keyword
MENU ▼
Read by QxMD icon Read
search

fMRI stroke

keyword
https://www.readbyqxmd.com/read/27920978/network-interactions-underlying-mirror-feedback-in-stroke-a-dynamic-causal-modeling-study
#1
Soha Saleh, Mathew Yarossi, Thushini Manuweera, Sergei Adamovich, Eugene Tunik
Mirror visual feedback (MVF) is potentially a powerful tool to facilitate recovery of disordered movement and stimulate activation of under-active brain areas due to stroke. The neural mechanisms underlying MVF have therefore been a focus of recent inquiry. Although it is known that sensorimotor areas can be activated via mirror feedback, the network interactions driving this effect remain unknown. The aim of the current study was to fill this gap by using dynamic causal modeling to test the interactions between regions in the frontal and parietal lobes that may be important for modulating the activation of the ipsilesional motor cortex during mirror visual feedback of unaffected hand movement in stroke patients...
2017: NeuroImage: Clinical
https://www.readbyqxmd.com/read/27890008/functional-connectivity-analysis-of-brain-default-mode-networks-using-hamiltonian-path
#2
Zhuqing Jiao, Kai Ma, Huan Wang, Ling Zou, Jianbo Xiang
The aim of this study is to introduce Hamiltonian path to analyze functional connectivity of brain default mode networks (DMNs). Firstly, the brain DMNs in resting state are constructed with the employment of functional Magnetic Resonance Imaging (fMRI) data. Then, the Dijkstra algorithm is used to calculate the shortest path length of the node which represents each brain region, and the Hamiltonian path of the default network is solved through the improved adaptive ant colony algorithm. Finally, complex network analysis methods are introduced to discuss the node and network properties of brain functional connectivity in both normal subjects and stroke patients...
November 24, 2016: CNS & Neurological Disorders Drug Targets
https://www.readbyqxmd.com/read/27859982/transcranial-direct-current-stimulation-effects-on-neural-processing-in-post-stroke-aphasia
#3
Robert Darkow, Andrew Martin, Anna Würtz, Agnes Flöel, Marcus Meinzer
Non-invasive transcranial direct current stimulation (tDCS) can enhance recovery after stroke. However, fundamental knowledge about how tDCS impacts neural processing in the lesioned human brain is currently lacking. In the present study, it was investigated how tDCS modulates brain function in patients with post-stroke language impairment (aphasia). In a cross-over, randomized trial, patients named pictures of common objects during functional magnetic resonance imaging (fMRI). Concurrently, excitatory (anodal-) or sham-tDCS (1 mA, 20 min, or 30 s, respectively) was administered to the left primary motor cortex, a montage with demonstrated potential to improve aphasic language...
November 11, 2016: Human Brain Mapping
https://www.readbyqxmd.com/read/27859975/population-level-correction-of-systematic-motion-artifacts-in-fmri-in-patients-with-ischemic-stroke
#4
Csaba Aranyi, Gábor Opposits, Marianna Nagy, Ervin Berényi, Csilla Vér, László Csiba, Péter Katona, Tamás Spisák, Miklós Emri
BACKGROUND: The aim of this study was to reveal potential sources of systematic motion artifacts in stroke functional magnetic resonance imaging (fMRI) focusing on those causing stimulus-correlated motion on the individual-level and separate the motion effect on the fMRI signal changing from the activation-induced alteration at population level. METHODS: Eleven ischemic stroke patients were examined by fMRI. The fMRI paradigm was based on passive ankle movement on both the healthy and the paretic leg's side...
November 17, 2016: Journal of Neuroimaging: Official Journal of the American Society of Neuroimaging
https://www.readbyqxmd.com/read/27859933/spectroscopic-biomarkers-of-motor-cortex-developmental-plasticity-in-hemiparetic-children-after-perinatal-stroke
#5
Helen L Carlson, Frank P MacMaster, Ashley D Harris, Adam Kirton
Perinatal stroke causes hemiparetic cerebral palsy and lifelong motor disability. Bilateral motor cortices are key hubs within the motor network and their neurophysiology determines clinical function. Establishing biomarkers of motor cortex function is imperative for developing and evaluating restorative interventional strategies. Proton magnetic resonance spectroscopy (MRS) quantifies metabolite concentrations indicative of underlying neuronal health and metabolism in vivo. We used functional magnetic resonance imaging (MRI)-guided MRS to investigate motor cortex metabolism in children with perinatal stroke...
November 17, 2016: Human Brain Mapping
