Is the impact of fatigue related to walking capacity and perceived ability in persons with multiple sclerosis? A multicenter study

Fatigue insights from walking tests in spinal cord injury and multiple sclerosis individuals

In the last decade, fatigue in clinical populations has been re-conceptualized, including dimensions such as perceived fatigue (trait and state fatigue) and fatigability. The aim of this study was to evaluate different expressions of fatigue in Spinal Cord Injury (SCI) and Multiple Sclerosis (MS) participants compared to able-bodied controls, during activities of daily living, especially during gait. A total of 67 participants were included in this study (23 with SCI, 23 with MS, and 21 able-bodied controls). All participants performed two functional tests (6-Minute Walk Test and 10-Meter Walk Test) and they completed the Fatigue Severity Scale (FSS). The rate of trait fatigue was different between groups, with MS participants showing the highest rate. Moreover, scores on functional tests and state fatigue were different between groups after the tests. Our results indicate that trait fatigue and state fatigue in individuals with SCI and MS are different with respect to able-bodied population. Both SCI and MS groups experienced more trait fatigue than control group in daily life. In addition, walking tasks produced similar levels of state fatigue between healthy people and patients with MS/SCI. However, these tests induced longer-lasting levels of state fatigue in the patients.

Correlation of fatigue on walking ability in myasthenia gravis patients: a cross-sectional study

Introduction

Myasthenia gravis (MG) is a neuromuscular junction autoimmune disease characterised of intermittent muscle weakness that increases with activity and recovers with rest.

Objective

Analysing the correlation of fatigue on walking ability in MG patients.

Methods

This study used a cross-sectional design with consecutive sampling. Participants MG patients took in this trial. Data collection encompasses fatigue and walking ability, with fatigue being assessed using the fatigue severity scale (FSS) and walking ability being assessed using the 10-metre walking test. The 10-metre walking test assessment contains three components: comfortable walking speed (CWS), maximum walking speed (MWS), and natural cadence. The statistical analysis used in this study includes the Pearson correlation and Spearman rank tests with P<0.05.

Results

The number of participants was 23 MG patients, and most of the participant was female (69.6%). The participant's fatigue value was 5.46±1.13, including MGFA 1=5.32±1.15, MGFA 2A=5.5±1.11, and MGFA 2B=5.61±1.30. Meanwhile, the participant's walking abilities included CWS of 1.10±0.11 m/s, MWS of 1.31±0.15 m/s, and natural cadence of 110.91±7.74 steps/min. No significant correlation of fatigue on walking ability including FSS vs. CWS (r=-0.141; P=0.520), FSS vs MWS (r=-0.169; P=0.442), and FSS vs. natural cadence (r=-0.050; P=0.822).

Conclusion

There was no significant correlation between fatigue and walking ability in MG patients who had MGFA 1, MGFA 2A, and MGFA 2B.

Automatic Assessment of the 2-Minute Walk Distance for Remote Monitoring of People with Multiple Sclerosis

The aim of this study was to investigate the feasibility of automatically assessing the 2-Minute Walk Distance (2MWD) for monitoring people with multiple sclerosis (pwMS). For 154 pwMS, MS-related clinical outcomes as well as the 2MWDs as evaluated by clinicians and derived from accelerometer data were collected from a total of 323 periodic clinical visits. Accelerometer data from a wearable device during 100 home-based 2MWD assessments were also acquired. The error in estimating the 2MWD was validated for walk tests performed at hospital, and then the correlation (r) between clinical outcomes and home-based 2MWD assessments was evaluated. Robust performance in estimating the 2MWD from the wearable device was obtained, yielding an error of less than 10% in about two-thirds of clinical visits. Correlation analysis showed that there is a strong association between the actual and the estimated 2MWD obtained either at hospital (r = 0.71) or at home (r = 0.58). Furthermore, the estimated 2MWD exhibits moderate-to-strong correlation with various MS-related clinical outcomes, including disability and fatigue severity scores. Automatic assessment of the 2MWD in pwMS is feasible with the usage of a consumer-friendly wearable device in clinical and non-clinical settings. Wearable devices can also enhance the assessment of MS-related clinical outcomes.

Motoric cognitive risk syndrome in people with multiple sclerosis: prevalence and correlations with disease-related factors

Background:

The motoric cognitive risk (MCR) syndrome, defined as the coexistence of slow gait and subjective cognitive complaints, has as yet not been researched in people with multiple sclerosis (pwMS).

