Constraint induced movement therapy promotes contralesional-oriented structural and bihemispheric functional neuroplasticity after stroke

The effect of exercise on balance function in stroke patients: a systematic review and meta-analysis of randomized controlled trials

OBJECTIVE

A growing body of studies has examined the effect of exercise on balance function in stroke patients, with conflicting findings. This study aimed to investigate the effect of exercise on balance function in stroke patients and to determine the optimal exercise prescription for stroke patients.

METHODS

We conducted an extensive search across various databases, including PubMed, Web of Science, EBSCO, Cochrane, and Scopus. The search was conducted until March 11th, 2024. Data were pooled using the weighted mean difference (WMD) and 95% confidence interval.

RESULTS

Twenty-nine studies fulfilled the inclusion criteria. Exercise significantly improved Berg balance scale (BBS, WMD, 5.24, P < 0.00001) and timed up and go test (TUG, WMD, - 2.91, P < 0.00001) in stroke patients. Subgroup analyses showed that aerobic exercise (WMD, 6.71, P = 0.003), exercise conducted ≥ 8 weeks (WMD, 6.43, P < 0.00001), > 3 times per week (WMD, 6.18, P < 0.00001), ≥ 60 min per session (WMD, 6.40, P < 0.0001), and ≥ 180 min per week (WMD, 7.49, P < 0.00001) were more effective in improving BBS.

CONCLUSIONS

Exercise improved balance function in stroke patients, and aerobic exercise might be the most effective intervention. To improve balance function, this meta-analysis provides clinicians with evidence to recommend that stroke patients participate in a minimum of 8 weeks of exercise at least 3 times per week for more than 60 min per session, with a goal of 180 min per week being achieved by increasing the frequency of exercise.

Constraint-Induced Movement Therapy Modulates Neuron Recruitment and Neurotransmission Homeostasis of the Contralesional Cortex to Enhance Function Recovery after Ischemic Stroke

Stroke often results in long-term and severe limb dysfunction for a majority of patients, significantly limiting their activities and social participation. Constraint-induced movement therapy (CIMT) is a rehabilitation approach aimed explicitly at enhancing upper limb motor function following a stroke. However, the precise mechanism remains unknown. This study explores how CIMT may alleviate forelimb paralysis in ischemic mice, potentially through structural and functional remodeling of brain regions beyond the infarct area, especially the contralateral cortex. We demonstrated that CIMT recruits neurons from the contralesional cortex into the network that innervates the affected forelimb, as evidenced by PRV retrograde nerve tracing. Additionally, we investigated how CIMT influences synaptic plasticity in the contralateral cortex by evaluating synaptic growth marker levels and neurotransmission's homeostatic regulation. Our findings uncover a rehabilitative mechanism by which CIMT treats ischemic stroke, characterized by increased recruitment of neurons from the contralateral cortex into the network that innervates the affected forelimb, facilitated by homeostatic regulation of neurotransmission.

Shoulder complex and trunk coordination of individuals with severe hemiparesis following a constraint-induced movement therapy protocol: A case series

INTRODUCTION

Constraint Induced Movement Therapy (CIMT) has been shown to be an effective rehabilitation technique in individuals with mild and moderate upper limb (UL) hemiparesis. The aim was to evaluate the effect the CIMT for improving paretic UL use and interjoint coordination with individuals in severe hemiparesis.

METHODS

Six individuals with severe chronic hemiparesis (mean age = 55 ± 16 years) received a UL CIMT intervention for 2 weeks. UL clinical assessments were conducted five times: two assessments at pre-intervention and then, one assessment at post-intervention and 1- and 3-month follow-up using the Graded Motor Activity Log GMAL) and the Graded Wolf Motor Function Test (GWMFT). Scapula, humerus and trunk coordination variability were assessed using the 3-D kinematics during arm elevation, combing hair, turning on the switch and grasp a washcloth. A paired t-test was used to check differences between coordination variability and a one-way ANOVA repeated measures was used to check differences between GMAL and GWMFT scores.

