Effects of aerobic physical exercise on neuroplasticity after stroke: systematic review

Effects of exercise on post-stroke cognitive function: a systematic review and meta-analysis of randomized controlled trials

BACKGROUND

A growing body of research examining the effect of exercise on cognitive function in stroke patients, while findings of available studies were conflicting.

OBJECTIVES

We aimed to estimate the effect of exercise on cognitive function in stroke patients.

METHODS

For this systematic review and meta-analysis, we searched PubMed, Web of Science, Embase, Cochrane, and Scopus electronic databases, through 13 March 2023. The three-level restricted maximum likelihood random effects model was used to synthesize the data.

RESULTS

Twenty-five studies met the inclusion criteria. There was a significant effect of exercise on improving cognitive function in stroke patients (Cohen's d = 0.37, 95% CI, 0.16 to 0.58, p < 0.01, I2  = 22.12%). Subgroup analysis showed that exercise significantly improved memory. In addition, aerobic exercise, exercise conducted 12 weeks or more, 3 times or more per week, less than 60 minutes per session, less than 180 minutes per week, and up to 12 months post-stroke increased cognitive function significantly.

CONCLUSIONS

Exercise improved cognitive function in stroke patients. To improve cognitive function, this meta-analysis provides clinicians with evidence to recommend that stroke patients participate in aerobic exercise at least 3 times per week for 30-60 minutes, with a goal of 180 minutes per week being achieved by increasing the frequency of exercise. Exercise initiated within 12 months post-stroke and continued for 12 weeks or more is most beneficial for improving cognitive function.

The relationship between levels of physical activity and participation in everyday life in stroke survivors: A systematic review and meta-analysis

BACKGROUND

Stroke survivors demonstrate decreased physical activity (PA) and take time to return to participation in everyday life, but the relationship between the two variables is unknown.

OBJECTIVE

To investigate the correlation and trajectory over time between levels of PA and participation in everyday life in stroke survivors.

METHODS

PubMed, Web of Science, Scopus, SPORTDiscus, Rehabilitation&Sport Medicine Source, and PEDro databases were searched from inception to January 2024. Cross-sectional and prospective studies evaluating both levels of PA and participation in stroke survivors were included. Two reviewers independently conducted the study selection, data extraction, and quality assessment. Meta-analyses of pooled correlation coefficients were calculated when at least two studies reported a correlation coefficient between the same PA and participation outcomes.

RESULTS

Of 4962 studies identified, 49 were included in the systematic review. Studies were rated high (55%%) or fair (45%) quality. A wide range of monitoring methodologies for assessing PA and participation were found in the 23 prospective studies. Seven studies were included in the meta-analyses, showing a positive moderate correlation between PA time and participation in activities of daily living (n = 148; r = 0.52; P < 0.01; I2 = 81%) in participants <6 months post-stroke, and between PA time and the participation in all areas (n = 126; r = 0.44; P < 0.01; I2 = 0%) in participants ≥6 months post-stroke. Overall, while PA showed significant improvements over time, participation only showed a tendency.

CONCLUSIONS

Despite the heterogeneity, consistent positive associations were found between PA time and participation levels in some areas. Establishing consensus is crucial to reduce heterogeneity and facilitate data pooling.

Effects of Rehabilitation Robot Training on Physical Function, Functional Recovery, and Daily Living Activities in Patients with Sub-Acute Stroke