https://www.readbyqxmd.com/read/27859903/corticostriatal-connectivity-fingerprints-probability-maps-based-on-resting-state-functional-connectivity
#6
Ellen Jaspers, Joshua H Balsters, Pegah Kassraian Fard, Dante Mantini, Nicole Wenderoth
Over the last decade, structure-function relationships have begun to encompass networks of brain areas rather than individual structures. For example, corticostriatal circuits have been associated with sensorimotor, limbic, and cognitive information processing, and damage to these circuits has been shown to produce unique behavioral outcomes in Autism, Parkinson's Disease, Schizophrenia and healthy ageing. However, it remains an open question how abnormal or absent connectivity can be detected at the individual level...
November 12, 2016: Human Brain Mapping
https://www.readbyqxmd.com/read/27846290/altered-effective-connectivity-of-the-primary-motor-cortex-in-stroke-a-resting-state-fmri-study-with-granger-causality-analysis
#7
Zhiyong Zhao, Xiangmin Wang, Mingxia Fan, Dazhi Yin, Limin Sun, Jie Jia, Chaozheng Tang, Xiaohui Zheng, Yuwei Jiang, Jie Wu, Jiayu Gong
The primary motor cortex (M1) is often abnormally recruited in stroke patients with motor disabilities. However, little is known about the alterations in the causal connectivity of M1 following stroke. The purpose of the present study was to investigate whether the effective connectivity of the ipsilesional M1 is disturbed in stroke patients who show different outcomes in hand motor function. 23 patients with left-hemisphere subcortical stroke were selected and divided into two subgroups: partially paralyzed hands (PPH) and completely paralyzed hands (CPH)...
2016: PloS One
https://www.readbyqxmd.com/read/27826107/increased-functional-connectivity-one-week-after-motor-learning-and-tdcs-in-stroke-patients
#8
Stéphanie Lefebvre, Laurence Dricot, Patrice Laloux, Philippe Desfontaines, Frédéric Evrard, André Peeters, Jacques Jamart, Yves Vandermeeren
Recent studies using resting-state functional magnetic resonance imaging (rs-fMRI) demonstrated that changes in functional connectivity (FC) after stroke correlate with recovery. The aim of this study was to explore whether combining motor learning to dual transcranial direct current stimulation (dual-tDCS, applied over both primary motor cortices (M1)) modulated FC in stroke patients. Twenty-two chronic hemiparetic stroke patients participated in a baseline rs-fMRI session. One week later, dual-tDCS/sham was applied during motor skill learning (intervention session); one week later, the retention session started with the acquisition of a run of rs-fMRI imaging...
November 5, 2016: Neuroscience
https://www.readbyqxmd.com/read/27790102/the-calculation-of-language-lateralization-indices-in-post-stroke-aphasia-a-comparison-of-a-standard-and-a-lesion-adjusted-formula
#9
Aimee Dietz, Jennifer Vannest, Thomas Maloney, Mekibib Altaye, Jerzy P Szaflarski, Scott K Holland
Background: The language lateralization index (LI) is a valuable tool in functional magnetic resonance imaging (fMRI) research, especially in people with post-stroke aphasia. However, there is inconsistent consideration for the overlap of lesions with regions of interest (ROIs). The purpose of this study was to determine whether standard LI (SLI) and lesion-adjusted LI (LALI) formulae generate different LI values and language lateralization classification for people with post-stroke chronic aphasia. Methods: SLI and LALI were calculated for an event-related (overt) verb generation task in an anterior and a posterior language ROI...
2016: Frontiers in Human Neuroscience
https://www.readbyqxmd.com/read/27676998/effect-of-visual-feedback-on-speech-recovery-and-language-plasticity-in-patients-with-post-stroke-non-fluent-aphasia-functional-mri-assessment
#10
Monica Baciu, Audrey Acher, Louise Kauffmann, Emilie Cousin, Claire Boilley, Thomas Hueber, Pierre Badin, Pascal Perrier, Diandra Fabre, Assia Jaillard, Olivier Detante, Dominique Perennou
OBJECTIVE: To assess the efficiency of Visual Feedback (VF) on language recovery and plasticity in three chronic non-fluent aphasic patients. VF is based on language-action interaction, thus, language skills are improved by rehabilitation strategies based on execution and observation of motor actions. VF is an ultrasound system coupled with video images, allowing patients to 'see their own lips and tongue at work' during speech and improve their awareness of their lingual and labial movements and their ability to coordinate and combine phonemes and syllables...
September 2016: Annals of Physical and Rehabilitation Medicine
