Walking and thinking in persons with multiple sclerosis who vary in disability

Sosnoff JJ, Boes MK, Sandroff BM, Socie MJ, Pula JH, Motl RW. Walking and thinking in persons with multiple sclerosis who vary in disability.

Objective

To examine the effect of a cognitive task on spatiotemporal parameters of gait in persons with multiple sclerosis (MS) with varying disability.

Design

Cohort.

Setting

Testing occurred at a local hospital.

Participants

Community-living persons (N=78) with MS participated in this investigation. They were divided into 3 groups based on Expanded Disability Status Scale (EDSS) scores: mild (2.0–3.5 EDSS; n=21); moderate (4.0–5.5 EDSS; n=25); and severe (6.0–6.5 EDSS; n=32).

Interventions

Not applicable.

Main Outcome Measures

Participants walked at a self-selected pace on an electronic pathway, which recorded spatiotemporal parameters of gait, in 4 separate trials and completed a cognitive task in the last 2 trials. The effect of the cognitive task was quantified as the change in spatiotemporal parameters of gait.

Results

There was an overall decline in gait with the additive cognitive task. The magnitude of the adverse changes ranged from 1.8% for step length (P=.02) to 12% for gait velocity (P<.001). Moreover, adverse changes in gait function were greatest in the severe and moderate disability group (P<.05).

Conclusions

Persons with MS have impaired walking while doing a cognitive task, and the adverse effect of a cognitive task on walking function is greatest in persons with severe and moderate disability. Difficulty walking while thinking has implications for everyday life and may be related to the risk of falls. Further work is needed to determine whether the adverse effect of an additive cognitive task can be minimized with rehabilitative interventions.     

Gait impairments in persons with multiple sclerosis across preferred and fixed walking speeds

Remelius JG, Jones SL, House JD, Busa MA, Averill JL, Sugumaran K, Kent-Braun JA, Van Emmerik RE. Gait impairments in persons with multiple sclerosis across preferred and fixed walking speeds.ObjectivesTo investigate (1) whether previously observed changes in gait parameters in individuals with multiple sclerosis (MS) are the result of slower preferred walking speeds or reflect adaptations independent of gait speed; and (2) the changes in spatiotemporal features of the unstable swing phase of gait in people with MS.DesignCross-sectional study assessing changes in gait parameters during preferred, slow (0.6m/s), medium (1.0m/s), and fast (1.4m/s) walking speeds.SettingGait laboratory with instrumented walkway and motion capture system.ParticipantsMS group with mild to moderate impairment (n=19, 16 women) with a median Expanded Disability Status Scale score of 3.75 (range, 2.5–6), and a sex- and age-matched control group (n=19).InterventionsNot applicable.Main Outcome MeasuresGait speed, stride length, stride width, cadence, dual support time, swing time, and timing of swing foot and body/head center of mass during swing phase.ResultsIndividuals with MS walked at slower preferred speeds with longer dual support times compared with controls. In fixed-speed conditions, dual support times were longer and swing times were shorter in MS compared with controls. Stride width was wider for all speed conditions in the MS group. In fixed-speed conditions, the MS group positioned their head and body centers of mass closer to the anterior base of support boundary when entering the unstable equilibrium of the swing phase.ConclusionsLonger dual support time is part of a gait strategy in MS that is apparent even when controlling for the confounding effect of slower preferred speed. However, a gait strategy featuring longer dual support times may have limitations if potentially destabilizing swing dynamics exist, which especially occur at walking speeds other than preferred for people with MS.     

