A Controlled Clinical Trial on the Effects of Exercise on Cognition and Mobility in Adults With Multiple Sclerosis

The effects of balance training on cognitive function in persons with multiple sclerosis: A systematic review and meta-analysis

BACKGROUND

There is growing literature examining the effects of balance training on cognitive function in individuals with multiple sclerosis (MS), yet the findings remain inconsistent. This study aimed to investigate methodological characteristics of balance training studies and examine the effects of this modality on cognitive function.

METHODS

This study performed literature search using MEDLINE, EMBASE, PsycINFO, SPORTSDiscus, and CINAHL databases from inception to April 2024. Randomized and non-randomized controlled trials of balance training studies that assessed cognitive function were included. The Tool for the Assessment of Study Quality and Reporting in Exercise was used to evaluate methodological quality of included studies. We calculated effect sizes as standardized mean differences (SMD) using Hedge's g and employed multi-level random-effects model for meta-analysis.

RESULTS

Fourteen articles with 1,020 participants were included in this review, and a subset of seven studies with 26 effect sizes were further used for meta-analysis. Balance training indicated medium effects on global cognition (SMD [95 % CI] = 0.39 [0.13, 0.64]), processing speed (SMD [95 % CI] = 0.36 [0.00, 0.73]), and visuospatial memory (SMD [95 % CI] = 0.53 [0.12, 0.93]) and large effect on verbal memory (SMD [95 % CI] = 0.66 [0.25, 1.06]). We found that intervention characteristics and exercise doses significantly moderated the effects on cognition.

CONCLUSIONS

Balance training may effectively improve overall and specific domains of cognitive function in persons with MS. Exercise doses of at least 120 min per week and a total duration of 720 min or more were significant moderators for greater cognitive improvement.

Effects of Balance Exercise Interventions on Balance-Related Performance in People With Multiple Sclerosis: A Systematic Review and a Meta-Analysis of Randomized Controlled Trials

BACKGROUND

Balance training covers a range of different modalities and complexity levels for people with multiple sclerosis (MS). When evaluating the effects of balance training across different kinds of interventions, determination of the specific intervention content that predict effects are needed.

OBJECTIVE

To investigate the effects of balance training on gait and dynamic balance outcomes.

METHODS

Four databases were systematically searched. Randomized controlled trials involving people with MS (Expanded Disability Status Scale [EDSS] score ≤7.5) where at least 50% of the intervention targeted balance control were included. Interventions were categorized based on training types. Risk-of-bias was assessed using the Tool for the Assessment of Study Quality and Reporting in Exercise (TESTEX).

RESULTS

A total of 18 included studies involved 902 people with MS (EDSS range from 0 to 7.5). Interventions evaluated with a balance composite score or a mobility test showed a moderate effect size (ES = 0.46 [95% confidence interval (CI) = 0.18 to 0.74]; p < .01) and a small overall ES (ES = 0.19 [95% CI = 0.01-0.36]; p = .04), respectively, across different training types. Stepping and gait speed outcomes showed no effect. Cognitive dual-task training showed a significant effect (ES = 0.81 [95% CI = 0.24 to 1.37]) on subgroup level, when evaluated with a mobility outcome measure. The median TESTEX score on study quality and reporting was 11 (maximum score = 15).

CONCLUSIONS

Improvements of balance were found across interventions when measured by balance composite scores and mobility tests, but not when measured by stepping or gait speed outcomes. Large training volume was positively associated with effect on balance. A definition of intensity in balance training is needed for evaluation of its impact on the effect of balance interventions.

Safety of exercise training in multiple sclerosis: An updated systematic review and meta-analysis

BACKGROUND

A review of the safety profile of exercise training in multiple sclerosis (MS) has not been conducted since 2013.

OBJECTIVE

We undertook a systematic review and meta-analysis of randomised controlled trials (RCTs) of exercise training published since 2013 and quantified estimated population risks of clinical relapse, adverse events (AE) and serious adverse event (SAE).

METHODS

Articles reporting safety outcomes from comparisons of exercise training with non-exercise among persons with MS were identified. The risk of bias was established from study's internal validity assessed using Physiotherapy Evidence Database (PEDro). Rates and estimated mean population relative risks (RRs; 95% confidence interval (CI)) of safety outcomes were calculated, and random-effects meta-analysis estimated the mean RR.

