH), microbleeds, cortical microinfarcts, cortical infarcts and intracranial stenosis (ICS). White matter microstructure damage was measured as fractional anisotropy and mean diffusivity by tract based spatial statistics from diffusion tensor imaging. Cognitive function was summarized as domain-specific Z-scores. Lacunar counts, WMH volume and ICS were associated with worse performance in executive function, attention, language, verbal and visual memory. These three CeVD markers were also associated with white matter microstructural damage in the projection, commissural, association, and limbic fibers. Path analyses showed that lacunar counts, higher WMH volume and ICS were associated with executive and verbal memory impairment via white matter disruption in commissural fibers whereas impairment in the attention, visual memory and language were mediated through projection fibers. Our study shows that the abnormalities in white matter connectivity may underlie the relationship between CeVD and cognition. Further longitudinal studies are needed to understand the cause-effect relationship between CeVD, white matter damage and cognition.


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