scholarly journals The Distinct Disrupted Plasticity in Structural and Functional Network in Mild Stroke With Basal Ganglia Region Infarcts

2021 ◽  
Author(s):  
Hua Zhu ◽  
Lijun Zuo ◽  
Wanlin Zhu ◽  
Jing Jing ◽  
Zhe Zhang ◽  
...  
Keyword(s):  
Cognitive Impairment ◽  
Basal Ganglia ◽  
Functional Connectivity ◽  
Network Analysis ◽  
Structural Connectivity ◽  
Functional Network ◽  
Imaging Biomarkers ◽  
Functional Networks ◽  
Stroke Patients ◽  
Post Stroke

Abstract ObjectiveTo characterize brain structural and functional networks in post-stroke patients with or without cognitive impairment. MethodsGraph theory analysis was applied to diffusion-weighted imaging (DWI) data and resting-state functional MRI (fMRI) data from 23 post-stroke patients with cognitive impairment (PSCI), 17 post-stroke patients without cognitive impairment (NPSCI), and 29 healthy controls (HC). Structural and functional connectivity between 90 cortical and subcortical brain regions was estimated and thresholded to construct a set of undirected graphs. Network-based statistics (NBS) was used to characterize altered connectivity patterns among the three groups. ResultsCompared to HC, the PSCI group demonstrated substantial reductions in all three types of connections - rich club, feeder, and local - in structural and functional networks. Specifically, in structural network analysis, reduced connections were observed within basal ganglia and basal ganglia-frontal networks, whereas in the functional network analysis, reduced connections were observed in fronto-parietal network (FPN) and cingulo-opercular networks (CON). Meanwhile, compared to HC, the NPSCI group demonstrated reductions in both feeder and local connections only within occipital area and occipital-temporal structural networks. ConclusionsThe findings of reduced structural connectivity in regions stemming from a basal ganglia core and reduced functional connectivity in FPN and CON may indicate a bottom-up cognitive impairment induced by stroke. Graph analysis and connectomics may aid clinical diagnosis and serve as potential imaging biomarkers for post-stroke patients with cognitive impairment.

scholarly journals Alterations of Functional Connectivity in Stroke Patients With Basal Ganglia Damage and Cognitive Impairment

2020 ◽  
Vol 11 ◽  
Author(s):  
Guanqun Yao ◽  
Jing Li ◽  
Sha Liu ◽  
Jiaojian Wang ◽  
Xiaohua Cao ◽  
...  
Keyword(s):  
Cognitive Impairment ◽  
Basal Ganglia ◽  
Functional Connectivity ◽  
Stroke Patients

Brain parenchymal fraction and post-stroke cognitive impairment in chronic focal stroke patients

2017 ◽  
Vol 381 ◽  
pp. 197
Author(s):  
K. Honjo ◽  
D. Nyenhuis ◽  
F. Gao ◽  
C. Scott ◽  
A. Ganda ◽  
...  
Keyword(s):  
Cognitive Impairment ◽  
Stroke Patients ◽  
Post Stroke ◽  
Brain Parenchymal Fraction ◽  
Brain Parenchymal

scholarly journals COGNITIVE IMPAIRMENT, THEIR DYNAMICS AND STRUCTURE IN THE ACUTE AND RECOVERY PERIODS OF STROKE, DEPENDING ON ARTERIAL HYPERTENSION SEVERITY AND DURATION

2018 ◽  
Vol 13 (3-4) ◽  
pp. 22-27
Author(s):  
T.M. Cherenko ◽  
Yu.L. Heletyuk
Keyword(s):  
Blood Pressure ◽  
Cognitive Impairment ◽  
Arterial Hypertension ◽  
Blood Pressure Monitoring ◽  
Cognitive Status ◽  
Neurological Deficits ◽  
Stroke Patients ◽  
Mean Values ◽  
Post Stroke ◽  
The Mean