RESULTS

There were no differences in GMAL and GWMFT between the patient screening and the baseline data collection (p > 0.05). GMAL scores increased at post-intervention and at follow-ups (p < 0.02). GWMFT performance time score decreased at post-intervention and at 1-month follow-up (p < 0.04). Improvements in kinematic variability of the paretic UL at pre and post-intervention were observed in all tasks, except in the activity of turn on the light switch.

CONCLUSION

Following the CIMT protocol, improvements in GMAL and GWMFT scores may reflect improvements in paretic UL performance, in real-life environment. Improvements in kinematic variability may reflect an improving of UL interjoint coordination for individuals with chronic severe hemiparesis.

Effect of the physical rehabilitation program based on self-care ability in patients with acute ischemic stroke: a quasi-experimental study

Introduction

It is the most practical goal of limb rehabilitation for stroke patients to make the upper limb, trunk, and lower limb joints link together as a whole and restore the ability to self-care. However, many previous studies focused on the single joint or single muscle group movement of stroke patients and did not integrate self-care ability training into the whole process of rehabilitation, which lacks accuracy, integrity, and systematization.

Methods

A quasi-experimental study was conducted in a tertiary hospital. Eligible patients were recruited according to the inclusion criteria and exclusion criteria and then divided into an experimental group (n = 80) and a control group (n = 80) by the medical district. The control group received the routine physical rehabilitation intervention. The experimental group adopted the physical rehabilitation program based on self-care ability led by the nurses specializing in stroke rehabilitation to carry out the multi-joint coordinated exercise based on the control group. The training time and frequency were the same in both groups (45 min per session, one session per day for three consecutive months). The primary outcome was myodynamia. Secondary outcomes were the modified Barthel Index (MBI) and Stroke Specific Quality of Life Scale (SS-QOL). The primary and secondary outcomes were assessed before the intervention and at 1 and 3 months of intervention. In this study, the TREND checklist was followed for non-randomized controlled trials.

Results

A total of 160 participants completed the study. The physical rehabilitation program based on self-care ability was better than the routine rehabilitation program. With the prolongation of intervention time, all outcomes improved gradually in the experimental group (P < 0.05), and the myodynamia of lower limbs recovered faster than that of upper limbs. In the control group, the myodynamia of the affected limb was not significantly improved (P > 0.05), with only a small increase in MBI and SS-QOL scores (P < 0.05).

Conclusion

The physical rehabilitation program based on self-care ability after stroke was beneficial for acute ischemic stroke patients and improved the patient's myodynamia, quality of life, and self-care ability within the third month.

Effect of different constraint-induced movement therapy protocols on recovery of stroke survivors with upper extremity dysfunction: a systematic review and network meta-analysis

We aimed to assess and rank comparative efficacy of different constraint-induced movement therapy (CIMT) protocols on motor function of upper extremity and activities of daily living (ADL) in stroke survivors. A comprehensive search was conducted in PubMed, EMBASE, Web of Science and Cochrane Library to identify randomized controlled trials on CIMT. Included studies were evaluated using the revised Cochrane risk of bias tool. Then a random-effects network meta-analysis was performed within a frequentist framework using Stata v16.0. Of the 1150 studies retrieved, 44 studies with 1779 participants were included. In terms of motor recovery of upper extremity, CIMT combined with trunk restraint, in which the less affected arm was constrained at least 4 h but no more than 6 h per day, ranked as the most effective intervention for the improvement of the Fugl-Meyer Assessment-Upper Extremity and the Action Research Arm Test score. In terms of ADL improvement, constraining the less affected arm for at least 4 h but no more than 6 h per day in CIMT combined with trunk restraint, was found to significantly improve the Motor Activity Log of quality of movement scale and amount of use scale score. The protocol of CIMT combined with trunk restraint, in which the less affected arm was constrained at least 4 h but no more than 6 h per day, ranked the highest in this analysis and might be considered in practice.

