Ambulation and Multiple Sclerosis

Backwards walking speed reserve in persons with multiple sclerosis

BACKGROUND

Decreased gait speed is common in persons with Multiple Sclerosis (PwMS) and has been associated with elevated fall risk. The walking speed reserve (WSR) indicates the ability to increase gait speed on demand and has previously been examined in PwMS. Backward walking is a sensitive measure of fall risk in PwMS; however, no studies have reported on the utility of backward walking speed reserve (BW-WSR) as a clinical assessment tool of functional mobility or fall risk in PwMS, nor have they associated this measure with cognition.

METHODS

23 PwMS completed walking trials at their preferred walking speed (PWS) and maximal walking speed (MWS). Participants performed these walking trials in both the forward (FW) and backward direction (BW). The forward walking speed reserve (FW-WSR) was calculated as the difference between MWS and PWS in the forward direction, while the backward walking speed reserve (BW-WSR) was calculated as the difference between MWS and PWS in the back backward direction. Correlation analyses examined the relationship between the FW- and BW-WSR with clinical assessments of functional mobility (the timed up-and-go) as well as cognitive functioning (the Symbol Digit Modalities Test, the Brief Visuospatial Memory Test-Revised, the California Verbal Learning Test, and the Trail Making Test A and B). Correlations also examined the relationship between FW- and BW-WSR with prospective falls.

RESULTS

A lower BW-WSR was associated with disease severity and poorer performance on clinical walking and balance assessment, as well as with decreased information processing speed and attentional performance. Interestingly, FW-WSR showed similar relations. Neither FW- or BW-WSR were associated with prospective risk in this small sample of PwMS.

CONCLUSION

The BW-WSR did not offer a distinct advantage over other measures, such as the FW-WSR, PWS, or MWS, in the forward or backward direction. The selection of the most sensitive clinical measures of functional mobility and fall risk is crucial; our study holds valuable clinical implications for PwMS by providing novel insights into functional mobility assessments in PwMS.

Comorbid Conditions and Physical Function in Adults With Multiple Sclerosis

OBJECTIVE

We examined the total number of comorbid conditions as a correlate of physical function in persons with multiple sclerosis (MS). We further identified the presence of common comorbid conditions and examined physical function outcomes based on presence or absence of the comorbid conditions in persons with MS.

DESIGN

Cross-sectional, comparative study.

SETTING

University-based laboratory.

PARTICIPANTS

Two hundred seven persons with MS (N=207) completed the study.

MAIN OUTCOME MEASURES

Participants provided demographic, clinical, and comorbidity information. Participants then completed the 6-minute walk (6MW), timed 25-foot walk (T25FW), timed Up and Go (TUG), and short physical performance battery (SPPB).

INTERVENTIONS

Not applicable.

RESULTS

The number of comorbid conditions was associated with 6MW, T25FW, TUG, and SPPB scores (all P≤.001). Persons with MS who had hypertension performed worse on the 6MW, T25FW, TUG, and SPPB than persons without hypertension. Persons who had osteoarthritis performed worse on the 6MW, T25FW, and SPPB than persons without osteoarthritis.

CONCLUSIONS

The results demonstrate that persons who report more comorbid conditions have worse physical function, and this may largely be associated with hypertension or osteoarthritis. There are opportunities for the design of behavioral interventions that target physical activity and/or diet for improving physical function via comorbid conditions in persons with MS.

Smartphone-based gait assessment for multiple sclerosis

INTRODUCTION

Multiple Sclerosis causes gait alteration, even in the early stages of the disease. Traditional methods to quantify gait impairment, such as performance-based measures, lab-based motion analyses, and self-report, have limited ecological relevance. The Mon4t® app is a digital tool that uses sensors embedded in standard smartphones to measure various gait parameters.

OBJECTIVES

To evaluate the use of Mon4t® technology in monitoring MS patients.

METHODS

100 MS patients and age-matched healthy controls were evaluated using both a human rater and the Mon4t Clinic™ app. Three motor tasks were performed: 3m Timed up and go test (TUG), 10m TUG, and tandem walk. The digital markers were used to compare MS vs. HC, MS with EDSS=0 vs. HC, and MS with EDSS=0 vs. MS with EDSS>0. Within the MS EDSS>0 group, correlations between digital gait markers and the EDSS score were calculated.

RESULTS

Significant differences were found between MS patients and HC in multiple gait parameters. When comparing MS patients with minimal disability (EDSS=0) and HC: On the 3m TUG task, MS patients took longer to complete the task (mean difference 0.167seconds, p =0.034), took more steps (mean difference 1.32 steps, p =0.003), and had a weaker ML step-to-step correlation (mean difference 0.1, p = 0.001). The combination of features from the three motor tasks allowed distinguishing a nondisabled MS patient from a HC with high confidence (AUC of 85.65 on the ROC). When comparing MS patients with minimal disability (EDSS=0) to those with higher disability (EDSS>0): On the tandem walk task, patients with EDSS>0 took significantly longer to complete 10 steps than those with EDSS=0 (mean difference 4.63 seconds, p < 0.001), showed greater ML sway (mean difference 0.2, p < 0.001), and had larger angular velocity in the SI axis on average (mean difference 2.31 degrees/sec, p = 0.01). A classification model achieved 81.79 ROC AUC. In the subgroup of patients with EDSS>0, gait features significantly correlated with EDSS score in all three tasks.

CONCLUSION

The findings demonstrate the potential of digital gait assessment to augment traditional disease monitoring and support clinical decision making. The Mon4t® app provides a convenient and ecologically relevant tool for monitoring MS patients and detecting early changes in gait impairment.

Oxygen cost of walking and its relationship with body composition in multiple sclerosis

BACKGROUND/OBJECTIVES

This cross-sectional study examined the relationship between the oxygen (O2) cost of walking and body composition metrics, while considering potential covariates such as disability status, step length, and cadence, in persons with multiple sclerosis (MS).

SUBJECTS/METHODS

The sample included 63 persons with MS across a wide distribution of body mass index (BMI). O2 cost of walking was assessed using portable, indirect calorimetry, and percent body fat (%Fat), fat-free mass (FFM), bone mineral content, bone mineral density (BMD), and weight/FFM were determined from dual-energy x-ray absorptiometry. Other outcome measures included step length, cadence, physical activity, and disability status.

RESULTS

The O2 cost of walking had small-to-moderate associations with BMI (rs = -31, p = 0.015), %Fat (rs = -0.26, p = 0.041), and BMD (rs = -0.31, p = 0.013). O2 cost of walking was significantly associated with these outcomes even after controlling for age, sex, disability status, and gait outcomes. The O2 cost of walking was further significantly associated with shorter step length (rs = -0.40, p = 0.001), slower cadence (rs = -0.38, p = 0.002), and higher disability status (rs = 0.44, p < 0.001), but not physical activity. Body composition metrics were not associated with gait parameters, physical activity or disability status in our sample of persons with mild-to-moderate MS.

CONCLUSIONS

The results indicated that higher O2 cost of walking was associated with lower fat and worse bone health after taking factors such as disability status into consideration. Researchers may focus on interventions that change body composition, or perhaps gait profiles, as possible approaches for changing O2 cost of walking and its consequences such as disability status in persons with MS.

No association between body composition and walking outcomes in multiple sclerosis

BACKGROUND

One major concern of excess body weight is diminished physical function. The excess body weight associated with obesity can bring about challenges for physical function, particularly walking performance, among persons living with the consequences of a chronic, neurological disease. There is evidence that persons with multiple sclerosis (MS) have significantly reduced walking performance compared with controls; however, the relationship between body composition and walking outcomes has not been well-defined in persons with MS. To that end, the study examined the associations between body composition metrics and a comprehensive battery of walking outcomes in persons with MS recruited across a wide distribution of body mass index.

METHODS

Ambulatory participants with MS (n=64) underwent an assessment of neurological disability status using the Expanded Disability Status Scale (EDSS) and body composition metrics (i.e., percent body fat, fat mass, lean mass, bone mineral content and density) using dual-energy x-ray absorptiometry. Participants then completed the Timed 25-Foot Walk (T25FW), Timed Up and Go (TUG), 6-Minute Walk (6MW), and 12-Item Multiple Sclerosis Walking Scale (MSWS-12). We examined Spearman rank-order bivariate correlations among percent body fat, fat mass, lean mass, bone mineral content and density, T25FW, TUG, 6MW, MSWS-12, and EDSS.

