scholarly journals Intervention-Induced Changes in Cortical Connectivity and Activity in Severe Chronic Hemiparetic Stroke

2019 ◽  
Author(s):  
Kevin B. Wilkins ◽  
Julius P.A. Dewald ◽  
Jun Yao
Keyword(s):  
Sensorimotor Cortex ◽  
Hand Function ◽  
Cortical Activity ◽  
Chronic Stroke ◽  
Movement Preparation ◽  
Movement Execution ◽  
Post Intervention ◽  
Primary Sensorimotor Cortex ◽  
Hemiparetic Stroke ◽  
Hand Opening

AbstractObjectiveEffective interventions have demonstrated the ability to improve motor function by reengaging ipsilesional resources, which has been shown to be critical and feasible for hand function recovery even in individuals with severe chronic stroke. However, the question remains how these focal activity changes (i.e., changes in activity within motor regions) relate to altered cortico-cortico interactions within/across multiple regions.MethodsEight individuals with severe chronic stroke participated in a device-assisted intervention. Pre- and post-intervention, we collected EEG while performing hand opening with/without lifting the paretic arm. We quantified changes in focal cortical activity at movement execution and connectivity during movement preparation.ResultsPost-intervention, individuals displayed a reduction in coupling from ipsilesional M1 to contralesional M1 within gamma frequencies during movement preparation for hand opening. This was followed by a reduction in activity in contralesional primary sensorimotor cortex during movement execution. Meanwhile, during lifting and opening, a more inhibitory coupling within ipsilesional M1 from gamma to beta frequencies was accompanied by an increase in ipsilesional primary sensorimotor cortex activity.ConclusionsChanges in coupling within or between motor regions during movement preparation complement topographical activity changes at movement execution.SignificanceOur results suggest that changes in cortico-cortico interactions may lead to corresponding changes in focal cortical activity.

scholarly journals Acupuncture Enhances Effective Connectivity between Cerebellum and Primary Sensorimotor Cortex in Patients with Stable Recovery Stroke

2014 ◽  
Vol 2014 ◽  
pp. 1-9 ◽  
Author(s):  
Zijing Xie ◽  
Fangyuan Cui ◽  
Yihuai Zou ◽  
Lijun Bai
Keyword(s):  
Motor Learning ◽  
Sensorimotor Cortex ◽  
Effective Connectivity ◽  
Motor Task ◽  
Stroke Patients ◽  
Movement Coordination ◽  
Subacute Stroke ◽  
Primary Sensorimotor Cortex ◽  
Recovery Stroke ◽  
Hemiparetic Stroke

Recent neuroimaging studies have demonstrated that stimulation of acupuncture at motor-implicated acupoints modulates activities of brain areas relevant to the processing of motor functions. This study aims to investigate acupuncture-induced changes in effective connectivity among motor areas in hemiparetic stroke patients by using the multivariate Granger causal analysis. A total of 9 stable recovery stroke patients and 8 healthy controls were recruited and underwent three runs of fMRI scan: passive finger movements and resting state before and after manual acupuncture stimuli. Stroke patients showed significantly attenuated effective connectivity between cortical and subcortical areas during passive motor task, which indicates inefficient information transmissions between cortical and subcortical motor-related regions. Acupuncture at motor-implicated acupoints showed specific modulations of motor-related network in stroke patients relative to healthy control subjects. This specific modulation enhanced bidirectionally effective connectivity between the cerebellum and primary sensorimotor cortex in stroke patients, which may compensate for the attenuated effective connectivity between cortical and subcortical areas during passive motor task and, consequently, contribute to improvement of movement coordination and motor learning in subacute stroke patients. Our results suggested that further efficacy studies of acupuncture in motor recovery can focus on the improvement of movement coordination and motor learning during motor rehabilitation.

scholarly journals Limited Capacity for Ipsilateral Secondary Motor Areas to Support Hand Function Post-Stroke

2019 ◽  
Author(s):  
Kevin B. Wilkins ◽  
Jun Yao ◽  
Meriel Owen ◽  
Haleh Karbasforoushan ◽  
Carolina Carmona ◽  
...  
Keyword(s):  
Hand Function ◽  
Shoulder Abduction ◽  
Limited Capacity ◽  
Post Stroke ◽  
Backup System ◽  
Reticulospinal Tract ◽  
Hemiparetic Stroke ◽  
Chronic Hemiparetic Stroke ◽  
Hand Opening ◽  
Motor Areas

AbstractRecent findings have shown connections of ipsilateral cortico-reticulospinal tract (CRST), predominantly originating from secondary motor areas, to not only proximal but also distal portions of the arm. In unilateral stroke, CRST from the ipsilateral side is intact and thus has been proposed as a possible backup system for post-stroke rehabilitation even for the hand. We argue that although CRST from ipsilateral secondary motor areas can provide control for proximal joints, it is insufficient to control either hand or coordinated shoulder and hand movements due to its extensive branching compared to contralateral corticospinal tract. To address this issue, we combined MRI, high-density EEG, and robotics in 17 individuals with severe chronic hemiparetic stroke and 12 age-matched controls. We tested for changes in structural morphometry of the sensorimotor cortex and found that individuals with stroke demonstrated higher gray matter density in secondary motor areas ipsilateral to the paretic arm compared to controls. We then measured cortical activity while participants attempted to generate hand opening either supported on a table or while lifting against a shoulder abduction load. The addition of shoulder abduction during hand opening increased reliance on ipsilateral secondary motor areas in stroke, but not controls. Crucially, increased use of ipsilateral secondary motor areas was associated with decreased hand opening ability while lifting the arm due to involuntary coupling between the shoulder and wrist/finger flexors. Together, this evidence implicates a compensatory role for ipsilateral (i.e., contralesional) secondary motor areas post-stroke, but with limited capacity to support hand function.

