scholarly journals Effect of Integrated Cognitive Therapy on Hippocampal Functional Connectivity Patterns in Stroke Patients with Cognitive Dysfunction: A Resting-State fMRI Study

2014 ◽  
Vol 2014 ◽  
pp. 1-9 ◽  
Author(s):  
Shanli Yang ◽  
Cai Jiang ◽  
Haicheng Ye ◽  
Jing Tao ◽  
Jia Huang ◽  
...  
Keyword(s):  
Ischemic Stroke ◽  
Functional Connectivity ◽  
Cognitive Therapy ◽  
Resting State ◽  
Insular Cortex ◽  
Resting State Fmri ◽  
Compensatory Mechanism ◽  
Seed Region ◽  
Stroke Patients ◽  
Cognitive Improvement

Objective. This study aimed to identify abnormal hippocampal functional connectivity (FC) following ischemic stroke using resting-state fMRI. We also explored whether abnormal hippocampal FC could be modulated by integrated cognitive therapy and tested whether these alterations were associated with cognitive performance.Methods. 18 right-handed cognitively impaired ischemic stroke patients and 18 healty control (HC) subjects were included in this study. Stroke subjects were scanned at baseline and after integrated cognitive therapy, while HCs were only scanned at baseline, to identify regions that show significant correlations with the seed region. Behavioral and cognitive assessments were obtained before each scan.Results. During the resting state, we found abnormal hippocampal FC associated with temporal regions, insular cortex, cerebellum, and prefrontal cortex in stroke patients compared to HCs. After integrated cognitive therapy, however, the stroke group showed increased hippocampal FC mainly located in the prefrontal gyrus and the default mode network (DMN). Altered hippocampal FC was associated with cognitive improvement.Conclusion. Resting-state fMRI may provide novel insight into the study of functional networks in the brain after stroke. Furthermore, altered hippocampal FC may be a compensatory mechanism for cognitive recovery after ischemic stroke.

scholarly journals Altered hippocampal functional connectivity patterns in patients with cognitive impairments following ischaemic stroke: a resting-state fMRI study

2020 ◽  
Author(s):  
JeYoung Jung ◽  
Rosanna Laverick ◽  
Kurdow Nader ◽  
Martin Wilson ◽  
Dorothee P. Auer ◽  
...  
Keyword(s):  
Ischemic Stroke ◽  
Cognitive Impairment ◽  
Functional Connectivity ◽  
Resting State ◽  
Parietal Lobe ◽  
Memory Function ◽  
Resting State Fmri ◽  
Angular Gyrus ◽  
Seed Region ◽  
Hippocampal Subfields

AbstractBackgroundIschemic stroke with cognitive impairment is a considerable risk factor for developing dementia. Identifying imaging markers of cognitive impairment following ischemic stroke will help to develop prevention strategies against post-stroke dementia.MethodsHere, we investigated the hippocampal functional connectivity (FC) pattern following ischemic stroke, using resting-state fMRI (rs-fMRI). Thirty-three cognitively impaired patients after ischemic stroke and sixteen age-matched controls with no known history of neurological disorder, were recruited for the study. Importantly, no patient had a direct ischaemic insult to hippocampus on examination of brain imaging. Seven subfields of hippocampus were used as a seed region for FC analyses.ResultsAcross all hippocampal subfields, FC with the inferior parietal lobe in patients was reduced as compared with healthy controls. This decreased FC included both supramarginal gyrus and angular gyrus. The FC of hippocampal subfields with cerebellum was increased. Importantly, the degree of the altered FC between hippocampal subfields and IPL was associated with their impaired memory function.ConclusionOur results demonstrated that decreased hippocampal-IPL connectivity was associated with cognitive impairment in patients with ischemic stroke. These findings provide novel insights into the role of hippocampus in cognitive impairment following ischemic stroke.

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.

