Aerobic exercise improves cognition and motor function poststroke

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 effects of cycling on walking outcomes in adults with stroke: a systematic review

BACKGROUND

Stationary cycling is often prescribed for survivors of stroke as a safe means of aerobic exercise to improve cardiovascular health. While cycling is typically not prescribed to restore ambulatory function, improvements in measures of walking after cycling interventions have been reported in the literature.

OBJECTIVE

To investigate the effects of cycling on walking outcomes in adults with stroke.

METHODS

Relevant databases were searched through 15 August. Walking-related outcomes were extracted. Correlation coefficients were computed to measure the relationship between exercise protocol parameters and change in walking outcomes.

RESULTS

Eleven articles were included in the review. Eight studies representing nine cycling intervention groups reported change in walking capacity measured by the six-minute walk test with improvements ranging from 6.1 to 63.0 m. Seven studies measured gait velocity, reporting improvements ranging from 0.01 to 0.21 m/sec. Protocols that yielded the greatest improvement in walking capacity prescribed moderate- to high-intensity aerobic training. Significant positive correlations were measured between change in gait velocity and number of exercise sessions and total minutes of exercise prescribed.

CONCLUSION

Considerable heterogeneity was observed across cycling protocols with respect to intensity, frequency, exercise duration and protocol duration. However, none of the studies reported declines in walking outcomes and improvements were measured in the absence of task-specific gait training. Cycling interventions employing moderate- to high-intensity aerobic training and 24 sessions or more may be optimal in improving gait velocity and walking capacity.

Comparative Efficacy of High-Intensity Training Versus Conventional Training in Individuals With Chronic Traumatic Brain Injury: A Pilot Randomized Controlled Study

Numerous studies have evaluated the efficacy of interventions to improve locomotion after acute-onset brain injury, although most focus on patients with stroke, with less attention toward traumatic brain injury (TBI). For example, a number of studies in patients post-stroke have evaluated the effects of high-intensity training (HIT) attempting to maximize stepping practice, while no studies have attempted this intervention in patients with TBI. The purpose of this blinded-assessor randomized trial was to evaluate the effects of HIT focused on stepping practice versus conventional training on walking and secondary outcomes in individuals with TBI. Using a crossover design, ambulatory participants with TBI >6-months duration performed HIT focused on stepping in variable contexts (overground, treadmill, stairs) or conventional training for up to 15 sessions over five weeks, with interventions alternated >4 weeks later. HIT focused on maximizing stepping practice while trying to achieve higher cardiovascular intensities (>70% heart rate reserve), while conventional training focused on impairment-based and functional exercises with no restrictions on intensities achieved. Greater increases in 6-min walk test and peak treadmill speed during graded exercise testing were observed after HIT versus conventional training, with moderate associations between differences in stepping practice and outcomes. Greater gains were also observed in estimates of aerobic capacity and efficiency after HIT, with additional improvements in selected cognitive assessments. The present study suggests that the amount and intensity of stepping practice may be important determinants of improved locomotor outcomes in patients with chronic TBI, with possible secondary benefits on aerobic capacity/efficiency and cognition. Clinical Trial Registration-URL: https://clinicaltrials.gov/; Unique Identifier: NCT04503473.

Aerobic exercise interventions for promoting cardiovascular health and mobility after stroke: a systematic review with Bayesian network meta-analysis

OBJECTIVE

To determine the superiority of aerobic exercise (AE) interventions on key outcomes of stroke recovery, including cardiorespiratory fitness (V̇O2peak, primary outcome), systolic blood pressure (SBP) and mobility (6 min Walk Test (6MWT) distance and 10 m Usual Gait Speed) after stroke.

DATA SOURCES

MEDLINE, EMBASE, Web of Science, CINAHL, CENTRAL, SPORTDiscus, PsycINFO and AMED Allied and Complementary Medicine were searched from inception to February 2023.

ELIGIBILITY CRITERIA

Randomised controlled trials were included that compared the effects of any AE interventions (low-intensity, moderate-intensity, high-intensity continuous training (HICT), high-intensity interval training (HIIT)) to no exercise, usual care or other AE interventions in individuals poststroke.

ANALYSES

Systematic review with Bayesian network meta-analysis (NMA) methodology was employed. Surface under the cumulative ranking curve (SUCRA) values were used to rank interventions. The Grading of Recommendations, Assessment, Development and Evaluation minimally contextualised framework for NMA was followed.

RESULTS

There were 28 studies (n=1298) included in the NMA for V̇O2peak, 11 (n=648) for SBP, 28 (n=1494) for 6MWT and 18 (n=775) for the 10 m Usual Gait Speed. The greatest effect on V̇O2peak, 6MWT and 10 m Usual Gait Speed was observed after HIIT and HICT. No differences between interventions were found for SBP. SUCRA values identified HIIT as the superior AE intervention for all outcomes of interest. HIIT was the most effective intervention for improving V̇O2peak (2.9 mL/kg/min (95% credible interval 0.8 to 5.0) moderate certainty) compared with usual care.

CONCLUSION

This NMA suggests that higher-intensity AE is superior to traditional low-intensity to moderate-intensity AE for improving outcomes after stroke.

The effect of moderate and vigorous aerobic exercise training on the cognitive and walking ability among stroke patients during different periods: A systematic review and meta-analysis

OBJECTIVE

The study examined whether rehabilitation using aerobic exercise is more appropriate for patients less than 3 months post-stroke or more appropriate for patients more than 3 months post-stroke.

METHOD

PubMed, Embase, Web of Science, Scopus and CNKI databases were searched from inception to September 2023. All studies included must be written in English and grey literature was excluded. The quality of the study was evaluated using the PEDro scale. Standard mean difference (SMD) and 95% confidence interval (CI) were calculated. The primary outcomes are cognitive ability and walking ability. The intervention of the experimental group must be or include high-intensity aerobic training or moderate-intensity aerobic training. In addition, we required low intensity routine exercises in control group.

RESULT

Only 15 studies were included in this meta-analysis. The results showed that aerobic exercise has a positive rehabilitation effect on cognitive and walking ability of stroke patients. Global Cognitive Function (SMD = 0.81 95%CI 0.49-1.12), Walking Capacity (SMD = 1.19, 95%CI 0.75-1.62), VO2peak (SMD = 0.97, 95%CI 0.66-1.28), and brain-derived neurotrophic factor (SMD = 2.73, 95%CI 2.03-3.43). We further observed that patients who suffered a stroke within the past three months exhibited superior rehabilitation outcomes compared to patients who suffered a stroke more than three months ago, specifically in terms of cognitive ability, walking tests, and cardiopulmonary function.

CONCLUSIONS

It is recommended to carry out treatment for patients in the initial stage of stroke, and it is required to pay attention to exercise intensity in the process of treatment to ensure patient safety.

Rehabilitation Training after Spinal Cord Injury Affects Brain Structure and Function: From Mechanisms to Methods

Spinal cord injury (SCI) is a serious neurological insult that disrupts the ascending and descending neural pathways between the peripheral nerves and the brain, leading to not only functional deficits in the injured area and below the level of the lesion but also morphological, structural, and functional reorganization of the brain. These changes introduce new challenges and uncertainties into the treatment of SCI. Rehabilitation training, a clinical intervention designed to promote functional recovery after spinal cord and brain injuries, has been reported to promote activation and functional reorganization of the cerebral cortex through multiple physiological mechanisms. In this review, we evaluate the potential mechanisms of exercise that affect the brain structure and function, as well as the rehabilitation training process for the brain after SCI. Additionally, we compare and discuss the principles, effects, and future directions of several rehabilitation training methods that facilitate cerebral cortex activation and recovery after SCI. Understanding the regulatory role of rehabilitation training at the supraspinal center is of great significance for clinicians to develop SCI treatment strategies and optimize rehabilitation plans.