Relevance. Cognitive impairment is common in the post-stroke period. Different characteristics of arterial hypertension (AH), namely its severity, duration and variability of blood pressure, can affect the development of cognitive impairment in stroke patients. Objective: to investigate cognitive impairment, their dynamics and structure in acute and recovering stroke periods, depending on the arterial hypertension severity and duration. Materials and methods. 150 patients with a primary ischemic stroke and history of hypertension: 74 (49,3 %) women and 76 (50,7 %) men, the mean age (67,4±0,7) years have been examined. Neurological deficits was evaluated by the NIHSS scale. The cognitive status was evaluated by the MMSE scale at the end of an acute period of 21 days and 1 year. Diagnosis of hypertension was based on the clinical and instrumental examination results and medical documents. Daily blood pressure monitoring was using on admission and every 4 hours during 6 days of acute stroke stage. Mean SBP, mean DBP, maximum SBP and DBP, standard deviation (SD) of SBP and DBP were studied. Results. By the mean score on the MMSE scale, there are differences in patients during acute post-stroke period, depending on the severity of hypertension: 27,2±0,6 points in the case of hypertension stage 1, 24,3±0,6 in the case of hypertension stage 2 and 20,7±0,8 in case of AH stage 3, (p=0.001). By this indicator, patients with different AH duration were different: 26,4±0,9 points; 25,1±0,5 points; 20,5±0,7 points, respectively. The significance of these differences by the mean values of MMSE score was obtained in patients with a duration of AH less than 5 years and more than 10 years, as well as when comparing the group of "6-10 years" and "over 10 years" (p=0,001). Significant differences in the structure of cognitive deficits severity, depending on the hypertension stage and its duration, were observed only in patients with moderate and severe stroke (p=0,006). Cognitive deterioration a year after a stroke was observed in 40 (31,5 %) patients. They have significantly higher mean values SD 1-3, SD 1-6, SBP on the first day after a stroke, and duration of hypertension. Conclusions. The relationship between the degree of intellectual decline and the duration of hypertension (r=0,592, p=0,001), severity of hypertension (r=0,459, p=0,001) was found. The severity of the neurological deficiency affects the structure of cognitive impairment at discharge in patients with different severity and duration of hypertension, and higher mean values of the variability of blood pressure from 1 to 6 days, SBP on the first day after stroke and higher duration of hypertension in the history is associated with a negative dynamics of cognitive impairment in stroke patients in a year after stroke.

scholarly journals Association among depression, cognitive impairment and executive dysfunction after stroke

2012 ◽  
Vol 6 (3) ◽  
pp. 152-157 ◽  
Author(s):  
Luisa Terroni ◽  
Matildes F.M. Sobreiro ◽  
Adriana B. Conforto ◽  
Carla C. Adda ◽  
Valeri D. Guajardo ◽  
...  
Keyword(s):  
Cognitive Impairment ◽  
Neuropsychological Tests ◽  
Executive Dysfunction ◽  
Stroke Survivors ◽  
Stroke Patients ◽  
Adequate Treatment ◽  
Post Stroke ◽  
Quantitative Studies ◽  
Post Stroke Depression ◽  
The Relationship

ABSTRACT The relationship between depression and cognitive impairment, frequent after stroke, is complex and has not been sufficiently elucidated. Objective: To review the relationship between post-stroke depression and cognitive impairment. Methods: We performed a PubMed database search spanning the last ten years, using the terms post-stroke depression, cognitive dysfunction, cognitive impairment and neuropsychological tests. Our target studies were original quantitative studies that investigated the relationship between post-stroke depression (PSD) and cognitive impairment in stroke patients. Articles published in English, Spanish, Italian and Portuguese were considered. Selection criteria were the use of neuropsychological tests to assess cognitive function, and of either instruments to diagnose major depression, or scales to assess depressive symptoms, within the first three months after stroke. Results: Six original quantitative studies fulfilled the criteria. The prevalence of PSD within the first three months after stroke ranged from 22% to 31%. Incidence ranged from 25% to 27% and was evaluated in only two studies. PSD was associated with increased cognitive impairment. Cognitive impairment was reported in 35.2% to 87% of the patients. Post-stroke cognitive deficits were reported mostly in executive function, memory, language, and speed of processing. Conclusion: Executive dysfunction and depression occur in stroke survivors, are frequently coexistent, and also associated with worse stroke prognosis. Healthcare professionals need to address and provide adequate treatment for depression and executive dysfunctions in stroke patients early in the first three months after stroke. Future studies should evaluate the efficacy of programs evaluating the early detection and treatment of PSD and executive dysfunction in stroke survivors.

