Aerobic capacity in persons with multiple sclerosis: a systematic review and meta-analysis

Associations between fatigue impact and physical and neurobehavioural factors: An exploration in people with progressive multiple sclerosis

BACKGROUND

Fatigue is common in people with multiple sclerosis (MS). Understanding the relationship between fatigue, physical and neurobehavioural factors is important to inform future research and practice. Few studies explore this explicitly in people with progressive MS (pwPMS).

OBJECTIVE

To explore relationships between self-reported fatigue, physical and neurobehavioural measures in a large, international progressive MS sample of cognitively impaired people recruited to the CogEx trial.

METHODS

Baseline assessments of fatigue (Modified Fatigue Impact Scale; MFIS), aerobic capacity (VO2peak), time in moderate-vigorous physical activity (MVPA; accelerometery over seven-days), walking performance (6-minute walk test; 6MWT), self-reported walking difficulty (MS Walking Scale; MSWS-12), anxiety and depression (Hospital Anxiety and Depression Scale; HADS and Beck Depression Inventory-II; BDI-II), and disease impact (MS Impact Scale-29, MSIS-29) were assessed. Participants were categorised as fatigued (MFISTotal >=38) or non-fatigued (MFISTotal ≤38).

STATISTICAL ANALYSIS

Differences in individuals categorised as fatigued or non-fatigued were assessed (t-tests, chi square). Pearson's correlation and partial correlations (adjusted for EDSS score, country, sex, and depressive symptoms) determined associations with MFISTotal, MFISPhysical, MFISCognitive and MFISPsychosocial, and the other measures. Multivariable logistic regression evaluated the independent association of fatigue (categorised MFISTotal) with physical and neurobehavioural measures.

RESULTS

The sample comprised 308 pwPMS (62 % female, 27 % primary progressive, 73 % secondary progressive), mean age 52.5 ± 7.2 yrs, median EDSS score 6.0 (4.5-6.5), mean MFISTotal 44.1 ± 17.1, with 67.2 % categorised as fatigued. Fatigued participants walked shorter distances (6MWT, p = 0.043), had worse MSWS-12 scores (p < 0.001), and lower average % in MVPA (p = 0.026). The magnitude of associations was mostly weak between MFISTotal and physical measures (r = 0.13 to 0.18), apart from the MSWS-12 where it was strong (r = 0.51). The magnitude of correlations were strong between the MFISTotal and neurobehavioural measures of anxiety (r = 0.56), depression (r = 0.59), and measures of disease impact (MSIS-physical r = 0.67; MSIS-mental r = 0.71). This pattern was broadly similar for the MSIF subscales. The multivariable model indicated a five-point increase in MSWS-12 was associated with a 14 % increase in the odds of being fatigued (OR [95 %CI]: 1.14 [1.07-1.22], p < 0.0001) CONCLUSION: Management of fatigue should consider both physical and neurobehavioural factors, in cognitively impaired persons with progressive MS.

Rationale and methodology for examining the combination of aerobic exercise and cognitive rehabilitation on new learning and memory in persons with multiple sclerosis and mobility disability: Protocol for a randomized controlled trial

BACKGROUND

This paper describes the protocol for a Phase I/II, parallel-group, single-blind randomized controlled trial (RCT). The RCT investigates the combined effects of 12-weeks of aerobic exercise training (AET) integrated with virtual reality (VR) and cognitive rehabilitation (CR) on new learning and memory in 78 persons with multiple sclerosis (MS) who have mobility disability and objective impairments in learning and memory.

METHODS

Participants will undergo baseline assessments consisting of neuropsychological testing, neuroimaging, self-report questionnaires, and cardiorespiratory fitness. Participants will then be randomized into one of two conditions using concealed allocation: aerobic cycling exercise that incorporates VR combined with CR or stretching and toning (i.e., active control; S/T) combined with CR. Participants will be masked regarding the intent of the conditions. After 7-weeks of exercise alone, the 5-week Kessler Foundation modified Story Memory Technique (KF-mSMT®) will be integrated into the training. After the 12-week training period, participants will complete the same measures as at baseline administered by treatment-blinded assessors. Primary study outcomes include new learning and memory (NLM) measured by a small battery of neuropsychological assessments that assess list learning (California Verbal Learning Test-II), prose memory (Memory Assessment Scale), visuospatial memory (Brief Visuospatial Memory Test-Revised), and everyday memory (Ecological Memory Simulations). Secondary study outcomes include neuroimaging outcomes of hippocampal structure, function, and connectivity.

CONCLUSION

If successful, this trial will provide the first Class I evidence supporting the unique combination of aerobic cycling exercise with VR and CR for treating MS-related learning and memory impairments in persons with mobility disability.

Benefits of Individualized Training in Fatigued Patients with Multiple Sclerosis

INTRODUCTION

Chronic fatigue is the most common and debilitating symptom in people with multiple sclerosis (PwMS). Recently, exercise has been proven to alleviate chronic fatigue and improve physical functions. Tailoring the training intervention to the potential fatigue causes could optimize the beneficial effects of training on fatigue. The objective of this study was to compare the effectiveness of an individualized (IND) versus a traditional (TRAD) exercise intervention in reducing chronic fatigue.

METHODS

Twenty-nine PwMS with high chronic fatigue were randomly assigned to 12 wk of either a TRAD or IND exercise intervention. TRAD comprised aerobic and resistance exercises according to the guidelines for PwMS. IND specifically addressed identified individual weaknesses. Participants visited the laboratory before and after training for the following assessments: patient-reported outcomes (fatigue, quality of life, depression questionnaires), incremental cycling test (peak oxygen uptake (V̇O 2peak )), and cycling fatigue test (maximal voluntary contraction, rating of perceived exertion).

RESULTS

Similar improvements in fatigue, depression, and quality of life were observed between groups ( P > 0.05). Compared with TRAD, IND induced a significant greater increase in V̇O 2peak (+21.0% ± 13.9% vs 6.8% ± 11.5%, P < 0.05) and a greater reduction in rating of perceived exertion at a given submaximal intensity (-30.3% ± 18.9% vs -12.1% ± 20.4%, P < 0.001), whereas maximal voluntary contraction increased similarly in both groups ( P > 0.05).

CONCLUSIONS

Although tailored exercise improved similarly fatigue and other subjective parameters (depression, quality of life, sleep quality) compared with than traditional exercise intervention, prescribing an individualized intervention led to greater improvement in V̇O 2peak (but not maximal strength) and perception of effort. This may have positive functional consequences for patients.

Physiological fitness in people with advanced multiple sclerosis

INTRODUCTION

Physiological fitness, encompassing cardiorespiratory fitness (CRF) and body composition, are important markers of overall health, functional capacity, and quality of life in general and clinical populations. Characterizing fitness is important for the development of tailored interventions and strategies to optimize well-being across the spectrum of disability in multiple sclerosis (MS). While existing research has explored fitness in people with mild-to-moderate disability, there is a scarcity of data in people with advanced MS (Expanded Disability Severity Scale, EDSS≥7.0).

OBJECTIVE

To characterize CRF and body composition and their associations with fatigue, quality of life, and function in individuals with advanced MS.

METHODS

Participants (n=18, mean age=60.7 years-old, median EDSS=7.5) underwent a cardiopulmonary exercise test and dual-energy X-ray absorptiometry scanning. Main outcomes included peak volume of oxygen uptake (V̇O2peak) and whole and regional body fat, lean mass, bone mineral content, and bone density. Symptoms of fatigue (Modified Fatigue Impact Scale, MFIS), quality of life (29-item MS Impact Scale, MSIS-29), and daily function (Late-Life Function and Disability Instrument, LLFDI) were collected.

RESULTS

Participants exhibited notably low CRF levels (V̇O2peak=9.8 mL/min/kg) and poor body composition (lower lean mass, bone mineral content and density) compared to previous studies in the general population and in individuals with MS with lower disability. V̇O2peak was most consistently associated with function in daily life (LLFDI scores, rs≥0.637, p≤0.004).

CONCLUSION

These findings reinforce the potential importance of physiological fitness to preserve function in people with advanced MS.

Individualized activity recommendation based on a physical fitness assessment increases short- and long-term regular physical activity in people with multiple sclerosis in a retrospective cohort study

Background

Despite the evidence of beneficial effects of physical activity (PA), people with multiple sclerosis (pwMS) are less physically active than the general population. To increase PA in pwMS, we developed a structured individually tailored PA promotion program which is conducted within clinical practice in a university-based outpatient clinic since 2016. This study serves as retrospective quality control of this program.

Objective

In a retrospective cohort study, we assessed the physical fitness of pwMS and the impact of the program on short- and long-term PA changes and behavioral determinants.

Methods

The program consisted of four appointments each 2-4 weeks apart. Spiroergometric test results of female pwMS were compared to female non-MS controls who underwent a voluntary physical fitness analysis. The short version of the Freiburger questionnaire, self-developed questions and the modified Physical activity screening questionnaire (PASQ) were sent to all participants assessing the PA levels before the program, 3 months after the program (short-term), and at the time of the survey (long-term). Additionally, established questionnaires assessed behavioral determinants before the program and long-term.

Results

A total of 166 participants [mean age 38.32 (± 10.61 SD), mean EDSS 2.30 (±1.29 SD)] and mostly females (63.3%, n = 105) were included in the study and started the program. A total of 136 participants completed the program. Out of these 63.9% (n = 87) answered the questionnaires in 12.38 (±11.34 SD) months after finishing the program. At baseline female pwMS (n = 100) showed a lower physical fitness in comparison to non-MS controls (n = 26) (maximal workload (Watts): 138.86 ± 37.85 vs. 191.73 ± 45.25, p < 0.001; peak oxygen consumption (ml min-1 kg-1): 26.40 ± 7.23 vs. 31.56 ± 10.10, p = 0.020). pwMS were more regularly active in short- (62.1%) and long-term (55.2%) compared to baseline (24.2%, p < 0.001). Among the activated participants, we observed improved internal motivation (p = 0.002) and decreased perception of barriers (p = 0.006) compared to baseline.

Conclusion

PwMS showed a lower physical fitness in comparison to non-MS controls. An individually tailored PA promotion program might improve behavioral determinants and thereby increase short- and long-term PA levels of pwMS.

Is High-Intensity Interval Training More Effective Than Moderate Continuous Training in Rehabilitation of Multiple Sclerosis: A Comprehensive Systematic Review and Meta-analysis

OBJECTIVES

The present study aimed to conduct meta-analysis to determine whether the high intensity interval training (HIIT) protocol is more beneficial in improving outcome measures compared to moderate continuous training (MCT) in people with multiple sclerosis (PwMS). It also aimed to systematically review the exercise protocols differences.

DATA SOURCES

A search strategy, locating HIIT in PwMS, was executed in six databases, PubMed, EMBASE, Web of Science, Central Cochrane, Pedro, and Ovid MEDLine.

STUDY SELECTION

Randomized control trials of HIIT utilizing cycle ergometer or recumbent stepper as exercise modalities were included in analysis. Intervention arms should include at least two intervention arms, including HIIT in one arm, and MCT in the other group.

DATA EXTRACTION

Data extracted from each study includes the following items: basic details of the study (such as author, date of publication, location, and study design), participant characteristics (sample size, mean age, sex, mean disease duration, and extended disability status scale), specifications of the HITT protocol (exercise modality, session duration, number of intervals/session, interval intensity, recovery intensity, recovery interval, and adverse effect), as well as primary outcomes at baseline and post-intervention (cardiorespiratory fitness, fatigue, body composition, cognitive functions, and blood biomarkers).