Exercise alters cortico-basal ganglia network metabolic connectivity: a mesoscopic level analysis informed by anatomic parcellation defined in the mouse brain connectome

The basal ganglia are important modulators of the cognitive and motor benefits of exercise. However, the neural networks underlying these benefits remain poorly understood. Our study systematically analyzed exercise-associated changes in metabolic connectivity in the cortico-basal ganglia-thalamic network during the performance of a new motor task, with regions-of-interest defined based on mesoscopic domains recently defined in the mouse brain structural connectome. Mice were trained on a motorized treadmill for six weeks or remained sedentary (control), thereafter undergoing [14C]-2-deoxyglucose metabolic brain mapping during wheel walking. Regional cerebral glucose uptake (rCGU) was analyzed in 3-dimensional brains reconstructed from autoradiographic brain sections using statistical parametric mapping. Metabolic connectivity was assessed by calculating inter-regional correlation of rCGU cross-sectionally across subjects within a group. Compared to controls, exercised animals showed broad decreases in rCGU in motor areas, but increases in limbic areas, as well as the visual and association cortices. In addition, exercised animals showed (i) increased positive metabolic connectivity within and between the motor cortex and caudoputamen (CP), (ii) newly emerged negative connectivity of the substantia nigra pars reticulata with the globus pallidus externus, and CP, and (iii) reduced connectivity of the prefrontal cortex (PFC). Increased metabolic connectivity in the motor circuit in the absence of increases in rCGU strongly suggests greater network efficiency, which is also supported by the reduced involvement of PFC-mediated cognitive control during the performance of a new motor task. Our study delineates exercise-associated changes in functional circuitry at the subregional level and provides a framework for understanding the effects of exercise on functions of the cortico-basal ganglia-thalamic network.

Moderate-intensity cardiovascular exercise performed before motor practice attenuates offline implicit motor learning in stroke survivors but not age-matched neurotypical adults

The acute impact of cardiovascular exercise on implicit motor learning of stroke survivors is still unknown. We investigated the effects of cardiovascular exercise on implicit motor learning of mild-moderately impaired chronic stroke survivors and neurotypical adults. We addressed whether exercise priming effects are time-dependent (e.g., exercise before or after practice) in the encoding (acquisition) and recall (retention) phases. Forty-five stroke survivors and 45 age-matched neurotypical adults were randomized into three sub-groups: BEFORE (exercise, then motor practice), AFTER (motor practice, then exercise), and No-EX (motor practice alone). All sub-groups practiced a serial reaction time task (five repeated and two pseudorandom sequences per day) on three consecutive days, followed 7 days later by a retention test (one repeated sequence). Exercise was performed on a stationary bike, (one 20-min bout per day) at 50% to 70% heart rate reserve. Implicit motor learning was measured as a difference score (repeated-pseudorandom sequence response time) during practice (acquisition) and recall (delayed retention). Separate analyses were performed on the stroke and neurotypical groups using linear mixed-effects models (participant ID was a random effect). There was no exercise-induced benefit on implicit motor learning for any sub-group. However, exercise performed before practice impaired encoding in neurotypical adults and attenuated retention performance of stroke survivors. There is no benefit to implicit motor learning of moderately intense cardiovascular exercise for stroke survivors or age-matched neurotypical adults, regardless of timing. Practice under a high arousal state and exercise-induced fatigue may have attenuated offline learning in stroke survivors.

Rehabilitation assisted by Space technology-A SAHC approach in immobilized patients-A case of stroke

Introduction: The idea behind the presentation of this case relates to utilizing space technology in earth applications with mutual benefit for both patients confined to bed and astronauts. Deconditioning and the progressiveness of skeletal muscle loss in the absence of adequate gravity stimulus have been of physiological concern. A robust countermeasure to muscle disuse is still a challenge for both immobilized patients and astronauts in long duration space missions. Researchers in the space medicine field concluded that artificial gravity (AG) produced by short-radius centrifugation on a passive movement therapy device, combined with exercise, has been a robust multi-system countermeasure as it re-introduces an acceleration field and gravity load. Methods: A short-arm human centrifuge (SAHC) alone or combined with exercise was evaluated as a novel, artificial gravity device for an effective rehabilitation strategy in the case of a stroke patient with disability. The results reveal valuable information on an individualized rehabilitation strategy against physiological deconditioning. A 73-year-old woman was suddenly unable to speak, follow directions or move her left arm and leg. She could not walk, and self-care tasks required maximal assistance. Her condition was getting worse over the years, also she was receiving conventional rehabilitation treatment. Intermittent short-arm human centrifuge individualized protocols were applied for 5 months, three times a week, 60 treatments in total. Results: It resulted in significant improvement in her gait, decreased atrophy with less spasticity on the left body side, and ability to walk at least 100 m with a cane. Balance and muscle strength were improved significantly. Cardiovascular parameters improved responding to adaptations to aerobic exercise. Electroencephalography (EEG) showed brain reorganization/plasticity evidenced through functional connectivity alterations and activation in the cortical regions, especially of the precentral and postcentral gyrus. Stroke immobility-related disability was also improved. Discussion: These alterations were attributed to the short-arm human centrifuge intervention. This case study provides novel evidence supporting the use of the short-arm human centrifuge as a promising therapeutic strategy in patients with restricted mobility, with application to astronauts with long-term muscle disuse in space.

Exercise dosage to facilitate the recovery of balance, walking, and quality of life after stroke

Background

Although aerobic training (AT) and resistance training (RT) are recommended after stroke, the optimal dosage of these interventions and their effectiveness on balance, walking capacity, and quality of life (QoL) remain conflicting.

Objectives

Our study aimed to quantify the effects of different modes, dosages and settings of exercise therapy on balance, walking capacity, and QoL in stroke survivors.

Method

PubMed, CINHAL, and Hinari databases were searched for randomised controlled trials (RCTs) evaluating the effects of AT and RT on balance, walking, and QoL in stroke survivors. The treatment effect was computed by the standard mean differences (SMDs).

Results

Twenty-eight trials (n = 1571 participants) were included. Aerobic training and RT interventions were ineffective on balance. Aerobic training interventions were the most effective in improving walking capacity (SMD = 0.37 [0.02, 0.71], p = 0.04). For walking, capacity, a higher dosage (duration ≥ 120 min/week; intensity ≥ 60% heart rate reserve) of AT interventions demonstrated a significantly greater effect (SMD = 0.58 [0.12, 1.04], p = 0.01). Combined AT and RT improved QoL (SMD = 0.56 [0.12, 0.98], p = 0.01). Hospital located rehabilitation setting was effective for improving walking capacity (SMD = 0.57 [0.06, 1.09], p = 0.03) compared with home and/or community and laboratory settings.

Conclusion

Our findings showed that neither AT nor RT have a significant effect on balance. However, AT executed in hospital-located settings with a higher dose is a more effective strategy to facilitate walking capacity in chronic stroke. In contrast, combined AT and RT is beneficial for improving QoL.

Clinical implications

A high dosage of aerobic exercise, duration ≥ 120 min/week; intensity ≥ 60% heart rate reserve is beneficial for improving walking capacity.

The Assessment of Acute Chorioretinal Changes Due to Intensive Physical Exercise in Senior Elite Athletes

Regular physical exercise is known to lower the incidence of age-related eye diseases. We aimed to assess the acute chorioretinal alterations in older adults following intense physical strain. Seventeen senior elite athletes were recruited who underwent an aerobic exercise on a cycle ergometer and macular scanning by optical coherence tomography. A significant thinning of the entire retina was observed 1 min after exercise, followed by a thickening at 5 min, after which the thickness returned to baseline. This trend was similar in almost every single retinal layer, although a significant change was observed only in the inner retina. Choroidal thickness changes were neither significant nor did they correlate with the thickness changes of intraretinal layers. The mechanism of how these immediate retinal changes chronically impact age-related sight-threatening pathologies that, in turn, result in a substantially reduced quality of life warrants further investigation on nontrained older adults as well.

Protective effects of early exercise on neuroinflammation, and neurotoxicity associated by traumatic brain injury: a behavioral and neurochemical approach

OBJECTIVE

The benefits of exercise in TBI have been proven. However, the time-dependent effects of exercise initiation and the involved mechanisms are controversial. We investigated the effects of preconditioning, continuous, early, and delayed treadmill exercise on motor behavior, brain edema, inflammation, and oxidative stress in experimental traumatic brain injury (TBI).

MATERIALS AND METHODS

48 male rats were assigned into two groups: sedentary control (Sham and TBI) and exercise groups: 1MB (preconditioning, initiation beginning at 1 month before trauma), 1MBA (continuous, initiation beginning at 1 month before and continuing 1 month after trauma), 24hA (early, initiation beginning at 24 h after trauma), and 1WA (delay, initiation beginning at 1 week after trauma). The rats in exercise groups were forced to run on a treadmill five days a week for 30 min per day. Rotarod and open file were used to assess motor behavior. ELISA was also used to measure total antioxidant capacity (TAC), tumor necrosis factor-alpha (TNF-α), and malondialdehyde (MDA) in serum and CSF.