scholarly journals Functional outcome of joint mobilization added to task-oriented training on hand function in chronic stroke patients

2020 ◽  
Vol 56 (1) ◽  
Author(s):  
Asmaa Sabbah ◽  
Sherine El Mously ◽  
Hanan Helmy Mohamed Elgendy ◽  
Mona Adel Abd Eltawab Farag ◽  
Abeer Abo Bakr Elwishy
Keyword(s):  
Functional Outcome ◽  
Hand Function ◽  
Chronic Stroke ◽  
Stroke Patients ◽  
Joint Mobilization ◽  
Task Oriented

scholarly journals Frequency-Dependent Changes of Regional Cerebral Blood Flow during Finger Movements

1996 ◽  
Vol 16 (1) ◽  
pp. 23-33 ◽  
Author(s):  
Norihiro Sadato ◽  
Vicente Ibañez ◽  
Marie-Pierre Deiber ◽  
Gregory Campbell ◽  
Marc Leonardo ◽  
...  
Keyword(s):  
Sensorimotor Cortex ◽  
Anterior Cingulate ◽  
Progressive Change ◽  
Positron Emission ◽  
Primary Sensorimotor Cortex ◽  
Neuronal Recruitment ◽  
Simple Movement ◽  
The Right ◽  
Fast Rates ◽  
Significant Activation

To study the effect of the repetition rate of a simple movement on the distribution and magnitude of neuronal recruitment, we measured regional CBF (rCBF) in eight normal volunteers, using positron emission tomography and 15O-labeled water. An auditory-cued, repetitive flexion movement of the right index finger against the thumb was performed at very slow (0.25 and 0.5 Hz), slow (0.75 and 1 Hz), fast (2 and 2.5 Hz), and very fast (3 and 4 Hz) rates. The increase of rCBF during movement relative to the resting condition was calculated for each pair of movement conditions. Left primary sensorimotor cortex showed no significant activation at the very slow rates. There was a rapid rise of rCBF between the slow and the fast rates, but no further increase at the very fast rates. The right cerebellum showed similar changes. Changes in the left primary sensorimotor cortex and the cerebellum likely reflect the effect of the movement rate. The posterior supplementary motor area (SMA) showed its highest activation at the very slow rates but no significant activation at the very fast rates. Changes correlating with those in the SMA were found in the anterior cingulate gyrus, right prefrontal area, and right thalamus. The decreases in CBF may reflect a progressive change in performance from reactive to predictive.

scholarly journals Measurement of passive ankle stiffness in subjects with chronic hemiparesis using a novel ankle robot

2011 ◽  
Vol 105 (5) ◽  
pp. 2132-2149 ◽  
Author(s):  
Anindo Roy ◽  
Hermano I. Krebs ◽  
Christopher T. Bever ◽  
Larry W. Forrester ◽  
Richard F. Macko ◽  
...  
Keyword(s):  
Ankle Joint ◽  
Frontal Plane ◽  
Chronic Stroke ◽  
Healthy Adults ◽  
Stroke Survivors ◽  
Passive Stiffness ◽  
Mechanical Stiffness ◽  
Treatment Protocols ◽  
Ankle Stiffness ◽  
Hemiparetic Stroke

Our objective in this study was to assess passive mechanical stiffness in the ankle of chronic hemiparetic stroke survivors and to compare it with those of healthy young and older (age-matched) individuals. Given the importance of the ankle during locomotion, an accurate estimate of passive ankle stiffness would be valuable for locomotor rehabilitation, potentially providing a measure of recovery and a quantitative basis to design treatment protocols. Using a novel ankle robot, we characterized passive ankle stiffness both in sagittal and in frontal planes by applying perturbations to the ankle joint over the entire range of motion with subjects in a relaxed state. We found that passive stiffness of the affected ankle joint was significantly higher in chronic stroke survivors than in healthy adults of a similar cohort, both in the sagittal as well as frontal plane of movement, in three out of four directions tested with indistinguishable stiffness values in plantarflexion direction. Our findings are comparable to the literature, thus indicating its plausibility, and, to our knowledge, report for the first time passive stiffness in the frontal plane for persons with chronic stroke and older healthy adults.

scholarly journals Electric and acoustic stimulation during movement preparation can facilitate movement execution in healthy participants and stroke survivors

2016 ◽  
Vol 618 ◽  
pp. 134-138 ◽  
Author(s):  
Welber Marinovic ◽  
Sandra G. Brauer ◽  
Kathryn S. Hayward ◽  
Timothy J. Carroll ◽  
Stephan Riek
Keyword(s):  
Acoustic Stimulation ◽  
Stroke Survivors ◽  
Movement Preparation ◽  
Movement Execution ◽  
Healthy Participants
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