RESULTS

Body composition metrics were not significantly associated with T25FW (rs=-.11, .12), TUG (rs=-.04, .11), 6MW (rs=-.01, .20), and MSWS-12 (rs=-.16, .03). Of note, body composition metrics were not correlated with disability status based on EDSS (rs=-.11, .03). Body composition metrics were not associated with walking outcomes even after controlling for EDSS.

CONCLUSION

Our data indicated that worse body composition profiles are not necessarily associated with worse walking performance, greater perception of MS-related walking impairment, or more severe disability status in MS. Future research may consider examining other health-related or disease outcomes of overweight or obesity in MS. Overall, our findings suggest that optimization of body composition may not be a target of interventions for improving walking outcomes, and future research might explore other factors that influence lower physical function in MS.

CoachMS, an innovative closed-loop, interdisciplinary platform to monitor and proactively treat MS symptoms: A pilot study

Background

There are numerous challenges to treating co-occurring symptoms in multiple sclerosis (MS).

Objective

To pilot the feasibility of a novel symptom management platform, CoachMS, to monitor MS symptoms (bladder function, ambulation, and mood: BAM) and respond to changes in real-time.

Methods

In this 12-week randomized controlled pilot trial, participants’ symptoms were monitored using weekly questionnaires and remote ambulatory monitoring (Fitbit Flex2®). Behavioral change principles used included shared goal setting at 2 weeks. Between weeks 2-12, the CoachMS group received targeted contact and interventions if symptoms worsened; the control group were treated through usual clinic practice. Our outcomes were feasibility (retention, adherence and acceptability; primary) and proportion of recommended treatments pursued (secondary); efficacy was explored.

Results

Of 21 participants enrolled, 13 (62%) completed the study; protocol adherence was excellent. CoachMS participants demonstrated greater follow-through with clinical recommendations than controls (OR 9.3, 95% CI (0.9, 97.6)). As a cohort, each BAM symptom tended to improve. Suicidality was detected in one control participant, resulting in urgent evaluation and hospitalization.

Conclusions

The innovative CoachMS platform was feasible and acceptable in this cohort with baseline BAM symptoms. It could represent an accessible, cost-effective tool to monitor MS symptoms in real-time; a larger trial is planned.

Cognitive Processing Speed Impairment Does Not Influence the Construct Validity of Six-Spot Step Test Performance in People With Multiple Sclerosis

OBJECTIVE

There is evidence supporting the construct validity of Six-Spot Step Test (SSST) performance as a functional mobility measure in people with multiple sclerosis (MS); however, it is unknown if cognitive processing speed impairment confounds the construct validity of SSST performance in MS, as this test seemingly requires intact cognitive processing. The objective of this study was to examine the influence of cognitive processing speed impairment on the construct validity and precision of SSST performance as a functional mobility measure in MS.

METHODS

Participants (N = 213) completed the SSST, timed 25-foot walk, 6-Minute Walk Test, Timed "Up and Go" Test, Multiple Sclerosis Walking Scale-12, device-measured steps per day, and Late-Life Function and Disability Inventory, Patient-Determined Disease Steps, and the Symbol-Digit Modalities Test as a cognitive processing speed measure. The overall sample was divided into subsamples with (n = 75) and without (n = 138) cognitive processing speed impairment based on normative Symbol-Digit Modalities Test data. Correlations between SSST performance with other mobility outcomes in the overall sample and cognitive processing speed impairment subsamples were examined and compared. SSST performance was compared relative to other mobility measures for differentiating MS walking function levels in people with and without cognitive processing speed impairment.

RESULTS

SSST performance was significantly and strongly correlated with most mobility outcomes in the overall sample and cognitive processing speed impairment subsamples. The magnitudes of correlations between SSST performance with most mobility outcomes were not statistically different among subsamples. Cognitive processing speed impairment did not diminish the relative precision of SSST performance for differentiating walking function levels.

CONCLUSION

The presence of cognitive processing speed impairment is not a source of invalidity or imprecision when interpreting SSST performance as a functional mobility measure among people with MS.

IMPACT

The SSST is a high-quality endpoint for inclusion in interventions targeting mobility in MS, regardless of cognitive processing speed status. This information is critical for rehabilitation research and clinical practice given that mobility and cognitive impairment are highly prevalent, co-occurring, and disabling in MS.

Overground Robotic Program Preserves Gait in Individuals With Multiple Sclerosis and Moderate to Severe Impairments: A Randomized Controlled Trial

OBJECTIVE

To determine how overground robotic (OR) training added to ongoing rehabilitation affects gait speed, lower extremity function, functional mobility, and fatigue in individuals with multiple sclerosis (MS) and moderate to severe gait impairments.

DESIGN

Randomized controlled trial.

SETTING

Outpatient setting at the Multiple Sclerosis Association of Bizkaia, an association serving MS patients in Bizkaia, Spain.

PARTICIPANTS

Individuals with MS (N=36) participated in this interventional study. Inclusion criteria were age of 18 years or older, Expanded Disability Status Scale score between 4.5 and 7, and the need for assistive devices for walking outdoors.

INTERVENTIONS

The control group (CG) engaged in an ongoing rehabilitation program consisting of weekly 1-hour individualized sessions. The intervention group (OR group) also participated in this program in addition to a twice-weekly individualized and progressive OR gait training intervention for 3 months, aiming to reach a maximum of 40 minutes by the end of the 3-month period.

MAIN OUTCOME MEASURES

Primary outcome was the 10-meter walking test (10MWT). Secondary variables included the Short Physical Performance Battery, the timed Up and Go (TUG) test, and the Modified Fatigue Impact Scale.

RESULTS

The OR group maintained 10MWT performance and significantly improved on the TUG test (P=.049, medium effect size) without increasing fatigue perception. The CG demonstrated a decline on the 10MWT (P=.044, small effect size) and reduced fatigue (P=.024, medium effect size). No time per group interaction was observed for any variable.

CONCLUSION

The evaluated intervention could preserve gait speed and significantly improve functional mobility without increasing perceived fatigue in participants. Thus, OR exoskeletons could be considered a tool to deliver intensive practice of good-quality gait training in individuals with MS and moderate to severe gait impairments. Further studies are necessary to confirm these preliminary results.

Neuromuscular and Mobility Responses to a Vibration Session in Hypoxia in Multiple Sclerosis

The aim of this study was to investigate the acute effects of vibration training (WBVT) under hypoxic and normoxic conditions on the voluntary rate of force development (RFD), balance and muscle oxygen saturation (SMO₂) in persons with Multiple Sclerosis (MS). 10 participants completed the study (30% males, 44.4±7.7 years, 164.3±8.9 cm, 65.2±11.1 kg, 2.5±1.3 Expanded Disability Status Scale, 24.1±4.0 kg.m^-2 BMI). Maximal force, RFD during isometric knee extension, static balance with eyes open and closed and sit-to-stand test were evaluated before and immediately after one session of WBVT (12 60-s bout of vibration; frequency 35 Hz; amplitude 4 mm; 1-min rest intervals) under both normoxic and hypoxic conditions. In addition, SMO₂ of the gastrocnemius lateralis was assessed during each condition. No changes were found in force, static balance and sit-to-stand test. Time-to-peak RFD increased in the left leg (p=0.02) and tended to increase in the right leg (p=0.06) after the hypoxic session. SMO₂ resulted in significant increases from the initial to final intervals of the WBVT under both hypoxic and normoxic conditions (p<0.05). Increases in SMO₂ during WBVT demonstrates muscle work that may contribute to the observed muscle adaptations in long-term WBVT programs without inducing decreases in neuromuscular activation, physical function and balance within a session.

Beyond cognitive dysfunction: Relevance of ecological validity of neuropsychological tests in multiple sclerosis

In neurological diseases such as multiple sclerosis (MS), a neuropsychological assessment is often requested to assist clinicians in evaluating the role of cognition in a patient's level of everyday functioning. To be effective in this charge, it is assumed that performance on neuropsychological tests is related to how a person may function in everyday life, and the question is often asked: "Are neuropsychological tests ecologically valid?" In this review, we synthesize the literature that examines the use of neuropsychological tests to assess functioning across a variety of everyday functioning domains in MS (i.e. driving, employment, instrumental activities of daily living (IADLs)). However, we critically examine the usefulness of asking this broad question regarding ecological validity, given the psychometric and conceptual pitfalls it may yield. While many neuropsychological tests may be generally considered "ecologically valid" in MS, it is much more helpful to specify for whom, under what circumstances, and to what degree.

