scholarly journals No evidence for motor recovery-related cortical connectivity changes after stroke using resting-state fMRI

2021 ◽  
Author(s):  
Meret Branscheidt ◽  
Naveed Ejaz ◽  
Jing Xu ◽  
Mario Widmer ◽  
Michelle D Harran ◽  
...  
Keyword(s):  
Resting State ◽  
Resting State Fmri ◽  
Motor Recovery ◽  
Cortical Reorganization ◽  
Cortical Connectivity ◽  
Behavioral Recovery ◽  
Brain Areas ◽  
Data Set ◽  
Post Stroke ◽  
One Year

It has been proposed that a form of cortical reorganization (changes in functional connectivity between brain areas) can be assessed with resting-state (rs) fMRI. Here we report a longitudinal data-set collected from 19 patients with subcortical stroke and 11 controls. Patients were imaged up to five times over one year. We found no evidence, using rs-fMRI, for post-stroke cortical connectivity changes despite substantial behavioral recovery. These results could be construed as questioning the value of resting-state imaging. Here we argue instead that they are consistent with other emerging reasons to challenge the idea of motor recovery-related cortical reorganization post-stroke when conceived of as changes in connectivity between cortical areas.

scholarly journals No evidence for motor recovery-related cortical reorganization after stroke using resting-state fMRI

2019 ◽  
Author(s):  
Meret Branscheidt ◽  
Naveed Ejaz ◽  
Jing Xu ◽  
Mario Widmer ◽  
Michelle D. Harran ◽  
...  
Keyword(s):  
Resting State ◽  
Resting State Fmri ◽  
Motor Recovery ◽  
Cortical Reorganization ◽  
Behavioral Recovery ◽  
Brain Areas ◽  
Data Set ◽  
Post Stroke ◽  
Cortical Areas ◽  
One Year

AbstractCortical reorganization has been suggested as mechanism for recovery after stroke. It has been proposed that a form of cortical reorganization (changes in functional connectivity between brain areas) can be assessed with resting-state fMRI. Here we report the largest longitudinal data-set in terms of overall sessions in 19 patients with subcortical stroke and 11 controls. Patients were imaged up to 5 times over one year. We found no evidence for post-stroke cortical reorganization despite substantial behavioral recovery. These results could be construed as questioning the value of resting-state imaging. Here we argue instead that they are consistent with other emerging reasons to challenge the idea of motor recovery-related cortical reorganization post-stroke when conceived as changes in connectivity between cortical areas.

Functional Brain Areas Mapping in Patients with Glioma Based on Resting-State fMRI Data Decomposition

2018 ◽  
Author(s):  
Maksim Sharaev ◽  
Alexander Smirnov ◽  
Tatiana Melnikova-Pitskhelauri ◽  
Vyacheslav Orlov ◽  
Evgeny Burnaev ◽  
...  
Keyword(s):  
Resting State ◽  
Resting State Fmri ◽  
Fmri Data ◽  
Data Decomposition ◽  
Brain Areas ◽  
Functional Brain

scholarly journals Correlation between the Effects of Acupuncture atTaichong(LR3) and Functional Brain Areas: A Resting-State Functional Magnetic Resonance Imaging Study Using True versus Sham Acupuncture

2014 ◽  
Vol 2014 ◽  
pp. 1-7 ◽  
Author(s):  
Chunxiao Wu ◽  
Shanshan Qu ◽  
Jiping Zhang ◽  
Junqi Chen ◽  
Shaoqun Zhang ◽  
...  
Keyword(s):  
Magnetic Resonance Imaging ◽  
Magnetic Resonance ◽  
Functional Magnetic Resonance Imaging ◽  
Data Processing ◽  
Resting State ◽  
Resting State Fmri ◽  
Sham Acupuncture ◽  
Functional Magnetic Resonance ◽  
Resonance Imaging ◽  
Brain Areas