RESULTS

Exercise significantly decreased neurological impairments, motor deficits, and apoptosis compared with the sedentary group. Early (within 24 h) and ongoing (1 MBA) exercise significantly improved motor behavior after TBI. In addition, these exercise programs inhibited brain edema and the number of apoptotic cells. MDA and TNF-α levels increased in all exercise groups, but the effects were greater after early exercise than after delayed exercise, resulting in a significant decrease in TAC levels in serum and CSF. We discovered a positive correlation between MDA, TAC, and TNF-α concentration in serum and CSF.

CONCLUSION

Our finding suggests that early exercise (24hA) and 1MBA groups afford neuroprotection and reduce the second injury consequence, probably by reducing neuronal apoptosis and oxidative stress.

Aerobic exercises and cognitive function in post-stroke patients: A systematic review with meta-analysis

OBJECTIVE

To study the effect of aerobic exercise on cognitive function of post-stroke patients, especially to identify specific interventions that the most likely to maximize cognitive benefits of stroke patients.

METHODS

According to the PRISMA principle, the databases of Web of Science, EMBASE, PubMed and Cochrane library were searched to collect randomized controlled trial data of aerobic exercise on cognitive function intervention of post-stroke patients. The Cochrane bias risk evaluation instrument was used to assess the methodological quality of included studies. Review Manager 5.4.1 software was used to analyze heterogeneity and potential publication bias.

RESULTS

A total of 11 criteria studies that satisfied the association between aerobic exercise and cognitive function following stroke were selected to be included in the review. Global cognition ability was significantly improved after aerobic exercise intervention (0.51; 95% confidence interval [CI] 0.16-0.86; P = .004), moderate intensity had the largest effect size on improving global cognition ability (0.98; 95% CI 0.48-1.47; P = .0001), none of cognitive flexibility, working memory, selective attention and conflict resolution showed the significant difference from zero.

CONCLUSION

Aerobic exercise has a good impact on enhancing the cognitive dysfunction of patients after stroke, which stroke patients were found to benefit the most from moderate-intensity exercise. However, our studies did not found that aerobic exercise had an active result on cognitive flexibility, working memory, selective attention and contention resolution.

Rehabilitation interventions for cognitive deficits in stroke survivors: A systematic review of randomized controlled trials

Cognitive deficits are one of the most common impairments after stroke. It negatively affects physical and social functioning. Rehabilitation interventions for cognitive deficits post-stroke have taken less consideration. The present study aimed to provide an overview of the effects of various rehabilitation interventions on cognitive functions in patients with stroke. PUBMED, SCOPUS, PEDro, EMBASE, MEDLINE, and REHABDATA were searched for randomized controlled trials (RCTs) investigating the effects of rehabilitation interventions on cognitive domains poststroke until August 2021. The methodological quality of the selected studies was evaluated using the Cochrane Collaboration tool, and the effect sizes were calculated. Forty-four studies met the inclusion criteria. A total of 3561 individuals with stroke, 57.60% of whom were males. The mean age for all participants was 65.48 years. Eighteen RCTs were high, moderate (n = 17), and low methodological quality (n = 9). The results showed evidence for the beneficial effects of many rehabilitation interventions on cognition in individuals with stroke. Rehabilitation plays a crucial role in improving cognitive functions in stroke patients with mild cognitive deficits. Virtual reality (VR), computer-based cognitive rehabilitation (CBCR), and non-aerobic exercises may promote cognitive functions in patients with stroke.

Effect of Pulmonary Function Training with a Respirator on Functional Recovery and Quality of Life of Patients with Stroke

A stroke is a sudden onset cerebral blood circulation disorder. It occurs in patients with cerebrovascular disease due to various predisposing factors causing stenosis, occlusion, or rupture of intracerebral arteries, which, in turn, causes acute cerebral blood circulation disturbance and clinically manifests as symptoms and signs of excessive or permanent cerebral dysfunction. It can cause serious harm to patients' physical and mental health. This study aimed to evaluate the effect of Breathe-Link breathing trainers on lung function and the ability to perform activities of daily living in patients with stroke. Sixty patients with stroke were randomly divided into two groups. One group was set as the control group and received routine breathing training. The experimental group received a Breathe-Link trainer based on regular training, with rehabilitation training for 12 weeks as the time node. Respiratory muscle strength, respiratory velocity, respiratory capacity, forced vital capacity (FVC), forced expiratory volume in the first second (FEV1), and rate in the first second (FEV1/FVC) were used to evaluate the respiratory function of patients, and the Barthel index was used to evaluate the ability to perform activities of daily living. Improvements in respiratory function and daily living ability were compared between the two groups. After 12 weeks of training, respiratory muscle strength, respiratory velocity, respiratory volume, FVC, FEV1, FEV1/FVC, and Barthel index of patients in the two groups improved compared with those before training (P < 0.05), and the improvement in the treatment group was better than that in the control group (P < 0.05). Breathe-Link breathing trainers can improve lung function and the ability to perform activities of daily living in patients with stroke, and its effect is acceptable. It can be recommended for clinical use.

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.

Effect of Physical Activity on Cognitive Impairment in Patients With Cerebrovascular Diseases: A Systematic Review and Meta-Analysis

Background and Purpose

This study investigates the effect of physical activity (PA) on cognition in patients with cerebrovascular disease and explored the maximum benefit of different PA characteristics.

Methods

Databases, such as Pubmed, Web of Science, Embase, and Cochrane Library, were searched from their inception to May 31, 2021. Standardized mean difference (SMD) and 95% confidence intervals (CIs) were calculated to generate a forest plot. In addition, subgroup analysis, moderation analysis, and regression analysis were performed to explore the possible adjustment factors.

Results

In total, 22 studies that met the criteria were included, demonstrating data from 1,601 participants. The results indicated that PA produced a positive effect on the global cognition for patients with cerebrovascular disease (SMD: 0.20 [95% CI: 0.12-0.27]), at the same time, PA training prominently improved executive function (SMD: 0.09 [95% CI: 0.00-0.17]) and working memory (SMD: 0.25 [95% CI: 0.10-0.40]). Furthermore, patients with baseline cognitive impairment received the greater benefit of PA on cognition (SMD: 0.24 [95% CI: 0.14-0.34]) than those without cognitive impairment before intervention (SMD: 0.15 [95% CI: 0.04-0.26]). For patients in the acute stage (≤ 3 months), PA did not rescue impairment dysfunction significantly (SMD: 0.08 [95% CI: -0.04-0.21]) and remarkable cognitive gains were detected in the chronic stage of participants (>3 months) (SMD: 0.25 [95% CI: 0.16-0.35]). Moderate intensity PA showed a larger pooled effect size (SMD: 0.23 [95% CI: 0.11-0.36]) than low intensity (SMD: -0.01 [95% CI: -0.44-0.43]) and high intensity (SMD: 0.16 [95% CI: 0.03-0.29]). However, the different types, duration, and frequency of PA resulted in no differences in the improvement of cognitive function. Further regression analysis demonstrated that the beneficial effects of PA on cognition are negatively correlated with age (p < 0.05).

Conclusions

This study revealed that PA can prominently improve the cognitive ability in patients with cerebrovascular diseases and strengthened the evidence that PA held promise as a widely accessible and effective non-drug therapy for vascular cognitive impairment (VCI).

Immersive Virtual Reality for the Cognitive Rehabilitation of Stroke Survivors

We present the results of a double-blind phase 2b randomized control trial that used a custom built virtual reality environment for the cognitive rehabilitation of stroke survivors. A stroke causes damage to the brain and problem solving, memory and task sequencing are commonly affected. The brain can recover to some extent, however, and stroke patients have to relearn how to carry out activities of daily living. We have created an application called VIRTUE to enable such activities to be practiced using immersive virtual reality. Gamification techniques enhance the motivation of patients such as by making the level of difficulty of a task increase over time. The design and implementation of VIRTUE is described together with the results of the trial conducted within the Stroke Unit of a large hospital. We report on the safety and acceptability of VIRTUE. We have also observed particular benefits of VR treatment for stroke survivors that experienced more severe cognitive impairment, and an encouraging reduction in time spent in the hospital for all patients that received the VR treatment.