Objective:

To examine the prevalence of the MCR syndrome in pwMS and its association with disability, disease duration, perceived fatigue, and fear of falling.

Methods:

The study comprised 618 pwMS [43.7 (SD = 12.6) years, 61.7% females]. Gait speed was measured by the GAITRite™ electronic walkway (CIR Systems, Inc. Haverton, PA, USA). Cognitive status was defined according to the global cognitive score computed by the NeuroTrax™ cognitive battery (NeuroTrax Corporation, Medina, NY, USA). The sample was divided into four main groups: ‘normal’, ‘cognitively impaired’, ‘gait impaired’ or ‘MCR’. Perceived fatigue was assessed by the Modified Fatigue Impact Scale; fear of falling by the Falls Efficacy Scale International.

Results:

Sixty-three (10.2%) patients were diagnosed with MCR. The percentage of subjects categorized as MCR was 26.0% in severely disabled pwMS compared with 10.9%, 6.0%, and 4.6% in moderately, mildly and very mildly disabled pwMS, respectively. Subjects in the MCR group presented with elevated fatigue compared with patients classified as normal [49.7 (SD = 23.3) vs 26.5 (SD = 19.2), p < 0.001]. Fear of falling was significantly higher in the MCR and gait impairment groups compared with the cognitively impaired and normal groups.

Conclusions:

The current study corroborates the presence of MCR in pwMS. Nevertheless, future longitudinal research is warranted to better understand its application.

The Role of Remote Monitoring in Evaluating Fatigue in Multiple Sclerosis: A Review

Fatigue is one of the most common multiple sclerosis (MS) symptoms. Despite this, monitoring and measuring fatigue (subjective lack of energy)- and fatigability (objectively measurable and quantifiable performance decline)- in people with MS have remained challenging. Traditionally, administration of self-report questionnaires during in-person visits has been used to measure fatigue. However, remote measurement and monitoring of fatigue and fatigability have become feasible in the past decade. Traditional questionnaires can be administered through the web in any setting. The ubiquitous availability of smartphones allows for momentary and frequent measurement of MS fatigue in the ecological home-setting. This approach reduces the recall bias inherent in many traditional questionnaires and demonstrates the fluctuation of fatigue that cannot be captured by standard measures. Wearable devices can assess patients' fatigability and activity levels, often influenced by the severity of subjective fatigue. Remote monitoring of fatigue, fatigability, and activity in real-world situations can facilitate quantifying symptom-severity in clinical and research settings. Combining remote measures of fatigue as well as objective fatigability in a single construct, composite score, may provide a more comprehensive outcome. The more granular data obtained through remote monitoring techniques may also help with the development of interventions aimed at improving fatigue and lowering the burden of this disabling symptom.

Fatigue in multiple sclerosis: A UK MS-register based study

BACKGROUND

Fatigue is a widely experienced, incapacitating symptom of MS. It hinders daily functioning and has deleterious effects on quality of life. The UK MS Register is an online registry of over 20,000 participants with MS. The aim of this study was to estimate the prevalence, predictors, and impact of fatigue on people with MS using data from the UKMS register.

METHODS

All participants who completed the Fatigue Severity Scale (FSS), WebEDSS, Hospital Anxiety and Depression Scale (HADS) within 28 days of each other were selected from the UK MS Register. Data on age, gender, duration and type of MS, use of disease modifying drugs and comorbidities were obtained from the UKMS register. We categorised people with FSS score of 5 or more as with fatigue and those with scores of 4 or less as without fatigue. Descriptive statistics and logistical and multiple regressions were used to explore predictors of fatigue and the effect of fatigue on mobility (MS Walking Scale), physical and psychological aspects of life (MS Impact Scale) and quality of life (European Quality of Life 5D-3 L).

RESULTS

Amongst the 20,946 participants of the UK MS registry, 4620 completed FSS. Out of these, 775 (mean age= 54.71 years, SD= 10.90; mean duration of MS diagnosis =13.21 years, SD=9.75) had completed the FSS, Web EDSS and Hospital Anxiety and Depression Scale within 28 days of each other. 427 (55.1%) of pwMS had a FSS score >5 consistent with clinical fatigue. Logistic regression analysis showed that depression (p=<0.001), duration of MS (p = 0.017), secondary progressive MS (p = 0.001) and EDSS (p=<0.001) predicted fatigue. FSS scores had a significant negative impact on both psychological (p > 0.001) and physical (p > 0.001) domains of the MS Impact scale, MS walking scale (p = 0.003) and EQoL (p = 0.005).