Stroke often results in sensory deficits, muscular weakness, and diminished postural control, thereby restricting mobility and functional capabilities. It is important to promote neuroplasticity by implementing task-oriented exercises that induce changes in patients. Therefore, this study aimed to investigate the effects of rehabilitation robot training on physical function, functional recovery, and activities of daily living (ADLs) in patients with subacute stroke. The study participants were patients with subacute stroke receiving treatment at Hospitals A and B. They were selected as research subjects based on selection and exclusion criteria. The experimental group received rehabilitation robot training in sessions of 30 min, five times weekly, for a total of 20 sessions over four weeks. Conversely, the control group underwent standard rehabilitation equipment training with an identical frequency, duration, and number of sessions. Measurements were taken before and after the training period to assess changes in physical function, functional recovery, and activities of daily living using tools such as the MMT, BBS, FBG, FAC, FIM, and MBI. The results were as follows: in the within-group comparison, the rehabilitation robot training group showed significant differences in MMT, BBS, FBG, FAC, FIM, and MBI (p < 0.05), while the control group showed significant differences in FIM (p < 0.05). Statistically significant differences were observed in the time, group, and time × group interaction effects among the MMT, static seated FBG, dynamic seated FBG, FIM, and MBI (p < 0.05). Based on these results, rehabilitation robotic training resulted in significant improvements in physical function, functional recovery, and activities of daily living in patients with subacute stroke. Based on these findings, providing a basic protocol for a rehabilitation program that applies rehabilitation robot training to patients with subacute stroke may offer more effective treatment and outcomes in the future.

Mechanisms and benefits of cardiac rehabilitation in individuals with stroke: emerging role of its impact on improving cardiovascular and neurovascular health

Human and animal studies have demonstrated the mechanisms and benefits of aerobic exercise for both cardiovascular and neurovascular health. Aerobic exercise induces neuroplasticity and neurophysiologic reorganization of brain networks, improves cerebral blood flow, and increases whole-body VO2peak (peak oxygen consumption). The effectiveness of a structured cardiac rehabilitation (CR) program is well established and a vital part of the continuum of care for people with cardiovascular disease. Individuals post stroke exhibit decreased cardiovascular capacity which impacts their neurologic recovery and extends disability. Stroke survivors share the same risk factors as patients with cardiac disease and can therefore benefit significantly from a comprehensive CR program in addition to neurorehabilitation to address their cardiovascular health. The inclusion of individuals with stroke into a CR program, with appropriate adaptations, can significantly improve their cardiovascular health, promote functional recovery, and reduce future cardiovascular and cerebrovascular events thereby reducing the economic burden of stroke.

Top-Down and Bottom-Up Mechanisms of Motor Recovery Poststroke

Stroke remains a leading cause of disability. Motor recovery requires the interaction of top-down and bottom-up mechanisms, which reinforce each other. Injury to the brain initiates a biphasic neuroimmune process, which opens a window for spontaneous recovery during which the brain is particularly sensitive to activity. Physical activity during this sensitive period can lead to rapid recovery by potentiating anti-inflammatory and neuroplastic processes. On the other hand, lack of physical activity can lead to early closure of the sensitive period and downstream changes in muscles, such as sarcopenia, muscle stiffness, and reduced cardiovascular capacity, and blood flow that impede recovery.

Potential effect of physical exercise on the downregulation of BDNF mRNA expression in rat hippocampus following intracerebral hemorrhage

OBJECTIVES

Physical exercise is known to induce expression of the neuroprotective brain derived neurotrophic factor (BDNF) in the hippocampus. This study examined the effects of physical exercise on hippocampal BDNF expression and the potential benefits for preventing remote secondary hippocampal damage and neurological impairment following intracerebral hemorrhage (ICH).

MATERIALS AND METHODS

Wistar rats were randomly assigned to sham-operated, ICH, and ICH followed by exercise (ICH/Ex) groups. The two ICH groups were injected with type IV collagenase into the left basal ganglia, while sham animals were injected with equal-volume saline. The ICH/Ex group rats ran on a treadmill at 11 m/min for 30 min/day from day 3 to 16 post-ICH. All animals were examined for neurological function on day 2 pretreatment and from day 3 to 15 posttreatment, for spontaneous motor activity in the open field on day 15, and for cognitive ability using the object location test on day 16. Animals were then euthanized and bilateral hippocampi collected for gene expression analyses.