Cognitive and Linguistic Benefits of Aerobic Exercise: A State-of-the-Art Systematic Review of the Stroke Literature

This systematic review aimed to determine how aerobic exercise affects cognition after stroke, with particular focus on aphasia and language improvement. Methodological quality was assessed with the PEDro+ scale with half of the 27 included studies rated as high quality. Data extraction focused on cognitive effects of aerobic exercise post-stroke, intervention characteristics, outcome measures, and participant characteristics. Whereas attention, memory, and executive functioning measures were common across the included studies, no study included a language-specific, performance-based measure. Seventeen studies reported positive cognitive effects, most frequently in the domains of attention, memory and executive functioning. Variability in outcome measures, intervention characteristics, and participant characteristics made it difficult to identify similarities among studies reporting positive cognitive effects of exercise or among those studies reporting null outcomes. Only three studies provided specific information about the number of individuals with aphasia included or excluded, who comprise approximately one-third of the stroke population. The review identified patent gaps in our understanding of how aerobic exercise may affect not only the cognitive domain of language post-stroke but also the broader cognitive functioning of individuals with post-stroke aphasia. Methodological limitations of the reviewed studies also warrant further examination of the direct impact of aerobic exercise on cognition post-stroke with careful attention to the selection and reporting of population, intervention, and outcomes.

Associations Between Time After Stroke and Exercise Training Outcomes: A Meta-Regression Analysis

Background Knowledge gaps exist regarding the effect of time elapsed after stroke on the effectiveness of exercise training interventions, offering incomplete guidance to clinicians. Methods and Results To determine the associations between time after stroke and 6-minute walk distance, 10-meter walk time, cardiorespiratory fitness and balance (Berg Balance Scale score [BBS]) in exercise training interventions, relevant studies in post-stroke populations were identified by systematic review. Time after stroke as continuous or dichotomized (≤3 months versus >3 months, and ≤6 months versus >6 months) variables and weighted mean differences in postintervention outcomes were examined in meta-regression analyses adjusted for study baseline mean values (pre-post comparisons) or baseline mean values and baseline control-intervention differences (controlled comparisons). Secondary models were adjusted additionally for mean age, sex, and aerobic exercise intensity, dose, and modality. We included 148 studies. Earlier exercise training initiation was associated with larger pre-post differences in mobility; studies initiated ≤3 months versus >3 months after stroke were associated with larger differences (weighted mean differences [95% confidence interval]) in 6-minute walk distance (36.3 meters; 95% CI, 14.2-58.5), comfortable 10-meter walk time (0.13 m/s; 95% CI, 0.06-0.19) and fast 10-meter walk time (0.16 m/s; 95% CI, 0.03-0.3), in fully adjusted models. Initiation ≤3 months versus >3 months was not associated with cardiorespiratory fitness but was associated with a higher but not clinically important Berg Balance Scale score difference (2.9 points; 95% CI, 0.41-5.5). In exercise training versus control studies, initiation ≤3 months was associated with a greater difference in only postintervention 6-minute walk distance (baseline-adjusted 27.3 meters; 95% CI, 6.1-48.5; fully adjusted, 24.9 meters; 95% CI, 0.82-49.1; a similar association was seen for ≤6 months versus >6 months after stroke (fully adjusted, 26.6 meters; 95% CI, 2.6-50.6). Conclusions There may be a clinically meaningful benefit to mobility outcomes when exercise is initiated within 3 months and up to 6 months after stroke.

Trajectories of stroke recovery of impairment, function, and quality of life in response to 12-month mobility and fitness intervention

BACKGROUND

Gait deficits and functional disability are persistent problems for many stroke survivors, even after standard neurorehabilitation. There is little quantified information regarding the trajectories of response to a long-dose, 12-month intervention.

OBJECTIVE

We quantified treatment response to an intensive neurorehabilitation mobility and fitness program.

METHODS

The 12-month neurorehabilitation program targeted impairments in balance, limb coordination, gait coordination, and functional mobility, for five chronic stroke survivors. We obtained measures of those variables every two months.

RESULTS

We found statistically and clinically significant group improvement in measures of impairment and function. There was high variation across individuals in terms of the timing and the gains exhibited.

CONCLUSIONS

Long-duration neurorehabilitation (12 months) for mobility/fitness produced clinically and/or statistically significant gains in impairment and function. There was unique pattern of change for each individual. Gains exhibited late in the treatment support a 12-month intervention. Some measures for some subjects did not reach a plateau at 12 months, justifying further investigation of a longer program (>12 months) of rehabilitation and/or maintenance care for stroke survivors.

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

BACKGROUND

Stroke is among the leading causes of death and disability worldwide. Interventions for stroke rehabilitation aim to minimize sequelae, promote individuals' independence and potentially recover functional damage. The role of aerobic exercise as a facilitator of post-stroke neuroplasticity in humans is still questionable.

OBJECTIVE

To investigate the impact of aerobic exercise on neuroplasticity in patients with stroke sequelae.

METHODS

A systematic review of randomized clinical trials and crossover studies was performed, with searches for human studies in the following databases: PUBMED, EMBASE, LILACS and PeDRO, only in English, following the PRISMA protocol. The keywords used for selecting articles were defined based on the PICO strategy.

RESULTS

This systematic review evaluated the impacts of aerobic exercise on neuroplasticity through assessment of neural networks and neuronal excitability, neurotrophic factors, or cognitive and functional assessment. Studies that evaluated the effects of aerobic exercise on neuroplasticity after stroke measured through functional resonance (fMRI) or cortical excitability have shown divergent results, but aerobic exercise potentially can modify the neural network, as measured through fMRI. Additionally, aerobic exercise combined with cognitive training improves certain cognitive domains linked to motor learning. Studies that involved analysis of neurotrophic factors to assess neuroplasticity had conflicting results.

CONCLUSIONS

Physical exercise is a therapeutic intervention in rehabilitation programs that, beyond the known benefits relating to physical conditioning, functionality, mood and cardiovascular health, may also potentiate the neuroplasticity process. Neuroplasticity responses seem more robust in moderate to high-intensity exercise training programs, but dose-response heterogeneity and non-uniform neuroplasticity assessments limit generalizability.

Carbohydrate ingestion attenuates cognitive dysfunction following long-duration exercise in the heat in humans

INTRODUCTION

To determine if electrolyte or carbohydrate supplementation vs. water would limit the magnitude of dehydration and decline in cognitive function in humans following long-duration hyperthermic-exercise.

METHODS

24 subjects performed 3 visits of 2 h walking (3mph/7% grade) in an environmental chamber (33 °C/10% relative humidity). In random order, subjects consumed water (W), electrolytes (Gatorade Zero; E), or electrolytes+carbohydrates (Gatorade; E+C). Throughout exercise (EX), subjects carried a 23 kg pack and drank ad-libitum. Pre-and post-EX, body mass (BM) and plasma osmolality (pOsm) were measured. Physiological Strain Index (PSI) and core temperature (T_C) were recorded every 15 min. Plasma glucose (GLU) was measured every 30 min. Cognitive processing (SCWT) was measured post-EX and compared to baseline (BL). A subset of 8 subjects performed a normothermic (N) protocol (21 °C/ambient humidity) to ascertain how the exercise stimulus influenced hydration status and cognition without heat.

RESULTS

There were no significant differences between fluid conditions (W, E, E+C) for BM loss (Δ2.5 ± 0.2, 2.5 ± 0.2, 2.3 ± 0.2 kg), fluid consumption (1.9 ± 0.2, 1.9 ± 0.2, 1.8 ± 0.2L), pOsm (Δ1.5 ± 2.7, 2.2 ± 2.4, 2.0 ± 1.5 mmol/L), peak-PSI (7.5 ± 0.4, 7.0 ± 0.6, 7.9 ± 0.5), and peak-T_C (38.7 ± 0.1, 38.6 ± 0.2, 38.8 ± 0.2 °C). GLU decreased significantly in W and E, whereas it increased above BL in E+C at 60, 90, and 120 min (P < 0.05). Compared to BL values (43.6 ± 26 ms), SCWT performance significantly decreased in all conditions (463 ± 93, 422 ± 83, 140 ± 52 ms, P < 0.05). Importantly, compared to W and E, the impairment in SCWT was significantly attenuated in E+C (P < 0.05). As expected, when compared to the heat-stress protocol (W, E, E+C), N resulted in lower BM loss, fluid consumption, and peak-PSI (1.1 ± 0.1 kg, 1.2 ± 0.7L, 4.8, respectively), and improved SCWT performance.

CONCLUSIONS

These data are the first to suggest that, independent of supplementation variety, cognitive processing significantly decreases immediately following long-duration exercise in the heat in healthy humans. Compared to water and fluids supplemented with only electrolytes, fluids supplemented with carbohydrates significantly blunts this decrease in cognitive function.

Clinical efficacy of aerobic exercise combined with computer-based cognitive training in stroke: a multicenter randomized controlled trial

PURPOSE

The objectives are to evaluate the effects of a sequential combination of aerobic exercise and cognitive training, compared with exercise or cognitive training alone, on cognitive function, physical function, daily function, quality of life, and social participation in stroke survivors with cognitive impairment.