Quantifying muscle fatigue during walking in people with multiple sclerosis

BackgroundThis study aimed to examine muscle fatigue in lower leg muscles in of people with multiple sclerosis and healthy controls, and whether muscle fatigue coincided with potential changes in gait.MethodsIn this case-control study, people with multiple sclerosis (n = 8; 3male; mean age (SD) = 49.7 (9.6) yr) and age-matched healthy controls (n = 10; 4male; mean age (SD) = 47.4 (8.7) yr) walked on a treadmill for 12-min at self-paced speed. Muscle fatigue was indirectly quantified by a decrease in median frequency and increase in root mean square of surface electromyographic recordings of lower leg muscles. Walking speed, ankle push-off power and net ankle work were calculated from marker positions and force plate data using inverse dynamic calculations.ResultsPeople with multiple sclerosis showed larger decreases in median frequency of soleus (most affected leg: p = 0.003; least affected leg: p = 0.009) and larger increases in root mean square of soleus (most and least affected leg: p = 0.037), gastrocnemius medialis (most affected leg: p = 0.003; least affected leg: p = 0.005) and lateralis (most and least affected leg: p < 0.001) compared to controls. Walking speed (p = 0.001), ankle push-off power (most affected leg: p = 0.018; least affected leg: p = 0.001) and net work around the ankle (most affected leg: p = 0.046; least affected leg: p = 0.001) were lower in people with multiple sclerosis compared to controls, but increased in both groups.InterpretationThe results yield preliminary evidence that soleus muscles of people with multiple sclerosis fatigue during prolonged walking. Changes in electromyography of gastrocnemius muscles could however be related to muscle fatigue, changes in gait or a combination.     

Depression in persons with multiple sclerosis

This article provides a critical review of what is currently known concerning the nature and scope of depression in persons who have MS. It begins with a discussion of relevant terminology,which is followed by a summary of the research literature concern-ing the prevalence; severity; and risk factors for, and impact of, depression in MS. Assessment issues also are reviewed. Gaps in the literature on the treatment of depression in persons who have MS also are discussed. The article concludes with a discussion of future directions that will improve our understanding of depression, its treatment, and the other side-resilience in the face of a serious neurologic condition.     

Teaching memory strategies to persons with multiple sclerosis

A memory-training program previously used effectively upon persons with head-injury (HI) was conducted upon eight subjects with multiple sclerosis (MS). The program involved computer-assisted teaching of imagery-based mnemonic strategies for recall of lengthy lists of words, and for associating names with faces. Results were similar to those found in individuals with HI, but the MS subjects learned the strategies quickly, and did not appear to require the lengthy training needed by persons with HI. It was concluded that memory training of those with MS may sometimes only require teaching of mnemonic strategies without extensive practice.     

Chronic pain in persons with multiple sclerosis

The MS literature clearly indicates that chronic pain is a significant problem for many, although not all, persons with MS. The rates of pain have been found to vary in different studies, from 44% to 80%, depending on the sample and the specific questions used to assess the incidence and severity of pain. What is not clear is the proportion of persons who have acute pain relative to chronic pain. Although the specific frequency of pain problems in patients with MS may not be clear, there is a subgroup of patients (about 38% of those with pain in one sample) who report experiencing severe pain [8]. Preliminary research suggests that chronic pain can have a significant negative impact on a number of aspects of functioning in persons with MS, such as the ability to engage in household work and psychologic functioning. A biopsychosocial model of chronic pain, which has proved to be useful in understanding chronic pain as a primary condition and chronic pain in persons with other physical disabilities, may also be useful for understanding pain in persons with MS. Research,however, has not yet tested the utility of this model among MS populations.Longitudinal research is needed to help us learn how MS-related pain may fluctuate over time and with changes in disease status. There also is a strong need for research that examines access to pain treatment and that evaluates the efficacy of currently available pain treatments in persons with MS. The results of such research, as it is applied to help patients with MS, should contribute to an overall increase in well-being and a decrease in suffering among persons with MS and chronic pain.     

Experimental protocol of a randomized controlled clinical trial investigating exercise,subclinical atherosclerosis,and walking mobility in persons with multiple sclerosis

BackgroundThis randomized controlled trial (RCT) will investigate the effects of a home-based aerobic exercise training regimen (i.e., cycle ergometry) on subclinical atherosclerosis and walking mobility in persons with multiple sclerosis (MS) and minimal disability.Methods/designThis RCT will recruit 54 men and women who have an Expanded Disability Status Scale characteristic of the 1st stage of MS (i.e., 0–4.0) to participate in a 3 month exercise or stretching intervention, with assessments of subclinical atherosclerosis and walking mobility conducted at baseline, week 6 (midpoint), and week 12 (conclusion) of the program. The exercise intervention will consist of 3 days/week of cycling, with a gradual increase of duration followed by an increase in intensity across the 3 month period. The attention-control condition will incorporate stretching activities and will require the same contact time commitment as the exercise condition. Both study groups will participate in weekly video chat sessions with study personnel in order to monitor and track program adherence. Primary outcomes will consist of assessments of vascular structure and function, as well as several walking tasks. Additional outcomes will include questionnaires, cardiorespiratory fitness assessment, and a 1-week free-living physical activity assessment.DiscussionThis investigation will increase understanding of the role of aerobic exercise as part of a treatment plan for managing subclinical atherosclerosis and improving walking mobility persons in the 1st stage of MS. Overall, this study design has the potential to lead to effective aerobic exercise intervention strategies for this population and improve program adherence.     