A wearable sensor identifies alterations in community ambulation in multiple sclerosis: contributors to real-world gait quality and physical activity

People with multiple sclerosis (pwMS) often suffer from gait impairments. These changes in gait have been well studied in laboratory and clinical settings. A thorough investigation of gait alterations during community ambulation and their contributing factors, however, is lacking. The aim of the present study was to evaluate community ambulation and physical activity in pwMS and healthy controls and to compare in-lab gait to community ambulation. To this end, 104 subjects were studied: 44 pwMS and 60 healthy controls (whose age was similar to the controls). The subjects wore a tri-axial, lower back accelerometer during usual-walking and dual-task walking in the lab and during community ambulation (1 week) to evaluate the amount, type, and quality of activity. The results showed that during community ambulation, pwMS took fewer steps and walked more slowly, with greater asymmetry, and larger stride-to-stride variability, compared to the healthy controls (p < 0.001). Gait speed during most of community ambulation was significantly lower than the in-lab usual-walking value and similar to the in-lab dual-tasking value. Significant group (pwMS /controls)-by-walking condition (in-lab/community ambulation) interactions were observed (e.g., gait speed). Greater disability was associated with fewer steps and reduced gait speed during community ambulation. In contrast, physical fatigue was correlated with sedentary activity, but was not related to any of the measures of community ambulation gait quality including gait speed. This disparity suggests that more than one mechanism contributes to community ambulation and physical activity in pwMS. Together, these findings demonstrate that during community ambulation, pwMS have marked gait alterations in multiple gait features, reminiscent of dual-task walking measured in the laboratory. Disease-related factors associated with these changes might be targets of rehabilitation.

Physical activity and peak oxygen consumption are associated with walking in multiple sclerosis

INTRODUCTION

Multiple sclerosis (MS) is a chronic inflammatory disease of the central nervous system with a prevalence of nearly 1 million adults in the United States. MS results in declines in physical activity and peak oxygen consumption that might be independently associated with declines in walking performance. Therefore our purpose was to evaluate the association between physical activity and peak oxygen consumption with walking performance in individuals with MS.

METHODS

Fifty individuals with MS between the ages of 18-70 yrs. (Female: 38; 46  ±  12 yrs.; BMI: 28.5  ±  6.4; EDSS: 3.3 [IQR: 2.5-4]) performed a maximal incremental cycle test to assess peak oxygen consumption (VO_2peak), and wore an accelerometer for one week to measure moderate-to-vigorous physical activity (MVPA). Subjects further completed a timed 25-foot walk test (T25FW) and 6-minute walk (6MW) to measure walking performance.

RESULTS

MVPA and VO₂peak were correlated with 6MW and T25FW (p < 0.05). When combined in multivariate regression analyses, VO_2peak and MVPA were both significant contributors of T25FW speed and 6MW, but after controlling for sex and age, MVPA was the only significant contributor (β = 0.32 and β = 0.44, respectively).

CONCLUSION

Both higher MVPA and VO_2peak were associated with better walking performance and in a combined model physical activity, but not peak oxygen consumption, remained an independent contributor to walking performance in individuals with MS. These results suggest that improving MVPA is a potential target for interventions to improve walking performance in persons with MS.

Evaluating functional electrical stimulation (FES) cycling on cardiovascular, musculoskeletal and functional outcomes in adults with multiple sclerosis and mobility impairment: A systematic review

BACKGROUND

People with Multiple Sclerosis (PwMS) are at an increased risk of diseases associated with low levels of physical activity (PA). Deconditioning may lead to an acceleration in the development of secondary complications from MS, impairing physical function and exacerbating disease progression. Functional Electrical Stimulation (FES) Cycling may provide a suitable lower limb exercise intervention for PwMS with mobility impairment. The effects of FES cycling on cardiovascular, musculoskeletal and functional outcomes for PwMS with mobility impairment are yet to be investigated to date.

OBJECTIVE

The objective of this review was to systematically examine the outcomes of PwMS with mobility impairment following FES cycling intervention.

METHODS

A systematic search of four electronic databases (MEDLINE, Web of Science, CINAHL and PEDro) from their inception to 8th January 2019 was performed. Inclusion criteria was (1) include human participants with definite diagnosis of MS (2) participants had to be aged 18 years or older (3) include participants with mobility impairment (determined as an average participant EDSS ≥ 6.0) (4) evaluate FES cycling as an intervention study.

RESULTS

Initial searches found 1163 studies. 9 of which met the full inclusion criteria: 5 pre-post studies with no control group, 2 randomised controlled trials (RCTs), 1 retrospective study and 1 case study. Two studies had the same participant group and intervention but reported different outcomes. Outcome data was available for n = =76 unique participants, with n = =82 completing a FES cycling intervention. Of the n = =4 papers with clear dropout rates, pooled dropout rate was 25.81%. Two papers reported non-significant improvements in aerobic capacity following a FES cycling intervention. Four papers reported no change in lower limb strength and two papers reported significant reductions in spasticity post training. Four studies failed to provide information regarding adverse events with the other studies reporting n = =10 adverse events across 36 participants.

CONCLUSION

Findings suggest FES cycle training may reduce CVD risk alongside trends for a reduction in spasticity post training, however the low quality of the literature precludes any definitive conclusions. FES cycle training appears to be well tolerated in PwMS with mobility impairment, with no serious adverse events.

Self-efficacy and walking performance across the lifespan among adults with multiple sclerosis

Aim: We examined associations between self-efficacy and walking mobility across the lifespan in multiple sclerosis (MS). Methods: This study included 39 young, 44 middle-aged and 41 older adults with MS who completed the Six-Minute Walk (6MW), Timed 25-foot Walk (T25FW), MS Walking Scale-12 (MSWS-12) and MS Self-efficacy Scale. Results: Self-efficacy for function explained 45 and 48% of variance in MSWS-12 scores for young and older adults with MS, respectively; 13, 29 and 23% of variance in T25FW for young, middle-aged and older adults, respectively; and 28, 31 and 28% of variance in 6MW for young, middle-aged and older adults with MS, respectively. Conclusion: This study highlights self-efficacy as a target of in-walking mobility interventions across the lifespan in MS.

Brain Activation Changes During Balance- and Attention-Demanding Tasks in Middle- and Older-Aged Adults With Multiple Sclerosis

Functional near-infrared spectroscopy was used to evaluate prefrontal cortex activation differences between older adults with multiple sclerosis (MS) and healthy older adults (HOA) during the performance of a balance- and attention-demanding motor task. Ten older adults with MS and 12 HOA underwent functional near-infrared spectroscopy recording while talking, virtual beam walking, or virtual beam walking while talking on a self-paced treadmill. The MS group demonstrated smaller increases in prefrontal cortex oxygenation levels than HOA during virtual beam walking while talking than talking tasks. These findings indicate a decreased ability to allocate additional attentional resources in challenging walking conditions among MS compared with HOA. This study is the first to investigate brain activation dynamics during the performance of balance- and attention-demanding motor tasks in persons with MS.

Deterioration of specific aspects of gait during the instrumented 6-min walk test among people with multiple sclerosis

Prolonged walking is typically impaired among people with multiple sclerosis (pwMS), however, it is unclear what the contributing factors are or how to evaluate this deterioration. We aimed to determine which gait features become worse during sustained walking and to examine the clinical correlates of gait fatigability in pwMS. Fifty-eight pwMS performed the 6-min walk test while wearing body-fixed sensors. Multiple gait domains (e.g., pace, rhythm, variability, asymmetry and complexity) were compared across each minute of the test and between mild- and moderate-disability patient groups. Associations between the decline in gait performance (i.e., gait fatigability) and patient-reported gait disability, fatigue and falls were also determined. Cadence, stride time variability, stride regularity, step regularity and gait complexity significantly deteriorated during the test. In contrast, somewhat surprisingly, gait speed and swing time asymmetry did not change. As expected, subjects with moderate disability (n = 24) walked more poorly in most gait domains compared to the mild-disability group (n = 34). Interestingly, a group × fatigue interaction effect was observed for cadence and gait complexity; these measures decreased over time in the moderate-disability group, but not in the mild group. Gait fatigability rate was significantly correlated with physical fatigue, gait disability, and fall history. These findings suggest that sustained walking affects specific aspects of gait, which can be used as markers for fatigability in MS. This effect on gait depends on the degree of disability, and may increase fall risk in pwMS. To more fully understand and monitor correlates that reflect everyday walking in pwMS, multiple domains of gait should be quantified.