Altered thalamic connectivity during spontaneous attacks of migraine without aura: A resting-state fMRI study

Cephalalgia ◽  
2017 ◽  
Vol 38 (7) ◽  
pp. 1237-1244 ◽  
Author(s):  
Faisal Mohammad Amin ◽  
Anders Hougaard ◽  
Stefano Magon ◽  
Till Sprenger ◽  
Frauke Wolfram ◽  
...  
Keyword(s):  
Functional Connectivity ◽  
Resting State ◽  
Migraine Without Aura ◽  
Primary Motor Cortex ◽  
Premotor Cortex ◽  
Network Connectivity ◽  
Insular Cortex ◽  
Resting State Fmri ◽  
Brain Regions ◽  
The Right

Background Functional connectivity of brain networks may be altered in migraine without aura patients. Functional magnetic resonance imaging (fMRI) studies have demonstrated changed activity in the thalamus, pons and cerebellum in migraineurs. Here, we investigated the thalamic, pontine and cerebellar network connectivity during spontaneous migraine attacks. Methods Seventeen patients with episodic migraine without aura underwent resting-state fMRI scan during and outside of a spontaneous migraine attack. Primary endpoint was a difference in functional connectivity between the attack and the headache-free days. Functional connectivity was assessed in four different networks using seed-based analysis. The chosen seeds were in the thalamus (MNI coordinates x,y,z: right, 22,–24,0 and left, –22,–28,6), pons (right, 8,–24,–32 and left, –8,–24,–32), cerebellum crus I (right, 46,–58,–30 and left, –46,–58,–30) and cerebellum lobule VI (right, 34,–42,–36 and left, –32,–42,–36). Results We found increased functional connectivity between the right thalamus and several contralateral brain regions (superior parietal lobule, insular cortex, primary motor cortex, supplementary motor area and orbitofrontal cortex). There was decreased functional connectivity between the right thalamus and three ipsilateral brain areas (primary somatosensory cortex and premotor cortex). We found no change in functional connectivity in the pontine or the cerebellar networks. Conclusions The study indicates that network connectivity between thalamus and pain modulating as well as pain encoding cortical areas are affected during spontaneous migraine attacks.

scholarly journals The effects of hemodynamic lag on functional connectivity and behavior after stroke

2016 ◽  
Vol 36 (12) ◽  
pp. 2162-2176 ◽  
Author(s):  
Joshua S Siegel ◽  
Abraham Z Snyder ◽  
Lenny Ramsey ◽  
Gordon L Shulman ◽  
Maurizio Corbetta
Keyword(s):  
Functional Connectivity ◽  
Resting State ◽  
Clinical Importance ◽  
Resting State Fmri ◽  
Vascular Supply ◽  
Stroke Patients ◽  
Performance Deficits ◽  
Post Stroke ◽  
Attention Systems ◽  
Multiple Domains

Stroke disrupts the brain’s vascular supply, not only within but also outside areas of infarction. We investigated temporal delays (lag) in resting state functional magnetic resonance imaging signals in 130 stroke patients scanned two weeks, three months and 12 months post stroke onset. Thirty controls were scanned twice at an interval of three months. Hemodynamic lag was determined using cross-correlation with the global gray matter signal. Behavioral performance in multiple domains was assessed in all patients. Regional cerebral blood flow and carotid patency were assessed in subsets of the cohort using arterial spin labeling and carotid Doppler ultrasonography. Significant hemodynamic lag was observed in 30% of stroke patients sub-acutely. Approximately 10% of patients showed lag at one-year post-stroke. Hemodynamic lag corresponded to gross aberrancy in functional connectivity measures, performance deficits in multiple domains and local and global perfusion deficits. Correcting for lag partially normalized abnormalities in measured functional connectivity. Yet post-stroke FC–behavior relationships in the motor and attention systems persisted even after hemodynamic delays were corrected. Resting state fMRI can reliably identify areas of hemodynamic delay following stroke. Our data reveal that hemodynamic delay is common sub-acutely, alters functional connectivity, and may be of clinical importance.

scholarly journals Decreased Functional Connectivity of Homotopic Brain Regions in Chronic Stroke Patients: A Resting State fMRI Study

PLoS ONE ◽  
2016 ◽  
Vol 11 (4) ◽  
pp. e0152875 ◽  
Author(s):  
Chaozheng Tang ◽  
Zhiyong Zhao ◽  
Chuang Chen ◽  
Xiaohui Zheng ◽  
Fenfen Sun ◽  
...  
Keyword(s):  
Functional Connectivity ◽  
Resting State ◽  
Resting State Fmri ◽  
Brain Regions ◽  
Chronic Stroke ◽  
Stroke Patients ◽  
Fmri Study

Abstract TP312: Longitudinal Functional Connectivity Change Associated With Rehabilitation Training In Sub-acute Stroke Patients