METHODS

This is a single-blind, parallel, randomized controlled trial. Stroke patients with mild cognitive impairment (n = 56) were randomly assigned to aerobic exercise training (n = 18), computerized cognitive training (n = 18), and the sequential combination of aerobic exercise and computerized cognitive training (n = 20) group. All groups underwent training 60 min/day, 3 days/week, for a total of 12 weeks. The primary outcomes included Montreal Cognitive Assessment (MoCA), Wechsler Memory Scale-Third Edition, and the Stroop color-word test. Secondary outcomes were the Timed Up and Go test, 6-Minute Walk Test, Functional Independence Measure, Lawton Instrumental Activities of Daily Living Scale, Community Integration Questionnaire, and Stroke Impact Scale.

RESULTS

56 participants completed the trial. Compared with a single type of aerobic exercise or cognitive training, the combined training group showed significant improvement in MoCA (P < .05, η2 = 0.13), and two sub-tests in WMS-III (both P's < 0.05) following the intervention. However, no between-group differences were observed for physical functions, daily function, quality of life, and social participation measures.

CONCLUSIONS

The findings provide evidence for the potential synergistic intervention in stroke survivors. Future studies investigating the transfer effects and the optimal training parameters with a larger sample is needed.

Effects of Aerobic Exercise on Serum Biomarkers of Neuroplasticity and Brain Repair in Stroke: A Systematic Review

OBJECTIVE

To provide a novel overview of the literature and to summarize the evidence for the effects of aerobic exercise (AE) on serum biomarkers neuroplasticity and brain repair in survivors of stroke.

DATA SOURCES

We conducted a systematic review and searched MEDLINE, Embase, and Cochrane CENTRAL using terms related to AE, neuroplasticity, brain repair, and stroke.

STUDY SELECTION

Titles, abstracts, and selected full texts were screened by 2 independent reviewers against the following inclusion criteria: including adult survivors of stroke, completing an AE intervention working within the AE capacity, and measuring at least 1 blood biomarker outcome of interest.

DATA EXTRACTION

Two independent reviewers extracted data and assessed risk of bias using Risk of Bias in Nonrandomized Studies-of Interventions and Cochrane's Risk of Bias 2 tools.

DATA SYNTHESIS

Nine studies (n=215 participants) were included, reporting on the following outcomes: brain-derived neurotrophic factor (BDNF), insulin-like growth factor 1 (IGF-1), vascular endothelial growth factor (VEGF), cortisol, interleukin 6, and myeloperoxidase. A single bout of high-intensity interval training significantly increased BDNF, IGF-1, and VEGF levels, and a 40-45-minute, 24-session, continuous 8-week AE training program significantly increased BDNF levels. No significant difference in response to any other AE intervention was found in other serum biomarkers.

CONCLUSIONS

AE can significantly increase BDNF, IGF-1, and VEGF across different AE protocols in survivors of stroke. However, more research is needed to determine the optimal exercise intensity and modalities, specifically in survivors of acute and subacute stroke, and how this may relate to functional outcomes.

Current Methodological Pitfalls and Caveats in the Assessment of Exercise-Induced Changes in Peripheral Brain-Derived Neurotrophic Factor: How Result Reproducibility Can Be Improved

Neural mechanisms, such as enhanced neuroplasticity within the motor system, underpin exercise-induced motor improvements. Being a key mediator of motor plasticity, brain-derived neurotrophic factor (BDNF) is likely to play an important role in mediating exercise positive effects on motor function. Difficulties in assessing brain BDNF levels in humans have drawn attention to quantification of blood BDNF and raise the question of whether peripheral BDNF contributes to exercise-related motor improvements. Methodological and non-methodological factors influence measurements of blood BDNF introducing a substantial variability that complicates result interpretation and leads to inconsistencies among studies. Here, we discuss methodology-related issues and approaches emerging from current findings to reduce variability and increase result reproducibility.

A Single Bout of High-intensity Interval Exercise Increases Corticospinal Excitability, Brain-derived Neurotrophic Factor, and Uncarboxylated Osteolcalcin in Sedentary, Healthy Males

Exercise induces neuroplasticity in descending motor pathways facilitating motor learning, and as such it could be utilized as an intervention in neurorehabilitation, for example when re-learning motor skills after stroke. To date, however, the neurophysiological and molecular mechanisms underlying exercise-induced neuroplasticity remain largely unknown impeding the potential utilization of exercise protocols as 'motor learning boosters' in clinical and non-clinical settings. Here, we assessed corticospinal excitability, intracortical facilitation (ICF) and short-interval intracortical inhibition (SICI) using transcranial magnetic stimulation (TMS) and serum biochemical markers including brain-derived neurotrophic factor (BDNF), total and precursor cathepsin B (tCTSB, proCTSB), uncarboxylated and carboxylated osteocalcin (unOCN, cOCN) and irisin using ELISA. Measurements were carried out in sedentary, healthy males before and after a single session of high-intensity interval exercise (HIIE) or in individuals who rested and did not perform exercise (No Exercise). We found that HIIE increased corticospinal excitability, BDNF and unOCN, and decreased cOCN. We also determined that greater increases in BDNF were associated with increases in unOCN and irisin and decreases in cOCN only in participants who underwent HIIE, suggesting that unOCN and irisin may contribute to exercise-induced BDNF increases. Conversely, no changes other than a decrease in serum unOCN/tOCN were found in No Exercise participants. The present findings show that a single session of HIIE is sufficient to modulate corticospinal excitability and to increase BDNF and unOCN in sedentary, healthy males.

Effects of aerobic cycling training on mobility and functionality of acute stroke subjects: A randomized clinical trial

BACKGROUND

Studies demonstrate the benefits of aerobic cycling training in subacute and chronic stroke subjects, but there is a lack in the literature about its effects on the acute phase.

OBJECTIVE

Verify the effects of aerobic cycling training on lower limbs muscle strength, gait speed, balance, mobility and functionality of acute stroke subjects.

METHODS

Control group (CG) performed conventional physiotherapy twice a day and the intervention group (IG) performed a conventional physiotherapy and a cycle ergometer session, for five consecutive days. Subjects were assessed for muscle strength by a digital dynamometer, gait speed by the 10-meter-walk-test, balance by the Berg Balance Scale, mobility by the ICU-Mobility-Scale and functionality by the Perme Score.

RESULTS

Twenty subjects were enrolled in the study, 10 in the CG and 10 in the IG. Lower limbs muscle strength, the main endpoint, was better in the IG compared to the CG. The same was found in the secondary endpoints. The intragroup analysis was also positive for the CG in the mobility and functionality.

CONCLUSIONS

Conventional physiotherapy combined with cycling exercise showed better results in the improvement of muscle strength of lower limbs, mobility and functionality of subjects who suffered from acute stroke.

Is High-Intensity Interval Training Suitable to Promote Neuroplasticity and Cognitive Functions after Stroke?

Stroke-induced cognitive impairments affect the long-term quality of life. High-intensity interval training (HIIT) is now considered a promising strategy to enhance cognitive functions. This review is designed to examine the role of HIIT in promoting neuroplasticity processes and/or cognitive functions after stroke. The various methodological limitations related to the clinical relevance of studies on the exercise recommendations in individuals with stroke are first discussed. Then, the relevance of HIIT in improving neurotrophic factors expression, neurogenesis and synaptic plasticity is debated in both stroke and healthy individuals (humans and rodents). Moreover, HIIT may have a preventive role on stroke severity, as found in rodents. The potential role of HIIT in stroke rehabilitation is reinforced by findings showing its powerful neurogenic effect that might potentiate cognitive benefits induced by cognitive tasks. In addition, the clinical role of neuroplasticity observed in each hemisphere needs to be clarified by coupling more frequently to cellular/molecular measurements and behavioral testing.

Evaluation of eight-style Tai chi on cognitive function in patients with cognitive impairment of cerebral small vessel disease: study protocol for a randomised controlled trial

INTRODUCTION

Cerebral small vessel disease (CSVD) is a critical factor that causes cognitive decline and progresses to vascular dementia and acute cerebrovascular events. Tai chi has been proven to improve nerve plasticity formation and directly improve cognitive function compared with other sports therapy, which has shown its unique advantages. However, more medical evidence needs to be collected in order to verify that Tai chi exercises can improve cognitive impairment due to CSVD. The main purposes of this study are to investigate the effect of Tai chi exercise on neuropsychological outcomes of patients with cognitive impairment related to CSVD and to explore its mechanism of action with neuroimaging, including functional MRI (fMRI) and event-related potential (P300).