Rationale and design of the STEP for MS Trial: Comparative effectiveness of Supervised versus Telerehabilitation Exercise Programs for Multiple Sclerosis

BACKGROUND

We propose a Phase III trial that compares the effectiveness of an exercise training program delivered in a facility-based setting with direct, in-person supervision or a home-based setting with remote supervision via telerehabilitation for improving walking performance in persons with multiple sclerosis(MS) who have walking dysfunction and mobility disability.

METHODS/DESIGN

The study was developed with stakeholder engagement and is a multi-site trial that follows a 2-stage, randomized choice design. The trial compares the effectiveness of a 16-week evidence-based, individualized exercise program delivered in a supervised, facility-based setting versus a remotely coached/guided, home-based setting using telerehabilitation in physically inactive and cognitively intact people with MS who have walking dysfunction and mobility disability(N = 500). The primary outcome is walking speed. The secondary outcomes are walking endurance, disability status, and patient-reported outcomes of physical activity, walking impairment, fatigue, and quality of life. The components of the exercise program itself are similar between the groups and follow the Guidelines for Exercise in MS protocol. This includes a program manual, exercise prescription, exercise equipment, social-cognitive theory materials including newsletters, logs, and calendars, and one-on-one behavioral coaching by exercise specialists with background in MS. The main difference between groups is the coaching approach and setting for delivering the exercise training program. The outcomes will be collected by treatment-blinded assessors at baseline(week 0), mid-intervention(week 8), post-intervention(week 16), and follow-up(week 52).

DISCUSSION

The proposed study will provide evidence for the effectiveness of a novel, widely-scalable program for delivering exercise training in persons with MS who have walking dysfunction and mobility disability.

Gait tests in multiple sclerosis: Reliability and cut-off values

BACKGROUND

Gait limitation is one of the most common disabilities in people with multiple sclerosis (MS). Several studies have used gait parameters to determine the effects of different therapies. However, few studies have determined their reproducibility, also the therapeutic effects could be overestimated.

RESEARCH QUESTION

To examine the reproducibility in gait measurements during short and long distances.

METHODS

In this cross-sectional study we recruited a group of MS patients and compare it to a control group. The participants performed the following tests in a fixed order: a 25-foot walk at a comfortable speed, at a fast speed and during a dual task, a timed up-and-go test (TUG) and a six- minute walk test (6MWT). Two measurements were conducted a week apart. Systematic error was evaluated by the Student t-test, reliability by the intra-class correlation coefficients (ICC) and agreement by the minimum detectable change (MDC₉₅).

RESULTS

A total of 58 people with MS and 19 healthy people were included. The absence of systematic error was only found for the fast speed condition. The reliability of the gait parameters had moderate to high ICC values (ICC > 0.7) except for the dual task cost (DTC) which was 0.45. The MDC₉₅ was higher in people with MS compared to healthy people, and it was higher in people with MS for gait speeds in all conditions (> 34%). For the TUG and 6MWT, the MDC₉₅ were 51.5% and 31.7% respectively. For people with MS the smallest MDC₉₅ was found for the stance time for all conditions (6.8%), whereas the highest was found for the dual task cost (158.7%).

SIGNIFICANCE

The MDC₉₅ values were higher than the cut-off point based on the minimally important clinical difference (MICD) proposed in previous studies. Thus, the MDC₉₅ should be used as a cut-off rather than MICD values.

Effects of moderate- versus high- intensity swimming training on inflammatory and CD4+ T cell subset profiles in experimental autoimmune encephalomyelitis mice

Multiple sclerosis (MS) is an inflammatory neurodegenerative disease of the central nervous system (CNS). Evidence about experimental autoimmune encephalomyelitis (EAE), a mouse model of MS, has been shown to modulate disease parameters within exercise intervention. However, these initial studies weren't carried out intensity of exercise in mice. This study explored the impacts of different-intensity swimming training on EAE mice. Female mice were given access to swimming with predetermined weight (moderated-intensity (ME) group is 0% body weight; high-intensity (HE) group is 4% body weight) for 6 weeks, were immunized to induce EAE and then continued swimming until sacrificed. Compared to non-exercise mice, ME training didn't affect EAE clinical symptoms and neuropathology. However, HE swimming attenuated EAE clinical scores, reduced infiltrating cells and demyelination of spinal cords. Analysis of CD4⁺ T cell subsets from CNS of EAE showed the reduction of Th1 and Th17 populations and an increase of Treg in HE, not ME mice. Accordingly, HE training lead to a decrease of IFN-γ and IL-17 and an increase of IL-10 and TGF-β. Of note, HE, not ME, swimming induced an increase of brain derived neurotrophic factor in the CNS of EAE. Moreover, HE training upregulated Treg and downregualted antigen-specific T cell proliferation and Th1 and Th17 populations from draining lymph node cells. These results suggest that HE swimming training might have benefits on attenuating the progression and pathological hallmarks of EAE, thus representing an important non-pharmacological intervention for improvement of chronic inflammation or T-cell mediated autoimmunity.

Perspectives on walking from people with multiple sclerosis and reactions to video self-observation

Purpose: People with multiple sclerosis (MS) rank walking among the most challenging aspects of their condition. A greater understanding of people's perspectives concerning their walking may help to prioritize walking outcomes and strategies for optimizing walking. The purpose was to explore perceptions of walking in people with MS and to describe their reactions after observing themselves walk on video.Materials and methods: An interpretive thematic analysis study using face-to-face, semi-structured interviews was conducted with 14 people who self-identified a change in their walking due to MS. Participants were video-recorded walking and watched their video during the interview.Results: Four themes were identified: "awareness," "acceptance," "constant change," and "increased effort." People with MS develop awareness of how their walking performance looks and awareness of constantly-changing internal factors and external factors which impact their walking. Awareness of change in fatigue, temperature, terrain, and the use of aids in particular are perceived relevant to walking and to impact the effort required to walk. People with MS also describe differences in their acceptance of how others view their walking and the changes related to walking. An analogy with a marionette performing describes how people perceive walking as no longer automatic; instead walking requires the person to consciously pull the strings to walk. An increase in both the physical and cognitive effort is required to walk and an awareness and acceptance of a variety of changes in oneself and the lived world may help or hinder walking. People with MS are willing to watch themselves walk on video and are not surprised by what they observe.Conclusions: People with MS develop a learned self-awareness with variable levels of acceptance about their walking function and what it looks like. The perceptions on walking from persons with MS suggest that focusing on reducing the effort to walk and minimizing the constantly-changing variables may help to optimize walking.Implications for rehabilitationPeople with multiple sclerosis are challenged by the increased effort and constant change required to walk in their day-to-day lives.A focus on minimizing both the effort to walk and the changing variables (i.e., fluctuating symptoms and environmental factors) is warranted.People with multiple sclerosis develop a learned awareness of how they walk and how their walking looks.Acceptance of loss of walking function is variable.Video self-observation is a feasible tool which warrants further exploration for enhancing acceptance of walking function and accommodating strategies.

Naturally occurring change in Multiple Sclerosis Walking Scale-12 scores over time in multiple sclerosis

AIM

This study examined the trajectory and pattern of naturally occurring change in perceived walking impairment over a 30-month period in relapsing-remitting multiple sclerosis (RRMS).

PATIENTS & METHODS

Two hundred and sixty-nine persons with RRMS completed the 12-item Multiple Sclerosis Walking Scale (MSWS-12) every 6 months over a 30-month period. Data were analyzed using latent growth curve modeling and latent class growth curve modeling.

RESULTS

Latent growth curve modeling demonstrated that a linear trajectory adequately described the group-level pattern of change in MSWS-12 scores over time. Latent class growth curve modeling supported a three-class model for describing the heterogeneity of changes in MSWS-12 scores over time.

CONCLUSION

Walking impairment does change over time in RRMS, and this can be described by three patterns of change trajectories that differed based on initial status of walking impairment.

Cognitive-motor interference during gait in patients with Multiple Sclerosis: a mixed methods Systematic Review

BACKGROUND

Cognitive-motor interference (CMI) has been proposed as a valid marker of daily life impairment in Multiple Sclerosis (MS). The heterogeneity and scarce number of studies regarding CMI in MS has hampered the synthesis of the existing evidence. The present systematic review employed a mixed methods approach with the aim of identifying and describing variables under which CMI is particularly useful to assess patients with MS.