The Mechanism and Clinical Application of Constraint-Induced Movement Therapy in Stroke Rehabilitation

Constraint-induced movement therapy (CIMT) has been widely applied in stroke rehabilitation, and most relevant studies have shown that CIMT helps improve patients' motor function. In practice, however, principal issues include inconsistent immobilization durations and methods, while incidental issues include a narrow application scope and an emotional impact. Although many studies have explored the possible internal mechanisms of CIMT, a mainstream understanding has not been established.

Enhancing Post-Stroke Rehabilitation and Preventing Exo-Focal Dopaminergic Degeneration in Rats-A Role for Substance P

Dopaminergic signaling is a prerequisite for motor learning. Delayed degeneration of dopaminergic neurons after stroke is linked to motor learning deficits impairing motor rehabilitation. This study investigates safety and efficacy of substance P (SP) treatment on post-stroke rehabilitation, as this neuropeptide combines neuroprotective and plasticity-promoting properties. Male Sprague Dawley rats received a photothrombotic stroke within the primary motor cortex (M1) after which a previously acquired skilled reaching task was rehabilitated. Rats were treated with intraperitoneal saline (control group, n = 7) or SP-injections (250 µg/kg) 30 min before (SP-pre; n = 7) or 16 h (SP-post; n = 6) after rehabilitation training. Dopaminergic neurodegeneration, microglial activation and substance P-immunoreactivity (IR) were analyzed immunohistochemically. Systemic SP significantly facilitated motor rehabilitation. This effect was more pronounced in SP-pre compared to SP-post animals. SP prevented dopaminergic cell loss after stroke, particularly in the SP-pre condition. Despite its proinflammatory propensity, SP administration did not increase stroke volumes, post-stroke deficits or activation of microglia in the midbrain. Finally, SP administration prevented ipsilesional hypertrophy of striatal SPergic innervation, particularly in the SP-post condition. Mechanistically, SP-pre likely involved plasticity-promoting effects in the early phase of rehabilitation, whereas preservation of dopaminergic signaling may have ameliorated rehabilitative success in both SP groups during later stages of training. Our results demonstrate the facilitating effect of SP treatment on motor rehabilitation after stroke, especially if administered prior to training. SP furthermore prevented delayed dopaminergic degeneration and preserved physiological endogenous SPergic innervation.

Contralesional plasticity following constraint-induced movement therapy benefits outcome: contributions of the intact hemisphere to functional recovery

Stroke is a leading cause of death and disability worldwide. A common, chronic deficit after stroke is upper limb impairment, which can be exacerbated by compensatory use of the nonparetic limb. Resulting in learned nonuse of the paretic limb, compensatory reliance on the nonparetic limb can be discouraged with constraint-induced movement therapy (CIMT). CIMT is a rehabilitative strategy that may promote functional recovery of the paretic limb in both acute and chronic stroke patients through intensive practice of the paretic limb combined with binding, or otherwise preventing activation of, the nonparetic limb during daily living exercises. The neural mechanisms that support CIMT have been described in the lesioned hemisphere, but there is a less thorough understanding of the contralesional changes that support improved functional outcome following CIMT. Using both human and non-human animal studies, the current review explores the role of the contralesional hemisphere in functional recovery of stroke as it relates to CIMT. Current findings point to a need for a better understanding of the functional significance of contralesional changes, which may be determined by lesion size, location, and severity as well stroke chronicity.

Axonal remodeling of the corticospinal tract during neurological recovery after stroke

Stroke remains the leading cause of long-term disability. Hemiparesis is one of the most common post-stroke motor deficits and is largely attributed to loss or disruption of the motor signals from the affected motor cortex. As the only direct descending motor pathway, the corticospinal tract (CST) is the primary pathway to innervate spinal motor neurons, and thus, forms the neuroanatomical basis to control the peripheral muscles for voluntary movements. Here, we review evidence from both experimental animals and stroke patients, regarding CST axonal damage, functional contribution of CST axonal integrity and remodeling to neurological recovery, and therapeutic approaches aimed to enhance CST axonal remodeling after stroke. The new insights gleaned from preclinical and clinical studies may encourage the development of more rational therapeutics with a strategy targeted to promote axonal rewiring for corticospinal innervation, which will significantly impact the current clinical needs of subacute and chronic stroke treatment.