METHODS AND ANALYSIS

The design of this study is a randomised controlled trial with two parallel groups in a 1:1 allocation ratio with allocation concealment and assessor blinding. A total of 106 participants will be enrolled and randomised to the 24-week Tai chi exercise intervention group and 24-week health education control group. Global cognitive function and the specific domains of cognition (memory, processing speed, executive function, attention and verbal learning and memory) will be assessed at baseline and 12 and 24 weeks after randomisation. At the same time, fMRI and P300 will be measured the structure and function of brain regions related to cognitive function at baseline and 24 weeks after randomisation. Recruitment is currently ongoing (recruitment began on 9 November 2020). The approximate completion date for recruitment is in April 2021, and we anticipate to complete the study by December 2021.

ETHICS AND DISSEMINATION

Ethics approval was given by the Medical Ethics Committee of the Affiliated People's Hospital of Fujian University of Traditional Chinese Medicine (approval number: 2019-058-04). The findings will be disseminated through peer-reviewed publications and at scientific conferences.

TRIAL REGISTRATION NUMBER

ChiCTR2000033176; Pre-results.

Therapeutic effectiveness of a single exercise session combined with WalkAide functional electrical stimulation in post-stroke patients: a crossover design study

A growing body of evidence has suggested that the imbalance of epigenetic markers and oxidative stress appears to be involved in the pathophysiology and progression of stroke. Thus, strategies that modulate these biomarkers might be considered targets for neuroprotection and novel therapeutic opportunities for these patients. Physical exercise has been reported to induce changes in these epigenetic markers and improve clinical outcomes in different populations. However, little is reported on this in post-stroke patients. The purpose of this study was to investigate the effect of a single exercise session with WalkAide functional electrical stimulation (FES) on cognitive performance, clinical functional parameters, oxidative stress and epigenetic modulation in post-stroke individuals. In this crossover design study, 12 post-stroke individuals aged 54–72 years of either sexes were included and subjected to a single session of exercise (45 minutes) without WalkAide functional electrical stimulation (EXE alone group), followed by another single session of exercise (45 minutes) with WalkAide functional electrical stimulation (EXE + FES group). The clinical functional outcome measures, cognitive performance and blood collections for biomarker measurements were assessed pre- and post-intervention. After intervention, higher Berg Balance Scale scores were obtained in the EXE + FES group than in the EXE alone group. There was no significant difference in the Timed Up and Go test results post-intervention between EXE alone and EXE + FES groups. After intervention, a better cognitive performance was found in both groups compared with before the intervention. After intervention, the Timed Up and Go test scores were higher in the EXE + FES group than in the EXE alone group. In addition, the intervention induced lower levels of lipid peroxidation. After intervention, carbonyl level was lower, superoxide dismutase activity and superoxide dismutase/catalase activity ratio were higher in the EXE + FES group, compared with the EXE group alone. In each group, both histone deacetylase (HDAC2) and histone acetyltransferase activities were increased after intervention compared with before the intervention. These findings suggest that a single exercise session with WalkAide FES is more effective on balance ability and cognitive performance compared with conventional exercise alone in post-stroke patients. This is likely to be related to the regulation of oxidative stress markers. The present study was approved by the Research Ethics Committee of the Methodist University Center-IPA (approval No. 2.423.376) on December 7, 2017 and registered in the Brazilian Registry of Clinical Trials—ReBEC (RBR-9phj2q) on February 11, 2019.

Understanding the Neurophysiological and Molecular Mechanisms of Exercise-Induced Neuroplasticity in Cortical and Descending Motor Pathways: Where Do We Stand?

Exercise is a promising, cost-effective intervention to augment successful aging and neurorehabilitation. Decline of gray and white matter accompanies physiological aging and contributes to motor deficits in older adults. Exercise is believed to reduce atrophy within the motor system and induce neuroplasticity which, in turn, helps preserve motor function during aging and promote re-learning of motor skills, for example after stroke. To fully exploit the benefits of exercise, it is crucial to gain a greater understanding of the neurophysiological and molecular mechanisms underlying exercise-induced brain changes that prime neuroplasticity and thus contribute to postponing, slowing, and ameliorating age- and disease-related impairments in motor function. This knowledge will allow us to develop more effective, personalized exercise protocols that meet individual needs, thereby increasing the utility of exercise strategies in clinical and non-clinical settings. Here, we review findings from studies that investigated neurophysiological and molecular changes associated with acute or long-term exercise in healthy, young adults and in healthy, postmenopausal women.

Cognitive Gains of Aerobic Exercise in Patients With Ischemic Cerebrovascular Disorder: A Systematic Review and Meta-Analysis

Background: Cognitive impairment has become an important problem in ischemic cerebrovascular disorder survivors as disease related deaths have been significantly reduced. Aerobic exercise, the most prevalent mode of physical activity, positively contributes to cognition in both healthy population and people with cognitive impairment. However, studies on its associations with cognitive gains in patients with ischemic cerebrovascular disease showed mixed findings.

Objective: To explore the cognitive effects of aerobic exercise on ischemic cerebrovascular disorder survivors and investigate the possible moderators on exercise benefits.

Method: Randomized controlled trials investigating the effects of sole aerobic exercise on cognitive function in population with ischemic intracranial vascular disorder compared to any control group who did not receive the intervention were enrolled in this systematic review and meta-analysis. Four online database (Pubmed, Cochrane Library, Embase, and Web of Science) were searched.

Results: The initial search returned 1,522 citations and ultimately 11 studies were included in the systematic review. Analysis of seven studies showed the beneficial but not statistically significant impact of aerobic exercise on global cognitive function (0.13; 95% Cl −0.09 to 0.35; p = 0.25). Participants already with cognitive impairment benefited more from this intervention (0.31; 95% Cl 0.07–0.55; p = 0.01) and moderate intensity might be the optimal choice (0.34; 95% Cl −0.01 to 0.69; p = 0.06). The program duration and initiation time after stroke occurrence did not predict better cognitive outcome. Aerobic exercise was not associated with improvement of processing speed and executive function, the two subdomains of cognitive function.

Conclusions: Aerobic exercise may contribute to cognitive gains in survivors of ischemic cerebrovascular disorder, especially for population already with cognitive decline. Our findings suggest that the adoption of moderate intensity aerobic exercise might improve cognition in such population.

Aerobic exercise attenuates neurodegeneration and promotes functional recovery - Why it matters for neurorehabilitation & neural repair

Aerobic exercise facilitates optimal neurological function and exerts beneficial effects in neurologic injuries. Both animal and clinical studies have shown that aerobic exercise reduces brain lesion volume and improves multiple aspects of cognition and motor function after stroke. Studies using animal models have proposed a wide range of potential molecular mechanisms that underlie the neurological benefits of aerobic exercise. Furthermore, additional exercise parameters, including time of initiation, exercise dosage (exercise duration and intensity), and treatment modality are also critical for clinical application, as identifying the optimal combination of parameters will afford patients with maximal functional gains. To clarify these issues, the current review summarizes the known neurological benefits of aerobic exercise under both physiological and pathological conditions and then considers the molecular mechanisms underlying these benefits in the contexts of stroke-like focal cerebral ischemia and cardiac arrest-induced global cerebral ischemia. In addition, we explore the key roles of exercise parameters on the extent of aerobic exercise-induced neurological benefits to elucidate the optimal combination for aerobic exercise intervention. Finally, the current challenges for aerobic exercise implementation after stroke are discussed.

Choice reaction time can be influenced by intervention protocols after stroke: A systematic review

INTRODUCTION

Post-stroke individuals usually present a delay in choice reaction time (CRT), and it would be important to verify the efficacy in the reduction of CRT after intervention protocols.

OBJECTIVE

The main question of this review is 'What are the characteristics of the CRT test and the interventions that decrease the CRT?'

STUDY DESIGN

Systematic review.

METHODS

The search was performed in March 2019 using the electronic databases, PubMed, Science Direct, Scopus, Web of Science, Lilacs, Cinahal, Cochrane, Ovid, Scielo, PEDro, and Embase. There was no restriction regarding publication dates, and studies written in English that were conducted on poststroke patients and presented CRT results were included.

RESULTS

Six studies were included in this systematic review, and the majority showed varied objectives, methodologies, and groups, regarding the number and characteristics of the sample, varying from complex to simple tasks for the CRT evaluation.