Myelin water imaging reflects clinical variability in multiple sclerosis

Whilst MRI is routinely used for the assessment and diagnosis of multiple sclerosis, there is poor correspondence between clinical disability in primary progressive multiple sclerosis (PPMS) patients and conventional MRI markers of disease activity (e.g., number of enhancing lesions). As PPMS patients show diffuse and global myelin loss, the aim of this study was to evaluate the efficacy of whole-brain myelin water fraction (MWF) imaging in PPMS. Specifically, we sought to use full-brain analysis techniques to: 1) determine the reproducibility of MWF estimates in PPMS brain; 2) compare MWF values in PPMS brain to healthy controls; and 3) establish the relationship between MWF and clinical disability, regionally and globally throughout the brain. Seventeen PPMS patients and seventeen age-matched controls were imaged using a whole-brain multi-component relaxation imaging technique to measure MWF. Analysis of MWF reduction was performed on three spatial levels: 1) histogram; 2) white matter skeleton; and 3) voxel-wise at the single-subject level. From histogram analysis, PPMS patients had significantly reduced global normal appearing white matter MWF (6%, p=0.04) compared to controls. Focal lesions showed lower MWF values than white matter in controls (61%, p<0.001) and patients (59%, p<0.001). Along the white matter skeleton, MWF was diffusely reduced throughout the PPMS brain, with significant correlations between reduced MWF and increased clinical disability (more severe symptoms), as measured by the Expanded Disability Status Scale, within the corpus callosum and frontal, temporal, parietal and occipital white matter. Correlations with the more specific mental and sensory functional system scores were localized to clinically eloquent locations: reduced MWF was significantly associated with increased mental scores in anterior regions (i.e., frontal lobes and genu of the corpus callosum), and increased sensory scores in more posterior regions closer to the sensory cortex. Individual patient MWF maps were also compared to a normative population atlas, which highlighted areas of statistical difference between the individual patient and the population mean. A significant correlation was found between the volume of significantly reduced MWF and clinical disability (p=0.008, R=0.58). Our results show that clinical disability is reflected in particular regions of cerebral white matter that are consistent between subjects, and illustrates a method to examine tissue alteration throughout the brain of individual patients. These results strongly support the use of MWF imaging to evaluate disease activity in PPMS.     

Self-reported use of the upper limbs related to clinical tests in persons with multiple sclerosis

Abstract

Purpose: This study investigated the relationship between self-reported use of the upper limbs and clinical tests in persons with multiple sclerosis (pwMS). Methods: This cross-sectional study involved 25?pwMS with upper limb dysfunction. The Motor Activity Log (MAL) was bilaterally applied to investigate the self-reported use of both upper limbs. Clinical tests on function level were the Motricity Index (MI) and the Brunnström–Fugl–Meyer (BFM). On activity level, the Action Research Arm test (ARAt) was conducted. To identify the relationship between the self-reported use and the clinical tests, Spearman correlation coefficients were calculated. Subgroups of dominant and non-dominant arms were differentiated, and compared with the Wilcoxon Signed rank test. Results: The highest correlations were found between the MAL and function level tests: MI (r?=?0.83, p?<?0.01) and BFM (r?=?0.75, p?<?0.01). A lower correlation was found between the MAL and the ARAt (r?=?0.49, p?<?0.01). For all outcome measures, the absolute scores were higher for the dominant hand. Higher correlations were found for the non-dominant compared to the dominant hand. Conclusion: The self-reported use of the upper limbs was highly associated with measures on function level. The association with activity level was, however, less pronounced. Magnitudes of relationships were influenced by hand dominance.