RESULTS

Forty-six interventions from 40 RCTs (N = 1780) yielded 46, 40 and 39 effects for relapse, AE, adverse effects and SAE, respectively. The mean population RRs ((95% CI), p-value) for relapse, AE and SAE were 0.95 ((0.61, 1.48), p = 0.82), 1.40 ((0.90, 2.19), p = 0.14) and 1.05 ((0.62, 1.80), p = 0.85), respectively. No significant heterogeneity is observed for any outcome.

CONCLUSION

In studies that reported safety outcomes, there was no higher risk of relapse, AE, adverse effects or SAE for exercise training than the comparator. Exercise training may be promoted as safe and beneficial to persons with MS.

A highly challenging balance training intervention for people with multiple sclerosis: a feasibility trial

BACKGROUND

Balance training interventions with a gradual progression of difficulty and highly challenging tasks designed specifically for people with multiple sclerosis (MS) are rare. The objective was to adapt a balance training intervention originally developed for Parkinson's disease through a co-design process and then conduct a pilot trial in MS to evaluate the feasibility of a large, full-scale study.

METHODS

Twelve people with MS with mild to moderate overall MS-disability were included in this single-group feasibility trial. Participants received one-hour training sessions twice or three times weekly for 10 weeks. The assessment included tests of physical and cognitive functioning and patient-reported quality of life-related outcomes. Data on feasibility aspects were collected at baseline and follow-up assessments and three times during the intervention period to inform the recruitment process, as well as to monitor retention and inclusion rates, study procedures, intervention delivery, and dynamic changes in the selected potential outcome measures. Progression criteria were used to determine whether to proceed to a full-scale trial. Descriptive statistics were used to present the data.

RESULTS

Out of six progression criteria, only retention and attendance at training sessions were not met. Reasons reported for not completing the intervention period mainly depended on external circumstances beyond the control of the study. In contrast, study procedures, intervention delivery, and intervention content (progression, adjustment, and control of challenge level of exercises) were considered feasible for a future, full-scale trial. The Mini-BESTest, which was used for the assessment of balance control, was considered suitable as the primary outcome in a full-scale trial with no ceiling or floor effects. Further, the Mini-BESTest showed a positive trend in outcome response with a median difference of 3.5 points between baseline and follow-up assessments. The power calculation performed suggests a feasible number of participants for recruitment.

CONCLUSIONS

Overall trial aspects and intervention delivery were deemed feasible for a full-scale trial, but adjustments are needed to increase retention and attendance.

Effects of multi-task training on motor and cognitive performances in multiple sclerosis patients without clinical disability: a single-blinded randomized controlled trial

OBJECTIVE

This study aimed to investigate the effects of multi-task training on motor and cognitive performance in People with Multiple Sclerosis (PwMS) without clinical disability compared to single-task training and a control group.

METHODS

A total of 42 patients were randomly assigned to three groups labeled as Multi-Task Training Group (MTTG, n:14), Single-Task Training Group (STTG, n:14), and Control Group (CG, n:14). The STTG performed only motor tasks based on the task-oriented training program twice a week for 6 weeks while the MTTG performed the same tasks concurrently with additional motor and cognitive tasks. The CG performed relaxation exercises at home. Postural stability by posturography, walking by Timed Up-and-Go, manual dexterity by Nine-Hole Peg Test, mental tracking by Counting Backward, and verbal fluency by Word List Generation were assessed before and after the intervention under single and dual-task conditions.

RESULTS

In the MTTG, both single cognitive and single motor task performances increased, and, moreover, the cognitive Dual-Task Costs (DTCs) decreased although the motor DTCs were not changed significantly. There were significant group-by-time interactions in favor of MTTG only on the mental tracking DTC during walking compared to the STTG. Moreover, the changes in postural and walking DTCs were associated with changes in single-motor task performance.

CONCLUSION

This study suggests that multi-task training is effective in reducing cognitive DTC rather than motor DTC under dual-task conditions in PwMS without clinical disability.