RESULTS

Experimental ICH induced neurological deficits that were not reversed by exercise. In contrast, ICH did not alter spontaneous activity or object location ability. Expression of BDNF mRNA of the ICH group was significantly downregulated in the ipsilateral hippocampus compared to the SHAM group, but this downregulation was not shown in the ICH/Ex group. The ICH/Ex group showed the downregulation of caspase-3 mRNA expression in the contralateral hippocampus compared to the SHAM group, while neither ICH nor exercise influenced toll-like receptor 4 mRNA expression.

CONCLUSIONS

ICH induced the secondary BDNF downregulation in the hippocampus remote from the lesion, whereas physical exercise might partially mitigate the downregulation.

Bibliometric analysis of traditional Chinese exercises in stroke rehabilitation from 2003 to 2022 using CiteSpace

Background

A comprehensive analysis was conducted on the relevant literature pertaining to the application of traditional Chinese exercises in stroke rehabilitation over the past 20 years. Additionally, a scientific knowledge map was created to elucidate the current research status, investigate its development process and research trends, and offer novel research perspectives for future studies.

Methods

The data is sourced from the WOS Core Collection, and CiteSpace software is used to analyze the relevant literature on traditional Chinese exercises in stroke rehabilitation. The analysis began with the selection of publications, countries, institutions, highly cited authors, and co-cited references to summarize the current research status of traditional exercises in stroke rehabilitation. Second, keywords were employed to identify research hotspots, and keyword clustering time zone diagrams were chosen to track the research development process. Finally, burst keywords were employed to explore the research frontiers and trends in this field.

Results

In total, 937 documents were retrieved, and the annual publication volume consistently and sustainably increased. China and the USA emerged as significant contributors. The Chinese University of Hong Kong had the highest publication count, with ADA L from the University of Sydney being a highly cited author. Initially, keywords focused on cardiac output, blood flow, pressure, and performance. Over time, the focus shifted to heart failure, muscle strength, mortality, and exercise capacity. Current trends encompass outcome, impact, virtual reality, and anxiety.

Conclusion

Integrating key elements of traditional exercise approaches with the specific attributes of movement disorders during the stroke recovery phase is essential. Therefore, enhancing the stroke rehabilitation training program and exploring novel avenues for traditional exercise-based interventions are critical.

A comparative study on the overlapping effects of clinically applicable therapeutic interventions in patients with central nervous system damage

This study was conducted to investigate the effects of anti-gravity treadmill (AGT) training, which provides visual feedback and Biorescue training on proprioception, muscle strength, balance, and gait, in stroke patients. A total of 45 people diagnosed with post-stroke were included as study subjects; they were randomized to an AGT training group provided with visual feedback (Group A), a Biorescue training group provided with visual feedback (Group B), and an AGT/Biorescue group that subsequently received AGT training and Biorescue training (Group C). A muscle strength-measuring device was used to evaluate muscle strength. Timed Up and Go and Bug Balance Scale assessment sheets were used to evaluate balance ability. Dartfish software was used to evaluate gait ability. The results of the study showed that Groups A and C had a significant increase in muscle strength compared with Group B; in terms of balance and gait abilities, Group C showed a significant increase in balance ability and gait speed and a significant change in knee joint angle compared with Groups A and B. In conclusion, this study suggests that including a method that applies multiple therapeutic interventions is desirable in the rehabilitation of stroke patients to improve their independence.