DATA SYNTHESIS

22 studies included in the systematic review, 11 were included in random effects model pooled analysis. There was a significant effect in favor of HIIT for VO2max of cardiorespiratory functions compared to MCT (ES=0.45 95%, CI [0.14, 0.76], P=.004), and for memory domain of cognitive functions (ES=0.34 95% CI [0.05, 0.63], P=.02). Statistical significance was not achieved for the other variables.

CONCLUSION

HIIT and MCT yield similar results in terms of fatigue, body composition, cognitive functions, and blood biomarkers. However, VO2max of cardiorespiratory functions and memory domain of cognitive functions were in favor of HIIT protocol.

Maximal Oxygen Consumption Is Negatively Associated with Fat Mass in Facioscapulohumeral Dystrophy

Facioscapulohumeral dystrophy (FSHD) leads to progressive changes in body composition such as loss of muscle mass and increase in adiposity. In healthy subjects, anthropometric parameters are associated with the maximum volume of oxygen consumed per minute (VO2max), which is a health and function indicator in several populations of subjects, both healthy and pathological. Since VO2max can be difficult to test in patients with FSHD due to exercise intolerance, the identification of associated anthropometric parameters could provide new easily obtainable elements for the patients' clinical stratification. The aim of this study was to evaluate whether anthropometric and body composition parameters are associated with VO2max in patients with FSHD. A total of 22 subjects with a molecular genetics-based diagnosis of FSHD (6 females, 16 males, mean age of 35.18 years) were recruited for the study. VO2max was measured by cardiopulmonary exercise tests (CPETs) on a cycle ergometer, utilizing a step incremental technique (15 Watts (W) every 30 s). Weight (Kg) and height (m) were obtained and utilized to calculate body mass index (BMI). Body composition parameters (fat mass (FM), fat free mass (FFM), and body cell mass (BCM)) were obtained by bioelectrical impedance analysis (BIA). Significant negative associations were found between VO2max and FM (Spearman correlation coefficient (SCC) -0.712), BMI (SCC -0.673), age (SCC -0.480), and weight (SCC -0.634), unlike FFM and BCM. Our results indicate that FM, BMI, age, and body weight are negatively associated with VO2max in patients with FSHD. This evidence may help practitioners to better stratify patients with FSHD.

Exploring the effectiveness of circuit training rehabilitation on balance, gait, and fatigue in multiple sclerosis: a systematic review and meta-analysis

BACKGROUND

People with Multiple Sclerosis (PwMS) often experience imbalance, gait dysfunction, and fatigue. Circuit Training (CT) can be viable for improving balance, gait, and fatigue in MS. To the author's knowledge, no studies have systematically reviewed the existing literature evaluating the effectiveness of CT in PwMS.

OBJECTIVES

To investigate the effectiveness of CT in improving balance, gait, and reducing fatigue in PwMS and provide a quantitative and qualitative synthesis of Randomized Controlled Trials (RCTs).

DATA SOURCES

MEDLINE, Cochrane Central Register of Controlled Trials, EMBASE, CINAHL, Google Scholar, and PEDro Database (Dec 2021 to May 2024).

STUDY SELECTION

RCTs using CT in PwMS including balance, gait, or fatigue outcomes.

DATA SYNTHESIS

Search inclusion criteria were: i) available full text, ii) CT rehabilitation, iii) balance, gait, or fatigue measured as outcomes, and iv) articles in English. Full text articles were analyzed by two screeners. If there was disagreement regarding inclusion, a further reviewer was consulted. No discrepancies were found.

RESULTS

We identified 878 studies, 14 studies were eligible including 716 PwMS with a mean (standard deviation) age of 49.9 (10.9) years, disease duration of 10.8 (7.2) years, and Expanded Disability Status Scale score of 4.3 (0.9) points. RevMan 5.4.1 was used to run the meta-analysis. We found a significant overall effect on Berg Balance Scale (Mean Difference (MD) = 6.07 points, 95%CI:1.40,10.75; p = 0.01) and in Fatigue Severity Scale (MD = 0.98 points, 95%CI:0.30,1.66; p = 0.005) in favor of CT. We did not find a significant effect in Timed Up and Go (MD = 0.46 second, 95%CI:-0.04,0.96; p = 0.07), in Six-Minute Walk Test (MD = 17.46 m, 95%CI:-8.06,42.97; p = 0.18), and in Modified Fatigue Impact Scale (MD = 3.34 points, 95%CI:-0.41,7.09; p = 0.08) in favor of CT. We assessed methodological quality using RoB 2.0, and quality of evidence using GRADE.

LIMITATIONS

Small number of studies, all identifying having some risk of bias.

CONCLUSION

Circuit training can have positive effects on PwMS in terms of increasing balance, gait, and reducing fatigue. Further research is needed.

SYSTEMATIC REVIEW REGISTRATION NUMBER

PROSPERO CRD42021286834. CONTRIBUTION OF THE PAPER.

Advanced neuroimaging techniques to explore the effects of motor and cognitive rehabilitation in multiple sclerosis

INTRODUCTION

Progress in magnetic resonance imaging (MRI) technology and analyses is improving our comprehension of multiple sclerosis (MS) pathophysiology. These advancements, which enable the evaluation of atrophy, microstructural tissue abnormalities, and functional plasticity, are broadening our insights into the effectiveness and working mechanisms of motor and cognitive rehabilitative treatments.

AREAS COVERED

This narrative review with selected studies discusses findings derived from the application of advanced MRI techniques to evaluate structural and functional neuroplasticity modifications underlying the effects of motor and cognitive rehabilitative treatments in people with MS (PwMS). Current applications as outcome measure in longitudinal trials and observational studies, their interpretation and possible pitfalls and limitations in their use are covered. Finally, we examine how the use of these techniques could evolve in the future to improve monitoring of motor and cognitive rehabilitative treatments.

EXPERT COMMENTARY

Despite substantial variability in study design and participant characteristics in rehabilitative studies for PwMS, improvements in motor and cognitive functions accompanied by structural and functional brain modifications induced by rehabilitation can be observed. However, significant enhancements to refine rehabilitation strategies are needed. Future studies in this field should strive to implement standardized methodologies regarding MRI acquisition and processing, possibly integrating multimodal measures. This will help identifying relevant markers of treatment response in PwMS, thus improving the use of rehabilitative interventions at individual level. The combination of motor and cognitive strategies, longer periods of treatment, as well as adequate follow-up assessments will contribute to enhance the quality of evidence in support of their routine use.

Utilizing Aerobic Capacity Data for EDSS Score Estimation in Multiple Sclerosis: A Machine Learning Approach

The Expanded Disability Status Scale (EDSS) is the most popular method to assess disease progression and treatment effectiveness in patients with multiple sclerosis (PwMS). One of the main problems with the EDSS method is that different results can be determined by different physicians for the same patient. In this case, it is necessary to produce autonomous solutions that will increase the reliability of the EDSS, which has a decision-making role. This study proposes a machine learning approach to predict EDSS scores using aerobic capacity data from PwMS. The primary goal is to reduce potential complications resulting from incorrect scoring procedures. Cardiovascular and aerobic capacity parameters of individuals, including aerobic capacity, ventilation, respiratory frequency, heart rate, average oxygen density, load, and energy expenditure, were evaluated. These parameters were given as input to CatBoost, gradient boosting (GBM), extreme gradient boosting (XGBoost), and decision tree (DT) machine learning methods. The most significant EDSS results were determined with the XGBoost algorithm. Mean absolute error, root mean square error, mean square error, mean absolute percent error, and R square values were obtained as 0.26, 0.4, 0.26, 16, and 0.68, respectively. The XGBoost based machine learning technique was shown to be effective in predicting EDSS based on aerobic capacity and cardiovascular data in PwMS.

Thalamic nuclei volume partially mediates the effects of aerobic capacity on fatigue in people with multiple sclerosis

BACKGROUND

Fatigue is frequent in people with multiple sclerosis (pwMS) impacting physical and cognitive functions. Lower aerobic capacity and regional thalamic volume may be involved in the pathophysiology of fatigue in pwMS.

OBJECTIVES

To identify associations between thalamic nuclei volumes, aerobic capacity and fatigue and to investigate whether the influence of aerobic capacity on fatigue in pwMS is mediated by thalamic integrity.

METHODS

Eighty-three pwMS underwent a clinical evaluation with assessment of fatigue (Modified Fatigue Impact Scale [MFIS]), including physical (pMFIS) and cognitive (cMFIS) components, and peak of oxygen uptake (VO2peak). PwMS and 63 sex- and age-matched healthy controls (HC) underwent a 3 T brain MRI to quantify volume of the whole thalamus and its nuclei.

RESULTS

Compared to HC, pwMS showed higher global MFIS, pMFIS and cMFIS scores, and lower VO2peak and thalamic volumes (p < 0.001). In pwMS, higher VO2peak was significantly associated with lower MFIS and pMFIS scores (r value = - 0.326 and - 0.356; pFDR ≤ 0.046) and higher laterodorsal thalamic nucleus (Dor) cluster volume (r value = 0.300; pFDR = 0.047). Moreover, lower Dor thalamic cluster volume was significantly associated with higher MFIS, pMFIS and cMFIS scores (r value range = - 0.305; - 0.293; pFDR ≤ 0.049). The volume of Dor thalamic cluster partially mediated the positive effects of VO2peak on both MFIS and cMFIS, with relative indirect effects of 21% and 32% respectively. No mediation was found for pMFIS.

CONCLUSIONS

Higher VO2peak is associated with lower fatigue in pwMS, likely acting on Dor thalamic cluster volume integrity. Such an effect might be different according to the type of fatigue (cognitive or physical).

The measurement of fatigability severity in individuals with multiple sclerosis and healthy controls

BACKGROUND

Multiple Sclerosis (MS) is a chronic disease that substantially diminishes one's ability to undertake daily living activities. Fatigue has been reported by at least 80 % of persons with MS (PwMS). Yet, little is known concerning the quantification of fatigability using prolonged walking tests.

OBJECTIVES

To compare fatigability severity measures using the 10-minute walk test for PwMS against age- and gender-matched healthy controls (HCs).

METHODS

Participants included 53 ambulatory PwMS and 49 HCs. Perceived fatigability was measured by dividing a participant's change in self-reported tiredness by the number of meters walked. Performance fatigability was calculated by dividing the change in walking speed (at 2.5 and 10 min) by the total distance walked in meters.

RESULTS

There was a significant difference in perceived fatigability between PwMS and HCs (mean difference: 2.73 ± 0.83; p = 0.001) and in performance fatigability (mean difference: 0.24 ± 0.11; p = 0.01). Moreover, there were significant differences in speed and distance at all time points (p ≤ 0.05) between PwMS and HCs.

CONCLUSIONS

PwMS have significant walking deficits as reflected by greater fatigability in both perceived and performance measures. These methods can enhance therapeutic strategies that improve the walking performances of PwMS.

Functional electrical stimulation combined with voluntary cycling accentuates VO2 response in people with severe multiple sclerosis: A pilot study

BACKGROUND

Lower limb muscle weakness and reduced balance due to disease progression in multiple sclerosis (MS) may make robust aerobic exercise difficult. Functional electrical stimulation (FES) cycling combined with voluntary cycling may allow people with severe MS to enhance the intensity of aerobic exercise. The aim of this study was to investigate the cardiorespiratory, power, and participant-reported perceptions during acute bouts of FES cycling, voluntary cycling, and FES cycling combined with voluntary cycling (FES assist cycling).