RESULTS

MS patients showed significant CMI. The motor variables that were most sensitive in detecting significant CMI were velocity (m/s), cadence (steps/min), and double support (% gait cycle), which was also specific for MS. Among the cognitive tasks, Alternate Alphabet and Serial Subtracting 7 s were sensitive, whereas Verbal Fluency were both sensitive and specific to CMI in MS.

CONCLUSIONS

CMI should be assessed in MS with a standardised dual task such as the Verbal Fluency task while walking, with measurements of the double support time and the effect on the cognitive task. The clinical usefulness of CMI in the assessment of patients with MS is discussed.

Tasks of activities of daily living (ADL) are more valuable than the classical neurological examination to assess upper extremity function and mobility in multiple sclerosis

BACKGROUND

Accurate clinical assessment in multiple sclerosis (MS) is challenging. The Assess MS system is being developed to automatically quantify motor dysfunction in MS, including upper extremity function (UEF) and mobility.

OBJECTIVE

To determine to what extent combinations of standardized movements included in the Assess MS system explain accepted measures of UEF and mobility.

METHODS

MS patients were recruited at four European MS centres. Eight movements were selected, including tasks of activities of daily living (ADL) and classical neurological tests. Movements were recorded on video and rated by experienced neurologists (n = 5). Subsequently, multivariate linear regression models were performed to explain the variance of the Nine-Hole Peg Test (9HPT), Arm Function in Multiple Sclerosis Questionnaire (AMSQ) and Timed-25 Foot Walk test (T25WT).

RESULTS

In total, 257 patients were included. The movements explained 62.9% to 80.1% of the variance of the 9HPT models, 43.3% and 44.3% of the AMSQ models and 70.8% of the T25WT. In all models, tasks of ADL contributed most to the variance.

CONCLUSION

Combinations of movements are valuable to assess UEF and mobility. Incorporating ADL tasks into daily clinical practice and clinical trials may be more valuable than the classical neurological examination of UEF and mobility.

Pioglitazone is superior to quetiapine, clozapine and tamoxifen at alleviating experimental autoimmune encephalomyelitis in mice

Recent evidence suggests that clozapine and quetiapine (atypical antipsychotics), tamoxifen (selective-estrogen receptor modulator) and pioglitazone (PPARγ agonist) may improve functional recovery in multiple sclerosis (MS). We have compared the effectiveness of oral administration of these drugs, beginning at peak disease, at reducing ascending paralysis, motor deficits and demyelination in mice subjected to experimental autoimmune encephalomyelitis (EAE). Mice were immunized with an immunogenic peptide corresponding to amino acids 35-55 of the myelin oligodendrocyte glycoprotein (MOG_35-55) in complete Freund's adjuvant and injected with pertussis toxin to induce EAE. Unlike clozapine, quetiapine and tamoxifen, administration of pioglitazone beginning at peak disease decreased both clinical scores and lumbar white matter loss in EAE mice. Using kinematic gait analysis, we found that pioglitazone also maintained normal movement of the hip, knee and ankle joints for at least 44 days after MOG_35-55 immunization. This long-lasting preservation of hindleg joint movements was accompanied by reduced white matter loss, microglial and macrophage activation and the expression of pro-inflammatory genes in the lumbar spinal cords of EAE mice. These results support clinical findings that suggest pioglitazone may reduce the progressive loss of motor function in MS by decreasing inflammation and myelin damage.

Therapies for mobility disability in persons with multiple sclerosis

INTRODUCTION

Mobility disability is one of the most widespread and impactful consequences of multiple sclerosis (MS). Disease modifying drugs (DMDs) may delay the progression of disability over time; however, there is minimal evidence supporting the efficacy of DMDs for reversing mobility disability or restoring ambulatory function in persons with MS. Areas covered: This review outlines symptomatic pharmacologic and non-pharmacologic therapeutic approaches that target mobility disability with the goal of restoring and improving walking function. First, the efficacy of dalfampridine, currently the only Food and Drug Administration approved symptomatic pharmacologic agent that improves walking in persons with MS is described. Next, a review of the efficacy of non-pharmacologic therapies for improving walking, including exercise training, physical therapy, and gait training is given. Last, guidance on future research on mobility in MS is provided by emphasizing the importance of combinatory treatment approaches that include multiple intervention modalities, as the best treatment plan likely involves a comprehensive, multidisciplinary approach. Expert commentary: There has been an increased effort to develop symptom-specific treatments in MS that directly target mobility disability; however, more research is needed to determine the efficacy of these rehabilitative strategies alone and together for improving walking in persons with MS.

Free-living and laboratory gait characteristics in patients with multiple sclerosis

Background

Wearable sensors offer the potential to bring new knowledge to inform interventions in patients affected by multiple sclerosis (MS) by thoroughly quantifying gait characteristics and gait deficits from prolonged daily living measurements. The aim of this study was to characterise gait in both laboratory and daily life conditions for a group of patients with moderate to severe ambulatory impairment due to MS. To this purpose, algorithms to detect and characterise gait from wearable inertial sensors data were also validated.

Methods

Fourteen patients with MS were divided into two groups according to their disability level (EDSS 6.5–6.0 and EDSS 5.5–5.0, respectively). They performed both intermittent and continuous walking bouts (WBs) in a gait laboratory wearing waist and shank mounted inertial sensors. An algorithm (W-CWT) to estimate gait events and temporal parameters (mean and variability values) using data recorded from the waist mounted sensor (Dynaport, Mc Roberts) was tested against a reference algorithm (S-REF) based on the shank-worn sensors (OPAL, APDM). Subsequently, the accuracy of another algorithm (W-PAM) to detect and classify WBs was also tested. The validated algorithms were then used to quantify gait characteristics during short (sWB, 5–50 steps), intermediate (iWB, 51–100 steps) and long (lWB, >100 steps) daily living WBs and laboratory walking. Group means were compared using a two-way ANOVA.

Results

W-CWT compared to S-REF showed good gait event accuracy (0.05–0.10 s absolute error) and was not influenced by disability level. It slightly overestimated stride time in intermittent walking (0.012 s) and overestimated highly variability of temporal parameters in both intermittent (17.5%–58.2%) and continuous walking (11.2%–76.7%). The accuracy of W-PAM was speed-dependent and decreased with increasing disability. The ANOVA analysis showed that patients walked at a slower pace in daily living than in the laboratory. In daily living gait, all mean temporal parameters decreased as the WB duration increased. In the sWB, the patients with a lower disability score showed, on average, lower values of the temporal parameters. Variability decreased as the WB duration increased.

Conclusions

This study validated a method to quantify walking in real life in people with MS and showed how gait characteristics estimated from short walking bouts during daily living may be the most informative to quantify level of disability and effects of interventions in patients moderately affected by MS. The study provides a robust approach for the quantification of recognised clinically relevant outcomes and an innovative perspective in the study of real life walking.

Role of Demographic and Clinical Factors in Cognitive Functioning of Persons with Relapsing-Remitting and Progressive Multiple Sclerosis

BACKGROUND

Age and time post-diagnosis can significantly impact cognitive and motor functions in multiple sclerosis (MS); however, studies often fail to account for these factors when assessing differences between disease courses.

OBJECTIVES

Examine differences between relapsing-remitting and progressive MS in cognition, motor function, and everyday activities, controlling for age, education, and time post-diagnosis.

METHODS

Twenty-one persons with relapsing-remitting MS (RRMS group), 21 with progressive MS (PMS group), and 21 healthy participants (HCs), matched on age, education, and time post-diagnosis, completed tests of cognitive abilities, motor functions, and everyday functional activities.

RESULTS

The two groups with MS did not differ on cognitive performance. Poorer performance in processing speed was noted in both MS groups in comparison with the HC group. Motor function was worse for the PMS group compared with the HC and RRMS groups. The RRMS group showed poorer upper limb functioning compared to the HC group. The PMS group had more difficulty with everyday activities as compared with both the RRMS and HC group.

CONCLUSIONS

When comparing differences in functioning between MS disease courses, attention should be paid to the demographic characteristics of the samples. (JINS, 2018, 24, 139-146).

Randomised controlled pilot trial of an exercise plus behaviour change intervention in people with multiple sclerosis: the Step it Up study

OBJECTIVE

To investigate feasibility of multiple sclerosis (MS) exercise guidelines for inactive people with MS (PwMS) and to examine preliminary efficacy for walking. To investigate effect of augmenting that intervention with education based on social cognitive theory (SCT).

DESIGN

Pilot multicentre, double-blind, randomised, parallel, controlled trial.