TRIAL REGISTRATION NUMBER

NCT03512886.

Unwrapping the "black box" of balance training in people with multiple sclerosis - A descriptive systematic review of intervention components, progression, and intensity

BACKGROUND

Delineating the specific components of the existing balance training interventions in people with multiple sclerosis (PwMS) may contribute to a framework for future design and reporting of such interventions. Thus, we aimed to systematically synthesize how balance training frequency, intensity, time, type, duration, and progression are reported in balance training interventions for PwMS.

METHODS

A systematic literature search was conducted in Medline, Embase, Web of Science, and Cinahl. Search terms were MS, postural balance, walking, gait, and randomized/quasi-randomized controlled or clinical trials. Articles including ambulatory PwMS and interventions designed to challenge the balance control system were eligible. Two investigators screened, selected, and extracted data independently. Data on study characteristics such as design, population, and balance training content were extracted. Categorization of balance training based on balance control components was performed.

RESULTS

We included 40 studies grouped under five balance training categories. Balance interventions were well described regarding frequency, session time, and duration, but only two interventions described training intensity, and no systematic, gradual progression approach was reported for balance training adaptation over time. However, the balance training interventions included many sensory and motor components of the balance control system. Still, little focus was on reactive motor strategies, vestibular sense, and cognitive dual-tasking.

CONCLUSIONS

Existing balance training interventions in PwMS primarily consist of practicing sensory and motor strategies. Future balance training interventions are encouraged to systematically monitor individual advancements in balance training adaptations and to apply the progressive overload principle (i.e. continuous increase in balance exercise stimulus over time). Furthermore, we suggest that balance training in PwMS is performed with high intensity near an individual's balance capacity limits. Finally, individualized balance training is recommended to cover all relevant components of balance control using the proposed framework.

Cognitive assessment of Brazilian patients with multiple sclerosis: weighing the impact of disability and depressive symptoms

Multiple sclerosis (MS) is the most common demyelinating disease of the central nervous system. Cognition is not routinely assessed in patients with MS though they frequently have cognitive complaints or dysfunction.

Objective

The aim of this study was to compare the cognitive status of patients with MS with age, sex, and schooling matched controls and to evaluate the potential influence of clinical parameters on cognition.

Methods

A total of 35 patients with MS (mean±SD age 37.9 years±11.44, M/F: 12/23) and 33 healthy controls (mean±SD age 38.8 years±12.6, M/F: 12/21) were enrolled in this study. All subjects underwent a structured clinical assessment and the cognitive tools are as follows: Paced Auditory Serial Addition Test (PASAT), Symbol Digit Modalities Test (SDMT), Rey Auditory Verbal Learning Test (RAVLT), Digit Span, and Verbal Fluency Tests (letters F, A, and S and animal category). Psychopathology was assessed with the Mini International Neuropsychiatric Interview and the Beck Depression Inventory (BDI). The Expanded Disability Status Scale (EDSS) was used for patients.

Results

Patients performed worse than controls in almost all tests, with approximately 70% of patients presenting cognitive impairment. The most affected cognitive domain was episodic memory (45.7%), followed by verbal fluency (42.8%) and information processing speed (22.8%). SDMT was inversely correlated with disease severity, as assessed by the EDSS. Depression did not influence cognitive performance in this cohort.

Conclusions

Cognitive dysfunction is common among patients with MS. While motor impairment was associated with information processing speed, depression did not influence cognitive performance.

Outcome measures used in trials on gait rehabilitation in multiple sclerosis: A systematic literature review

BACKGROUND

Multiple Sclerosis (MS) is associated with impaired gait and a growing number of clinical trials have investigated efficacy of various interventions. Choice of outcome measures is crucial in determining efficiency of interventions. However, it remains unclear whether there is consensus on which outcome measures to use in gait intervention studies in MS.

OBJECTIVE

We aimed to identify the commonly selected outcome measures in randomized controlled trials (RCTs) on gait rehabilitation interventions in people with MS. Additional aims were to identify which of the domains of the International Classification of Functioning, Disability and Health (ICF) are the most studied and to characterize how outcome measures are combined and adapted to MS severity.