CONCLUSION

This review suggests the investigation of the CRT in stroke patients with functional tasks using auditory and/or visual stimulus. About the CRT training in stroke patients, this review also suggests bilateral training, including functional tasks, and the use of structural practice blocks, but more studies are needed to better demonstrate the effects of interventions on the CRT.

REGISTRATION NUMBER

PROSPERO (protocol no. CRD42017073995).

Including Patients With Stroke in Cardiac Rehabilitation: BARRIERS AND FACILITATORS

More than 13 million cases of stroke are occurring annually worldwide. Approximately a quarter of these strokes are recurrent strokes, and there is compelling evidence of the benefit of supervised exercise and risk factor modification programming in the secondary prevention of these strokes. However, there is insufficient time in inpatient and outpatient stroke rehabilitation for focused exercise interventions. General lifestyle interventions on their own, without guidance and supervision, are insufficient for improving physical activity levels. Cardiac rehabilitation (CR) is a setting where cardiac patients, and increasingly stroke patients, receive comprehensive secondary prevention programming, including structured exercise. Unfortunately, not all CR programs accept referrals for people following a stroke and for those that do, only a few patients participate. Therefore, the purpose of this review is to report the barriers and facilitators to improving linkage between health services, with a focus on increasing access to CR. In the next two decades, it is projected that there will be a marked increase in stroke prevalence globally. Therefore, there is an urgent need to create cross-program collaborations between hospitals, outpatient stroke rehabilitation, CR, and community programs. Improving access and removing disparities in access to evidence-based exercise treatments would positively affect the lives of millions of people recovering from stroke.

Effect of aerobic exercise on post-stroke cognitive function: a systematic review

Background/Aims

Literature suggests that aerobic exercise improves cognitive impairments post stroke. This systematic review was conducted to analyse evidence on the effectiveness of aerobic exercise in improving post-stroke cognitive impairments.

Methods

Online databases (PubMed, EMBASE and Web of Science) were systematically searched from inception until 13 July 2017 using the keywords stroke/exercise/cognition. Clinical trials that met the inclusion criteria were assessed for methodological quality using the PEDro scale. Extracted data were synthesised for evidence.

Results

A total of seven studies met the inclusion criteria. Participants in most of the studies were aged over 60 years and the majority had ischaemic stroke. The most commonly used measure for assessing cognition was the Mini Mental State Examination. The majority of studies included moderate to high intensity exercise (50–70% of VO2max) for 30–60 minutes three to five times per week. There is moderate evidence that aerobic exercise enhances global cognitive function, attention and working memory. Evidence that aerobic exercise improves memory, levels of brain-derived neurotrophic factor and executive function is conflicting and limited.

Conclusions

Aerobic exercise is moderately effective in improving post-stroke cognitive impairments. More clinical trials are needed in view of the methodological limitations and paucity of existing studies.

Innovative Long-Dose Neurorehabilitation for Balance and Mobility in Chronic Stroke: A Preliminary Case Series

(1) Objective: The objective was two-fold: (a) test a protocol of combined interventions; (b) administer this combined protocol within the framework of a six-month, intensive, long-duration program. The array of interventions was designed to target the treatment-resistant impairments underlying persistent mobility dysfunction: weakness, balance deficit, limb movement dyscoordination, and gait dyscoordination. (2) Methods: A convenience sample of eight chronic stroke survivors (>4 months post stroke) was enrolled. Treatment was 5 days/week, 1-2.5 h/day for 6 months, as follows: strengthening exercise, balance training, limb/gait coordination training, and aerobic exercise. Outcome measures: Berg Balance Scale (BBS), Fugl-Meyer Lower Limb Coordination (FM), gait speed, 6 Minute Walk Test (6MWT), Timed up and Go (TUG), Functional Independence Measure (FIM), Craig Handicap Assessment Rating Tool (CHART), and personal milestones. Pre-/post-treatment comparisons were conducted using the Permutation Test, suitable for ordinal measures and small sample size. (3) Results: For the group, there was a statistically (p ≤ 0.04) significant improvement in balance, limb movement coordination (FM), gait speed, functional mobility (TUG), and functional activities (FIM). There were measurable differences (minimum detectible change: MDC) in BBS, FM, gait speed, 6MWT, and TUG. There were clinically significant milestones achieved for selected subjects according to clinical benchmarks for the BBS, 6MWT, gait speed, and TUG, as well as achievement of personal milestones of life role participation. Effect sizes (Cohen's D) ranged from 0.5 to 1.0 (with the exception of the (6MWT)). After six months of treatment, the above array of gains were beyond that reported by other published studies of chronic stroke survivor interventions. Personal milestones included: walking to mailbox, gardening/yardwork, walking a distance to neighbors, return to driving, membership at a fitness center, vacation trip to the beach, swimming at local pool, returning to work, housework, cooking meals. (4) Conclusions: Stroke survivors with mobility dysfunction were able to participate in the long-duration, intensive program, with the intervention array targeted to address impairments underlying mobility dysfunction. There were either clinically or statistically significant improvements in an array of measures of impairment, functional mobility, and personal milestone achievements.

HIITing the brain with exercise: mechanisms, consequences and practical recommendations

The increasing number of older adults has seen a corresponding growth in those affected by neurovascular diseases, including stroke and dementia. Since cures are currently unavailable, major efforts in improving brain health need to focus on prevention, with emphasis on modifiable risk factors such as promoting physical activity. Moderate-intensity continuous training (MICT) paradigms have been shown to confer vascular benefits translating into improved musculoskeletal, cardiopulmonary and cerebrovascular function. However, the time commitment associated with MICT is a potential barrier to participation, and high-intensity interval training (HIIT) has since emerged as a more time-efficient mode of exercise that can promote similar if not indeed superior improvements in cardiorespiratory fitness for a given training volume and further promote vascular adaptation. However, randomised controlled trials (RCTs) investigating the impact of HIIT on the brain are surprisingly limited. The present review outlines how the HIIT paradigm has evolved from a historical perspective and describes the established physiological changes including its mechanistic bases. Given the dearth of RCTs, the vascular benefits of MICT are discussed with a focus on the translational neuroprotective benefits including their mechanistic bases that could be further potentiated through HIIT. Safety implications are highlighted and components of an optimal HIIT intervention are discussed including practical recommendations. Finally, statistical effect sizes have been calculated to allow prospective research to be appropriately powered and optimise the potential for detecting treatment effects. Future RCTs that focus on the potential clinical benefits of HIIT are encouraged given the prevalence of cognitive decline in an ever-ageing population.

The Effect of Priming on Outcomes of Task-Oriented Training for the Upper Extremity in Chronic Stroke: A Systematic Review and Meta-analysis

Background. Priming results in a type of implicit memory that prepares the brain for a more plastic response, thereby changing behavior. New evidence in neurorehabilitation points to the use of priming interventions to optimize functional gains of the upper extremity in poststroke individuals. Objective. To determine the effects of priming on task-oriented training on upper extremity outcomes (body function and activity) in chronic stroke. Methods. The PubMed, CINAHL, Web of Science, EMBASE, and PEDro databases were searched in October 2019. Outcome data were pooled into categories of measures considering the International Classification Functional (ICF) classifications of body function and activity. Means and standard deviations for each group were used to determine group effect sizes by calculating mean differences (MDs) and 95% confidence intervals via a fixed effects model. Heterogeneity among the included studies for each factor evaluated was measured using the I² statistic. Results. Thirty-six studies with 814 patients undergoing various types of task-oriented training were included in the analysis. Of these studies, 17 were associated with stimulation priming, 12 with sensory priming, 4 with movement priming, and 3 with action observation priming. Stimulation priming showed moderate-quality evidence of body function. Only the Wolf Motor Function Test (time) in the activity domain showed low-quality evidence. However, gains in motor function and in use of extremity members were measured by the Fugl-Meyer Assessment (UE-FMA). Regarding sensory priming, we found moderate-quality evidence and effect size for UE-FMA, corresponding to the body function domain (MD 4.77, 95% CI 3.25-6.29, Z = 6.15, P < .0001), and for the Action Research Arm Test, corresponding to the activity domain (MD 7.47, 95% CI 4.52-10.42, Z = 4.96, P < .0001). Despite the low-quality evidence, we found an effect size (MD 8.64, 95% CI 10.85-16.43, Z = 2.17, P = .003) in movement priming. Evidence for action observation priming was inconclusive. Conclusion. Combining priming and task-oriented training for the upper extremities of chronic stroke patients can be a promising intervention strategy. Studies that identify which priming techniques combined with task-oriented training for upper extremity function in chronic stroke yield effective outcomes in each ICF domain are needed and may be beneficial for the recovery of upper extremities poststroke.