METHODS

Participants with severe MS (Expanded Disability Status Scale [EDSS] ≥ 6.0) undertook three exercise trials on a leg cycle ergometer. Trial 1 involved 30 min of FES cycling; Trial 2 involved two 10-minute bouts of voluntary cycling separated by 10 min rest; and Trial 3 was a combination of trials 1 and 2 (FES assist cycling). Outcome measures included VO2 (volume of oxygen consumption), cycle power output, heart rate, RPE, and post-exercise perceptions of pain and fatigue.

RESULTS

Ten people with severe MS participated (9 female; age 52.4 ± 9.98 y; EDSS 7.1 ± 0.6). The average VO2 during the 30-minute trials was significantly higher for FES assist cycling compared to voluntary cycling (429.7 ± 111.0 vs 388.5 ± 101.0 mL/min, 95% CI 23.4 to 113.0 mL/min, p = 0.01), with a large effect size (Hedges' g = 1.04). Participants reported similar rates of perceived exertion at the end of FES cycling (13 ± 2), voluntary cycling (14 ± 2), and FES assist cycling (15 ± 1); p = 0.14. Self-reported pain was higher during both FES cycling (5.4 vs 0.3; 95% CI 3.4 to 6.7, p = 0.01, Hedges' g = 2.07) and FES assist cycling (4.2 vs. 0.3; 95% CI 2.3 to 5.5, p = 0.01, Hedges' g = 1.71) than voluntary cycling, both with large effect sizes. There was no difference in self-reported fatigue at the end of each trial (p = 0.21).

CONCLUSION

This study found FES assist cycling produced significantly higher VO2 values than voluntary cycling, although the clinical significance of these differences is unknown. Participants performed FES assist cycling at a self-reported RPE consistent with moderate to vigorous intensity, however it was considered light-intensity exercise when expressed by METS. FES assist cycling was no more fatiguing post-exercise than the other modes.

Comparison of patient-reported outcomes of physical activity and accelerometry in people with multiple sclerosis and ambulatory impairment: A cross-sectional study

BACKGROUND

Accelerometers and patient-reported outcomes (PRO) are used to assess physical activity (PA) in people with multiple sclerosis (pwMS). So far it is unknown, however, whether these assessments represent mobility limitations in pwMS with mild and moderate to severe disability alike. The primary aim of the study was to assess the correlation between accelerometry and International Physical Activity Questionnaire (IPAQ) scores in pwMS with different degrees of ambulatory impairment. Taken its frequent use into account, the Godin Leisure Time Exercise Questionnaire (GLTEQ) was investigated as additional PRO.

METHODS

In a prospective cohort of pwMS, correlational analyses were performed between the number of daily steps, time spent in light, moderate to vigorous PA (MVPA) and time spent sitting as assessed using accelerometry (ActiGraph®-GT3X), and the respective IPAQ and GLTEQ scores. Additionally, associations of PA with disease-specific characteristics, aerobic capacity (VO2peak), walking assessments (Timed 25-Foot Walk, T25FW; 2-Minute Walk Test, 2MWT) and walking perception (Multiple Sclerosis Walking Scale-12; MSWS-12) were explored. Patient subgroups with mild (Expanded Disability Status Scale; EDSS score <4.0) and moderate to severe disability (EDSS ≥4.0) were analysed for the impact of ambulatory impairment on PA. Multiple linear regression was used to determine predictors of PA.

RESULTS

A total of 56 pwMS completed the study, with a mean (standard deviation, SD) age of 48.4 (10.3) years, disease duration of 14.8 (9.6) years and median (interquartile range) EDSS score of 3.5 (2.0 - 4.4). Moderate to weak correlations were found between daily step count and IPAQ total metabolic equivalent (MET) minutes/week (p < 0.001; r = 0.506), MVPA MET-minutes/week (p < 0.01; r = 0.479) and walking MET-minutes/week (p < 0.05; r = 0.372) in the total cohort. Time spent sitting was inversely correlated with total MET-minutes/week and MVPA MET-minutes/week (p < 0.05; r = -0.358 and r = -0.365). Subgroup analysis revealed, that daily step count was significantly correlated with total MET-minutes/week, MVPA MET-minutes/week and walking MET-minutes/week (p < 0.01, r = 0.569; p < 0.01, r = 0.531 and p < 0.05, r = 0.480, respectively) in the "mild disability" subgroup only, whereas time spent sitting was inversely correlated with total MET-minutes/week (p < 0.05; r = -0.582) in the "moderate to severe disability" subgroup. There was no association between objectively assessed PA and GLTEQ scores in any group. In the total cohort, moderate to weak correlations were found between daily step count and walking assessments (T25FW: p < 0.01, ρ = -0.508; 2MWT: p < 0.01, ρ=0.463) and MSWS-12 (p < 0.001; ρ = -0.609). Moderate to weak correlations were also observed between VO2peak and walking assessments (T25FW: p < 0.01; ρ = -0.516; 2MWT: p < 0.01, ρ=0.480). Multiple linear regression analysis identified disability and VO2peak as predictors of PA (p = 0.045; β=0.25 and p < 0.001; β=0.49).

CONCLUSION

Significant associations of objective PA measurements using accelerometry with IPAQ were found only in pwMS with "mild disability". In pwMS with "moderate to severe disability", IPAQ did not reflect the objectively assessed amount of PA. In our cohort, GLTEQ showed no association with objectively assessed PA. Thus, an MS-specific self-reported questionnaire for assessing PA is warranted.

The effects of hybrid functional electrical stimulation interval training on aerobic fitness and fatigue in people with advanced multiple sclerosis: An exploratory pilot training study

BACKGROUND

Improving aerobic fitness in people with advanced multiple sclerosis (MS) may reduce fatigue, and lower the risk of cardiovascular disease, as has been found for people with mild to moderate MS. Training targeting aerobic fitness can be challenging due to paresis, access to suitable equipment and fatigue. The aim of this study was to investigate whether people with advanced multiple sclerosis could perform functional electrical stimulation (FES) cycling combined with arm crank interval exercise (hybrid FES interval training) training, and its effects on aerobic fitness and fatigue.

METHODS

Hybrid FES interval training was performed 2 d/wk for 12 weeks. Each session consisted of 40 min of continuous FES cycling with arm crank intervals of 30 s work/30 s rest added concurrently for 20 min. The intensity target was a minimum of 60 % of arm crank power and 'hard' measured by rate of perceived exertion (RPE). Attendance, compliance to intensity and time targets, adverse events, and drop outs were measured. Aerobic fitness was assessed by an arm crank maximal test. Fatigue was measured via the Modified Fatigue Impact Scale (MFIS).

RESULTS

Seven participants (6 female; age 57.1 ± 7.8y; Expanded Disability Status Scale 7.1 ± 0.8) with advanced MS attended 80 ± 10.4 % of the scheduled exercise sessions and there were no adverse events or drop outs. Average RPE at the end of each training session was 15.1 ± 2.1, representing vigorous intensity exercise. Aerobic fitness did not change pre- to post-intervention (14.2 ± 5.7 to 14.8 ± 6.0 mL/kg/min [p = 0.43]), and resulted in a small effect size (ES) (0.30). The reduction in fatigue during the intervention (31.0 ± 10.4 to 21.7 ± 11.4 [p = 0.10]), resulted in a moderate to large ES (-0.77).

CONCLUSION

Hybrid FES interval training could be performed 2 days per week for 12 weeks and represented vigorous intensity exercise, but there was no change in aerobic fitness. The reduction in participants' perceptions of fatigue represented a moderate to large ES, indicating hybrid FES interval training might be suitable for people with advanced MS who need exercise equipment appropriate for their condition.

CLINICAL TRIAL REGISTRATION

This study was registered with Australian and New Zealand Clinical Trials Register (U1111-1194-2040).

Relative aerobic load of walking in people with multiple sclerosis

OBJECTIVE

To examine the energy demand of walking relative to aerobic capacity in people with multiple sclerosis.

DESIGN

Cross-sectional cohort study.

PATIENTS

A total of 45 people with multiple sclerosis (32 females), median disease duration 15 years (interquartile range (IQR) 9; 20), median Expanded Disability Status Scale 4 (min-max range: 2.0; 6.0).

METHODS

Aerobic capacity, derived from a cardiopulmonary exercise test and gas exchange measurements, assessed during a 6-min overground walk test at comfortable speed, were analysed. The relative aerobic load of walking was determined as the energy demand of walking relative to oxygen uptake at peak and at the first ventilatory threshold. Healthy reference data were used for clinical inference.

RESULTS

People with multiple sclerosis walk at a mean relative aerobic load of 60.0% (standard deviation 12.8%) relative to peak aerobic capacity, and 89.1% (standard deviation 19.9%) relative to the first ventilatory threshold. Fourteen participants walked above the first ventilatory threshold (31%). Peak aerobic capacity was reduced in 45% of participants, and energy demands were increased in 52% of participants.

CONCLUSION

People with multiple sclerosis walk at a relative aerobic load close to their first ventilatory threshold. A high relative aerobic load can guide clinicians to improve aerobic capacity or reduce the energy demands of walking.

Cardiorespiratory fitness (V̇O2peak) across the adult lifespan in persons with multiple sclerosis and matched healthy controls

OBJECTIVES

Cardiorespiratory fitness (measured as peak oxygen uptake; V̇O2peak) is a well-established health predictor in the general population and in persons with multiple sclerosis (pwMS). We aimed to investigate differences in V̇O2peak between age groups and the prevalence of V̇O2peak impairments across the adult lifespan in pwMS compared to age- and sex-matched healthy controls (HC).

DESIGN

Cross-sectional study.

METHODS

Data from 469 pwMS (EDSS range 1.0-7.0), who carried out graded cardiopulmonary exercise testing during their rehabilitation stay at the Valens clinic from 07/2010 to 10/2022, were retrospectively analyzed. Data from 21,063 HC were extracted from previously published studies containing normative reference values.

RESULTS

With advanced age (i.e., across age groups), a continuous deterioration of V̇O2peak was observed in both pwMS and HC. Within all age groups, V̇O2peak was reduced in pwMS compared to HC with deficits ranging from 29 % to 40 % for females (p < .05), and from 30 % to 41 % for males (p < .05). However, no age ∗ group interaction was observed in neither males (p = .626) nor females (p = .557). With V̇O2peak impairments defined as values below the 5th percentile of HC, a high prevalence was observed in pwMS, with values ranging from 48 % to 100 % across age groups.

CONCLUSIONS

The present data provide evidence for a parallel deterioration of V̇O2peak in pwMS and matched controls with advancing age, coinciding with a high prevalence of impairments in V̇O2peak already present in young adulthood in pwMS. Understanding the extent of impairments as well as the age trajectories of cardiorespiratory fitness in pwMS is crucial for designing optimal rehabilitative and preventive interventions.

Age and asymmetry of corticospinal excitability, but not cardiorespiratory fitness, predict cognitive impairments in multiple sclerosis

Background

Cognitive impairment is a disabling and underestimated consequence of multiple sclerosis (MS), with multiple determinants that are poorly understood.

Objectives

We explored predictors of MS-related processing speed impairment (PSI) and age-related mild cognitive impairment (MCI) and hypothesized that cardiorespiratory fitness and corticospinal excitability would predict these impairments.