METHODS

Pubmed, Cochrane Central, Embase and Scopus databases were searched for RCT studies on gait interventions in people living with MS according to PRISMA guidelines.

RESULTS

In 46 RCTs, we identified 69 different outcome measures. The most used outcome measures were 6-minute walking test and the Timed Up and Go test, used in 37% of the analyzed studies. They were followed by gait spatiotemporal parameters (35%) most often used to inform on gait speed, cadence, and step length. Fatigue was measured in 39% of studies. Participation was assessed in 50% of studies, albeit with a wide variety of scales. Only 39% of studies included measures covering all ICF levels, and Participation measures were rarely combined with gait spatiotemporal parameters (only two studies).

CONCLUSIONS

Selection of outcome measures remains heterogenous in RCTs on gait rehabilitation interventions in MS. However, there is a growing consensus on the need for quantitative gait spatiotemporal parameter measures combined with clinical assessments of gait, balance, and mobility in RCTs on gait interventions in MS. Future RCTs should incorporate measures of fatigue and measures from Participation domain of ICF to provide comprehensive evaluation of trial efficacy across all levels of functioning.

Exercise leads to metabolic changes associated with improved strength and fatigue in people with MS

Objective

The goal of this exploratory study was to evaluate the effects of an exercise intervention – progressive resistance training (PRT) on the metabolome of people with MS (pwMS) and to link these to changes in clinical outcomes.

Methods

14 pwMS with EDSS <4.0 and 13 age‐ and sex‐matched healthy controls completed a 12‐week in‐person PRT exercise intervention. Outcome measures included: plasma metabolomics analysis, cardiovascular fitness tests, EDSS, timed 25‐foot walk (T25FW), six‐minute walk test (6MWT), hip strength, and modified fatigue impact scale (MFIS). We identified changes in the metabolome with PRT intervention in both groups using individual metabolite abundance and weighted correlation network defined metabolite module eigenvalues and then examined correlations in changes in metabolite modules with changes in various clinical outcomes.

Results

In both groups PRT intervention improved hip strength, distance walked in 6WMT, speed of walking, while fatigue (MFIS) was improved in pwMS. Fatty acid, phospholipid, and sex steroid metabolism were significantly altered by PRT in pwMS but not in controls. Changes in fatigue (MFIS score) were strongly inversely correlated and hip strength was moderately correlated with change in sex steroid metabolite module in pwMS. A similar relationship was noted between change in dehydroepiandrosterone sulfate abundance (sex steroid metabolite) and fatigue in pwMS. We also noted an inverse correlation between changes in fatty acid metabolism and cardiovascular fitness in pwMS.

Interpretation

PRT‐induced metabolic changes may underlie improved clinical parameters in pwMS and may warrant investigation as potential therapeutic targets in future studies.

Effect of dual-task training on balance in patients with multiple sclerosis: A systematic review and meta-analysis

OBJECTIVE

To evaluate the effects of dual-task training on static and dynamic balance in patients with multiple sclerosis.

DATA SOURCES

PubMed/MEDLINE, EMBASE, Scopus, and PEDro databases were searched from inception to March 1, 2021.

METHODS

This study was conducted in agreement with Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines. Two reviewers assessed studies for inclusion and extracted data. We used the Physiotherapy Evidence Database scale to evaluate the methodological quality and the risk-of-bias. Randomized clinical trial data were pooled for the meta-analysis. The effect sizes and 95% confidence interval (CI) were calculated by random-effect models. Egger regression and Begg-Mazumdar rank correlation test were used for publication bias.

RESULTS

A total of 13 studies involving 584 patients (42.3 ± 9 years mean ± SD; 377 females) met the inclusion criteria for the systematic review, while nine were included in the meta-analysis. People who received dual-task training interventions showed significant improvements in the Timed Up & Go test 0.44 [(95% CI = 0.22; 0.65), P-value<0.001], and in the Berg Balance scale 0.46 [(95% CI = 0.07; 0.85), P-value = 0.02]. Low and moderate heterogeneity between the studies was found for the Timed Up & Go test and the Berg Balance scale, respectively.