Moderate intensity aerobic exercise may enhance neuroplasticity of the contralesional hemisphere after stroke: a randomised controlled study

Upregulation of neuroplasticity might help maximize stroke recovery. One intervention that appears worthy of investigation is aerobic exercise. This study aimed to determine whether a single bout of moderate intensity aerobic exercise can enhance neuroplasticity in people with stroke. Participants were randomly assigned (1:1) to a 20-min moderate intensity exercise intervention or remained sedentary (control). Transcranial magnetic stimulation measured corticospinal excitability of the contralesional hemisphere by recording motor evoked potentials (MEPs). Intermittent Theta Burst Stimulation (iTBS) was used to repetitively activate synapses in the contralesional primary motor cortex, initiating the early stages of neuroplasticity and increasing excitability. It was surmised that if exercise increased neuroplasticity, there would be a greater facilitation of MEPs following iTBS. Thirty-three people with stroke participated in this study (aged 63.87 ± 10.30 years, 20 male, 6.13 ± 4.33 years since stroke). There was an interaction between Time*Group on MEP amplitudes (P = 0.009). Participants allocated to aerobic exercise had a stronger increase in MEP amplitude following iTBS. A non-significant trend indicated time since stroke might moderate this interaction (P = 0.055). Exploratory analysis suggested participants who were 2-7.5 years post stroke had a strong MEP facilitation following iTBS (P < 0.001). There was no effect of age, sex, resting motor threshold, self-reported physical activity levels, lesion volume or weighted lesion load (all P > 0.208). Moderate intensity cycling may enhance neuroplasticity in people with stroke. This therapy adjuvant could provide opportunities to maximize stroke recovery.

Defining, quantifying, and reporting intensity, dose, and dosage of neurorehabilitative interventions focusing on motor outcomes

Introduction

Determining the minimal amount of therapy needed for positive neurorehabilitative outcomes is important for optimizing active treatment interventions to improve motor outcomes. However, there are various challenges when quantifying these relationships: first, several consensuses on the definition and usage of the terms intensity, dose, and dosage of motor interventions have been proposed, but there seems to be no agreement, and the terms are still used inconsistently. Second, randomized controlled trials frequently underreport items relevant to determining the intensity, dose, and dosage of the interventions. Third, there is no universal measure to quantify therapy intensity accurately. This "perspectives" paper aims to increase awareness of these topics among neurorehabilitation specialists.

Defining quantifying and reporting

We searched the literature for definitions of intensity, dose, and dosage and adapted the ones we considered the most appropriate to fit the needs of neurorehabilitative interventions. Furthermore, we suggest refining the template for intervention description and replication (TIDieR) to enhance the reporting of randomized controlled trials. Finally, we performed a systematic literature search to provide a list of intensity measures and complemented these with some novel candidate measures.

Discussion

The proposed definitions of intensity, dose, and dosage could improve the communication between neurorehabilitation specialists and the reporting of dose and dosage in interventional studies. Quantifying intensity is necessary to improve our understanding of the minimal intensity, dose, and dosage of therapy needed to improve motor outcomes in neurorehabilitation. We consider the lack of appropriate intensity measures a significant gap in knowledge requiring future research.

Relationship between Participation in Daily Life Activities and Physical Activity in Stroke Survivors: A Protocol for a Systematic Review and Meta-Analysis

Stroke survivors undertake low levels of physical activity and participation in daily life activities, but the correlation between these two domains still carries some degree of uncertainty. This systematic review and meta-analyses-based data synthesis will aim to describe and estimate the relationship between participation in daily life activities and physical activity in stroke survivors. Six databases (MEDLINE/PubMed, Web of Science, Scopus, PEDro, SPORTDiscus, and Rehabilitation & Sport Medicine Source) will be searched. Studies assessing participation alongside physical activity levels in adult stroke survivors in English or Spanish will be included. The study selection, assessment of the risk of bias, and data extraction will be conducted independently by two investigators. If available, correlation values between physical activity and participation outcomes will be extracted. The Hedges-Olkin method will be used for pooling correlation values between participation and physical activity measures. Subgroup analyses will be performed according to the time elapsed since the stroke (i.e., ≤6 months and >6 months). This will be the first systematic review with a meta-analysis to provide information on the relationship between physical activity and participation in stroke survivors. Findings are likely to inform the design of health prevention protocols and the development of healthy behavior change interventions.