Constraint-induced movement therapy enhances AMPA receptor-dependent synaptic plasticity in the ipsilateral hemisphere following ischemic stroke

Constraint-induced movement therapy (CIMT) can promote the recovery of motor function in injured upper limbs following stroke, which may be associated with upregulation of α-amino-3-hydroxy-5-methyl-4-isoxazole propionic acid receptor (AMPAR) at synapses in the ipsilateral sensorimotor cortex in our previous study. However, AMPAR distribution is tightly regulated, and only AMPARs on the postsynaptic membrane can mediate synaptic transmission. We speculated that synaptic remodeling induced by movement-associated synaptic activity can promote functional recovery from stroke. To test this hypothesis, we compared AMPAR expression on the postsynaptic membrane surface in a rat model of ischemic stroke induced by middle cerebral artery occlusion (MCAO) with versus without CIMT, which consisted of daily running wheel training for 2 weeks starting on day 7 after MCAO. The results showed that CIMT increased the number of glutamate receptor (GluR)2-containing functional synapses in the ipsilateral sensorimotor cortex, and reduced non-GluR2 AMPARs in the ipsilateral sensorimotor cortex and hippocampal CA3 region. In addition, CIMT enhanced AMPAR expression on the surface of post-synaptic membrane in the ipsilateral sensorimotor cortex and hippocampus. Thus, CIMT promotes the recovery of motor function of injured upper limbs following stroke by enhancing AMPAR-mediated synaptic transmission in the ischemic hemisphere. These findings provide supporting evidence for the clinical value of CIMT for restoring limb movement in stroke patients. All experimental procedures and protocols were approved by the Department of Laboratory Animal Science of Fudan University, China (approval No. 201802173S) on March 3, 2018.

Brain Endothelial Cell-Derived Exosomes Induce Neuroplasticity in Rats with Ischemia/Reperfusion Injury

Exosomes derived from the cerebral endothelial cells play essential roles in protecting neurons from hypoxia injury, but little is known regarding the biological effects and mechanisms of exosomes on brain plasticity. In this study, exosomes were isolated from rodent cerebral endothelial cells (bEnd.3 cells) by ultracentrifugation, either endothelial cell-derived exosomes (EC-Exo) or PBS was injected intraventricularly 2 h after the middle cerebral artery occlusion/reperfusion (MCAO/R) model surgery in the Exo group and control group, respectively. Sham group rats received the same surgical but not ischemic procedure. We evaluated the motor function of rats after MCAO/R, and the foot-fault rate of the Exo group was significantly lower than that of the control group within 23 days (p < 0.05); the Catwalk analysis also showed gait difference between two groups (p < 0.05). On day 28 after MCAO/R, we euthanized the rats, removed the motor cortex from the brain, and then sequenced the genes by using GO and KEGG to find transcriptome analysis of biological terms and functional annotations: The pathway enrichment revealed that the function of synaptic transmission, regulation of synaptic plasticity, and regulation of synaptic vesicle cycle was significantly enriched with the Exo group than control group. Furthermore, the upregulation of synapsin-I expression in the motor cortex (p < 0.05) as well as the increase of the length of the dendrites were found in the Exo group (p < 0.05) than the control group. We determined the content of exosome microRNA levels, and microRNA-126-3p was the highest (TPM) by transcriptome analysis. Moreover, the microRNA-126-3p protected PC12 cells from apoptosis and increased neurite outgrowth, illustrating the mechanism of how exosomes play a role in altering brain plasticity. This study demonstrated that EC-Exo promoted functional motor recovery in the MCAO/R model, exosomes were critical for the reconstruction of synaptic function in ischemic brain injury, and microRNA-126-3p from EC-Exo could serve as a treatment for nerve damage.