SETTING

Community-delivered programme.

PARTICIPANTS

Sixty-five physically inactive PwMS walked independently, scored 0-3 on the Patient Determined Disease Steps Scale, had no MS relapse or change in MS medication in 12 weeks.

INTERVENTIONS

10-week exercise plus SCT education (SCT) compared with exercise plus attention control education (CON).

OUTCOME MEASURES

Six-Minute Walk Test (6MWT), Timed Up and Go (TUG) test and Multiple Sclerosis Walking Scale-12 (MSWS-12).

RESULTS

174 expressed interest, 92 were eligible and 65 enrolled (SCT, n=32; CON, n=33). The intervention was feasible and delivered as intended. 68% of SCT group and 50% of control group met the exercise guidelines after intervention. Using linear mixed effects models, intention-to-treat basis, there was insufficient evidence for difference between the groups over the trial (6MWT, p=0.30; TUG, p=0.4; MSWS-12, p=0.8). Using secondary analysis of a cohort with data for≥3 assessments (SCT, n=21; CON, n=20), there was significant treatment effect favouring the intervention group (p=0.04) with mean effect for 6MWT 39.0 m (95% CI 2.26 to 75.73) at 12 weeks and 40.0 m (95% CI 2.3 to 77.8) at 36 weeks. Both groups improved significantly in 6MWT following 10-week intervention (SCT, mean ∆=83.02, SD=60.1, p≤0.01; CON, mean ∆=56.92, SD=73.5, p≤0.01), TUG (SCT, ∆=-0.70, SD=1.25, p≤0.01; CON, ∆=-0.54, SD=0.95, p≤0.01) and MSWS-12 (SCT, ∆=-8.03, SD=16.18, p=0.02; CON, ∆=-0.86, SD=18.74, p=0.81).

CONCLUSIONS

A 10-week exercise programme based on the MS exercise guidelines for improving walking in previously inactive PwMS was feasible. There is marginal evidence of a treatment effect in favour of the exercise plus SCT intervention at 12 and 36 weeks.

TRIAL REGISTRATION NUMBER

NCT02301442; Results.

Do gait patterns differ in men and women with multiple sclerosis?

BACKGROUND

Multiple Sclerosis (MS) affects men and women differently from several points of view: prevalence, severity of cognitive impairments and disability accumulation. However, it is unknown whether ambulatory dysfunctions are sex-related. This study investigated the existence of differences in spatio-temporal and kinematic parameters of gait in men and women with MS using 3D gait analysis.

METHODS

Gait patterns of 60 people with MS (pwMS, 32F, 28M) with low to moderate disability (average Expanded Disability Status Scale score 3, range 1-5.5) who underwent a gait analysis in the period 2014-2017 were retrospectively analyzed to calculate spatio-temporal parameters of gait and kinematics in the sagittal plane at hip, knee and ankle joints.

RESULTS

Significant differences between the groups were found in kinematics of gait. In particular, men exhibited reduced ankle plantar-flexion, increased knee flexion and hip flexion. In contrast, no differences were found in spatio-temporal parameters normalized by considering individuals' anthropometry.

CONCLUSIONS

The findings of the present study highlight the need to investigate gait dysfunctions in pwMS taking sex into consideration. Such an approach might be useful not only in better understanding the pathophysiology of gait disturbances originated by MS, but also in supporting a better orientation of rehabilitative treatments.

The walking speed reserve in low disabled people with multiple sclerosis: Does it provide greater insight in detecting mobility deficits and risk of falling than preferred and fast walking speeds?

The extent of an increase from a preferred walking speed (PWS) to a fast walking speed (FWS) is defined as the walking speed reserve (WSR). The WSR is unique as it reflects an individual's ability to increase their walking speed on demand. The primary objective of this study was to examine whether the WSR was more advantageous than the PWS and FWS in terms of reflecting mobility deficits and risk of falling associated with multiple sclerosis (MS). The patient group included 235 people with MS (PwMS) (139 women) with a mean age of 43.6 (SD = 13.6) years. The WSR, PWS and FWS (m/s) were: 0.47 (SD = 0.29), 0.98 (SD = 0.28) and 1.45 (SD = 0.47), respectively. Significant correlation scores were found between the WSR and all clinical walking and balance outcome measures; Pearson's rho ranged from 0.240 to 0.517. However, stronger correlation scores were found between the PWS, FWS and all clinical walking and balance outcome measures with the Pearson's rho ranging from 0.415 to 0.797. In terms of fall status, non-significant differences were observed between the fallers (n = 133) and non-fallers' (n = 102) groups with respect to the WSR scores. We found that the PWS and FWS were more instructive measures for assessing mobility deficits and fall status in PwMS than the WSR. Nevertheless, we do not rule out the possibility that the WSR score may be a preferred predictor of other adverse events related to MS, such as lower limb muscle weakness, spasticity and aerobic capacity.

Self-efficacy and Walking Performance in Persons With Multiple Sclerosis

BACKGROUND AND PURPOSE

Impairment of walking function is a prevalent and burdensome feature of multiple sclerosis (MS), and represents a primary focus of rehabilitation research and clinical care. Research examining self-efficacy as a correlate of walking performance in MS is lacking; self-efficacy represents a theory-based, modifiable target of rehabilitation approaches for improving walking outcomes. This cross-sectional study examined the association between self-efficacy and walking performance in persons living with MS.

METHODS

The sample included 69 persons with MS who completed the Multiple Sclerosis Self-Efficacy (MSSE) Scale and Exercise Self-Efficacy (EXSE) Scale and undertook the Timed 25-Foot Walk (T25FW) and the 6-Minute Walk (6MW) tests. The data were analyzed using the Pearson product moment correlation coefficients and linear regression.

RESULTS

Correlation analysis indicated that function subscale scores on the MSSE correlated more strongly with T25FW (r = 0.55) than did the control subscale (r = 0.40) and EXSE (r = 0.38) scores, and both function (r = 0.67) and control (r = 0.53) subscale scores on the MSSE correlated more strongly with 6MW than did EXSE scores (r = 0.40). Linear regression analyses indicated that (1) function MSSE subscale, but not control subscale, explained significant variance in T25FW speed and 6MW distance and (2) function MSSE subscale, but not EXSE, explained significant variance in T25FW speed and 6MW distance.

DISCUSSION AND CONCLUSIONS

We provide the first evidence of an association between self-efficacy, particularly for functioning with MS, and objective walking performance in MS. Future research to replicate and extend these results can inform rehabilitation efforts that target improvement of walking performance in persons with MS.Digital Abstract available for more insights from the authors (see Slides, Supplemental Digital Content 1, http://links.lww.com/JNPT/A171).

A machine learning approach for gait speed estimation using skin-mounted wearable sensors: From healthy controls to individuals with multiple sclerosis

Gait speed is a powerful clinical marker for mobility impairment in patients suffering from neurological disorders. However, assessment of gait speed in coordination with delivery of comprehensive care is usually constrained to clinical environments and is often limited due to mounting demands on the availability of trained clinical staff. These limitations in assessment design could give rise to poor ecological validity and limited ability to tailor interventions to individual patients. Recent advances in wearable sensor technologies have fostered the development of new methods for monitoring parameters that characterize mobility impairment, such as gait speed, outside the clinic, and therefore address many of the limitations associated with clinical assessments. However, these methods are often validated using normal gait patterns; and extending their utility to subjects with gait impairments continues to be a challenge. In this paper, we present a machine learning method for estimating gait speed using a configurable array of skin-mounted, conformal accelerometers. We establish the accuracy of this technique on treadmill walking data from subjects with normal gait patterns and subjects with multiple sclerosis-induced gait impairments. For subjects with normal gait, the best performing model systematically overestimates speed by only 0.01 m/s, detects changes in speed to within less than 1%, and achieves a root-mean-square-error of 0.12 m/s. Extending these models trained on normal gait to subjects with gait impairments yields only minor changes in model performance. For example, for subjects with gait impairments, the best performing model systematically overestimates speed by 0.01 m/s, quantifies changes in speed to within 1%, and achieves a root-mean-square-error of 0.14 m/s. Additional analyses demonstrate that there is no correlation between gait speed estimation error and impairment severity, and that the estimated speeds maintain the clinical significance of ground truth speed in this population. These results support the use of wearable accelerometer arrays for estimating walking speed in normal subjects and their extension to MS patient cohorts with gait impairment.