Transcranial direct current stimulation combined with bodyweight support-tai chi footwork for motor function of stroke survivors: a study protocol of randomised controlled trial

INTRODUCTION

Our previous studies have proposed the bodyweight support-t'ai chi (BWS-TC) footwork training for stroke survivors with severe motor dysfunction and fear of falling, and have proven its positive effects for motor function. Transcranial direct current stimulation (tDCS) provides a non-invasive and safe way to modulate neuronal activity and provoke neuroplastic changes and to improve the motor function of stroke survivors. However, it is unclear whether the integration of BWS-TC and tDCS has synergistic effects on improving motor function of the stroke survivors.

METHODS AND ANALYSIS

This study will be an assessor-blinded randomised controlled trial involving 12-week intervention and 6-month follow-up. One hundred and thirty-five individuals with stroke will be randomly divided in a ratio of 1:1:1 into three groups. Control group A, control group B and intervention group C will receive tDCS and conventional rehabilitation programmes (CRPs), BWS-TC and CRP, tDCS-BWS-TC and CRP for 12 weeks, respectively. The primary outcome measures will include the efficacy (Fugl-Meyer Assessment), acceptability and safety of these interventions. The secondary outcome measures will include balance ability (ie, limits of stability and modified clinical test of sensory integration), walking function, brain structure and function, risk of falling, Barthel Index and 36-Item Short Form Survey. All outcomes will be assessed at baseline, 6 and 12 weeks during intervention, and 1, 3 and 6 months during the follow-up period. Two-way analysis of variance with repeated measures will be applied to examine the main effects of the group and the time factor and group-time interaction effects for all outcome measures.

ETHICS AND DISSEMINATION

Ethics approval was obtained from the ethics committee of the Shanghai Seventh People's Hospital (2021-7th-HIRB-017). The results of the study will be published in a peer-reviewed journal and presented at scientific conferences.

TRIAL REGISTRATION NUMBER

ChiCTR2200059329.

Effects of a 12-week, seated, virtual, home-based tele-exercise programme compared with a prerecorded video-based exercise programme in people with chronic neurological impairments: protocol for a randomised controlled trial

INTRODUCTION

Exercise is vital to staying well and preventing secondary complications in people with chronic neurological impairments (CNI). Appropriate exercise is often inaccessible to this population. The purpose of the study is to investigate the effects of a seated, virtual exercise programme on heart rate, recovery, fatigue, pain, motivation, enjoyment and quality of life in people with CNI.

METHODS AND ANALYSIS

Individuals with CNI will be screened for eligibility, and 60 participants will be randomised 1:1 into either a live or prerecorded group. There is no geographical limitation to where participants reside, since participation is virtual. The study will be coordinated by one site in White Plains, New York, USA. The live group will exercise with an instructor via Zoom while the prerecorded group will exercise at their chosen time using prerecorded videos, 3×/week for 12 weeks.

PRIMARY OUTCOME MEASURES

change in heart rate during exercise/recovery.

SECONDARY OUTCOME MEASURES

fatigue, motivation, level of pain and exertion, physical well-being, enjoyment of physical activity, motivation and quality of life. Outcomes will be assessed at baseline, midpoint, end of study and 1-month poststudy. Adverse events, medication changes and physical activity will be tracked throughout. Within-group and between-group comparisons will be performed by using analysis of covariance and regression.

ETHICS AND DISSEMINATION

BRANY IRB approval: 22 September 2020, protocol #20-08-388-512. All participants will provide written informed consent. Results will be disseminated through presentations, publications and ClinicalTrials.gov.

TRIAL REGISTRATION NUMBER

NCT04564495.