CONCLUSIONS

Fatigue was a common symptom amongst people with MS. Depression, longer duration of MS, secondary progressive MS, and high EDSS predicted fatigue. Fatigue had an adverse effect on physical activities, mobility, psychological wellbeing, and quality of life of people with MS.

Implications of lower extremity muscle power and force for walking and fatigability in multiple sclerosis - An exploratory pilot-study

BACKGROUND

Limitations in physical function are common in Multiple Sclerosis (MS), yet it is neither clear how muscle power implicates physical function and walking-fatigability. This pilot-study aims to investigate (1) deficits in muscle power/force alongside walking in persons with MS; (2) associations between muscle power/force and physical functions and (3) the impact of prolonged walking in muscle power/force.

METHODS

30 relapse-remitting persons with MS and 28 healthy controls performed chair rise and plantar flexion on a force platform before and after 12-minutes of intermittent walking to measure lower extremity muscle power/force. GaitRite measured walking speed. The percentage change in distance walked was also calculated. Persons with MS were classified into subgroups according to walking-fatigability and mobility disability status (Patient Determined Disease Steps).

FINDINGS

Higher deficits in muscle power compared to force were observed in persons with MS vs. healthy controls particularly in persons with MS having higher disability. Muscle power and force were associated with walking capacity, mobility disability and subjective fatigue, but not with percentage change in distance walked. Persons with MS slowed down over the course of the 12-min intermittent walking, whereas decrements in walking speed and muscle power/force (derived from chair rise) were observed in persons with MS presenting walking-fatigability only.

INTERPRETATION

Muscle power and force are impaired in persons with MS and appear to be critical for physical function in MS. This exploratory pilot study further suggests that muscle power/force from chair rise could contributes to walking-fatigability which therefore offer future treatment targets.

Disability assessment using Google Maps

Objectives

To evaluate the concordance between Google Maps® application (GM®) and clinical practice measurements of ambulatory function (e.g., Ambulation Score (AS) and respective Expanded Disability Status Scale (EDSS)) in people with multiple sclerosis (pwMS).

Materials and methods

This is a cross-sectional multicenter study. AS and EDSS were calculated using GM® and routine clinical methods; the correspondence between the two methods was assessed. A multinomial logistic model is investigated which demographic (age, sex) and clinical features (e.g., disease subtype, fatigue, depression) might have influenced discrepancies between the two methods.

Results

Two hundred forty-three pwMS were included; discrepancies in AS and in EDDS assessments between GM® and routine clinical methods were found in 81/243 (33.3%) and 74/243 (30.4%) pwMS, respectively. Progressive phenotype (odds ratio [OR] = 2.8; 95% confidence interval [CI] 1.1–7.11, p = 0.03), worse fatigue (OR = 1.03; 95% CI 1.01–1.06, p = 0.01), and more severe depression (OR = 1.1; 95% CI 1.04–1.17, p = 0.002) were associated with discrepancies between GM® and routine clinical scoring.

Conclusion

GM® could easily be used in a real-life clinical setting to calculate the AS and the related EDSS scores. GM® should be considered for validation in further clinical studies.

Supplementary Information

The online version contains supplementary material available at 10.1007/s10072-021-05389-7.

Instrumentally assessed gait quality is more relevant than gait endurance and velocity to explain patient-reported walking ability in early-stage multiple sclerosis

BACKGROUND AND PURPOSE

People with multiple sclerosis (PwMS) often report walking limitations even when the gold standard Expanded Disability Status Scale (EDSS) indicates normal walking endurance/autonomy. The present multicenter study on early-stage PwMS aims at analyzing which aspects are associated with patient-reported walking limitations measured with the 12-item Multiple Sclerosis Walking Scale (MSWS-12).