Pharmacological Interventions and Rehabilitation Approach for Enhancing Brain Self-repair and Stroke Recovery

Neuroplasticity is a natural process occurring in the brain for the entire life. Stroke is the leading cause of long term disability and a huge medical and financial problem throughout the world. Research conducted over the past decade focused mainly on neuroprotection in the acute phase of stroke while very little studies target the chronic stage. Recovery after stroke depends on the ability of our brain to reestablish the structural and functional organization of neurovascular networks. Combining adjuvant therapies and drugs may enhance the repair processes and restore impaired brain functions. Currently, there are some drugs and rehabilitative strategies that can facilitate brain repair and improve clinical effect even years after stroke onset. Moreover, some of the compounds such as citicoline, fluoxetine, niacin, levodopa, etc. are already in clinical use or are being trialed in clinical issues. Many studies are also testing cell therapies; in our review, we focused on studies where cells have been implemented at the early stage of stroke. Next, we discuss pharmaceutical interventions. In this section, we selected methods of cognitive, behavioral, and physical rehabilitation as well as adjuvant interventions for neuroprotection including noninvasive brain stimulation and extremely low-frequency electromagnetic field. The modern rehabilitation represents a new model of physical interventions with the limited therapeutic window up to six months after stroke. However, previous studies suggest that the time window for stroke recovery is much longer than previously thought. This review attempts to present the progress in neuroprotective strategies, both pharmacological and non-pharmacological that can stimulate the endogenous neuroplasticity in post-stroke patients.

Effects of Exercise on Cognitive Performance in Older Adults: A Narrative Review of the Evidence, Possible Biological Mechanisms, and Recommendations for Exercise Prescription

Physical activity and exercise have emerged as potential methods to improve brain health among older adults. However, there are currently no physical activity guidelines aimed at improving cognitive function, and the mechanisms underlying these cognitive benefits are poorly understood. The purpose of this narrative review is to present the current evidence regarding the effects of physical activity and exercise on cognition in older adults without cognitive impairment, identify potential mechanisms underlying these effects, and make recommendations for exercise prescription to enhance cognitive performance. The review begins with a summary of evidence of the effect of chronic physical activity and exercise on cognition. Attention then turns to four main biological mechanisms that appear to underlie exercise-induced cognitive improvement, including the upregulation of growth factors and neuroplasticity, inhibition of inflammatory biomarker production, improved vascular function, and hypothalamic-pituitary-adrenal axis regulation. The last section provides an overview of exercise parameters known to optimize cognition in older adults, such as exercise type, frequency, intensity, session duration, and exercise program duration.

Increased serum brain-derived neurotrophic factor with high-intensity interval training in stroke patients: A randomized controlled trial

BACKGROUND

Physiological adaptations of stroke patients after high-intensity interval training (HIIT) and moderate-intensity continuous training (MICT) remain unclear.

OBJECTIVE

This study determined the HIIT and MICT effects on aerobic capacity, cerebral oxygenation, peak cardiac output (CO), and serum brain-derived neurotrophic factor (BDNF) in stroke patients.

METHODS

We included 23 stroke patients with age about 55 years and stroke duration>24 months; participants completed 36 sessions of exercise training for 30min; 13 were randomly assigned to perform MICT at 60% of peak oxygen consumption (VO_2peak) and 10 to perform HIIT at alternating 80% (3min) and 40% (3min) VO_2peak. Before and after interventions, we evaluated VO_2peak, peak CO, arteriovenous oxygen difference (AV O_2diff), bilateral frontal cortex oxygenation (relative changes of oxyhemoglobin Δ[O₂Hb], deoxyhemoglobin Δ[HHb], and total hemoglobin Δ[THb] levels), serum brain-derived neurotrophic factor (BDNF) level, and fluorescent cell staining for neuron morphology and percentage of cell-bearing neurites (% neurites).

RESULTS

HIIT induced significant increases in VO_2peak (P=0.008), CO (P=0.038), Δ[HHb] (P=0.046), Δ[THb] (P=0.046), and serum BDNF level (P=0.012). The improvement in VO_2peak was significantly greater with HIIT than MICT (20.7% vs. 9.8%, P=0.031), as was AV O_2diff (P=0.041), Δ[HHb] (P=0.027), and serum BDNF level (P<0.001). HIIT facilitated neuron dendritic protrusions (greater % neurites, P=0.012) with prominent redistribution of mitochondria.

CONCLUSION

As compared with MICT, HIIT-improved aerobic capacity by increasing systemic tissue O₂ extraction in stroke patients. Increased cerebral O₂ utilization in the involved hemisphere was also identified after HIIT. These physiological adaptations may be associated with increased serum BDNF level. In vitro dendritic growth in neurons treated with serum from HIIT participants may imply significant effects on neuron activities as compared with MICT. CLINICALTRIALS.

GOV IDENTIFIER

NCT04135391.

The effects of exercise on cognition post-stroke: are there sex differences? A systematic review and meta-analysis

Purpose: The aim of this systematic review was to investigate if sex moderated the effect of exercise on cognition in adults post-stroke.Methods: A systematic review was conducted of randomized controlled trials that involved adults ≥18 years with stroke, any exercise intervention, and reported any outcome related to cognitive function. We compared effect sizes of cognitive outcomes between studies of lower and higher proportion of females (CRD42018092757).Results: The effects of exercise did not differ between studies of higher and lower female proportions with respect to memory (χ² =1.52, p = 0.22), executive function (χ² = 0.56, p = 0.45; Chi² = 0.00, p = 0.98), language (Chi² = 3.17, p = 0.08) or global cognition (χ² = 0.88, p = 0.35).Conclusion: There were no sex differences in the effects of exercise on memory, executive functioning, language or global cognition in individuals with stroke. Further research is warranted to address sex differences in individuals with stroke to enable better targeting, prevention, and interventions in stroke rehabilitation.IMPLICATIONS FOR REHABILITATIONUnderstanding sex differences and potentially similarities in the relationship between exercise and cognition is an important step in enhancing stroke rehabilitation and the development of optimal, sex-specific rehabilitation.Although our findings suggest that there is no clear rationale for incorporating sex into our clinical decision making, it is still imperative to consider sex factors in research and report results in the literature disaggregated by sex to help inform clinical practice.

Colocalized White Matter Plasticity and Increased Cerebral Blood Flow Mediate the Beneficial Effect of Cardiovascular Exercise on Long-Term Motor Learning

Cardiovascular exercise (CE) is a promising intervention strategy to facilitate cognition and motor learning in healthy and diseased populations of all ages. CE elevates humoral parameters, such as growth factors, and stimulates brain changes potentially relevant for learning and behavioral adaptations. However, the causal relationship between CE-induced brain changes and human's ability to learn remains unclear. We tested the hypothesis that CE elicits a positive effect on learning via alterations in brain structure (morphological changes of gray and white matter) and function (functional connectivity and cerebral blood flow in resting state). We conducted a randomized controlled trial with healthy male and female human participants to compare the effects of a 2 week CE intervention against a non-CE control group on subsequent learning of a challenging new motor task (dynamic balancing; DBT) over 6 consecutive weeks. We used multimodal neuroimaging [T1-weighted magnetic resonance imaging (MRI), diffusion-weighted MRI, perfusion-weighted MRI, and resting state functional MRI] to investigate the neural mechanisms mediating between CE and learning. As expected, subjects receiving CE subsequently learned the DBT at a higher rate. Using a modified nonparametric combination approach along with multiple mediator analysis, we show that this learning boost was conveyed by CE-induced increases in cerebral blood flow in frontal brain regions and changes in white matter microstructure in frontotemporal fiber tracts. Our study revealed neural mechanisms for the CE-learning link within the brain, probably allowing for a higher flexibility to adapt to highly novel environmental stimuli, such as learning a complex task.SIGNIFICANCE STATEMENT It is established that cardiovascular exercise (CE) is an effective approach to promote learning and memory, yet little is known about the underlying neural transfer mechanisms through which CE acts on learning. We provide evidence that CE facilitates learning in human participants via plasticity in prefrontal white matter tracts and a colocalized increase in cerebral blood flow. Our findings are among the first to demonstrate a transfer potential of experience-induced brain plasticity. In addition to practical implications for health professionals and coaches, our work paves the way for future studies investigating effects of CE in patients suffering from prefrontal hypoperfusion or white matter diseases.