Functional magnetic resonance imaging (fMRI) has been shown to detect the specificity of acupuncture points, as proved by numerous studies. In this study, resting-state fMRI was used to observe brain areas activated by acupuncture at theTaichong(LR3) acupoint. A total of 15 healthy subjects received brain resting-state fMRI before acupuncture and after sham and true acupuncture, respectively, at LR3. Image data processing was performed using Data Processing Assistant for Resting-State fMRI and REST software. The combination of amplitude of low-frequency fluctuation (ALFF) and regional homogeneity (ReHo) was used to analyze the changes in brain function during sham and true acupuncture. Acupuncture at LR3 can specifically activate or deactivate brain areas related to vision, movement, sensation, emotion, and analgesia. The specific alterations in the anterior cingulate gyrus, thalamus, and cerebellar posterior lobe have a crucial effect and provide a valuable reference. Sham acupuncture has a certain effect on psychological processes and does not affect brain areas related to function.

scholarly journals Longitudinal Effects of Lesions on Functional Networks after Stroke

2013 ◽  
Vol 33 (8) ◽  
pp. 1279-1285 ◽  
Author(s):  
Smadar Ovadia-Caro ◽  
Kersten Villringer ◽  
Jochen Fiebach ◽  
Gerhard Jan Jungehulsing ◽  
Elke van der Meer ◽  
...  
Keyword(s):  
Ischemic Stroke ◽  
Resting State ◽  
Large Scale ◽  
Clinical Symptoms ◽  
Resting State Fmri ◽  
Functional Change ◽  
Stroke Recovery ◽  
Focal Lesion ◽  
Supporting Evidence ◽  
Post Stroke

While ischemic stroke reflects focal damage determined by the affected vascular territory, clinical symptoms are often more complex and may be better explained by additional indirect effects of the focal lesion. Assumed to be structurally underpinned by anatomical connections, supporting evidence has been found using alterations in the functional connectivity of resting-state functional magnetic resonance imaging (fMRI) data in both sensorimotor and attention networks. To assess the generalizability of this phenomenon in a stroke population with heterogeneous lesions, we investigated the distal effects of lesions on a global level. Longitudinal resting-state fMRI scans were acquired at three consecutive time points, beginning during the acute phase (days 1, 7, and 90 post-stroke) in 12 patients after ischemic stroke. We found a preferential functional change in affected networks (i.e., networks containing lesions changed more during recovery when compared with unaffected networks). This change in connectivity was significantly correlated with clinical changes assessed with the National Institute of Health Stroke Scale. Our results provide evidence that the functional architecture of large-scale networks is critical to understanding the clinical effect and trajectory of post-stroke recovery.

scholarly journals Post-stroke fatigue is linked to resting state posterior hypoactivity and prefrontal hyperactivity

2021 ◽  
Author(s):  
Georgia Mary Cotter ◽  
Mohamed Salah Khlif ◽  
Laura Bird ◽  
Mark E Howard ◽  
Amy Brodtmann ◽  
...  
Keyword(s):  
Ischaemic Stroke ◽  
Resting State ◽  
Large Scale ◽  
Brain Activity ◽  
Low Frequency ◽  
Resting State Fmri ◽  
Stroke Severity ◽  
Stroke Survivors ◽  
Whole Brain ◽  
Post Stroke