• Implications for Rehabilitation

• Self-reported use of the upper limbs in persons with MS, measured by the MAL, is highly associated with muscle strength and movement control.

• The ARAt (activity level of the ICF) is less associated with self-reported use compared to outcome measures at function level.

• The ARAt seems to be less sensitive to mild arm dysfunction.

• This study indicates that it is feasible and clinically relevant to apply the MAL as a self-reported outcome measure of upper limb use in MS.

     

Multi-task functional MRI in multiple sclerosis patients without clinical disability

While the majority of individuals with multiple sclerosis (MS) develop significant clinical disability, a subset experiences a disease course with minimal impairment even in the presence of significant apparent tissue damage on magnetic resonance imaging (MRI). Functional magnetic resonance imaging (fMRI) in MS patients with low disability suggests that increased use of the cognitive control system may limit the clinical manifestation of the disease. The current fMRI studies tested the hypothesis that nondisabled MS patients show increased recruitment of cognitive control regions while performing sensory, motor and cognitive tasks. Twenty two patients with relapsing-remitting MS and an Expanded Disability Status Scale (EDSS) score of ≤ 1.5 and 23 matched healthy controls were recruited. Subjects underwent fMRI while observing flashing checkerboards, performing right or left hand movements, or executing the 2-back working memory task. Compared to control subjects, patients demonstrated increased activation of the right dorsolateral prefrontal cortex and anterior cingulate cortex during the performance of the working memory task. This pattern of functional recruitment also was observed during the performance of non-dominant hand movements. These results support the mounting evidence of increased functional recruitment of cognitive control regions in the working memory system of MS patients with low disability and provide new evidence for the role of increased cognitive control recruitment in the motor system.     

Multimodal exercise training in multiple sclerosis: A randomized controlled trial in persons with substantial mobility disability

BackgroundMobility disability is a common, debilitating feature of multiple sclerosis (MS). Exercise training has been identified as an approach to improve MS-related mobility disability. However, exercise randomized controlled trials (RCTs) on mobility in MS have generally not selectively targeted those with the onset of irreversible mobility disability.ObjectivesThe current multi-site RCT compared the efficacy of 6-months of supervised, multimodal exercise training with an active control condition for improving mobility, gait, physical fitness, and cognitive outcomes in persons with substantial MS-related mobility disability.Methods83 participants with substantial MS-related mobility disability underwent initial mobility, gait, fitness, and cognitive processing speed assessments and were randomly assigned to 6-months of supervised multimodal (progressive aerobic, resistance, and balance) exercise training (intervention condition) or stretching-and-toning activities (control condition). Participants completed the same outcome assessments halfway through and immediately following the 6-month study period.ResultsThere were statistically significant improvements in six-minute walk performance (F(2158) = 3.12, p = 0.05, η_p² = 0.04), peak power output (F(2150) = 8.16, p < 0.01, η_p² = 0.10), and Paced Auditory Serial Addition Test performance (F(2162) = 4.67, p = 0.01, η_p² = 0.05), but not gait outcomes, for those who underwent the intervention compared with those who underwent the control condition.ConclusionsThis RCT provides novel, preliminary evidence that multimodal exercise training may improve endurance walking performance and cognitive processing speed, perhaps based on improvements in cardiorespiratory capacity, in persons with MS with substantial mobility disability. This is critical for informing the development of multi-site exercise rehabilitation programs in larger samples of persons with MS-related mobility disability.     

Self-reported fatigue and energy cost during walking are not related in patients with multiple sclerosis