METHODS

Eighty-two PwMS (EDSS ≤ 2.5) were assessed using the Fullerton Advanced Balance Scale-short (FAB-s), the Fatigue Severity Scale (FSS) and the 6-min Walk Test (6MWT), the latter administered also to 21 healthy subjects. Participants performed the 6MWT wearing three inertial sensors on ankles and trunk. Instrumented metrics describing gait velocity (stride length and frequency) and quality (regularity, symmetry, instability) were computed from sensor data. Fatigue (FSS), balance (FAB-s), walking endurance (6MWT) and instrumented metrics were entered in a multiple regression model with MSWS-12 as dependent variable.

RESULTS

Gait symmetry, gait instability, fatigue and balance were significantly associated with self-rated walking ability, whilst walking endurance and velocity were not. Fatigue, balance, gait symmetry and instability were more impaired in participants reporting mild-to-moderate (MS_MM-PWL , 25 ≤ MSWS-12 < 75) compared to those reporting none-to-minimal (MS_nm-PWL , 0 ≤ MSWS-12 ≤ 25) perceived walking limitations. Compared to healthy subjects, gait symmetry and stability were reduced in MS_nm-PWL and MS_MM-PWL , even in those participants with EDSS ≤ 1.5.

CONCLUSION

Instrumentally assessed gait quality aspects (symmetry and instability) are associated with patient-reported walking ability in early-stage PwMS and seem sensitive biomarkers to detect subtle impairments even in the earliest stages of the disease (EDSS ≤ 1.5). Future studies should assess their ability to follow walking change due to MS progression or pharmacological/rehabilitation interventions.

Evaluation of Prolonged Walking in Persons with Multiple Sclerosis: Reliability of the Spatio-Temporal Walking Variables during the 6-Minute Walk Test

Background: Walking disorders represent the most disabling condition in persons with Multiple Sclerosis (PwMS). Several studies showed good reliability of the 6-min walk test (6MWT) (i.e., especially distance traveled), but little is known about the reliability of the Spatio-temporal (ST) variables in the 6MWT. Objective: To evaluate the test-retest reliability of ST variables and perceived exertion during the 6MWT in PwMS and comparable healthy persons. Methods: We explored three 1-min intervals (initial: 0′–1′, middle: 2′30″–3′30″, end: 5′–6′) of the 6MWT. Six ST variables and perceived exertion were measured (respectively, using the GAITRite system and the Borg Scale). These measurements were performed twice, 1 week apart. The test-retest effects were assessed using the intraclass correlation coefficient (ICC) or the weighted kappa. Results: Forty-five PwMS and 24 healthy persons were included. The test-retest reliability of ST variables values was good-to-excellent for PwMS (ICC range: 0.858–0.919) and moderate-to-excellent for healthy persons (ICC range: 0.569–0.946). The test-retest reliability values of perceived exertion were fair for PwMS (weighted kappa range: 0.279–0.376) and substantial for healthy persons (weighted kappa range: 0.734–0.788). Conclusion: The measurement of ST variables during these 6MWT intervals is reliable and applicable in clinical practice and research to adapt rehabilitation care in PwMS.

The Relationship Between Walking Speed and the Energetic Cost of Walking in Persons With Multiple Sclerosis and Healthy Controls: A Systematic Review

BACKGROUND

Persons with multiple sclerosis (pwMS) experience walking impairments, characterized by decreased walking speeds. In healthy subjects, the self-selected walking speed is the energetically most optimal. In pwMS, the energetically most optimal walking speed remains underexposed. Therefore, this review aimed to determine the relationship between walking speed and energetic cost of walking (Cw) in pwMS, compared with healthy subjects, thereby assessing the walking speed with the lowest energetic cost. As it is unclear whether the Cw in pwMS differs between overground and treadmill walking, as reported in healthy subjects, a second review aim was to compare both conditions.

METHOD

PubMed and Web of Science were systematically searched. Studies assessing pwMS, reporting walking speed (converted to meters per second), and reporting oxygen consumption were included. Study quality was assessed with a modified National Heart, Lung and Blood Institute checklist. The relationship between Cw and walking speed was calculated with a second-order polynomial function and compared between groups and conditions.

RESULTS

Twenty-nine studies were included (n = 1535 pwMS) of which 8 included healthy subjects (n = 179 healthy subjects). PwMS showed a similar energetically most optimal walking speed of 1.44 m/s with a Cw of 0.16, compared with 0.14 mL O₂/kg/m in healthy subjects. The most optimal walking speed in treadmill was 1.48 m/s, compared with 1.28 m/s in overground walking with a similar Cw.