Methods

We screened 73 adults with MS (53 females; median [range]: Age 48 [21-70] years, EDSS 2.0 [0.0-6.5]) for PSI and MCI using the Symbol Digit Modalities Test and Montréal Cognitive Assessment, respectively. We identified six persons with PSI (No PSI, n = 67) and 13 with MCI (No MCI, n = 60). We obtained clinical data from medical records and self-reports; used transcranial magnetic stimulation to test corticospinal excitability; and assessed cardiorespiratory fitness using a graded maximal exercise test. We used receiver operator characteristic (ROC) curves to discern predictors of PSI and MCI.

Results

Interhemispheric asymmetry of corticospinal excitability was specific for PSI, while age was both sensitive and specific for MCI. MS-related PSI was also associated with statin prescriptions, while age-related MCI was related to progressive MS and GABA agonist prescriptions. Cardiorespiratory fitness was associated with neither PSI nor MCI.

Discussion

Corticospinal excitability is a potential marker of neurodegeneration in MS-related PSI, independent of age-related effects on global cognitive function. Age is a key predictor of mild global cognitive impairment. Cardiorespiratory fitness did not predict cognitive impairments in this clinic-based sample of persons with MS.

An Overview of Physical Exercise Program Protocols and Effects on the Physical Function in Multiple Sclerosis: An Umbrella Review

Multiple sclerosis is a disease that concerns a growing number of people, especially females. There are different interventions proposed for this population, and physical activity is one of them. A proper and well-structured physical activity program can be a cheap, feasible, and practical instrument to help this population improve their quality of life. Consequently, the present study aimed to analyze, through an umbrella review, published articles to evaluate the protocols and the effect of intervention on different types of multiple sclerosis and eventually to propose a standardized intervention for this population. Systematic reviews and meta-analyses of randomized controlled trials on multiple sclerosis and physical activity effects were searched for on the electronic databases PubMed, Web of Science, and Scopus up to 22 December 2022. The quality of the studies included was determined and the results were narratively analyzed. The included studies present heterogeneity in the population, in the study design and protocols, and in the outcomes evaluated. Most of the studies detected positive outcomes on the physical function of people with multiple sclerosis. This study highlights the necessity of future studies on a population with similar characteristics, adopting similar protocols to evaluate their feasibility and validity to make physical intervention prescribed as a medicine.

A Comprehensive Evaluation of Multiple Sclerosis-Related Fatigue with a Special Focus on Fatigability

INTRODUCTION

Fatigue is the most common and disabling symptom in multiple sclerosis (MS), being reported by 55% to 78% of patients with MS (PwMS). Etiology of MS-related fatigue remains poorly understood, but an increased neuromuscular fatigability (i.e., greater loss of torque during exercise) could contribute to this phenomenon. This study aimed to characterize the correlates of MS-related fatigue in PwMS using a comprehensive group of physiological and psychosocial measures, with a particular focus on fatigability.

METHODS

Forty-two relapsing-remitting PwMS and 20 healthy subjects were recruited. PwMS were assigned in two groups (high (HF) and low (LF) fatigue) based on two fatigue questionnaires (Fatigue Severity Scale and Modified Fatigue Impact Scale). The main outcomes of this study are derived from incremental cycling completed to task failure (i.e., inability to pedal around 60 rpm). Maximal voluntary contraction (MVC), rating of perceived exertion, and central and peripheral parameters measured using transcranial magnetic and peripheral nerve stimulation were assessed in the knee extensor muscles before, during, and after the fatiguing task. Other potential correlates of fatigue were also tested.

RESULTS

MVC torque decreased to a greater extent for the HF group than LF group after the third common stage of the incremental fatiguing exercise (-15.7% ± 6.6% vs -5.9% ± 13.0%, P < 0.05), and this occurred concurrently with a higher rating of perceived exertion for HF (11.8 ± 2.5 vs 9.3 ± 2.6, P < 0.05). Subjective parameters (depression, quality of life) were worse for HF compared with LF and healthy subjects ( P < 0.001). Moreover, MVC torque loss at the final common stage and maximal heart rate explained 29% of the variance of the Modified Fatigue Impact Scale.

CONCLUSIONS

These results provide novel insight into the relationship between MS-related fatigue and fatigability among PwMS. The HF group exhibited greater performance fatigability, likely contributing to a higher perceived exertion than the LF group when measured during a dynamic task.

The MoXFo Initiative: Using consensus methodology to move forward towards internationally shared vocabulary in multiple sclerosis exercise research

BACKGROUND

Multiple sclerosis (MS) exercise terminology lacks consistency across disciplines, hindering research synthesis.

OBJECTIVE

The 'Moving exercise research in MS forward initiative' (MoXFo) aims to establish agreed definitions for key MS exercise terms.

METHODS

The Lexicon development methodology was employed. A three-step process identified key exercise terminology for people with multiple sclerosis (pwMS): (1) consensus and systematic review, (2) Delphi round 1 and consideration of existing definitions and (3) Delphi round 2 for consensus among MoXFo steering group and exercise experts. Final definitions and style harmonisation were agreed upon.

RESULTS

The two-stage Delphi process resulted in the selection and scoring of 30 terminology definitions. The agreement was 100% for resistance exercise, balance and physical activity. Most terms had agreement >75%, but 'posture' (60%) and 'exercise' (65%) had a lower agreement.

CONCLUSION

This study identified key terms and obtained agreement on definitions for 30 terms. The variability in agreement for some terms supports the need for clearly referencing or defining terminology within publications to enable clear communication across disciplines and to support precise synthesis and accurate interpretation of research.

Effects of Functional Electrical Stimulation Cycling Combined With Arm Cranking Exercise on Cardiorespiratory Fitness in People With Central Nervous System Disorders: A Systematic Review and Meta-analysis

OBJECTIVE

To examine the evidence regarding the potential of hybrid functional electrical stimulation (FES) cycling for improving cardiorespiratory fitness for people with a mobility disability related to a central nervous system (CNS) disorder.

DATA SOURCES

Nine electronic databases: MEDLINE, EMBASE, Web of Science, CINAHL, PsycInfo, SPORTDiscus, Pedro, Cochrane, and Scopus, were searched from inception until October 2022.

STUDY SELECTION

Search terms included multiple sclerosis, spinal cord injury (SCI), stroke, Parkinson's disease, cerebral palsy, synonyms of FES cycling, arm crank ergometry (ACE) or hybrid exercise, and V̇o2. All experimental studies, including randomized controlled trials that included an outcome measure related to peak or sub-maximal V̇o2 were eligible.

DATA EXTRACTION

From a total of 280 articles, 13 were studies included. The Downs and Black Checklist was used to assess study quality. Random effects (Hedges' g) meta-analyses were undertaken to determine whether there were differences in V̇o2peak during acute bouts of hybrid FES cycling vs other modes of exercise and changes resulting from longitudinal training.

DATA SYNTHESIS

During acute bouts of exercise, hybrid FES cycling was moderately more effective than ACE (effect size [ES] of 0.59 (95% CI 0.15-1.02, P=.008) in increasing V̇o2peak from rest. There was a large effect on the increase of V̇o2peak from rest for hybrid FES cycling compared with FES cycling (ES of 2.36 [95% CI 0.83-3.40, P=.003]). Longitudinal training with hybrid FES cycling showed a significant improvement in V̇o2peak from pre to post intervention with a large, pooled ES of 0.83 (95% CI 0.24-1.41, P=.006).

CONCLUSIONS

Hybrid FES cycling produced higher V̇o2peak compared with ACE or FES cycling during acute bouts of exercise. Hybrid FES cycling can improve cardiorespiratory fitness in people with SCI. Additionally, there is emerging evidence that hybrid FES cycling might increase aerobic fitness in people with mobility disability related to CNS disorders.

Cardiopulmonary exercise testing in people with minimally impaired multiple sclerosis

BACKGROUND

Multiple sclerosis (MS) is a chronic demyelinating inflammatory disorder of the central nervous system that may affect respiratory system at the later stages of the disease. The aim of our study was to evaluate respiratory function and cardiopulmonary exercise testing in ambulatory without aid people with MS (pwMS), and to investigate quality of life parameters and fatigue in this population.

METHODS

25 pwMS and 16 healthy controls were included in this study. Pulmonary function tests were performed and were followed by proper cardiopulmonary exercise testing with the use of treadmill. Quality of life assessment was done with SF-36 questionnaire.

RESULTS

The mean age of the patient group was 38.4 ± 8.2 years. Spirometric values were within normal limits, and so did lung diffusion capacity, while maximal voluntary ventilation was reduced. In cardiopulmonary exercise testing the patient group showed impairment compared to control group. The statistically significant lower parameters were V'O2 peak, V'CO2 peak, RER, V'O2/kg peak, V'CO2/kg peak, oxygen pulse peak and V'E/V'CO2 slope. Moreover, there was a negative and statistically significant correlation between CPET values and BMI and MFIS, while there was a positive and statistically significant correlation with quality of life, evaluated by SF-36.

CONCLUSION

Our study showed that the main cardiopulmonary exercise testing parameters were affected in ambulatory pwMS, even without evidence of respiratory symptoms. Therefore, these people should be evaluated for pulmonary function compromise.

The MoxFo initiative - outcomes: Outcome measures in studies of exercise training in multiple sclerosis; scoping review of reviews and classification according to the ICF framework

BACKGROUND

The number of published studies of exercise training in multiple sclerosis (MS) has grown exponentially with increasing numbers of outcomes capturing exercise effects. This has complicated the selection of relevant indicators and interpretation of intervention effects.

OBJECTIVES

The Outcomes subgroup of the MoXFo initiative aimed to (1) identify outcome measures and biomarkers in studies of exercise training in MS; (2) systematically map retrieved outcomes to International Classification of Functioning, Disability and Health (ICF) categories; (3) identify gaps where relevant ICF categories have been omitted.

METHODS

Electronic databases and registers were searched from 2010 to July 2020 to identify systematic reviews or meta-analyses of controlled trials of exercise training on any outcome in MS. Retrieved outcomes/biomarkers were mapped to the corresponding ICF category.

RESULTS

Eighty-one review articles reporting 235 different outcomes were included. The outcomes corresponded to 15 chapters and 45 categories within the ICF. Outcomes mapped primarily to body function (30 categories) and activities and participation (9 categories) components. Few outcomes mapped to body structures (2 categories) or environmental factors (1 category).

CONCLUSION

This sets the stage to develop a resource for researchers/clinicians that will aid in the selection of appropriate outcomes/biomarkers when examining exercise effects in MS.

Multiple sclerosis and exercise-A disease-modifying intervention of mice or men?

Research suggests that physical exercise can promote an anti-inflammatory and neuroprotective state. If so, increasing or optimizing exercise could be considered a 'disease-modifying intervention' in neuroinflammatory diseases, such as multiple sclerosis (MS). Exercise intervention studies conducted in animal models of MS are promising. Various aerobic and strength training regimes have been shown to delay disease onset and to reduce both the clinical and pathological disease severity in mice. However, fundamental differences between the physiology of animals and humans, the disease states studied, and the timing of exercise intervention are significant. In animal models of MS, most exercise interventions begin before disease initiation and before any clinical sign of disease. In contrast, studies in humans recruit participants on average nearly a decade after diagnosis and often once disability is established. If, as is thought to be the case for disease-modifying treatments, the immunomodulatory effect of exercise decreases with advancing disease duration, current studies may therefore fail to detect the true disease-modifying potential. Clinical studies in early disease cohorts are needed to determine the role of exercise as a disease-modifying intervention for people with MS.