Kempen JCE, de Groot V, Knol DL, Lankhorst GJ, Beckerman H. Self-reported fatigue and energy cost during walking are not related in patients with multiple sclerosis.ObjectivesTo determine whether there is a relationship between self-reported fatigue and the energy cost of walking (ECw), and how self-reported fatigue and ECw relate to physical functioning in patients with multiple sclerosis (MS).DesignCross-sectional cohort study, using structural equation modeling.SettingHome environment and at a university medical center.ParticipantsPatients (N=75) were obtained from a longitudinal study on outcome measurement and functional prognosis in early MS. Patients were included if they were able to walk for 6 minutes without being assisted by a person. The age range was between 28.0 and 69.7 years and the median Expanded Disability Status Scale was 2.5 (range, 1.0–6.5).InterventionsNot applicable.Main Outcome MeasuresSelf-reported fatigue was measured with the Fatigue Severity Scale, the vitality subscale of the Medical Outcomes Study 36-Item Short-Form Health Survey (SF-36), and a visual analog scale. Physical functioning was determined with the physical functioning subscale of the SF-36, fast walking speed, and comfortable walking speed. The ECw (J·kg^?1·m^?1) was measured with the energy cost of the walking test.ResultsThe relationship between ECw and latent variable fatigue had a β=?.188 (P=.236), that between ECw and physical functioning (SF-36 physical functioning) had a β=?.344 (P=.001), and that between fatigue and physical functioning had a β=?.448 (P=.000).ConclusionsFatigue and ECw are not related in patients with MS with mild to moderate walking problems. ECw and fatigue are independent determinants of physical functioning.     

Trunk control in unstable sitting posture during functional activities in healthy subjects and patients with multiple sclerosis

OBJECTIVE: To examine trunk stability in unstable sitting posture in 2 different functional activities. DESIGN: A randomized crossover design. SETTING: Rehabilitation center in Italy. PARTICIPANTS: Ten healthy subjects and 10 patients with multiple sclerosis. INTERVENTIONS: Subjects were seated on an unstable support surface. A task in which the subjects had to keep their trunk as stable as possible was compared with tasks in which they had to track an object with the head or grasp an object.Main outcome measures Angular displacement and mean absolute angular velocity in the anteroposterior and mediolateral planes of the support surface. RESULTS: Angular displacement showed differences between patients and healthy subjects both in the sagittal plane (P<.0001) and frontal plane (P<.002). Velocity of angular displacement differentiated between the groups in both planes (P<.0001). Differences between velocity of angular displacement in different tasks were also detected (P<.0001). Correlation coefficients between sitting balance scores and laboratory measures were low and not statistically significant. In the healthy subjects, instability in the frontal plane correlated positively with the subjects' weight and height. CONCLUSIONS: Both patients and healthy subjects had more difficulty with frontal plane stability than with sagittal plane stability. Angular velocity for a given task showed the greatest difference between the groups and between postural challenge tasks within a group. Patients were more unstable than healthy subjects during head movements in the frontal plane; conversely, arm movements produced larger angular displacement, especially in the sagittal plane.     

Persistent pain and uncomfortable sensations in persons with multiple sclerosis

The experience of pain has been documented in small studies of individuals with multiple sclerosis (MS). The present study examines the prevalence of persistent pain and uncomfortable sensations among participants in the large North American Research Committee on MS (NARCOMS) Patient Registry. Registrants (10,176) responded to a questionnaire on pain and 7579 reported experiencing some level of pain during the month prior to the survey. Among the respondents 49% reported mild to severe pain and 49% of those indicated severe pain. Increased pain intensity was positively associated with gender (more women), multiple pain sites (51% of the severe pain group reported four or more pain sites), and constancy of pain (44% among the group with severe pain). There was also a positive association with increased MS-related disability, relapsing-worsening type of MS, and depression. Respondents with severe pain made greater use of the healthcare system and of prescribed analgesics, but were less likely to be satisfied with their doctors' efforts to manage their pain. About one-third of the patients with moderate pain and 18% of those with severe pain reported no consultations for their pain. The effects of pain severity were fully evident in the respondents' daily life, their work, mood, recreational activities and enjoyment of life. Our results indicate that the high prevalence of MS-related severe pain, low satisfaction with management of intense pain, and the perceived interference with quality of life indicators necessitate greater attention by healthcare providers to the management of pain and uncomfortable sensations in the MS population.     

The perceived benefits and barriers to exercise participation in persons with multiple sclerosis

Purpose.?The purpose of this study was to examine the perceived benefits and barriers to exercise participation in persons with multiple sclerosis (MS).

Method.?A cross-sectional postal survey comprised of 93 adults with MS was conducted. Participants completed the Exercise Benefits and Barriers Scale (EBBS), Spinal Cord Injury Exercise Self-Efficacy Scale (EXSE), Multiple Sclerosis Impact Scale, Disease Steps Scale and International Physical Activity Questionnaire.