CONCLUSION

Overall, the Cw is elevated in pwMS but with a similar energetically most optimal walking speed, compared with healthy subjects. Treadmill walking showed a similar most optimal Cw but a higher speed, compared with overground walking.

Is maximal muscle strength and fatigability of three lower limb muscle groups associated with walking capacity and fatigability in multiple sclerosis? An exploratory study

BACKGROUND

Both muscle fatigability and walking fatigability are prevalent in persons with MS (pwMS), but their associations remains unclear. The aim of this study was to examine the association of muscle strength and fatigability from both isometric and concentric protocols of three different muscle groups, and their association to walking capacity and walking fatigability.

METHODS

Twenty-seven pwMS and 13 Healthy Controls (HC) were included in this exploratory study. All participants performed a six-minute walking test (6MWT), where the distance walked index (DWI) was calculated to measure walking fatigability with a cut-off score of -10%. In three different muscle groups (knee extensors (KE), knee flexors (KF), ankle dorsiflexors (DF)), isometric and concentric muscle fatigability protocols (FI_isometric or FI_concentric) were used to quantify maximal voluntary contraction (MVC) and muscle fatigability. Pearson or Spearman correlation coefficients and linear regression models were calculated to establish the association between muscle strength/fatigability and walking capacity/fatigability.

RESULTS

Higher MVCs values for all muscle groups were found in HC compared to pwMS (mainly those having walking fatigability) (p < 0.05). FI_isometric of DF was lower in pwMS having walking fatigability compared to no walking fatigability. MVC of KE, KF and DF had a low to moderate association with walking capacity (range r = 0.52-0.56; p < 0.05) and walking fatigability in pwMS (range r-r_s: 0.39-0.50; p<0.05). FI_concentric of KF and DF, but not of KE, were associated with walking fatigability (r = 0.39 and r_s = 0.47, respectively; p < 0.05). In contrast, FI_isometric for all muscle groups were not related to walking capacity or walking fatigability.

CONCLUSION

MVC of KE, KF and DF are associated with walking capacity and walking fatigability, while concentric (but not isometric) muscle fatigability of KF and DF are associated with walking fatigability.

Associations between fatigue impact and lifestyle factors in people with multiple sclerosis - The Danish MS hospitals rehabilitation study

BACKGROUND

The lack of medical treatment options to reduce fatigue in patients with multiple sclerosis (MS) emphasize the importance of identifying potential non-pharmacological modifiable factors, as this may help advance current treatment strategies. The aim of this study was to identify potential modifiable lifestyle factors as well as patient- and disease-related characteristics, that are associated with fatigue in a large sample of clinically well-characterized patients with MS.

METHODS

This study was a secondary analysis of a pragmatic randomized controlled trial of inpatient multidisciplinary rehabilitation in Denmark. MS patients aged 18 to 65 years and with a disease severity score ≤ 7.5 according to the Expanded Disability Status Scale participated. Data on patient- and disease-related characteristics, fatigue impact (Modified Fatigue Impact Scale (MFIS)), and on lifestyle factors (tobacco smoking, alcohol intake, and physical activity), were collected at baseline. A linear mixed model was used to compare MFIS total, physical, cognitive, and psychosocial scores across subgroups of selected characteristics. Regression analyses were used to examine associations between lifestyle factors and MFIS total, physical, cognitive, and psychosocial scores.

RESULTS

In the sample of 417 MS patients, median age was 51 years, 69% were female, median time since diagnosis was 8 years, with 41% having relapsing remitting MS. Higher MFIS total scores were observed in MS patients with shorter time since diagnosis, being a tobacco smoker, and not undertaking regular physical activity. Somewhat similar findings were observed for MFIS subscores (physical, cognitive, psychosocial), especially MFIS physical scores. In the multivariate analyses, physical activity was significantly associated with fatigue impact on total, physical and psychosocial functioning. Tobacco smoking was significantly associated with fatigue impact on psychosocial functioning. Alcohol intake was not associated with fatigue impact. None of the lifestyle factors were associated with fatigue impact on cognitive functioning. In the adjusted models time since diagnosis was significantly associated with fatigue impact on total, physical and cognitive functioning, as was disease severity with fatigue impact on physical and cognitive functioning.