Systematic review on post-stroke computerized cognitive training: Unveiling the impact of confounding factors

Background

Stroke is a highly incapacitating disease that can lead to disabilities due to cognitive impairment, physical, emotional, and social sequelae, and a decrease in the quality of life of those affected. Moreover, it has been suggested that cognitive reserve (patients' higher levels of education or having a skilled occupation), for instance, can promote faster cognitive recovery after a stroke. For this reason, this review aims to identify the cognitive, functional, and behavioral effects of computerized rehabilitation in patients aged 50 years or older who had a stroke, considering cognitive reserve proxies.

Methods

We followed the Preferred Reporting Items for Systematic Reviews and Meta-Analysis-PRISMA, and performed the search for peer-reviewed randomized controlled trials without a date restriction on CINAHL, LILACS, PubMed, Scopus, and Web of Science databases were chosen.

Results

We screened 780 papers and found 19 intervention studies, but only 4 met the inclusion criteria and shared data. These studies included computerized tools for motor and cognitive rehabilitation in the experimental groups. In all studies, computerized training was combined with other interventions, such as standard therapy, occupational therapy, and aerobic exercises. There were 104 participants affected by ischemic or hemorrhagic stroke, predominantly male (57.69%), and all with cognitive impairment.

Conclusion

Despite a limited number of studies, varied methods and insufficient information available, schooling as a CR proxy combined with high-intensity computerized cognitive training was key to mediating cognitive improvement. The systematic review also identified that the associated ischemic stroke and shorter time of onset for rehabilitation contribute to the cognitive evolution of patients. Findings do not support a greater benefit of computerized cognitive training compared to conventional cognitive therapies.

Systematic review registration

[https://www.crd.york.ac.uk/prospero/display_record.php?RecordID=296193], identifier [CRD42022296193].

The effect and mechanism of exercise for post-stroke pain

One of the common negative effects of a stroke that seriously lowers patients' quality of life is post-stroke pain (PSP). Thus, exercise in PSP management has become a hot research topic. The main advantages of exercise therapy are affordability and ease of acceptance by patients compared to other treatment methods. Therefore, this article reviews the effectiveness and possible mechanisms of exercise interventions for PSP. Exercise training for patients with PSP not only improves physical function but also effectively reduces pain intensity and attenuates the behavioral response to pain. In addition, exercise therapy can improve brain function and modulate levels of pro-inflammatory and neurotrophic factors to exert specific analgesic effects. Potential mechanisms for exercise intervention include modulation of synaptic plasticity in the anterior cingulate gyrus, modulation of endogenous opioids in vivo, reversal of brain-derived neurotrophic factor overexpression, inhibition of purinergic receptor (P2X4R, P2X7R) expression, and inhibition of microglia activation. However, current research on exercise for PSP remains limited, and the sustainable benefits of exercise interventions for PSP need to be further investigated.

The Effect of Endurance Training on Serum BDNF Levels in the Chronic Post-Stroke Phase: Current Evidence and Qualitative Systematic Review

Research in modern neurorehabilitation focusses on cognitive and motor recovery programmes tailored to each stroke patient, with particular emphasis on physiological parameters. The objectives of this review were to determine whether a single bout of endurance activity or long-term endurance activity regulates exercise-dependent serum brain-derived neurotrophic factor (BDNF) levels and to evaluate the methodological quality of the studies. To assess the effectiveness of endurance exercise among patients in the chronic post-stroke phase, a systematic review was performed, including searching EBSCOhost, PEDro, PubMed, and Scopus for articles published up to the end of October 2021. The PRISMA 2020 outline was used, and this review was registered on PROSPERO. Of the 180 papers identified, seven intervention studies (comprising 200 patients) met the inclusion criteria. The methodological quality of these studies was evaluated by using the Physiotherapy Evidence Database (PEDro) criteria. The effect of exercise was evaluated in four studies with a single bout of endurance activity, two studies with long-term endurance activity, and one study with a single bout of endurance activity as well as long-term endurance activity. The results of our systematic review provide evidence that endurance exercise might augment the peripheral BDNF concentration in post-stroke individuals.