https://www.readbyqxmd.com/read/27676986/cortical-activity-and-egocentric-representation-an-fmri-study
#11
Annelise Raillon Moulinet, Lucie Chochina, Stéphanie Challois Leplaideur, Elise Bannier, Jean-Christophe Ferre, Isabelle Bonan
OBJECTIVE: Subjects use different referentials for spatial localization, and the egocentric references are very often impaired especially during stroke. The objective is to find the difference between activations induced by 2 egocentric tasks MATERIAL/PATIENTS AND METHODS: Seventeen right-handed healthy subjects (50.4±14.9 years) were tested using fMRI during the realization of 2 egocentric spatial tasks: the perception of the straight ahead (retinocentric) and the longitudinal axis of the body (centered by the trunk)...
September 2016: Annals of Physical and Rehabilitation Medicine
https://www.readbyqxmd.com/read/27676978/modified-brain-activations-in-the-non-damaged-hemisphere-during-movements-of-the-supposed-to-be-healthy-upper-limb
#12
Liesjet Van Dokkum, Emmanuelle Le Bars, Denis Mottet, Alain Bonafe, Nicolas Menjot de Champfleur, Isabelle Laffont
OBJECTIVE: After stroke, the less affected upper-limb shows slight but substantial and longterm motor deficits [1]. Kinematically, this is reflected by an increased segmentation of movements. Here, we aim to define how these changes in behavior are accompanied by changes in brain activation. MATERIAL/PATIENTS AND METHODS: Twenty-one sub-acute post-stroke patients with a first-ever unilateral ischemic stroke of the middle cerebral artery participated in this study twice: within the first 6 weeks post-stroke and after 6 weeks of rehabilitation...
September 2016: Annals of Physical and Rehabilitation Medicine
https://www.readbyqxmd.com/read/27605617/glial-cell-calcium-signaling-mediates-capillary-regulation-of-blood-flow-in-the-retina
#13
Kyle R Biesecker, Anja I Srienc, Angela M Shimoda, Amit Agarwal, Dwight E Bergles, Paulo Kofuji, Eric A Newman
UNLABELLED: The brain is critically dependent on the regulation of blood flow to nourish active neurons. One widely held hypothesis of blood flow regulation holds that active neurons stimulate Ca(2+) increases in glial cells, triggering glial release of vasodilating agents. This hypothesis has been challenged, as arteriole dilation can occur in the absence of glial Ca(2+) signaling. We address this controversy by imaging glial Ca(2+) signaling and vessel dilation in the mouse retina. We find that sensory stimulation results in Ca(2+) increases in the glial endfeet contacting capillaries, but not arterioles, and that capillary dilations often follow spontaneous Ca(2+) signaling...
September 7, 2016: Journal of Neuroscience: the Official Journal of the Society for Neuroscience
https://www.readbyqxmd.com/read/27595065/decoding-post-stroke-motor-function-from-structural-brain-imaging
#14
Jane M Rondina, Maurizio Filippone, Mark Girolami, Nick S Ward
Clinical research based on neuroimaging data has benefited from machine learning methods, which have the ability to provide individualized predictions and to account for the interaction among units of information in the brain. Application of machine learning in structural imaging to investigate diseases that involve brain injury presents an additional challenge, especially in conditions like stroke, due to the high variability across patients regarding characteristics of the lesions. Extracting data from anatomical images in a way that translates brain damage information into features to be used as input to learning algorithms is still an open question...
2016: NeuroImage: Clinical
https://www.readbyqxmd.com/read/27590283/rtms-reduces-cortical-imbalance-associated-with-visual-hallucinations-after-occipital-stroke
#15
Sara A Rafique, John R Richards, Jennifer K E Steeves
OBJECTIVE: To investigate the efficacy of multiday repetitive transcranial magnetic stimulation (rTMS) to the occipital cortex in a patient with continuous visual phosphene hallucinations for more than 2 years following occipital stroke. METHODS: Low-frequency rTMS (1 Hz) was applied to the lesion site for 30 minutes daily over 5 consecutive days. Functional MRI (fMRI) was performed before and after rTMS treatment. RESULTS: Increased application of rTMS corresponded with a reduction in intensity of visual phosphene hallucinations and was reflected in altered blood oxygen level-dependent signal...
October 4, 2016: Neurology
https://www.readbyqxmd.com/read/27582702/the-hub-disruption-index-a-reliable-index-sensitive-to-the-brain-networks-reorganization-a-study-of-the-contralesional-hemisphere-in-stroke
#16
Maite Termenon, Sophie Achard, Assia Jaillard, Chantal Delon-Martin