Reliability and validity of the glittre activities of daily living test in fully ambulatory multiple sclerosis patients

BACKGROUND

Evaluation of activities of daily living (ADL) and functional exercise capacity in patients with multiple sclerosis (pwMS) is crucial in demonstrating the effectiveness of interventions.

AIMS

To investigate the reliability and validity of the Glittre ADL Test in pwMS.

METHODS

Twenty-five pwMS and 26 healthy adults were included in this methodological study. The Glittre ADL Test was applied. Six-Minute Walk Test (6MWT) and Nottingham Extended Activities of Daily Living Index (NEADL) were applied for concurrent validity. Expanded Disability Status Scale (EDSS), Fatigue Severity Scale (FSS), Mini Balance Evaluation Systems Test (Mini BESTest), Multiple Sclerosis Quality of Life Scale-54 (MSQoL-54), and Five Times Sit-to-Stand Test (5 STST) were applied for construct validity. The Glittre ADL Test was repeated after 3-6 days for test-retest reliability.

RESULTS

The test-retest reliability of the Glittre ADL Test was excellent (ICC = 0.941). There was strong correlation of the Glittre ADL Test with 6MWT (rho = - 0.710, p < 0.001), NEADL (rho = - 0.841, p < 0.001), EDSS, (rho = 0.836, p = < 0.001), Mini BESTest (rho = 0.792, p < 0.001), and 5 STST scores (rho = 0.720, p < 0.001). There was a moderate correlation between the Glittre ADL Test and the physical health sub-item score of the MSQoL-54 (rho = - 0.591, p = 0.002). No correlation was found between the Glittre ADL Test and FSS (rho = 0.348, p = 0.096). There was a difference in the Glittre ADL Test results between the pwMS and the healthy adults (p = 0.001).

CONCLUSIONS

The Glittre ADL Test has excellent reliability and strong construct and criterion validity for assessing functional exercise capacity and ADL in fully ambulatory pwMS.

TRIAL REGISTRATION

TRN: NCT04182269.

Cognitive rehabilitation and aerobic exercise for cognitive impairment in people with progressive multiple sclerosis (CogEx): a randomised, blinded, sham-controlled trial

BACKGROUND

Cognitive dysfunction in people with relapsing-remitting multiple sclerosis can improve with cognitive rehabilitation or exercise. Similar effects have not been clearly shown in people with progressive multiple sclerosis. We aimed to investigate the individual and synergistic effects of cognitive rehabilitation and exercise in patients with progressive multiple sclerosis.

METHODS

CogEx was a randomised, sham-controlled trial completed in 11 hospital clinics, universities, and rehabilitation centres in Belgium, Canada, Denmark, Italy, UK, and USA. Patients with progressive multiple sclerosis were eligible for inclusion if they were aged 25-65 years and had an Expanded Disability Status Scale (EDSS) score of less than 7. All had impaired processing speed defined as a performance of 1·282 SD or greater below normative data on the Symbol Digit modalities Tests (SDMT). Participants were randomly assigned (1:1:1:1), using an interactive web-response system accessed online from each centre, to cognitive rehabilitation plus exercise, cognitive rehabilitation plus sham exercise, exercise plus sham cognitive rehabilitation, or sham exercise plus sham cognitive rehabilitation. The study statistician created the randomisation sequence that was stratified by centre. Participants, outcome assessors, and investigators were blinded to group allocation. The study statistician was masked to treatment during analysis only. Interventions were conducted two times per week for 12 weeks: cognitive rehabilitation used an individualised, computer-based, incremental approach to improve processing speed; sham cognitive rehabilitation consisted of internet training provided individually; the exercise intervention involved individualised aerobic training using a recumbent arm-leg stepper; and the sham exercise involved stretching and balance tasks without inducing cardiovascular strain. The primary outcome measure was processing speed measured by SDMT at 12 weeks; least squares mean differences were compared between groups using linear mixed model in all participants who had a 12-week assessment. The trial is registered with ClinicalTrials.gov, NCT03679468, and is completed.

FINDINGS

Between Dec 14, 2018, and April 2, 2022, 311 people with progressive multiple sclerosis were enrolled and 284 (91%) completed the 12-week assessment (117/311 [38%] male and 194/311 [62%] female). The least squares mean group differences in SDMT at 12 weeks did not differ between groups (p=0·85). Compared with the sham cognitive rehabilitation and sham exercise group (n=67), differences were -1·30 (95% CI -3·75 to 1·16) for the cognitive rehabilitation plus exercise group (n=70); -2·78 (-5·23 to -0·33) for the sham cognitive rehabilitation plus exercise group (n=71); and -0·71 (-3·11 to 1·70) for the cognitive rehabilitation plus sham exercise group (n=76). 11 adverse events possibly related to the interventions occurred, six in the exercise plus sham cognitive rehabilitation group (pain, dizziness, and falls), two in the cognitive rehabilitation plus sham exercise group (headache and pain), two in the cognitive rehabilitation and exercise group (increased fatigue and pain), and one in the dual sham group (fall).

INTERPRETATION

Combined cognitive rehabilitation plus exercise does not seem to improve processing speed in people with progressive multiple sclerosis. However, our sham interventions were not inactive. Studies comparing interventions with a non-intervention group are needed to investigate whether clinically meaningful improvements in processing speed might be attainable in people with progressive multiple sclerosis.

FUNDING

MS Canada.

Effects of inpatient energy management education and high-intensity interval training on health-related quality of life in persons with multiple sclerosis: A randomized controlled superiority trial with six-month follow-up

BACKGROUND

Fatigue is one of the most frequent symptoms in persons with multiple sclerosis (pwMS) and impacts health-related quality of life (HRQoL). A multidisciplinary rehabilitation approach is recommended for the treatment of fatigue in pwMS. However, high-quality evidence exists only for unimodal interventions, such as physical therapies/exercise or energy/fatigue management programmes. The primary objective of the current study was to test the hypothesis that a combination of inpatient energy management education (IEME) and high-intensity interval training (HIIT) is superior to a combination of progressive muscle relaxation (PMR) and moderate continuous training (MCT) for improving HRQoL at 6-month follow-up in fatigued pwMS.

METHODS

A randomized (1:1) controlled superiority trial with fatigued pwMS >18 years of age, with Expanded Disability Status Scale (EDSS) score ≤6.5, recruited at the Valens clinic, Switzerland. Participants in the experimental group performed IEME twice and HIIT 3 times per week and those in the usual care group performed PMR twice and MCT 3 times per week, during a 3-week inpatient rehabilitation stay. Primary outcome was HRQoL (Physical and Mental Component Scales of the Medical Outcome Study 36-item Short Form Health Survey (SF-36)), assessed at entry to the clinic (T0), after 3 weeks' rehabilitation (T1) and 4 (T2) and 6 (T3) months after T0. Secondary outcomes included SF-36 subscales, fatigue (Fatigue Scale for Motor and Cognitive Functions (FSMC)), mood (Hospital Anxiety and Depression Scale (HADS)), self-efficacy for performing energy conservation strategies (Self-Efficacy for Performing Energy Conservation Strategies Assessment (SEPECSA)), self-perceived competence in activities of daily living (Occupational Self Assessment (OSA)) and cardiorespiratory fitness (peak oxygen consumption (VȮ2peak)). Data were analysed using a mixed model for repeated measures approach.

RESULTS

A total of 106 pwMS (age (years): 49.75 (9.87), 66% female, EDSS: 4.64 (1.32)) were recruited. There were no significant group × time interaction effects in the primary and secondary outcomes. There were significant between-group differences in the pairwise comparisons of the group × time interaction in favour of the IEME + HIIT group at: (i) T1 in cardiorespiratory fitness (p = 0.011) and SEPECSA (p = 0.032); (ii) T2 in SF-36 mental health subscale (p = 0.022), HADS anxiety subscale (p = 0.014) and SEPECSA (p = 0.040); (iii) T3 in SF-36 physical functioning subscale (p = 0.012) and SEPECSA (p = 0.003).

CONCLUSION

IEME + HIIT was not superior to PMR + MCT regarding the effects on HRQoL (SF-36 Physical and Mental Component Scales) at 6-month follow-up in pwMS. However, there were significant between-group differences in favour of IEME + HIIT in physical functioning and mental health (SF-36 subscales), anxiety (HADS), cardiorespiratory fitness (VȮ2peak) and self-efficacy (SEPECSA) at different measurement time-points that need to be considered in clinical practice.

Physical fitness moderates the association between brain network impairment and both motor function and cognition in progressive multiple sclerosis

BACKGROUND

Neurodegeneration leads to continuous accumulation of disability in progressive Multiple Sclerosis (MS). Exercise is considered to counteract disease progression, but little is known on the interaction between fitness, brain networks and disability in MS.

OBJECTIVE

The aim of this study to explore functional and structural brain connectivity and the interaction between fitness and disability based on motor and cognitive functional outcomes in a secondary analysis of a randomised, 3-month, waiting group controlled arm ergometry intervention in progressive MS.

METHODS

We modelled individual structural and functional brain networks based on magnetic resonance imaging (MRI). We used linear mixed effect models to compare changes in brain networks between the groups and explore the association between fitness, brain connectivity and functional outcomes in the entire cohort.

RESULTS

We recruited 34 persons with advanced progressive MS (pwMS, mean age 53 years, females 71%, mean disease duration 17 years and an average walking restriction of < 100 m without aid). Functional connectivity increased in highly connected brain regions of the exercise group (p = 0.017), but no structural changes (p = 0.817) were observed. Motor and cognitive task performance correlated positively with nodal structural connectivity but not nodal functional connectivity. We also found that the correlation between fitness and functional outcomes was stronger with lower connectivity.

CONCLUSIONS

Functional reorganisation seems to be an early indicator of exercise effects on brain networks. Fitness moderates the relationship between network disruption and both motor and cognitive outcomes, with growing importance in more disrupted brain networks. These findings underline the need and opportunities associated with exercise in advanced MS.

Complexity and pitfalls in maximal exercise testing for persons with multiple sclerosis

BACKGROUND AND PURPOSE

Valid measurements of cardiorespiratory fitness in persons with multiple sclerosis (pwMS) are essential during inpatient rehabilitation for a precise evaluation of the current health status, for defining appropriate exercise intensities, and for evaluation of exercise intervention studies. We aim (i) to examine the proportion of pwMS who attain the American College of Sports Medicine (ACSM) criteria for maximal effort during graded cardiopulmonary exercise testing (CPET) and (ii) to provide insight into participant characteristics that limit maximal exercise performance.

METHODS

This cross-sectional study comprises a retrospective examination of ACSM criteria for maximal effort during graded CPET of n = 380 inpatient pwMS (mean age = 48 ± 11 years, 66% female). Chi-squared or Fisher's exact tests were conducted to compare differences in the distribution of criteria achieved. Participants' characteristics were examined as potential predictors using binary logistic regression.

RESULTS

Only 60% of the overall sample attained a respiratory exchange ratio ≥ 1.10. With regard to the definition applied, only 24% or 40% of the participants achieved an oxygen consumption plateau, and 17% or 50% attained the heart rate criterion. Forty-six percent met at least two of three criteria. Disability status, gender, disease course, and body mass index were associated with the attainment of maximal effort.

CONCLUSIONS

Our findings suggest that a relevant proportion of inpatient pwMS do not attain common criteria utilized to verify maximal oxygen consumption. Identified predictors for criteria attainment can be used to create models to predict cardiorespiratory fitness and to optimize CPET protocols in restrictive groups of pwMS.