Background and Purpose. Fatigue is associated with poor functional outcomes and increased mortality following stroke. Survivors identify fatigue as one of their key unmet needs. Despite the growing body of research into post-stroke fatigue, the specific neural mechanisms remain largely unknown. Methods. This observational study included 63 stroke survivors (22 women; age 30-89 years; mean 67.5 years) from the Cognition And Neocortical Volume After Stroke (CANVAS) study, a cohort study examining cognition, mood, and brain volume in stroke survivors following ischaemic stroke. Participants underwent brain imaging 3 months post-stroke, including a 7-minute resting state fMRI echoplanar sequence. We calculated the fractional amplitude of low-frequency fluctuations, a measure of resting state brain activity at the whole-brain level. Results. Forty-five participants reported experiencing post-stroke fatigue as measured by an item on the Patient Health Questionnaire-9. A generalised linear regression model analysis with age, sex, and stroke severity covariates was conducted to compare resting state brain activity in the 0.01-0.08 Hz range, as well as its subcomponents - slow-5 (0.01-0.027 Hz), and slow-4 (0.027-0.073 Hz) frequency bands between fatigued and non-fatigued participants. We found no significant associations between post-stroke fatigue and ischaemic stroke lesion location or stroke volume. However, in the overall 0.01-0.08 Hz band, participants with post-stroke fatigue demonstrated significantly lower resting-state activity in the calcarine cortex (p<0.001, cluster-corrected pFDR=0.009, k=63) and lingual gyrus (p<0.001, cluster-corrected pFDR=0.025, k=42) and significantly higher activity in the medial prefrontal cortex (p<0.001, cluster-corrected pFDR=0.03, k=45), attributed to slow-4 and slow-5 oscillations, respectively. Conclusions. Post-stroke fatigue is associated with posterior hypoactivity and prefrontal hyperactivity, reflecting dysfunction within large-scale brain systems such as fronto-striatal-thalamic and frontal-occipital networks. These systems in turn might reflect a relationship between post-stroke fatigue and abnormalities in executive and visual functioning. This first whole-brain resting-state study provides new targets for further investigation of post-stroke fatigue beyond the lesion approach.

scholarly journals Extraction and Analysis of Dynamic Functional Connectome Patterns in Migraine Sufferers: A Resting-State fMRI Study

2021 ◽  
Vol 2021 ◽  
pp. 1-14
Author(s):  
Weifang Nie ◽  
Weiming Zeng ◽  
Jiajun Yang ◽  
Yuhu Shi ◽  
Le Zhao ◽  
...  
Keyword(s):  
Resting State ◽  
Occipital Lobe ◽  
Resting State Fmri ◽  
Brain Regions ◽  
Neural Mechanisms ◽  
Imaging Data ◽  
Physical And Mental Health ◽  
Brain Areas ◽  
Functional Connectome ◽  
Network Metrics

Migraine seriously affects the physical and mental health of patients because of its recurrence and the hypersensitivity to the environment that it causes. However, the pathogenesis and pathophysiology of migraine are not fully understood. We addressed this issue in the present study using an autodynamic functional connectome model (A-DFCM) with twice-clustering to compare dynamic functional connectome patterns (DFCPs) from resting-state functional magnetic resonance imaging data from migraine patients and normal control subjects. We used automatic localization of segment points to improve the efficiency of the model, and intergroup differences and network metrics were analyzed to identify the neural mechanisms of migraine. Using the A-DFCM model, we identified 17 DFCPs—including 1 that was specific and 16 that were general—based on intergroup differences. The specific DFCP was closely associated with neuronal dysfunction in migraine, whereas the general DFCPs showed that the 2 groups had similar functional topology as well as differences in the brain resting state. An analysis of network metrics revealed the critical brain regions in the specific DFCP; these were not only distributed in brain areas related to pain such as Brodmann area 1/2/3, basal ganglia, and thalamus but also located in regions that have been implicated in migraine symptoms such as the occipital lobe. An analysis of the dissimilarities in general DFCPs between the 2 groups identified 6 brain areas belonging to the so-called pain matrix. Our findings provide insight into the neural mechanisms of migraine while also identifying neuroimaging biomarkers that can aid in the diagnosis or monitoring of migraine patients.

scholarly journals Biological Characteristics of Connection-Wise Resting-State Functional Connectivity Strength

2019 ◽  
Vol 29 (11) ◽  
pp. 4646-4653 ◽  
Author(s):  
Rory Pijnenburg ◽  
Lianne H Scholtens ◽  
Dante Mantini ◽  
Wim Vanduffel ◽  
Lisa Feldman Barrett ◽  
...  
Keyword(s):  
Functional Connectivity ◽  
Resting State ◽  
Resting State Fmri ◽  
Biological Characteristics ◽  
Resting State Functional Connectivity ◽  
Brain Areas ◽  
Statistical Dependency ◽  
Functional Connectivity Strength ◽  
Functional Pathways ◽  
Subsequent Activation