Stroke, resulting in focal structural damage, induces changes in brain function at both local and global levels. Following stroke, cerebral networks present structural, and functional reorganization to compensate for the dysfunctioning provoked by the lesion itself and its remote effects. As some recent studies underlined the role of the contralesional hemisphere during recovery, we studied its role in the reorganization of brain function of stroke patients using resting state fMRI and graph theory. We explored this reorganization using the "hub disruption index" (κ), a global index sensitive to the reorganization of nodes within the graph...
2016: Frontiers in Computational Neuroscience
https://www.readbyqxmd.com/read/27578048/translational-mr-neuroimaging-of-stroke-and-recovery
#17
Emiri T Mandeville, Cenk Ayata, Yi Zheng, Joseph B Mandeville
Multiparametric magnetic resonance imaging (MRI) has become a critical clinical tool for diagnosing focal ischemic stroke severity, staging treatment, and predicting outcome. Imaging during the acute phase focuses on tissue viability in the stroke vicinity, while imaging during recovery requires the evaluation of distributed structural and functional connectivity. Preclinical MRI of experimental stroke models provides validation of non-invasive biomarkers in terms of cellular and molecular mechanisms, while also providing a translational platform for evaluation of prospective therapies...
August 31, 2016: Translational Stroke Research
https://www.readbyqxmd.com/read/27577057/the-effect-of-passive-movement-for-paretic-ankle-foot-and-brain-activity-in-post-stroke-patients
#18
Csilla Vér, Miklós Emri, Tamás Spisák, Ervin Berényi, Kázmér Kovács, Péter Katona, László Balkay, László Menyhárt, László Kardos, László Csiba
BACKGROUND: This study aims at investigating the short-term efficacy of the continuous passive motion (CPM) device developed for the therapy of ankle-foot paresis and to investigate by fMRI the blood oxygen level-dependent responses (BOLD) during ankle passive movement (PM). METHODS: Sixty-four stroke patients were investigated. Patients were assigned into 2 groups: 49 patients received both 15 min manual and 30 min device therapy (M + D), while the other group (n = 15) received only 15 min manual therapy (M)...
August 31, 2016: European Neurology
https://www.readbyqxmd.com/read/27574307/functional-magnetic-resonance-imaging-in-chronic-ischaemic-stroke
#19
REVIEW
Evelyn M R Lake, Paolo Bazzigaluppi, Bojana Stefanovic
Ischaemic stroke is the leading cause of adult disability worldwide. Effective rehabilitation is hindered by uncertainty surrounding the underlying mechanisms that govern long-term ischaemic injury progression. Despite its potential as a sensitive non-invasive in vivo marker of brain function that may aid in the development of new treatments, blood oxygenation level-dependent (BOLD) functional magnetic resonance imaging (fMRI) has found limited application in the clinical research on chronic stage stroke progression...
October 5, 2016: Philosophical Transactions of the Royal Society of London. Series B, Biological Sciences
https://www.readbyqxmd.com/read/27506234/changes-in-functional-connectivity-of-default-mode-network-with-auditory-and-right-frontoparietal-networks-in-post-stroke-aphasia
#20
Vladislav Balaev, Alexey Petruchevsky, Olga Martynova
To evaluate the influence of post-stroke aphasia on the functional association of widespread largescale neuronal networks, we analyzed functional connectivity between resting state brain networks (RSNs) in aphasic patients (N = 15) and in healthy volunteers (N = 17) of the same age using resting state fMRI. As a result, six RSNs were isolated and cross-correlation matrices were computed for their time courses. Aphasic patients showed decreased correlations between posterior part of the default mode (pDMN) and both auditory (AUD) and right frontoparietal (RFP) networks...
August 10, 2016: Brain Connectivity
keyword
keyword
69825
1
2
Fetch more papers »
Fetching more papers... Fetching...
Read by QxMD. Sign in or create an account to discover new knowledge that matter to you.
Remove bar
Read by QxMD icon Read
×

Search Tips

Use Boolean operators: AND/OR

diabetic AND foot
diabetes OR diabetic

Exclude a word using the 'minus' sign

Virchow -triad

Use Parentheses

water AND (cup OR glass)

Add an asterisk (*) at end of a word to include word stems

Neuro* will search for Neurology, Neuroscientist, Neurological, and so on

Use quotes to search for an exact phrase

"primary prevention of cancer"
(heart or cardiac or cardio*) AND arrest -"American Heart Association"