Cycling in primary progressive multiple sclerosis (CYPRO): study protocol for a randomized controlled superiority trial evaluating the effects of high-intensity interval training in persons with primary progressive multiple sclerosis

BACKGROUND

Primary progressive multiple sclerosis (PPMS) is the least prevalent multiple sclerosis (MS) phenotype. For persons with PPMS (pwPPMS), pharmacological treatment options are limited. As a complementary non-pharmacological treatment, endurance training improves the health-related quality of life (HRQoL), numerous MS symptoms, and MS-related performance impediments. High-intensity interval training (HIIT) has been shown to induce superior effects compared to moderate-intensity continuous training (MCT). As current evidence is based on MS samples with mixed phenotypes, generalizability to pwPPMS remains unclear.

METHODS

CYPRO is a parallel-group, single-center, and single-blind randomized controlled superiority trial evaluating the effects of HIIT compared to MCT in pwPPMS. Sixty-one pwPPMS are randomized (1:1) to perform volume-matched HIIT or MCT sessions on bicycle ergometers two to three times per week in addition to standard rehabilitative care during their three-week inpatient stay at Valens rehabilitation clinic, Switzerland. Standard rehabilitative care comprises endurance and strength training, physiotherapy, and occupational therapy. HIIT sessions include six 90-second intervals at 95% peak heart rate (HR_peak), interspersed by 90-second active breaks with unloaded pedaling, aimed to reach 60%HR_peak. MCT represents the standard treatment at Valens rehabilitation clinic and is performed as continuous cycling at 60%HR_peak for the duration of 26 minutes. The primary outcome is cardiorespiratory fitness, assessed as peak oxygen consumption (V̇O_2peak) during cardiopulmonary exercise testing (CPET). Secondary outcomes include peak power output during CPET, walking capacity, cognitive performance, HRQoL, fatigue, anxiety and depressive symptoms, and blood-derived biomarkers (e.g., serum neurofilament light chain, glial fibrillary acidic protein, kynurenine pathway metabolites) related to MS pathophysiology. All outcomes are assessed at baseline and discharge after three weeks. Venous blood sampling is additionally performed immediately and two hours after the first HIIT or MCT session.

DISCUSSION

CYPRO will expand current knowledge on symptom management and rehabilitation in MS to the subpopulation of pwPPMS, and will contribute to the exploration of potential disease-modifying effects of endurance training in MS. The superiority design of CYPRO will allow deriving explicit recommendations on endurance training design in pwPPMS that can be readily translated into clinical practice.

TRIAL REGISTRATION

CYPRO has been prospectively registered at ClinicalTrials.gov on 8 February 2022 (NCT05229861).

Abnormal thalamic functional connectivity correlates with cardiorespiratory fitness and physical activity in progressive multiple sclerosis

BACKGROUND

Altered thalamic volumes and resting state (RS) functional connectivity (FC) might be associated with physical activity (PA) and cardiorespiratory fitness (CRF) in people with progressive multiple sclerosis (PMS).

OBJECTIVES

To assess thalamic structural and functional alterations and investigate their correlations with PA/CRF levels in people with PMS.

METHODS

Seven-day accelerometry and cardiopulmonary exercise testing were used to assess PA/CRF levels in 91 persons with PMS. They underwent 3.0 T structural and RS fMRI acquisition with 37 age/sex-matched healthy controls (HC). Between-group comparisons of MRI measures and their correlations with PA/CRF variables were assessed.

RESULTS

PMS people had lower volumes compared to HC (all p < 0.001). At corrected threshold, PMS showed decreased intra- and inter-thalamic RS FC, and increased RS FC between the thalamus and the hippocampus, bilaterally. At uncorrected threshold, decreased thalamic RS FC with caudate nucleus, cerebellum and anterior cingulate cortex (ACC), as well as increased thalamic RS FC with occipital regions, were also detected. Lower CRF, measured as peak oxygen consumption (VO_2peak), correlated with lower white matter volume (r = 0.31, p = 0.03). Moreover, lower levels of light PA correlated with increased thalamic RS FC with the right hippocampus (r = - 0.3, p = 0.05).

DISCUSSION

People with PMS showed widespread brain atrophy, as well as pronounced intra-thalamic and thalamo-hippocampal RS FC abnormalities. White matter atrophy correlated with CRF, while increased thalamo-hippocampal RS FC was associated to worse PA levels. Thalamic RS FC might be used to monitor physical impairment and efficacy of rehabilitative and disease-modifying treatments in future studies.

Efficacy of aerobic exercise on aerobic capacity in slowly progressive neuromuscular diseases: A systematic review and meta-analysis

BACKGROUND

Aerobic exercise aims to improve aerobic capacity.

OBJECTIVE

To summarize the evidence on the efficacy of aerobic exercise on aerobic capacity in slowly progressive neuromuscular diseases (NMDs).

METHODS

We searched the electronic databases MEDLINE, EMBASE, SPORTDiscus and Web of Science Conference Proceedings Index for articles published up to June 17, 2021, selecting randomized controlled trials that included adults with slowly progressive NMDs and compared aerobic exercise to no aerobic exercise. The primary outcome was peak oxygen uptake (VO₂peak) directly post-intervention. Secondary outcomes included other peak test parameters, submaximal test parameters, long-term outcomes ≥8 weeks post-intervention, adherence and adverse events. Meta-analyses were performed for the primary outcome and for secondary outcomes when reported in more than 2 studies. Risk of bias was assessed with the Cochrane Risk of Bias tool and quality of evidence according to GRADE.

RESULTS

Nine studies were included (195 participants with 8 different NMDs). Eight studies were rated at high risk of bias and 1 study was rated at some concerns. Duration of exercise programs ranged from 6 to 26 weeks, with 3 weekly training sessions of 20 to 40 min, based on maximal capacity. Meta-analyses revealed short-term moderate beneficial effects of aerobic exercise on VO₂peak (standardized mean difference [SMD] 0.55, 95% CI 0.23; 0.86) and peak workload (SMD 0.61, 95% CI 0.24; 0.99). Long-term effects were not assessed. Most training sessions (83-97%) were completed, but time spent in target intensity zones was not reported. Included studies lacked detailed adverse event reporting.

CONCLUSIONS

There is low-quality evidence that aerobic exercise is safe and leads to moderate improvement of aerobic capacity directly post-intervention in slowly progressive NMDs, but the long-term efficacy remains unclear. Detailed information about the time spent in target intensity zones and adverse events is lacking.

PROSPERO

CRD42020200083.

Exercise therapy for fatigue in multiple sclerosis

This is a protocol for a Cochrane Review (intervention). The objectives are as follows:

Altered muscle oxidative phenotype impairs exercise tolerance but does not improve after exercise training in multiple sclerosis

BACKGROUND

Patients with multiple sclerosis (MS) experience reduced exercise tolerance that substantially reduces quality of life. The mechanisms underpinning exercise intolerance in MS are not fully clear. This study aimed to determine the contributions of the cardiopulmonary system and peripheral muscle in MS-induced exercise intolerance before and after exercise training.

METHODS

Twenty-three patients with MS (13 women) and 20 age-matched and sex-matched healthy controls (13 women) performed a cardiopulmonary exercise test. Muscle fibre type composition, size, succinate dehydrogenase (SDH) activity, capillarity, and gene expression and proteins related to mitochondrial density were determined in vastus lateralis muscle biopsies. Nine MS patients (five women) were re-examined following a 12 week exercise training programme consisting of high-intensity cycling interval and resistance training.

RESULTS

Patients with MS had lower maximal oxygen uptake compared with healthy controls (V̇O_2peak , 25.0 ± 8.5 vs. 35.7 ± 6.4 mL/kg/min, P < 0.001). The lower gas exchange threshold (MS: 14.5 ± 5.5 vs. controls: 19.7 ± 2.9 mL/kg/min, P = 0.01) and slope of V̇O₂ versus work rate (MS: 9.5 ± 1.7 vs. controls: 10.8 ± 1.1 mL/min/W, P = 0.01) suggested an intramuscular contribution to exercise intolerance in patients with MS. Muscle SDH activity was 22% lower in MS (P = 0.004), and strongly correlated with several indices of whole-body exercise capacity in MS patients (e.g. V̇O_2peak , Spearman's ρ = 0.81, P = 0.002), but not healthy controls (ρ = 0.24, P = 0.38). In addition, protein levels of mitochondrial OXPHOS complexes I (-40%, P = 0.047) and II (-45%, P = 0.026) were lower in MS patients versus controls. Muscle capillary/fibre ratio correlated with V̇O_2peak in healthy controls (ρ = 0.86, P < 0.001) but not in MS (ρ = 0.35, P = 0.22), and did not differ between groups (1.41 ± 0.30 vs. 1.47 ± 0.38, P = 0.65). Expression of genes involved in mitochondrial function, such as PPARA, PPARG, and TFAM, was markedly reduced in muscle tissue samples of MS patients (all P < 0.05). No differences in muscle fibre type composition or size were observed between groups (all P > 0.05). V̇O_2peak increased by 23% following exercise training in MS (P < 0.001); however, no changes in muscle capillarity, SDH activity, gene or protein expression were observed (all P > 0.05).

CONCLUSIONS

Skeletal muscle oxidative phenotype (mitochondrial complex I and II content, SDH activity) is lower in patients with MS, contributing to reduced exercise tolerance. However, skeletal muscle mitochondria appeared resistant to the beneficial effects of exercise training, suggesting that other physiological systems, at least in part, drive the improvements in exercise capacity following exercise training in MS.

IL-6 and TNF-α responses to acute and regular exercise in adult individuals with multiple sclerosis (MS): a systematic review and meta-analysis

Background

In both the general population and people with multiple sclerosis (PwMS), physical exercise is associated with improved mental well-being. Moreover, there is evidence of the possible protection of physical activity against disease progression in multiple sclerosis (MS). However, the question arises if acute or regular exercise has any impact on the immune system in PwMS. To answer this question, we performed a systematic review and meta-analysis on both plasma and serum cytokine levels (IL-6 and TNF-α) before and after acute and regular exercise among PwMS and compared to healthy controls.

Method

We performed an online search via PubMed, EMBASE, SCOPUS, Web of Science, and Cochrane Library till September 2021 to identify original studies on IL-6 and TNF-α changes after acute and regular exercise in PwMS and controls. Following the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA), 11 original studies were included in the meta-analysis. Sensitivity analyses were used to identify the origins of heterogeneity. R 4.0.4 was used to perform the meta-analysis of IL-6 and TNF-α levels before and after acute and regular exercise in PwMS, compared to controls. This study does not qualify for a clinical trial number.

Results

IL-6 levels did neither increase nor decrease after acute and regular exercise in PwMS, and compared to controls (pre- vs. post-intervention: Standardized Mean Difference (SMD) -0.09, 95% CI [−0.29; 0.11], p-value = 0.37, PwMS vs. Control: SMD −0.08, 95% CI [−0.33; 0.16], p-value = 0.47). In PwMS, TNF-α levels decreased after regular exercise and when TNF-α levels of both acute and regular exercise were pooled (pre- vs. post-intervention: SMD −0.51, 95% CI [-0.91; 0.11], p-value = 0.01, PwMS vs. Control: SMD −0.23, 95% CI [−0.66; 0.18], p-value = 0.26). TNF-α levels did neither increase nor decrease after acute and regular exercise in PwMS, when compared to controls.

Conclusion

This systematic review and meta-analysis show that exercise does not lead to significant changes in peripheral levels of IL-6 in PwMS in contrast to the observed response in healthy subjects and other medical contexts. However, regular exercise had a specific anti-inflammatory effect on blood TNF-α levels in PwMS. It remains to be investigated why PwMS display this different exercise-induced pattern of cytokines.