CONCLUSION

Physical activity showed the most pronounced associations with fatigue impact on physical and psychosocial functioning, while the impact on cognitive functioning showed a trend. Tobacco smoking contributed significantly to impact on psychosocial functioning, while alcohol intake did not contribute to fatigue impact. Introducing or supporting maintenance of physical activity/exercise and cessation of tobacco smoking seems to be a useful approach for rehabilitation services to help patients with MS manage fatigue.

Fatigue and fluctuations in physical and psychological wellbeing in people with multiple sclerosis: A longitudinal study

BACKGROUND

Fatigue is a highly prevalent and disabling symptom of multiple sclerosis (MS). The aetiology remains unclear, potentially resulting from neuroinflammatory or neurodegenerative processes, mood disturbance, MS symptoms including pain, poor sleep, physical decompensation or medication side effects. Cross-sectional associations have been reported between fatigue and markers of physical and psychological health in people with MS. The current study examined if fluctuations in markers of physical and psychological wellbeing were associated with between-person differences in fatigue in MS.

METHODS

Longitudinal data of up to 7 years was available of 3369 people with MS who were enrolled in the UK MS Register. Participants completed MS impact scale ratings and MS walking scales up to 4 times per year for up to 7 years. Fatigue was assessed at one time point using the Fatigue Severity Scale. Multilevel analyses were conducted to examine the degree of variance in the outcome measures accounted for by fatigue.

RESULTS

Fatigue was associated with fluctuations in depression, MS impact, and walking ability, and to a lesser extent with fluctuations in anxiety and perceived health status. Interference of fatigue in participation in social activities and work-related responsibilities and the physical effects of fatigue were most strongly related to MS-related outcomes.

CONCLUSION

Given the strong associations between fatigue and many MS outcomes, fatigue management interventions are likely to impact on different aspects of physical and psychological wellbeing in MS.

What's in a name? That which we call Multiple Sclerosis Fatigue

Very limited progress has been made to date in the treatment of debilitating Multiple Sclerosis (MS) daily onset symptoms. These daily symptoms include motor, sensory, and cognitive impairments as well as an overwhelming feeling of tiredness, often referred to as “MS fatigue.” Although widely cited as a main cause of inability to work and poor quality of life in patients with MS, daily onset MS-related tiredness continues to defy definition, and, consequently, measurement and treatment. Beginning with a historical overview of observations of daily onset MS-related tiredness, this Topical Review demonstrates how the misnomer “MS fatigue” has introduced ongoing misunderstanding for patients, investigators, clinicians, and therapists. Finally, combining current findings in clinical neuroscience with the striking set of long-standing commonalities present throughout the past 200 years of clinical observations, we underscore the immediate necessity for conceptual and applied change, to be initiated by the renaming of this distinct syndrome.

Responsiveness and clinically meaningful changes for the Persian versions of the multiple sclerosis walking scale-12 and the modified fatigue impact scale following balance and gait rehabilitation in people with multiple sclerosis

Background and Purpose: The Multiple sclerosis walking scale-12 (MSWS-12) and the Modified Fatigue Impact Scale (MFIS) are two popular outcome measures applied widely for assessing self-perceived walking ability and fatigue in people with multiple sclerosis (PwMS). The present study aimed to examine responsiveness and clinically meaningful changes for the Persian versions of the MSWS-12 and the MFIS following balance and gait rehabilitation in PwMS.Methods: Fifty-eight PwMS completed the Persian versions of the MSWS-12 and the MFIS before and after 4 weeks of balance and gait rehabilitation. Also, a 7-point global rating scale as an external criterion of change was completed at the post-intervention evaluation. The area under the receiver operating characteristics curve (AUC) and the correlation analysis were used to assess the responsiveness. In addition, the minimally clinically important change (MCIC) was measured to determine clinically meaningful changes following rehabilitation.Results: The AUC values for the Persian MSWS-12 and MFIS were 0.74 and 0.73, respectively. There were good to excellent correlations between the global rating scale of change and the Persian MSWS-12 (Gamma = 0.77) also MFIS (Gamma = 0.80) change scores (p = .001). Moreover, the MCICs of 7.5 and 4 points were obtained for the Persian MSWS-12 and MFIS, respectively.Conclusion: The Persian versions of the MSWS-12 and the MFIS were responsive outcome measures for monitoring changes in walking and fatigue after balance and gait rehabilitation in PwMS. The calculation of MCIC values would enhance the interpretation of changes in clinical and research settings.