Results.?Forty-three percent of the participants were classified as exercising individuals (EX group) as compared with non-exercising individuals (non-EX group). Participants in the EX group reported significantly higher scores on the EBBS and EXSE. Items related to physical performance and personal accomplishment were cited as the greatest perceived benefits to exercise participation and those items related to physical exertion as the greatest perceived barriers to both the EX and non-EX groups.

Conclusion.?When compared with previous studies conducted in the general population, the participants in the present study reported different perceived barriers to exercise participation. Furthermore, awareness of the benefits of physical activity is not sufficient to promote exercise participation in persons with MS. Perceived exercise self-efficacy is shown to play an important role in promoting exercise participation in persons with MS.     

Six-minute walk test for persons with mild or moderate disability from multiple sclerosis: performance and explanatory factors

Purpose: The primary purpose of this study was to determine the extent to which health factors, functional measures, and pulmonary impairment explain performance on 6-Minute Walk Test (6MWT) distance in ambulatory persons with multiple sclerosis (MS). Another purpose was to determine the effect of disability and age on 6MWT performance and explanatory factors.Methods: A cross-sectional study design was used to evaluate factors that explain performance on the 6MWT in 64 community-dwelling persons with MS-related disability (Expanded Disability Status Scale [EDSS] 3.8±1.6). Of the 64 participants, 43 (67.2%) exhibited mild disability (EDSS <4.0) and 21 (32.8%) had moderate disability (EDSS 4.0-6.5). A regression analysis compared 6MWT performance to measures of health factors (EDSS, number of medications, number of comorbidities, resting HR, systolic and diastolic blood pressure [BP]); physical performance (functional stair test [FST], sit-to-stand test [SST], static standing balance [BAL], Fatigue Severity Scale [FSS], Activities-specific Balance Confidence [ABC] Scale); and pulmonary function (forced expiratory volume in 1 second [FEV(1)], forced vital capacity [FVC], maximal voluntary ventilation [MVV], maximal inspiratory pressure [MIP], maximal expiratory pressure [MEP]).Results: EDSS, ABC, FST, SST, BAL, MVV, MIP, and MEP were significantly associated with 6MWT distance after adjusting for age. Multiple step-wise linear regression analysis revealed that ABC, FST, and BAL were significant and independent explanatory factors of 6MWT distance. ABC and FST explained 75% of the variance in 6MWT performance (R(2)=0.75). Curvilinear regression analysis revealed that the FST is the most significant explanatory factor for 6MWT distance, explaining 79% of the variance (R(2)=0.79).Conclusions: 6MWT performance in persons with MS was explained by balance confidence (ABC) and stair-climbing ability (FST). The ABC and FST may be practical clinical measures for explaining walking ability and determining risk for disablement in persons with MS.     

Driving performance in persons with mild to moderate symptoms of multiple sclerosis

Purpose: To investigate whether driving performance is impaired in persons with mild to moderate multiple sclerosis (MS). Method: This study included 15 persons with MS (pwMS) and 17 healthy controls. The MS group exhibited mild to moderate impairments on the Expanded Disability Status Scale (median, Q1–Q3; 3.5, 2.5–4). The driving simulation required participants to drive in daily traffic while attending to a divided attention (DA) task. Computerized measures on the driving task included number of accidents, tickets, speed maintenance, standard deviation of lateral position, and time to collision. Response times and accuracy on the DA task were also computer generated. Additionally, pwMS completed a clinical evaluation encompassing motor, functional, visual, psychosocial and cognitive tests. Results: No differences between healthy controls and pwMS were observed on all measures of the primary driving task. PwMS performed worse than healthy controls on DA response time (3.10 s, 2.87–3.68 versus 2.15 s, 2.04–2.43; p = 0.001) and accuracy (15 correct answers, 11–18 versus 24 correct answers, 22–25; p < 0.0001). Depression was significantly associated with time to collision (r = ?0.77; p < 0.01). Conclusions: Subjects with mild to moderate MS are able to prioritize the driving task above the DA task. The relationship between depression and driving performance in MS merits further investigation.

Implications for Rehabilitation

• Divided attention (DA) is one of the key determinants of safe driving.

• Driving-related DA is deteriorated in early MS, but does not affect driving performance.

• Drivers with MS should be advised to avoid unnecessary distraction while driving.