Abstract W P29: Tissue Plasminogen Activator Mediated Reperfusion, and Subsequent Improvement in Resting State Connectivity Correlates with Functional Outcome in Acute Ischemic Stroke Patients

Stroke ◽  
2015 ◽  
Vol 46 (suppl_1) ◽  
Author(s):  
Souvik Sen ◽  
Johann Fridriksson ◽  
Taylor Hanayik ◽  
Christopher Rorden ◽  
Isabel Hubbard ◽  
...  
Keyword(s):  
Ischemic Stroke ◽  
Functional Connectivity ◽  
Functional Outcome ◽  
Resting State ◽  
Network Connectivity ◽  
Stroke Patients ◽  
Post Stroke ◽  
Resting State Network ◽  
Tissue Plasminogen

Background: Intravenous Tissue Plasminogen Activator (TPA) is the only FDA approved medical therapy for acute ischemic stroke (AIS). Prior study suggests that early recanalization is associated with better stroke outcome. Our aim was to correlate task-negative and task-positive (TN/TP) resting state network activity with tissue perfusion and functional outcome, in stroke patients who received TPA. Method: AIS patients were consented and underwent NIH stroke scale (NIHSS) assessment and magnetic resonance imaging (MRI) scans during TPA infusion (baseline) and six hours post stroke. The MRI sequences include contrast-enhanced perfusion weighted image (PWI) and resting state Blood Oxygen Level-Dependent or BOLD (RSB) images acquired using a Siemens Treo 3T MRI scanner. Additionally, the RSB scan and the NIHSS were obtained at a 30-day follow up visit. Results: Fourteen patients (mean age ± SD=63 ±14, 50% male, 50% white, 43% black and 7% others) who qualified for TPA completed the study at baseline and 6 hours post stroke. Of these, 6 patients had valid follow up data at 30 days. Three patients without cerebral ischemia were excluded. A paired samples t-test comparing baseline and 6h post stroke showed a significantly improved TP network t(10)= -4.24 p< 0.05. The resting network connectivity improved from 6 hours post stroke to 30-days follow up, t(5)= -5.35 p< 0.01. Similarly, NIHSS, at 6h post stroke t(10)= 3.62 p< 0.01 and at 30-days follow up t(5)= -3.4 p< 0.01 were significantly better than the NIHSS at baseline. The 6-hours post-stroke perfusion correlated with the resting network connectivity in both the damaged (r=-0.56 p= 0.07) and intact hemispheres (r= -0.57 p= 0.06). Differences in functional connectivity and NIHSS scores from baseline to 6 h were positively correlated (r= 0.56 p=0.07). Conclusion: In this pilot study we found that TPA led to changes in MRI based resting state networks and associated functional outcome. Correlations were found between perfusion, functional connectivity and NIHSS. This suggests that the improvement of resting state network means improved efficiency of brain activity indicated by functional outcome and may be a potential predictive MRI biomarker for TPA response. A larger study is needed to verify this finding.