Physical activity in mild multiple sclerosis: contribution of perceived fatigue, energy cost, and speed of walking

Purpose: To clarify the relationship between leisure-time physical activity, perceived fatigue, and energy expenditure while walking in people with multiple sclerosis.Methods: Sixty-six people afflicted with multiple sclerosis (MS) (32 women) with a mild neurological disability, participated in this study. Energy expenditure was separately measured at rest, during comfortable walking and during fast walking via a portable metabolic device using breath-by-breath technology (COSMED K5, COSMED Srl, Rome, Italy). The Godin leisure-time exercise questionnaire assessed leisure-time physical activity. The Modified Fatigue Impact Scale determined the level of perceived fatigue.Results: Seventeen people with MS were classified as physically active; 49 were insufficiently active. Scores recorded on the Godin Leisure-Time Exercise Questionnaire were 47.8 (SD = 18.4), 7.0 (SD = 8.2), respectively. Insufficiently physically active people with MS walked slower at both normal and fast walking conditions. However, no differences between groups were observed in energy expenditure measures in both walking speeds. O₂ cost was 0.20 (SD = 0.13) and 0.21 (SD = 0.06) in the active and insufficiently active group, respectively. The insufficiently active group reported more perceived fatigue compared with the active patients; 33.3 (SD = 18.6) vs. 15.0 (SD = 19.0), p value = 0.002. Perceived fatigue was a significant variable maintaining a 10.4% variance related to leisure-time physical activity.Conclusions: Leisure-time physical activity was inversely associated with perceived fatigue and walking speed in persons with mild MS. Rehabilitation professionals should be aware of these relationships when planning rehabilitation strategies.Implication for rehabilitationThis study found that perceived fatigue is a barrier to physical activity participation even in people with mild multiple sclerosis and minimal disability.Insufficiently active people with multiple sclerosis expend the same amount of energy while walking as active multiple sclerosis individuals, though walking slower.The relationship between perceived fatigue and physical activity participation requires further exploration in the multiple sclerosis population.

Timed Up-and-Go and 2-Minute Walk Test in patients with multiple sclerosis with mild disability: reliability, responsiveness and link with perceived fatigue

BACKGROUND

Mobility limitations are frequent in patients with multiple sclerosis (MS), and could already be present in patients with so-called mild neurological disability (Expanded Disability Status Scale≤4). Assessing mobility in these patients is therefore of paramount importance. Timed Up-and-Go Test (TUG) and 2-Minute Walk Test (2MWT) are two clinically feasible tests which reliability and responsiveness are unknown among these patients. Whether fatigue, which is the number one symptom among these patients, is linked to these limitations remains unknown.

AIM

The aim of this study was to explore the intrarater reliability and minimal detectable change (MDC95), as an index of responsiveness, of TUG and 2MWT. To explore their link with perceived fatigue among patients with MS.

DESIGN

Cross-sectional observational study, including two measures.

SETTING

Two university hospital outpatient centers.

POPULATION

Patients (N.=63, 49 seen twice) with MS with mild disability (Expanded Disability Status Scale≤4).

METHODS

2MWT and TUG were performed twice in one occasion, and repeated 2 weeks later. Modified fatigue impact scale (MFIS) was used to assess fatigue. Intraclass coefficient correlations were calculated for immediate and 2-week reliability. MDC95 were computed. Correlations between mobility indices and fatigue were explored using Spearman's ρ.

RESULTS

Mobility was impaired in comparison to normative values (2MWT: -4.9% from normative distance; TUG: +32% from normative time). The immediate reliability was excellent for both the 2MWT (ICC=0.98) and TUG (ICC=0.98). Reliability at 2 weeks was excellent for 2MWT (ICC=0.95) and very good for TUG (ICC=0.90). MDC95 were respectively 20m (2MWT) and 1.3s (TUG). Both measures were significantly weakly correlated to total MFIS (ρ=-0.37 and 0.39, respectively; P<0.01).

CONCLUSIONS

The 2MWT and TUG are highly reliable and responsive in the assessment of respectively the walking capacity and general mobility of patients with MS with mild disability. Mobility impairments are linked to perceived fatigue among these patients.

CLINICAL REHABILITATION IMPACT

TUG and 2MWT are easy to administer and could be reliably used in so called mildly disabled patients with MS to assess mobility limitation.