Abstract Functional connectivity is defined as the statistical dependency of neurophysiological activity between 2 separate brain areas. To investigate the biological characteristics of resting-state functional connectivity (rsFC)—and in particular the significance of connection-wise variation in time-series correlations—rsFC was compared with strychnine-based connectivity measured in the macaque. Strychnine neuronography is a historical technique that induces activity in cortical areas through means of local administration of the substance strychnine. Strychnine causes local disinhibition through GABA suppression and leads to subsequent activation of functional pathways. Multiple resting-state fMRI recordings were acquired in 4 macaques (examining in total 299 imaging runs) from which a group-averaged rsFC matrix was constructed. rsFC was observed to be higher (P &lt; 0.0001) between region-pairs with a strychnine-based connection as compared with region-pairs with no strychnine-based connection present. In particular, higher resting-state connectivity was observed in connections that were relatively stronger (weak &lt; moderate &lt; strong; P &lt; 0.01) and in connections that were bidirectional (P &lt; 0.0001) instead of unidirectional in strychnine-based connectivity. Our results imply that the level of correlation between brain areas as extracted from resting-state fMRI relates to the strength of underlying interregional functional pathways.

scholarly journals Regional Coherence Alterations Revealed by Resting-State fMRI in Post-Stroke Patients with Cognitive Dysfunction

PLoS ONE ◽  
2016 ◽  
Vol 11 (7) ◽  
pp. e0159574 ◽  
Author(s):  
Cheng-Yu Peng ◽  
Yu-Chen Chen ◽  
Ying Cui ◽  
Deng-Ling Zhao ◽  
Yun Jiao ◽  
...  
Keyword(s):  
Cognitive Dysfunction ◽  
Resting State ◽  
Resting State Fmri ◽  
Stroke Patients ◽  
Post Stroke

scholarly journals A critical time window for recovery extends beyond one-year post-stroke

2019 ◽  
Vol 122 (1) ◽  
pp. 350-357 ◽  
Author(s):  
Belén Rubio Ballester ◽  
Martina Maier ◽  
Armin Duff ◽  
Mónica Cameirão ◽  
Sergi Bermúdez ◽  
...  
Keyword(s):  
Time Window ◽  
Temporal Structure ◽  
Critical Time ◽  
Motor Recovery ◽  
Homogeneous Sample ◽  
Critical Window ◽  
Post Stroke ◽  
Enhanced Sensitivity ◽  
One Year ◽  
The Impact

The impact of rehabilitation on post-stroke motor recovery and its dependency on the patient’s chronicity remain unclear. The field has widely accepted the notion of a proportional recovery rule with a “critical window for recovery” within the first 3–6 mo poststroke. This hypothesis justifies the general cessation of physical therapy at chronic stages. However, the limits of this critical window have, so far, been poorly defined. In this analysis, we address this question, and we further explore the temporal structure of motor recovery using individual patient data from a homogeneous sample of 219 individuals with mild to moderate upper-limb hemiparesis. We observed that improvement in body function and structure was possible even at late chronic stages. A bootstrapping analysis revealed a gradient of enhanced sensitivity to treatment that extended beyond 12 mo poststroke. Clinical guidelines for rehabilitation should be revised in the context of this temporal structure. NEW & NOTEWORTHY Previous studies in humans suggest that there is a 3- to 6-mo “critical window” of heightened neuroplasticity poststroke. We analyze the temporal structure of recovery in patients with hemiparesis and uncover a precise gradient of enhanced sensitivity to treatment that expands far beyond the limits of the so-called critical window. These findings highlight the need for providing therapy to patients at the chronic and late chronic stages.

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.

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