Supplementary Information

The online version contains supplementary material available at 10.1186/s40001-022-00814-9.

The pathophysiology of motor fatigue and fatigability in multiple sclerosis

Multiple Sclerosis (MS) is a heterogeneous immune mediated disease of the central nervous system (CNS). Fatigue is one of the most common and disabling symptom of MS. It interferes with daily activities on the level of cognition and motor endurance. Motor fatigue can either result from lesions in cortical networks or motor pathways (“primary fatigue”) or it may be a consequence of detraining with subsequent adaptions of muscle and autonomic function. Programmed exercise interventions are used frequently to increase physical fitness in MS-patients. Studies investigating the effects of training on aerobic capacity, objective endurance and perceived fatigability have yielded heterogenous results, most likely due to the heterogeneity of interventions and patients, but probably also due to the non-uniform pathophysiology of fatigability among MS-patients. The aim of this review is to summarize the current knowledge on the pathophysiology of motor fatigability with special reference to the basic exercise physiology that underlies our understanding of both pathogenesis and treatment interventions.

Six-Minute Walk Performance and Related Factors in Pediatric-Onset Multiple Sclerosis

OBJECTIVE

To investigate functional exercise capacity and its relationship between physical activity levels, muscle strength, balance, fatigue, and quality of life in patients with pediatric-onset multiple sclerosis.

METHODS

Fifteen patients with pediatric-onset multiple sclerosis were included. The 6-minute walk test was used to determine functional exercise capacity and walking distance. The Godin Leisure-Time Exercise Questionnaire and pedometer were used to evaluate physical activity, Timed-Up and Go for dynamic balance, isokinetic testing for lower extremity muscle strength, Fatigue Severity Scale for fatigue, and the Pediatric Quality of Life Inventory (PedsQL) for quality of life.

RESULTS

The 6-minute walking distance was positively correlated with GLTEQ and the School-Work subgroup score of the PedsQL-Self-report, and negatively correlated with Timed-Up and Go and Fatigue Severity Scale. Dynamic balance, physical activity, and fatigue were significant predictors of 6-minute walking distance.

CONCLUSIONS

Our results showed that 6-minute walk test is influenced by physical activity, dynamic balance, and fatigue, and related to quality of life in patients with pediatric-onset multiple sclerosis.

Oxygen Cost of Walking in People With Multiple Sclerosis and Its Association With Fatigue: A Systematic Review and Meta-analysis

BACKGROUND

This systematic review and meta-analysis aimed to compare the oxygen cost of walking in individuals with multiple sclerosis (MS) and controls and to assess the relationship between oxygen cost of walking and fatigue in individuals with MS.

METHODS

Four databases (CINAHL, MEDLINE, ProQuest, Web of Science) were searched up to September 2020. Studies were included if they recruited adults with MS and either compared oxygen cost of walking in those with MS and a control population or determined the relationship between oxygen cost of walking and fatigue. Meta-analysis of the standardized mean difference in oxygen cost of walking between individuals with MS and controls was performed.

RESULTS

Nine studies were included in this review, of which 7 compared oxygen cost of walking in individuals with MS (n = 176) and controls (n = 142) and 4 investigated the relationship between oxygen cost of walking and fatigue. Meta-analysis revealed that individuals with MS (with predominantly mild-to-moderate disability) had a significantly higher oxygen cost of walking compared with controls (standardized mean difference = 2.21, 95% CI = 0.88 to 3.54, P = .001). In addition, 3 studies found a significant yet weak positive association between oxygen cost of walking and fatigue.

CONCLUSIONS

Individuals with MS expend more energy when walking compared with controls. This increase in energy expenditure may contribute to the development of fatigue, as some studies found that higher oxygen costs of walking were associated with greater fatigue. Future studies should investigate whether reducing energy expenditure during movement improves fatigue.

Efficacy of high-intensity aerobic exercise on common multiple sclerosis symptoms

OBJECTIVES

Fatigue and walking impairment are disabling symptoms of multiple sclerosis (MS). We investigated the effects of progressive aerobic exercise (PAE) on fatigue, walking, cardiorespiratory fitness (VO₂ max), and quality of life in people with MS (pwMS).

MATERIALS & METHODS

Randomized controlled trial (1:1 ratio, stratified by sex) with a 24-week crossover follow-up and intention-to-treat analysis. Allocation to an exercise (24 weeks of PAE followed by self-guided physical activity) and a waitlist (24 weeks of habitual lifestyle followed by PAE) group. PAE comprised two supervised sessions per week; 30-60 min, 65-95% of maximum heart rate. Fatigue impact (Modified Fatigue Impact Scale; MFIS) and severity (Fatigue Severity Scale; FSS), walking ability (12-item MS Walking Scale; MSWS-12) and capacity (Six-Minute Walk Test; 6MWT, Six Spot Step Test; SSST), quality of life (Short Form 36 health survey; SF-36), and VO₂ max were measured at baseline, 24 weeks, and 48 weeks.

RESULTS

Eighty-six pwMS were enrolled. Following PAE between-group differences showed reductions in MFIS_total (-5.3 [95% CI: -10.9;0.4], point estimate >clinical relevance), MFIS_physical subscore (-2.8 [-5.6;-0.1]), and MFIS_psychosocial subscore (-0.9 [-1.6;-0.2]), and an increase in VO₂ max (+3.5 ml O₂ /min/kg [2.0;5.1]). MSWS-12 (-5.9 [-11.9; 0.2]) and 6MWT (+14 m [-5;33]) differences suggested potential small walking improvements. No changes observed in FSS, SSST, or SF-36.

CONCLUSIONS

In a representative sample of pwMS, PAE induced a clinically relevant reduction in fatigue impact, whereas small and no effects were seen for walking and quality of life, respectively. The results need confirmation in a future trial due to the study limitations.

Exercise Training for Multiple Sclerosis: A Narrative Review of History, Benefits, Safety, Guidelines, and Promotion

Background: There have been significant advances in the medical treatment and management of multiple sclerosis pathogenesis, relapse and disease progression over the past 30 years. There have been advancements in the symptomatic treatment of multiple sclerosis, including management of secondary multiple sclerosis expressions such as walking, cognitive dysfunction, fatigue and depression. Scientific evidence and expert opinion suggest that exercise may be the single most effective non-pharmacological symptomatic treatment for multiple sclerosis. This article presents the historical context of exercise training within the multidisciplinary management of multiple sclerosis. We guide neurologists and healthcare providers on the recommended prescription of exercise and practical, theoretical methods to overcome barriers to exercise. Method: We undertook a critical search of the historical and current literature regarding exercise and multiple sclerosis from the viewpoint of exercise promotion by neurologists and the multidisciplinary care team. Results: We highlight the ever-strengthening body of research indicating that exercise is safe and effective for improving symptoms of multiple sclerosis. Further, exercise training may be necessary for reducing disease progression. Conclusion: We seek to encourage neurologists and specialists in multidisciplinary healthcare teams to prescribe and promote exercise at diagnosis and across all stages of the disease trajectory using prescriptive guidelines as part of comprehensive MS care. Available tools include clinical education to dispel any historical myths related to exercise in multiple sclerosis, clinical exercise guidelines and behaviour change theory to overcome patients barriers to exercise.

Cardiorespiratory fitness and moderate-to-vigorous physical activity in older adults with multiple sclerosis

Background

Cardiorespiratory fitness (VO_2peak) may be a modifiable indicator of health status and well-being in older adults with multiple sclerosis.

Purpose

We examined differences in VO_2peak and moderate-to-vigorous physical activity between older adults with multiple sclerosis and healthy controls, and whether moderate-to-vigorous physical activity accounted for group differences in VO_2peak.

Methods

Older adults with multiple sclerosis (n = 31) and healthy controls (n = 29) completed a cardiopulmonary exercise test and wore an accelerometer for measuring moderate-to-vigorous physical activity. The data were analyzed using the Baron and Kenny approach for examining moderate-to-vigorous physical activity as a mediator of group differences in VO_2peak.

Results

The multiple sclerosis group had significantly lower VO_2peak and moderate-to-vigorous physical activity than healthy controls. VO_2peak had a large correlation with moderate-to-vigorous physical activity (r = .59). Group initially explained 8% of the variance in VO_2peak (β  =  -0.29). The inclusion of moderate-to-vigorous physical activity accounted for an additional 27% of the variance in VO_2peak, but only moderate-to-vigorous physical activity (β  =  0.57) was a statistically significant correlate of VO_2peak. The effect of Group was attenuated and non-significant with the addition of moderate-to-vigorous physical activity in Step 2 (Group β Step 1  =  -0.29, Group β Step 2  =  -0.05).

Conclusions

Our results provide initial support for targeting moderate-to-vigorous physical activity as an approach for improving VO_2peak in older adults with multiple sclerosis.

Blood lactate concentrations during rest and exercise in people with Multiple Sclerosis: A systematic review and meta-analysis

BACKGROUND

Multiple Sclerosis (MS) is a chronic disorder which irreversibly damages axons within brain matter. Blood lactate concentration could be a biomarker of MS onset and progression, but no systematic review has yet sought to confirm or dispute the elevation and biomarker potential of blood lactate in people with MS (PwMS) or to consolidate understanding of lactate production during exercise in PwMS.

OBJECTIVE

To perform a systematic review and meta-analysis on blood lactate in PwMS during rest and exertion compared to Healthy Controls (HC) and following chronic exercise intervention.

METHODS

A systematic search of six electronic databases (PubMed, CINAHL, Science Direct, Cochrane Library, SPORTDiscus and PEDro) was performed on 10th April 2020. Mean, standard deviation and sample size for lactate measures at rest and during exercise were pooled to determine overall effect size using a random effects model.  The 20-point Appraisal tool for Cross-Sectional Studies was utilised to assess study quality and inherent risk of bias. To qualify for inclusion, studies had to include human adults (>18 years) with a confirmed clinical diagnosis of MS, be published in English, have undergone peer review, report absolute blood lactate values for data extraction, and if involving testing during/after exercise, to do so during bilateral exercise methods.

RESULTS

18 studies were qualitatively analysed and 15 studies quantitatively analysed. Outcome data was available for 1986 participants (n_MS = 1129). A total of 7 papers tested blood lactate during rest (Lactate_REST), 7 papers tested during sub-maximal intensity exercise (Lactate_SUB-MAX), and 8 papers tested during maximal intensity exercise (Lactate_MAX). Meta analyses showed elevated Lactate_REST and reduced Lactate_MAX in PwMS compared to HC, higher Lactate_MAX in lower EDSS-scoring PwMS compared to higher EDSS-scoring PwMS, and that Lactate_SUB-MAX decreases and Lactate_MAX increases in PwMS following a chronic exercise intervention. Qualitative analysis reported Lactate_REST to be reduced in PwMS following a chronic exercise intervention.

CONCLUSIONS

Lactate_REST is elevated in PwMS compared to HC. Lactate_MAX is lower in PwMS compared to HC and lower still in higher compared to lower EDSS-scoring groups of PwMS. Chronic exercise interventions have the potential to reduce Lacatate_SUB-MAX for a given power output and increase Lactate_MAX in PwMS compared to baseline values. Lactate_REST may be reduced in PwMS following a chronic exercise intervention but more research is required for confirmation. The results of this review were limited by small sample sizes and number of studies available for each testing condition, limited data available for potentially confounding/correlating factors (eg. VO₂ and power output) as well as heterogeneity of methodology adopted across studies, often due to lactate testing being a secondary outcome measure. PLS: Lactate levels in the blood are different during rest and at intense exercise levels in people with Multiple Sclerosis (MS) compared to healthy counterparts, with people with MS showing a smaller jump in lactate during intense exercise from a higher resting level. After exercising for at least 3 months, blood lactate levels during exercise may become more similar to the levels seen in people without Multiple Sclerosis, but more research is required to give a clearer picture of this. We can hopefully use blood lactate in future to measure the progression of MS in an individual as well as the effectiveness of their exercise programme.