Stroke ◽  
2013 ◽  
Vol 44 (suppl_1) ◽  
Author(s):  
yumei zhang ◽  
jun wang
Keyword(s):  
Functional Connectivity ◽  
Acute Stroke ◽  
Motor Function ◽  
Resting State ◽  
Resting State Fmri ◽  
Motor Recovery ◽  
Stroke Patients ◽  
Rehabilitation Training ◽  
Inferior Temporal Gyrus ◽  
Crus I

Background and aims: The neural correlate of the motor recovery associated with different rehabilitation therapy is still unknown in stroke patients. In this study, the resting-state fMRI was employed to identify longitudinal functional connectivity changes associated with different rehabilitation training in sub-acute stroke patients. Methods: Twenty-four sub-acute ischemic stroke patients with right-handed were recruited from Beijing Tiantan Hospital, all of the patients had unilateral upper limb paresis. The subjects were randomly divided into conventional rehabilitation training (CRT) group and functional electrical stimulation (FES) training group. The motor function assessments included FMA, ARAT and MAS. Resting-state fMRI scan were acquired on a Siemens 3.0 T scanner at pre-training and post-training. Ipsilesional primary motor cortex (M1) was selected as the region of interest (ROI), then the functional connectivity (FC) with ipsilesional M1 were analyzed respectively for the two groups. Results: Compared with CRT group, the motor function assessments showed that each motor index increased significantly in FES group. For CRT group, compared with pre-training, we found that the FC of ipsilesional M1 increased with the contralesional cerebellum crus I&II, medial and inferior temporal gyrus at post-training . On the contrary, for FES group, compared with pre-training, FC of ipsilesional M1 decreased with the contralesional cerebellum crus I&II, medial and inferior temporal gyrus at post-training . Conclusion: The different pattern of the longitudinal changes of functional connectivity might contribute to the motor recovery with different rehabilitation training.

Abstract 6: Resting-state Functional Connectivity Changes After Stroke Rehabilitation Using Closed Loop Neurofeedback

Stroke ◽  
2015 ◽  
Vol 46 (suppl_1) ◽  
Author(s):  
Veena A Nair ◽  
Brittany M Young ◽  
Zack Nigogosyan ◽  
Alex Remsick ◽  
Sonya Weber ◽  
...  
Keyword(s):  
Functional Connectivity ◽  
Upper Extremity ◽  
Resting State ◽  
Primary Motor Cortex ◽  
Seed Region ◽  
Resting State Functional Connectivity ◽  
Stroke Patients ◽  
Motor Network ◽  
Brain Changes ◽  
Left And Right

Introduction: Brain-computer interface (BCI)-EEG is a promising intervention for improving motor function after stroke. However, brain changes following intervention on a BCI-EEG system are not yet fully understood. We examined changes in resting state functional connectivity (RSFC) MRI in the motor network defined by 6 key regions in the left and right primary motor cortex (M1), left and right supplementary motor area (SMA), and left and right premotor cortex (PMC). Additionally, we investigated brain-behavior correlation between rsFC and a battery of outcome measures including the Barthel Index (BI), the Stroke Impact Scale(SIS), and the Action Research Arm Test (ARAT). Methods: Fifteen stroke patients with persistent mild to severe upper extremity impairment following ischemic stroke received intervention using BCI-EEG and were tested before (T1) and at 2-3 weeks (T2) mid intervention. 11 of these patients were also tested a third time at 4-6 weeks at the end of intervention (T3). Eyes closed, 10 minute resting fMRI and anatomical scans were acquired on a GE 3T MRI scanner. Right hemisphere stroke patients’ scans were flipped so that as a group the lesion was in the left (L) hemisphere and the impaired limb right (R). Seed region based connectivity analyses were performed to examine changes in RSFC over time and in inter-hemispheric and intra-hemispheric connectivity, and correlations between brain changes and behavioral changes were investigated. Results: BCI-EEG intervention led to significant increase in intra-hemispheric connectivity (p = .03) from T1 to T3. Inter-hemispheric connectivity increased from T1 to T3, trending towards significance (p = .06). Significant positive correlations were observed between changes in RSFC (L.M1 and L.PMC, L.M1 and R.PMC, L.SMA and R.PMC, and R.PMC and R.SMA) and change in upper extremity BI score (p ranging from .01 to .001); changes in RSFC between L.PMC and R.PMC correlated with hand strength on the SIS (p = .03). A trend was observed between increase in RSFC (L.M1 and R.PMC) and increase in total ARAT score but this was not significant. Conclusions: Results suggest that BCI-EEG intervention facilitate changes in RSFC in the motor network in stroke patients and these changes are associated with improved outcomes.

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