scholarly journals Cerebral Reorganization in Subacute Stroke Survivors after Virtual Reality-Based Training: A Preliminary Study

2017 ◽  
Vol 2017 ◽  
pp. 1-8 ◽  
Author(s):  
Xiang Xiao ◽  
Qiang Lin ◽  
Wai-Leung Lo ◽  
Yu-Rong Mao ◽  
Xin-chong Shi ◽  
...  
Keyword(s):  
Virtual Reality ◽  
Sensorimotor Cortex ◽  
Brain Regions ◽  
Cortical Reorganization ◽  
Gait Velocity ◽  
Stroke Survivors ◽  
Subacute Stroke ◽  
Before And After ◽  
Primary Sensorimotor Cortex ◽  
Gait Function

Background. Functional magnetic resonance imaging (fMRI) is a promising method for quantifying brain recovery and investigating the intervention-induced changes in corticomotor excitability after stroke. This study aimed to evaluate cortical reorganization subsequent to virtual reality-enhanced treadmill (VRET) training in subacute stroke survivors.Methods. Eight participants with ischemic stroke underwent VRET for 5 sections per week and for 3 weeks. fMRI was conducted to quantify the activity of selected brain regions when the subject performed ankle dorsiflexion. Gait speed and clinical scales were also measured before and after intervention.Results. Increased activation in the primary sensorimotor cortex of the lesioned hemisphere and supplementary motor areas of both sides for the paretic foot (p<0.01) was observed postintervention. Statistically significant improvements were observed in gait velocity (p<0.05). The change in voxel counts in the primary sensorimotor cortex of the lesioned hemisphere is significantly correlated with improvement of 10 m walk time after VRET (r=−0.719).Conclusions. We observed improved walking and increased activation in cortical regions of stroke survivors after VRET training. Moreover, the cortical recruitment was associated with better walking function. Our study suggests that cortical networks could be a site of plasticity, and their recruitment may be one mechanism of training-induced recovery of gait function in stroke. This trial is registered with ChiCTR-IOC-15006064.

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 Limitations of compensatory plasticity: the organization of the primary sensorimotor cortex in foot-using bilateral upper limb dysplasics

2017 ◽  
Author(s):  
Ella Striem-Amit ◽  
Gilles Vannuscorps ◽  
Alfonso Caramazza
Keyword(s):  
Sensorimotor Cortex ◽  
Functional Organization ◽  
Brain Regions ◽  
Association Cortex ◽  
Body Parts ◽  
Brain Organization ◽  
Primary Sensorimotor Cortex ◽  
Hand Area ◽  
Compensatory Plasticity

SummaryWhat forces direct brain organization and its plasticity? When a brain region is deprived of its input would this region reorganize based on compensation for the disability and experience, or would strong limitations of brain structure limit its plasticity? People born without hands activate their sensorimotor hand region while moving body parts used to compensate for this ability (e.g. their feet). This has been taken to suggest a neural organization based on functions, such as performing manual-like dexterous actions, rather than on body parts. Here we test the selectivity for functionally-compensatory body parts in the sensorimotor cortex of people born without hands. Despite clear compensatory foot use, the sensorimotor hand area in the dysplasic subjects showed preference for body parts whose cortical territory is close to the hand area, but which are not compensatorily used as effectors. This suggests that function-based organization, originally proposed for congenital blindness and deafness, does not apply to cases of the primary sensorimotor cortex deprivation in dysplasia. This is consistent with the idea that experience-independent functional specialization occurs at relatively high levels of representation. Indeed, increased and selective foot movement preference in the dysplasics was found in the association cortex, in the inferior parietal lobule. Furthermore, it stresses the roles of neuroanatomical constraints such as topographical proximity and connectivity in determining the functional development of brain regions. These findings reveal limitations to brain plasticity and to the role of experience in shaping the functional organization of the brain.Significance StatementWhat determines the role of brain regions, and their plasticity when typical inputs or experience is not provided? To what extent can extreme compensatory use affect brain organization? We tested the functional reorganization of the primary sensorimotor cortex hand area in people born without hands, who use their feet for every-day tasks. We found that it is preferentially activated by close-by body-parts which cannot serve as effectors, and not by the feet. In contrast, foot-selective compensatory plasticity was found in the association cortex, in an area involved in tool use. This shows limitations of compensatory plasticity and experience in modifying brain organization of early topographical cortex, as compared to association cortices where function-based organization is the driving factor.ClassificationBiological Sciences\Neuroscience

scholarly journals Reassessing cortical reorganization in the primary sensorimotor cortex following arm amputation

Brain ◽  
2015 ◽  
Vol 138 (8) ◽  
pp. 2140-2146 ◽  
Author(s):  
Tamar R. Makin ◽  
Jan Scholz ◽  
David Henderson Slater ◽  
Heidi Johansen-Berg ◽  
Irene Tracey
Keyword(s):  
Sensorimotor Cortex ◽  
Cortical Reorganization ◽  
Arm Amputation ◽  
Primary Sensorimotor Cortex

scholarly journals Plasticity based on compensatory effector use in the association but not primary sensorimotor cortex of people born without hands