A Review of Exercise-Induced Neuroplasticity in Ischemic Stroke: Pathology and Mechanisms

After ischemic stroke, survivors experience motor dysfunction and deterioration of memory and cognition. These symptoms are associated with the disruption of normal neuronal function, i.e., the secretion of neurotrophic factors, interhemispheric connections, and synaptic activity, and hence the disruption of the normal neural circuit. Exercise is considered an effective and feasible rehabilitation strategy for improving cognitive and motor recovery following ischemic stroke through the facilitation of neuroplasticity. In this review, our aim was to discuss the mechanisms by which exercise-induced neuroplasticity improves motor function and cognitive ability after ischemic stroke. The associated mechanisms include increases in neurotrophins, improvements in synaptic structure and function, the enhancement of interhemispheric connections, the promotion of neural regeneration, the acceleration of neural function reorganization, and the facilitation of compensation beyond the infarcted tissue. We also discuss some common exercise strategies and a novel exercise therapy, robot-assisted movement, which might be widely applied in the clinic to help stroke patients in the future.

Constraint-induced movement therapy improves functional recovery after ischemic stroke and its impacts on synaptic plasticity in sensorimotor cortex and hippocampus

Constraint-induced movement therapy (CIMT) has proven to be an effective way to restore functional deficits following stroke in human and animal studies, but its underlying neural plasticity mechanism remains unknown. Accumulating evidence indicates that rehabilitation after stroke is closely associated with synaptic plasticity. We therefore investigated the impact of CIMT on synaptic plasticity in ipsilateral and contralateral brain of rats following stroke. Rats were subjected to 90 minutes of transient middle cerebral artery occlusion (MCAO). CIMT was performed from 7 days after stroke and lasted for two weeks. Modified Neurology Severity Score (mNSS) and the ladder rung walking task tests were conducted at 7,14 and 21 days after stroke. Golgi-Cox staining was used to observe the plasticity changes of dendrites and dendritic spines. The expression of glutamate receptors (GluR1, GluR2 and NR1) were examined by western blot. Our data suggest that the dendrites and dendritic spines are damaged to varying degrees in bilateral sensorimotor cortex and hippocampus after acute stroke. CIMT treatment enhances the plasticity of dendrites and dendritic spines in the ipsilateral and contralateral sensorimotor cortex, increases the expression of synaptic GluR2 in ipsilateral sensorimotor cortex, which may be mechanisms for CIMT to improve functional recovery after ischemic stroke.

Paired associated magnetic stimulation promotes neural repair in the rat middle cerebral artery occlusion model of stroke

Paired associative stimulation has been used in stroke patients as an innovative recovery treatment. However, the mechanisms underlying the therapeutic effectiveness of paired associative stimulation on neurological function remain unclear. In this study, rats were randomly divided into middle cerebral occlusion model (MCAO) and paired associated magnetic stimulation (PAMS) groups. The MCAO rat model was produced by middle cerebral artery embolization. The PAMS group received PAMS on days 3 to 20 post MCAO. The MCAO group received sham stimulation, three times every week. Within 18 days after ischemia, rats were subjected to behavioral experiments—the foot-fault test, the balance beam walking test, and the ladder walking test. Balance ability was improved on days 15 and 17, and the foot-fault rate was less in their affected limb on day 15 in the PAMS group compared with the MCAO group. Western blot assay showed that the expression levels of brain derived neurotrophic factor, glutamate receptor 2/3, postsynaptic density protein 95 and synapsin-1 were significantly increased in the PAMS group compared with the MCAO group in the ipsilateral sensorimotor cortex on day 21. Resting-state functional magnetic resonance imaging revealed that regional brain activities in the sensorimotor cortex were increased in the ipsilateral hemisphere, but decreased in the contralateral hemisphere on day 20. By finite element simulation, the electric field distribution showed a higher intensity, of approximately 0.4 A/m², in the ischemic cortex compared with the contralateral cortex in the template. Together, our findings show that PAMS upregulates neuroplasticity-related proteins, increases regional brain activity, and promotes functional recovery in the affected sensorimotor cortex in the rat MCAO model. The experiments were approved by the Institutional Animal Care and Use Committee of Fudan University, China (approval No. 201802173S) on March 3, 2018.