Identification of a specific functional network altered in poststroke cognitive impairment

Neurology ◽  
2018 ◽  
Vol 90 (21) ◽  
pp. e1879-e1888 ◽  
Author(s):  
Clément Bournonville ◽  
Hilde Hénon ◽  
Thibaut Dondaine ◽  
Christine Delmaire ◽  
Stephanie Bombois ◽  
...  
Keyword(s):  
Cognitive Impairment ◽  
Clustering Coefficient ◽  
Functional Network ◽  
Cognitive Domain ◽  
Cortical Atrophy ◽  
Node Degree ◽  
Resting State Functional Connectivity ◽  
Stroke Patients ◽  
Whole Brain ◽  
Cognitive Domains

ObjectiveTo study the association between poststroke cognitive impairment and defining a specific resting functional marker.MethodsThe resting-state functional connectivity 6 months after an ischemic stroke in 56 patients was investigated. Twenty-nine of the patients who had an impairment of one or several cognitive domains were compared to 27 without any cognitive deficit. We studied the whole-brain connectivity using 2 complementary approaches: graph theory to study the functional network organization and network-based statistics to explore connectivity between brain regions. We assessed the potential cortical atrophy using voxel-based morphometry analysis.ResultsThe overall topological organization of the functional network was not altered in cognitively impaired stroke patients, who had the same mean node degree, average clustering coefficient, and global efficiency as cognitively healthy stroke patients. Network-based statistics analysis showed that poststroke cognitive impairment was associated with dysfunction of a whole-brain network composed of 167 regions and 178 connections, and functional disconnections between superior, middle, and inferior frontal gyri and the superior and inferior temporal gyri. These regions had connections that were specifically and positively correlated with cognitive domain scores. No intergroup differences in overall gray matter thickness and ischemic infarct topography were observed. To assess the effect of prestroke white matter hyperintensities on connectivity, we included the initial Fazekas scale in the regression model for a second network-based analysis. The resulting network was associated with the same key alterations but had fewer connections.ConclusionsThe observed functional network alterations suggest that the appearance of a cognitive impairment following stroke may be associated with a particular functional alteration, shared specifically between cognitive domains.

scholarly journals Functional Segregation of Human Brain Networks Across the Lifespan: An Exploratory Analysis of Static and Dynamic Resting-State Functional Connectivity

2020 ◽  
Vol 14 ◽  
Author(s):  
Benjamin M. Rosenberg ◽  
Eva Mennigen ◽  
Martin M. Monti ◽  
Roselinde H. Kaiser
Keyword(s):  
Functional Connectivity ◽  
Resting State ◽  
Dwell Time ◽  
Brain Networks ◽  
Older Age ◽  
Functional Network ◽  
Functional Networks ◽  
Resting State Functional Connectivity ◽  
Network State ◽  
High Connectivity

Prior research has shown that during development, there is increased segregation between, and increased integration within, prototypical resting-state functional brain networks. Functional networks are typically defined by static functional connectivity over extended periods of rest. However, little is known about how time-varying properties of functional networks change with age. Likewise, a comparison of standard approaches to functional connectivity may provide a nuanced view of how network integration and segregation are reflected across the lifespan. Therefore, this exploratory study evaluated common approaches to static and dynamic functional network connectivity in a publicly available dataset of subjects ranging from 8 to 75 years of age. Analyses evaluated relationships between age and static resting-state functional connectivity, variability (standard deviation) of connectivity, and mean dwell time of functional network states defined by recurring patterns of whole-brain connectivity. Results showed that older age was associated with decreased static connectivity between nodes of different canonical networks, particularly between the visual system and nodes in other networks. Age was not significantly related to variability of connectivity. Mean dwell time of a network state reflecting high connectivity between visual regions decreased with age, but older age was also associated with increased mean dwell time of a network state reflecting high connectivity within and between canonical sensorimotor and visual networks. Results support a model of increased network segregation over the lifespan and also highlight potential pathways of top-down regulation among networks.

Changes in functional connectivity of motor zones in the course of treatment with a regent multimodal complex exoskeleton in neurorehabilitation of post-stroke patients

2016 ◽  
Vol 42 (1) ◽  
pp. 54-60
Author(s):  
I. V. Saenko ◽  
S. N. Morozova ◽  
E. A. Zmeykina ◽  
R. N. Konovalov ◽  
A. V. Chervyakov ◽  
...  
Keyword(s):  
Functional Connectivity ◽  
Stroke Patients ◽  
Post Stroke
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