2018 ◽  
Vol 115 (30) ◽  
pp. 7801-7806 ◽  
Author(s):  
Ella Striem-Amit ◽  
Gilles Vannuscorps ◽  
Alfonso Caramazza
Keyword(s):  
Sensorimotor Cortex ◽  
Brain Regions ◽  
Association Cortex ◽  
Body Parts ◽  
Brain Organization ◽  
Neural Organization ◽  
Functional Development ◽  
Primary Sensorimotor Cortex ◽  
Hand Region ◽  
High Level

What forces direct brain organization and its plasticity? When brain regions are deprived of their input, which regions reorganize based on compensation for the disability and experience, and which regions show topographically constrained plasticity? People born without hands activate their primary sensorimotor hand region while moving body parts used to compensate for this disability (e.g., their feet). This was taken to suggest a neural organization based on functions, such as performing manual-like dexterous actions, rather than on body parts, in primary sensorimotor cortex. We tested the selectivity for the compensatory body parts in the primary and association sensorimotor cortex of people born without hands (dysplasic individuals). Despite clear compensatory foot use, the primary sensorimotor hand area in the dysplasic subjects showed preference for adjacent body parts that are not compensatorily used as effectors. This suggests that function-based organization, proposed for congenital blindness and deafness, does not apply to the primary sensorimotor cortex deprivation in dysplasia. These findings stress the roles of neuroanatomical constraints like topographical proximity and connectivity in determining the functional development of primary cortex even in extreme, congenital deprivation. In contrast, increased and selective foot movement preference was found in dysplasics’ association cortex in the inferior parietal lobule. This suggests that the typical motor selectivity of this region for manual actions may correspond to high-level action representations that are effector-invariant. These findings reveal limitations to compensatory plasticity and experience in modifying brain organization of early topographical cortex compared with association cortices driven by function-based organization.

scholarly journals Seated Virtual Reality-Guided Exercise Improved Gait in a Postoperative Hallux Valgus Case

2021 ◽  
Vol 18 (24) ◽  
pp. 13267
Author(s):  
Masami Nakamoto ◽  
Akihiro Kakuda ◽  
Toshinori Miyashita ◽  
Takashi Kitagawa ◽  
Masashi Kitano ◽  
...  
Keyword(s):  
Virtual Reality ◽  
Hallux Valgus ◽  
Exercise Therapy ◽  
Foot Deformities ◽  
Sensory Threshold ◽  
Postural Adjustment ◽  
Plantar Pressure Distribution ◽  
Before And After ◽  
Gait Function ◽  
Therapy Interventions

Virtual reality (VR)-guided exercise therapy using mediVR KAGURA has been reported to improve gait function by extending the arm to spatial targets while sitting. We aimed to investigate toe and trunk–pelvic function and plantar sensation during gait in a postoperative patient with hallux valgus. A 60-year-old woman, whose foot deformities had improved 6 months earlier, participated in the study. The exercise therapy interventions were performed twice weekly for 15 min. This study used an A-B-A design: 1-week pre-phase, 3-week intervention phase, and 2-week post-phase. The plantar pressure distribution and thoracic and pelvic displacements during gait were recorded at the end of each phase. The tactile pressure thresholds of the foot were determined before and after each exercise. The maximum force and impulse under the hallux increased after the intervention. The sensory threshold of the hallux was reduced. The amplitude of the thoracic and pelvic displacement was shortened in lateral and extended in the vertical and progressional directions after the intervention. We found that a 3-week VR-guided exercise improved toe function, plantar sensation, and postural adjustment of the trunk and pelvis during gait in a patient who had undergone surgery for hallux valgus, and the effects continued for 2 weeks.

scholarly journals Retrospective Exploratory Analysis of Task-Specific Effects on Brain Activity after Stroke

2021 ◽  
Author(s):  
Marika Demers ◽  
Rini Varghese ◽  
Carolee J Winstein
Keyword(s):  
Primary Motor Cortex ◽  
Brain Activity ◽  
Premotor Cortex ◽  
Chronic Stroke ◽  
Exploratory Analysis ◽  
Cortical Reorganization ◽  
Control Group ◽  
Stroke Survivors ◽  
Task Specificity ◽  
Before And After

Background: Evidence supports cortical reorganization in sensorimotor areas induced by constraint-induced movement therapy (CIMT). However, only a few studies examined the neural plastic changes as a function of task specificity. This provoked us to retrospectively analyze a previously unpublished imaging dataset from chronic stroke survivors before and after participation in the signature CIMT protocol. This exploratory analysis aims to evaluate the functional brain activation changes during a precision and a power grasp task in chronic stroke survivors who received two-weeks of CIMT compared to a control group. Materials and methods: Fourteen chronic stroke survivors, randomized to CIMT (n=8) or non-CIMT (n=6), underwent functional MRI (fMRI) before and after a two-week period. During scan runs, participants performed two different grasp tasks (precision, power). Pre to post changes in laterality index (LI) were compared by group and task for two predetermined motor regions of interest: dorsal premotor cortex (PMd) and primary motor cortex (MI). Results: Two weeks of CIMT resulted in a relative increase in activity in a key region of the motor network, the PMd of the lesioned hemisphere, under precision grasp task conditions compared to a non-treatment control group. However, no changes in LI were observed in MI for either task or group. Conclusion: These findings provide evidence for the task specificity effects of CIMT in the promotion of recovery-supportive cortical reorganization in chronic stroke survivors.

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