Systematic Review of Exercise Studies in Persons with Multiple Sclerosis: Exploring the Quality of Interventions According to the Principles of Exercise Training

INTRODUCTION

The objective of this systematic review is to explore the application and reporting of (i) the principles of exercise training in exercise trials, (ii) the components of exercise prescription, and (iii) the adherence towards the prescribed programmes in randomised controlled trials (RCTs) in persons with multiple sclerosis (pwMS).

METHODS

The MEDLINE, CINAHL, SPORTDiscus, PubMed and Embase electronic databases were searched from 1 January 2000 to 16 October 2020. RCTs comprising at least 3 weeks of aerobic and/or resistance exercise intervention in pwMS that reported at least one physiological outcome and were published in peer-reviewed journals were eligible for inclusion.

RESULTS

Out of 52 RCTs included in this review, 58 intervention arms were examined. None applied more than four principles of exercise training. Specificity was addressed by 85%, progression by 33%, overload by 59%, initial values by 26%, reversibility by 0% and diminishing returns by 2% of trials. Fifty-two percent of trials reported all components of exercise prescription, and 3% of trials reported the level of adherence to the prescribed exercise.

CONCLUSION

This systematic review reveals that exercise training principles were not respected in the majority of included RCTs. The weak quality of reported exercise interventions limits the interpretation of the studies' results and potentially leads to an underestimation of 'exercise as medicine' in pwMS. Also, the vague descriptions of exercise prescription and adherence impede the reproducibility of results. Future studies must attend to all principles of exercise training and provide transparent information on the prescribed and performed programmes to develop specific and valid exercise recommendations for pwMS.

SYSTEMATIC REVIEW REGISTRATION

CRD42020162671, 28/04/2020, PROSPERO.

The type of exercise most beneficial for quality of life in people with multiple sclerosis: A network meta-analysis

BACKGROUND

There is overwhelming evidence regarding the beneficial effects of exercise on the management of symptoms, functionality and health-related quality of life (HRQoL) of people with multiple sclerosis (MS). However, few analyze have compared different types of exercise.

OBJECTIVE

The aim of this network meta-analysis (NMA) was to assess which type of physical exercise has the greatest positive effect on HRQoL in people with MS.

METHODS

MEDLINE, Cochrane Library, Embase, Web of Science, Physiotherapy Evidence Database and SPORTDiscus databases were searched from inception to June 2021 to identify randomized controlled trials (RCTs) examining the effect of physical exercise on HRQoL in people with MS. The NMA included pairwise and indirect comparisons. We ranked the effect of interventions calculating the surface under the cumulative ranking (SUCRA).

RESULTS

We included 45 RCTs in this NMA (2428 participants; 76% women; mean age 45 years). Five types of physical exercises were ranked. Sensorimotor training had the highest effect size (0.87, 95% confidence interval [CI] 0.60; 1.15) and the highest SUCRA (87%) for total HRQoL. The highest effect size and SUCRA for physical and mental HRQoL were for aerobic exercise (0.85, 95% CI 0.28; 1.42) (89%) and mind-body exercises (0.54, 95% CI 0.03; 1.06) (89%). Sensorimotor training was the best exercise for mild disease and aerobic exercise for severe disease for total HRQoL.

CONCLUSIONS

Sensorimotor training seems the most effective exercise to improve HRQoL and aerobic and mind-body exercises to improve physical and mental HRQoL, respectively.

Consumer experience of a flexible exercise participation program (FEPP) for individuals with multiple sclerosis: A mixed-methods study

BACKGROUND AND PURPOSE

The flexible exercise participation program (FEPP) is a novel intervention developed to enable individuals with multiple sclerosis (MS) participate and progress in an exercise or sport of their choice. The FEPP is underpinned by guidelines on aerobic exercise for individuals with MS and is supported by a physiotherapist using behaviour change techniques. As part of a FEPP feasibility trial, the aim of this nested study was to explore the experience of participation in the FEPP from the perspective of individuals with MS. The objectives were to (i) determine the acceptability of the FEPP and (ii) identify recommendations for improvement.

METHODS

A mixed methods study using a sequential explanatory design was conducted. Part I consisted of a quantitative participant survey. Survey data were analysed descriptively using SPSS and informed the protocol for part II - qualitative interviews. Interview data were analysed thematically using NVivo. Part III consisted of integration of quantitative and qualitative data to allow greater explanation of survey responses. Individuals with MS who had participated in the FEPP feasibility trial were invited to take part in the study.

RESULTS

The FEPP was highly acceptability to the 10 participants. Five themes emerged to describe the experience of participating in the FEPP: (i) exploring exercise boundaries, (ii) measuring energy, (iii) acknowledging accountability, (iv) adjusting to exercising in a pandemic and (v) sustaining participation. Recommendations for improving the FEPP included changes to energy level monitoring and incorporation of peer support mechanisms.

DISCUSSION

Participants found the FEPP highly acceptable and valued the flexibility to choose their own activity and the health professional support. Based on participant recommendations, future versions of the FEPP will include daily rather than weekly monitoring of exercise and peer support to further enable individuals with MS to find the right balance with exercise and sport.

Effects of walking exercise training on learning and memory and hippocampal neuroimaging outcomes in MS: A targeted, pilot randomized controlled trial

PURPOSE

The current pilot study involved a single-blind, randomized controlled trial (RCT) on the effects of treadmill walking exercise training compared with an active control condition on learning and memory (L/M) and hippocampal neuroimaging outcomes in 11 fully-ambulatory persons with multiple sclerosis (MS) who demonstrated impairments in new learning.

METHODS

The study protocol is registered at clinicaltrials.gov: NCT03319771 (February 2018). Eleven fully-ambulatory persons with MS-related impairments in new learning were randomly assigned into either 12-weeks of supervised, treadmill walking exercise training or 12-weeks of low-intensity resistive exercise (active control condition). Participants underwent neuropsychological tests of L/M and hippocampal neuroimaging before and after the 12-week study period; outcomes were administered by treatment-blinded assessors.

RESULTS

There were moderate-to-large intervention effects on measures of verbal L/M (η_p² = 0.11, d = 0.63, 95% CI: -0.61, 1.83), whereby those in the intervention condition demonstrated improvement in California Verbal Learning Test-II (CVLT-II) scores compared with the control condition. There were smaller effects on a composite L/M measure (η_p² = 0.02, d = 0.28, 95% CI: -0.93, 1.46). There were large intervention effects on normalized hippocampal volume (η_p² = 0.36, d = 1.13, 95% CI: 0.09, 2.82), whereby hippocampal volume was preserved in the intervention condition, compared with hippocampal atrophy in the control condition. By comparison, there were no intervention effects on hippocampal resting-state functional connectivity.

CONCLUSIONS

Collectively, this study provides initial proof-of-concept data for further examining treadmill walking exercise training as a possible behavioral approach for managing L/M impairment and preserving hippocampal volume as common and debilitating manifestations of MS.

Exercise and Sports Science Australia (ESSA) position statement on exercise for people with mild to moderate multiple sclerosis

OBJECTIVES

Multiple sclerosis (MS), the most common chronic and progressive neurological condition of the central nervous system, affects 26,000 Australian adults. Exercise training has beneficial effects on MS-related impairments including reduced muscular strength, poor aerobic capacity and impaired mobility, and in consequence can improve quality of life. This Position Statement provides evidence-based recommendations for exercise prescription and delivery of exercise training for people with MS with mild to moderate disability.

DESIGN AND METHODS

Synthesis of published works within the field of exercise training in MS.

RESULTS

Exercise provides many benefits to people with MS. There is strong evidence that resistance and aerobic training, performed 2 to 3 times per week at a moderate intensity, are safe and can improve muscle strength, cardiorespiratory fitness, balance, fatigue, functional capacity, mobility and quality of life in people with MS with mild to moderate disability (Expanded Disease Severity Scale (EDSS) ≤ 6.5). However, the evidence for those with severe disability (EDSS >6.5) is less clear. The effects of exercise on MS pathogenesis, central nervous structures and other outcomes such as depression and cognitive impairment, have not been adequately investigated. Effective exercise interventions to improve balance, joint contractures and reduce falls in people with MS are also urgently needed as well as investigations of long-term (≥1 year) effects of exercise training.

CONCLUSIONS

Resistance and aerobic training exercises are effective to alleviate some characteristic signs and symptoms in MS and should be supplemented by balance exercise to prevent falls. Exercise training programs should be prescribed and delivered by qualified exercise professionals. It is important to recognise and accommodate exercise-associated complications such as fatigue and heat sensitivity.

PILOT STUDY OF ENHANCING CARDIORESPIRATORY EXERCISE RESPONSE IN PEOPLE WITH ADVANCED MULTIPLE SCLEROSIS WITH HYBRID FUNCTIONAL ELECTRICAL STIMULATION

OBJECTIVE

To investigate through a pilot study the acute cardiorespiratory responses during functional electrical stimulation (FES) cycling, arm cranking exercise (ACE) and a combination of ACE and FES cycling (Hybrid FES cycling) in people with advanced multiple sclerosis (MS) to provide preliminary guidance for effective aerobic exercise prescription.

DESIGN

Acute repeated measures.

SETTING

Laboratory setting.

PARTICIPANTS

Inclusion criteria was a diagnosis of MS, with Expanded Disability Status Scale (EDSS) 6.0 to 8.5. Included were 9 participants (7 female, age 54.7 ± 8.8 years, EDSS 7.0 ± 7.2).

INTERVENTION

Participants were assessed on three different exercise modalities (FES cycling, ACE, Hybrid FES cycling) at 40%, 60%, 80% and 100% of mode-specific peak workload.

MAIN OUTCOME MEASURES

Oxygen consumption (VO₂) and heart rate (HR) were measured at each workload.

RESULTS

Hybrid FES cycling evoked a significantly higher VO_2relative (mL∙kg^-1∙min^-1) and HR (bpm) at most workloads as compared with ACE or FES cycling. At the 100% workload, HR for Hybrid FES cycling was 125 (113-148) bpm and was significantly higher than ACE at 99 (95-119) bpm (p=0.008) and FES cycling at 94 (79-100) bpm (p=0.008). Similarly, at the 100% workload, VO_2relative for Hybrid FES cycling was 11.8 (7.6-17.6) mL∙kg^-1∙min^-1 and was significantly higher than ACE at 8.9 (5.3-12.5) mL∙kg^-1∙min^-1 (p=0.012) and FES cycling at 6.8 (4.1-9.2) mL∙kg^-1∙min^-1 (p=0.012).

CONCLUSIONS

This pilot study showed that Hybrid FES cycling can elicit a greater cardiorespiratory response compared to ACE or FES cycling in people with advanced MS. Thus, Hybrid FES cycling might provide a potent enough stimulus to induce clinically relevant changes in cardiorespiratory fitness. Training studies are warranted to document the magnitude and sustainability of aerobic capacity adaptations to Hybrid FES cycling and associated health outcomes in advanced MS.