CONCLUSION

The findings from the current meta-analysis support dual-task training as a beneficial therapy for improving dynamic balance and functional mobility in patients with multiple sclerosis. The limited number of studies that investigated static balance performance after dual-task training do not currently allow us to draw a conclusion about any possible improvements in this ability.

Exercise rapidly alters proteomes in mice following spinal cord demyelination

Exercise affords broad benefits for people with multiple sclerosis (PwMS) including less fatigue, depression, and improved cognition. In animal models of multiple sclerosis (MS), exercise has been shown to improve remyelination, decrease blood-brain barrier permeability and reduce leukocyte infiltration. Despite these benefits many PwMS refrain from engaging in physical activity. This barrier to participation in exercise may be overcome by uncovering and describing the mechanisms by which exercise promotes beneficial changes in the central nervous system (CNS). Here, we show that acute bouts of exercise in mice profoundly alters the proteome in demyelinating lesions. Following lysolecithin induced demyelination of the ventral spinal cord, mice were given immediate access to a running wheel for 4 days. Lesioned spinal cords and peripheral blood serum were then subjected to tandem mass tag labeling shotgun proteomics workflow to identify alteration in protein levels. We identified 86 significantly upregulated and 85 downregulated proteins in the lesioned spinal cord as well as 14 significantly upregulated and 11 downregulated proteins in the serum following acute exercise. Altered pathways following exercise in demyelinated mice include oxidative stress response, metabolism and transmission across chemical synapses. Similar acute bout of exercise in naïve mice also changed several proteins in the serum and spinal cord, including those for metabolism and anti-oxidant responses. Improving our understanding of the mechanisms and duration of activity required to influence the injured CNS should motivate PwMS and other conditions to embrace exercise as part of their therapy to manage CNS disability.

Treatment and management of cognitive dysfunction in patients with multiple sclerosis

Cognitive impairment is a common and devastating manifestation of multiple sclerosis (MS). Although disease-modifying therapies have been efficacious for reducing relapse rates in MS, such treatments are ineffective for treating cognitive dysfunction. Alternative treatment approaches for mitigating cognitive problems are greatly needed in this population. To date, cognitive rehabilitation and exercise training have been identified as possible candidates for treating MS-related cognitive impairment; however, cognitive dysfunction is still often considered to be poorly managed in patients with MS. This Review provides a comprehensive overview of recent developments in the treatment and management of cognitive impairment in people with MS. We describe the theoretical rationales, current states of the science, field-wide challenges and recent advances in cognitive rehabilitation and exercise training for treating MS-related cognitive impairment. We also discuss future directions for research into the treatment of cognitive impairment in MS that should set the stage for the inclusion of cognitive rehabilitation and exercise training into clinical practice within the next decade.

Integrated Cognitive and Neuromotor Rehabilitation in Multiple Sclerosis: A Pragmatic Study

Background: Few studies examined the effects of combined motor and cognitive rehabilitation in patients with multiple sclerosis (MS). The present prospective, multicenter, observational study aimed to determine the efficacy of an integrated cognitive and neuromotor rehabilitation program versus a traditional neuromotor training on walking, balance, cognition and emotional functioning in MS patients.

Methods: Sixty three MS patients were selected and assigned either to the Integrated Treatment Group (ITG; n = 32), receiving neuropsychological treatment (performed by ERICA software and paper–pencil tasks) complemented by conventional neuromotor rehabilitation, or to the Motor Treatment Group (n = 31) receiving neuromotor rehabilitation only. The intervention included two 60-min sessions per week for 24 weeks. At baseline and at end of the training all patients underwent a wide-range neuropsychological, psychological/emotional, and motor assessment.

Results: At baseline the two groups did not differ for demographic, neuropsychological, psychological/emotional, and motor features significantly. After rehabilitation, only ITG group significantly (p-corrected for False Discovery Rate) improved on test tapping spatial memory, attention and cognitive flexibility, as well as on scales assessing depression and motor performance (balance and gait). A regression analysis showed that neuropsychological and motor improvement was not related to improvements in fatigue and depression.

Conclusion: The present study demonstrated positive effects in emotional, motor, and cognitive aspects in MS patients who received an integrated cognitive and neuromotor training. Overall, results are supportive of interventions combining motor and cognitive training for MS.