Unplanned gait termination in individuals with multiple sclerosis

Despite the pervasive nature of gait impairment in multiple sclerosis (MS), there is limited information concerning the control of gait termination in individuals with MS. The purpose of this investigation was to examine unplanned gait termination with and without cognitive distractors in individuals with MS compared to healthy controls. Thirty-one individuals with MS and 14 healthy controls completed a series of unplanned gait termination tasks over a pressure sensitive walkway under distracting and non-distracting conditions. Individuals with MS were further broken down into groups based on assistive device use: (no assistive device (MS_noAD) n=18; and assistive device (MS_AD) n=13). Individuals with MS who walked with an assistive device (MS_AD: 67.8±15.1cm/s) walked slower than individuals without an assistive device (MS_noAD: 110.4±32.3cm/s, p<0.01) and controls (120.0±30.0cm/s; p<0.01). There was a significant reduction in velocity in the cognitively distracting condition (93.4±32.1cm/s) compared to the normal condition [108.8±36.2cm/s; F(1,43)=3.4, p=0.04]. All participants took longer to stop during the distracting condition (1.7±0.6s) than the non-distracting condition (1.4±0.4s; U=673.0 p<0.01). After controlling for gait velocity, post-hoc analysis revealed the MS_AD group took significantly longer to stop compared to the control group (p=0.05). Further research investigating the control of unplanned gait termination in MS is warranted.

Validity of the timed 25-foot walk as an ambulatory performance outcome measure for multiple sclerosis

The Multiple Sclerosis Outcome Assessments Consortium (MSOAC) includes representatives from advocacy organizations, Food and Drug Administration (FDA), European Medicines Agency (EMA), National Institute of Neurological Disorders and Stroke (NINDS), academic institutions, and industry partners along with persons living with multiple sclerosis (MS). One of the MSOAC goals is acceptance and qualification by regulators of performance outcomes that are highly reliable and valid, practical, cost-effective, and meaningful in MS. This article addresses the history, application, and psychometric properties of one such MSOAC metric of ambulation or walking namely, the timed 25-foot walk (T25FW). The T25FW has strong reliability over both brief and long periods of time in MS across a large range of disability levels. The outcome of walking speed from the T25FW has obvious real-world relevance and has correlated strongly with other measures of walking and lower extremity function. The T25FW is responsive for capturing intervention effects in pharmacological and rehabilitation trials and has an established value for capturing clinically meaningful change in ambulation. Directions for future research involve validating clinically meaningful improvements on the T25FW as well as determining whether 20% change is clinically meaningful across the disability spectrum. Researchers might further consider synchronizing accelerometers and motion sensors with the T25FW for capturing walking speed in everyday life and the patient's real environment.

Monitoring gait in multiple sclerosis with novel wearable motion sensors

BACKGROUND

Mobility impairment is common in people with multiple sclerosis (PwMS) and there is a need to assess mobility in remote settings. Here, we apply a novel wireless, skin-mounted, and conformal inertial sensor (BioStampRC, MC10 Inc.) to examine gait characteristics of PwMS under controlled conditions. We determine the accuracy and precision of BioStampRC in measuring gait kinematics by comparing to contemporary research-grade measurement devices.

METHODS

A total of 45 PwMS, who presented with diverse walking impairment (Mild MS = 15, Moderate MS = 15, Severe MS = 15), and 15 healthy control subjects participated in the study. Participants completed a series of clinical walking tests. During the tests participants were instrumented with BioStampRC and MTx (Xsens, Inc.) sensors on their shanks, as well as an activity monitor GT3X (Actigraph, Inc.) on their non-dominant hip. Shank angular velocity was simultaneously measured with the inertial sensors. Step number and temporal gait parameters were calculated from the data recorded by each sensor. Visual inspection and the MTx served as the reference standards for computing the step number and temporal parameters, respectively. Accuracy (error) and precision (variance of error) was assessed based on absolute and relative metrics. Temporal parameters were compared across groups using ANOVA.

RESULTS

Mean accuracy±precision for the BioStampRC was 2±2 steps error for step number, 6±9ms error for stride time and 6±7ms error for step time (0.6-2.6% relative error). Swing time had the least accuracy±precision (25±19ms error, 5±4% relative error) among the parameters. GT3X had the least accuracy±precision (8±14% relative error) in step number estimate among the devices. Both MTx and BioStampRC detected significantly distinct gait characteristics between PwMS with different disability levels (p<0.01).

CONCLUSION

BioStampRC sensors accurately and precisely measure gait parameters in PwMS across diverse walking impairment levels and detected differences in gait characteristics by disability level in PwMS. This technology has the potential to provide granular monitoring of gait both inside and outside the clinic.

Outcomes of Bariatric Surgery in Morbidly Obese Patients with Multiple Sclerosis

Obesity is common in patients with multiple sclerosis (MS); however, safety and efficacy of bariatric surgery in this population remain unclear. A database of 2,918 was retrospectively reviewed, yielding 22 (0.75%) severely obese patients with MS who underwent bariatric surgery. Sixteen surgical patients with complete follow-up data were matched to a nonsurgical control group of MS patients, based on age, BMI, MS subtype, and length of follow-up. MS relapse rates and trends in the timed twenty-five foot walk test (T25FW) were compared. In the surgical group (gastric bypass n = 19, sleeve gastrectomy n = 3), preoperative BMI was 46.5 ± 7.2 Kg/m² and average excess weight was 60.4 kg. Follow-up data was collected at 59.0 ± 29.8 months. There were two major and four minor complications. Five patients required readmission and there were no mortalities. Percent excess weight loss was 75.5 ± 27.0%. In the 16 patients with follow-up data, patients who underwent bariatric surgery were significantly faster on the T25FW compared to the nonsurgical population. In conclusion, bariatric surgery is relatively safe and effective in achieving weight loss in patients with MS. In addition, surgery may help patients maintain ambulation. Findings support the need for further studies on bariatric surgery and disease-specific outcomes in this population.

Cognitive Motor Interference in Multiple Sclerosis: Insights From a Systematic Quantitative Review

OBJECTIVE

To synthesize the evidence for differences in cognitive motor interference (CMI) between persons with multiple sclerosis (MS) and those without MS by using systematic review and meta-analysis.

DATA SOURCES

EMBASE, PubMed, ScienceDirect, Scopus, SPORTDiscus, and Web of Science. Our focused literature search was informed by past systematic reviews of CMI during walking in MS.

STUDY SELECTION

The key terms searched included Multiple sclerosis and synonyms of motor function (eg, Gait disorders, Gait, Walking, Balance, or Fall) and motor and cognitive functions (eg, Cognitive motor interference or Thinking).

DATA EXTRACTION

From the 116 abstract-identified articles, 13 experimental studies were selected for the final analysis and were rated using the Quality Assessment of Diagnostic Accuracy Studies tool. A meta-analysis was performed for all considered outcomes.

DATA SYNTHESIS

The results yielded a small overall effect size (ES) of .08 (SE=.17; 95% confidence interval, -.25 to .40; z=.49; P>.05), which indicated a nonsignificant minimal difference in CMI between persons with MS and those without MS. The moderator analysis for motor task (mobility task: ES, .22; postural task: ES, -.11) was not significantly different between persons with MS and those without MS. The moderator analysis for cognitive task (verbal fluency task: ES, .66; mental tracking task: ES, .04; discrimination and decision-making task: ES, -.30) resulted in a significant difference in CMI between persons with MS and those without MS (P<.05).

CONCLUSIONS

We provide evidence that overall there is a minimal difference in CMI between persons with MS and those without MS.

Rationale and design of a randomized controlled clinical trial of functional electrical stimulation cycling in persons with severe multiple sclerosis

BACKGROUND

This randomized controlled trial (RCT) will examine the efficacy of supervised functional electrical stimulation (FES) cycling on walking performance and physiological function among persons with multiple sclerosis (MS) with severe mobility disability.

METHODS/DESIGN

This RCT will recruit 16 persons with MS that require unilateral or bilateral assistance for ambulation (i.e., Expanded Disability Status Scale (EDSS) score = 6.0-6.5). Participants will be randomized to one of two conditions: supervised FES cycling or passive cycling. The FES cycling condition will involve mild electrical stimulation that will generate an activation pattern that results in cycling the leg ergometer. The passive cycling condition will not provide any electrical stimulation, rather the movement of the pedals will be controlled by the electrical motor. Both conditions will be delivered 3 days/week for the same duration, over 6 months. Primary outcomes will include walking performance assessed as walking speed, endurance, and agility. Secondary outcomes will include physiological function assessed as cardiorespiratory fitness, muscular strength, and balance. Assessments will take place at baseline, mid-point (3-months), and immediately following the intervention (6-months).

DISCUSSION

This study will lay the foundation for the design of a future RCT by: (1) providing effect sizes that can be included in a power analysis for optimal sample size estimation; and (2) identifying cardiorespiratory fitness, muscular strength, and balance (i.e., physiological function) as mechanisms for the beneficial effects of FES cycling on walking performance. This trial will provide important information on a novel exercise rehabilitation therapy for managing walking impairment in persons with severe MS.

Longitudinal association between depressive symptoms and walking impairment in people with relapsing-remitting multiple sclerosis

Worsening depressive symptoms and walking impairment are significant burdens in multiple sclerosis. We explored the reciprocal relationship between depressive symptoms and walking impairment in a cohort of 269 people with relapsing-remitting multiple sclerosis over 2 years. The data were examined using longitudinal panel analysis in Mplus. Baseline depressive symptoms predicted change in walking impairment at 1-year follow-up (path coefficient = .074), and change in walking impairment at 1-year follow-up predicted change in depressive symptoms at 2-year follow-up (path coefficient = .177). Our study provides preliminary evidence for initiation of a reciprocal relationship between depressive symptoms and walking impairment in relapsing-remitting multiple sclerosis.

Early effect of dalfampridine in patients with MS: A multi-instrumental approach to better investigate responsiveness

BACKGROUND

4-aminopyridine (4-AP) is a potassium-channel blocker able to enhance walking speed in MS improving the action potentials of demyelinated axons on which internodal potassium channels are exposed.

OBJECTIVE

to study early 4-AP effect with clinical, subjective, neurophysiological and neuroradiological tools.

METHODS

Clinical (Timed 25-Foot Walk - T25FW, Timed Up-And-Go - TUG), subjective (MS Walking Scale-12 - MSWS-12), neurophysiological (Motor Evoked Potentials - MEPs) and imaging (Diffusion Tensor Imaging - DTI) evaluations were performed before (T0) and after (T1) 14days of 4-AP treatment. MEPs were recorded from Abductor Hallucis of both legs. A Tract-Based-Spatial-Statistics (TBSS) was performed on DTI.

RESULTS

We found a significant difference between T0 and T1 for T25FW, TUG, MSWS-12 (p≤0.001) in the whole patients' sample (23 subjects, median EDSS 6.0) and decrease of Central Motor Conduction Time and increase of mean Amplitude (Amp) at T1 (p=0.008 and p=0.006). We also recorded a significant difference of T25FW, TUG, MSWS-12 and Amp in clinical responder (CR) patients (CR: amelioration >20% at T25FW). TBSS showed a significant Mean and Radial Diffusivity reduction in the corticospinal tracts (p<0.05) of the whole group of patients; this reduction was also found in the CR subgroup.

CONCLUSION

Neurophysiological and neuroradiological parameters were modified in MS patients treated with 4-AP, and most of them reported a subjective improvement of their motor performances after treatment. The use of clinical, subjective, neurophysiological and neuroradiological tools could help to better explore MS patients responsiveness to 4-AP.

Validity of the Timed Up and Go Test as a Measure of Functional Mobility in Persons With Multiple Sclerosis

OBJECTIVE

To examine the validity of the timed Up and Go (TUG) test as a measure of functional mobility in persons with multiple sclerosis (MS) by using a comprehensive framework based on construct validity (ie, convergent and divergent validity).

DESIGN

Cross-sectional study.

SETTING

Hospital setting.

PARTICIPANTS

Community-residing persons with MS (N=47).

INTERVENTIONS

Not applicable.

MAIN OUTCOME MEASURES

Main outcome measures included the TUG test, timed 25-foot walk test, 6-minute walk test, Multiple Sclerosis Walking Scale-12, Late-Life Function and Disability Instrument, posturography evaluation, Activities-specific Balance Confidence scale, Symbol Digits Modalities Test, Expanded Disability Status Scale, and the number of steps taken per day.

RESULTS

The TUG test was strongly associated with other valid outcome measures of ambulatory mobility (Spearman rank correlation, rs=.71-.90) and disability status (rs=.80), moderately to strongly associated with balance confidence (rs=.66), and weakly associated with postural control (ie, balance) (rs=.31). The TUG test was moderately associated with cognitive processing speed (rs=.59), but not associated with other nonambulatory measures (ie, Late-Life Function and Disability Instrument-upper extremity function).

CONCLUSIONS

Our findings support the validity of the TUG test as a measure of functional mobility. This warrants its inclusion in patients' assessment alongside other valid measures of functional mobility in both clinical and research practice in persons with MS.

Diffusion tensor imaging of the corticospinal tract and walking performance in multiple sclerosis

Research has identified a significant relationship between DTI (Diffusion Tensor Imaging) indices in the Corticospinal Tract (CST) and disability status in persons with multiple sclerosis (MS). To date, there is little known about the association between DTI indices of the CST with walking and gait outcomes in MS. This study examined the associations among DTI indices [fractional anisotropy (FA), radial diffusivity (RD), and axial diffusivity (AD)] of the CST with walking and gait outcomes in persons with MS. We enrolled 69 persons with MS who underwent 3T brain magnetic resonance imaging (MRI) and examined white matter structural integrity in the CST in the brain with DTI. Participants completed three walking performance assessments: 6-minute walk (6MW), timed 25-foot walk (T25FW), and gait testing. We examined associations using Spearman (r(s)) and partial Spearman correlation (pr(s)) analyses, using the entire sample and stratifying by disability status after controlling for age and sex. After controlling for age, sex, and disease duration, RD was significantly correlated (p<0.05) with step time (pr(s)=0.30). AD was significantly correlated (p<0.05) with step length (pr(s)=-0.32). MD was significantly associated (p<0.05) with 6MW (pr(s)=-0.35), T25FW (pr(s)=-0.34), gait velocity (pr(s)=-0.31), step time (pr(s)=0.29), and step length (pr(s)=-0.36). FA was not significantly correlated with any of the walking parameters (p>0.05). We provide novel evidence of possible motor pathway damage involved in walking performance in MS. There may be subtle differences in associations between MD, AD, and RD with walking outcomes, and these could be assessed in future longitudinal examinations and clinical trials of motor rehabilitation.

Thalamus volume and ambulation in multiple sclerosis: a cross-sectional study

Aim: This cross-sectional study examined if subcortical gray matter (SGM) structures accounted for differences in timed 25-foot walk (T25FW) speed between multiple sclerosis (MS) patients and controls. Methods: Subjects underwent brain MRI and completed the T25FW. Volumes of the thalamus, caudate, putamen and pallidum were calculated from 3D T1-weighted structural brain images. T2 lesion volume (T2LV) was determined by using a semiautomated edge detection contouring-thresholding technique. Results: There were differences in T25FW speed, SGM volumes and T2LV between MS and controls. T25FW speed was associated with SGM volumes and T2LV in MS and controls. Thalamic volume partially accounted for the difference in T25FW speed between the MS and controls. Conclusion: The reduction of thalamus volume is associated with compromised ambulation in MS patients.

Step-rate cut-points for physical activity intensity in patients with multiple sclerosis: The effect of disability status

BACKGROUND

Evaluating the relationship between step-rate and rate of oxygen uptake (VO2) may allow for practical physical activity assessment in patients with multiple sclerosis (MS) of differing disability levels.

AIMS

To examine whether the VO2 to step-rate relationship during over-ground walking differs across varying disability levels among patients with MS and to develop step-rate thresholds for moderate- and vigorous-intensity physical activity.

MATERIALS AND METHODS

Adults with MS (N=58; age: 51 ± 9 years; 48 women) completed one over-ground walking trial at comfortable speed, one at 0.22 m · s(-1) slower, and one at 0.22 m · s(-1) faster. Each trial lasted 6 min. VO2 was measured with portable spirometry and steps with hand-tally. Disability status was classified as mild, moderate, or severe based on Expanded Disability Status Scale scores.

RESULTS

Multi-level regression indicated that step-rate, disability status, and height significantly predicted VO2 (p<0.05). Based on this model, we developed step-rate thresholds for activity intensity that vary by disability status and height. A separate regression without height allowed for development of step-rate thresholds that vary only by disability status.

CONCLUSION

The VO2 during over-ground walking differs among ambulatory patients with MS based on disability level and height, yielding different step-rate thresholds for physical activity intensity.