Reliability of gait and dual-task measures in multiple sclerosis.

BACKGROUND: Single-task (ST) and dual-task (DT) assessments are commonly used to evaluate motor and cognitive impairment in people with multiple sclerosis (MS). Although variability can influence repeated DT testing measures, the reliability of several DT variables over time has not been adequately explored. For instance, a third testing session has never been included to observe whether DT has a learning effect. DT cognition rate reliability has not yet been examined and dual-task cost (DTC), a widely used calculation for DT interpretation, has not been proven reliable. RESEARCH QUESTION: To evaluate the reliability of ST and DT measures of gait and cognition over three test sessions. METHODS: This was a cross-sectional study involving 18 people with MS and 12 controls. Participants attended three test sessions, each one week apart. ST and DT (serial seven subtraction) gait variables, DTC, coefficient of variability (CV), and cognition rate were extracted and calculated using an instrumented walkway. Reliability was assessed using intraclass correlation coefficients (ICC) or Kendall's coefficient of concordance (KCC; nonparametric test) and minimum detectable change (MDC); between-session learning effect was assessed using repeated measures ANOVA. RESULTS: ICC/KCC values for ST and DT gait variables ranged from moderate to excellent (0.50-0.99). However, reliability for DT stride width and cognition rate was lower in controls. In general, DTC and CV variables had poor ICCs and high MDC values (49.19-1478.67 %), although some DTC variables had moderate or higher reliability in controls. Cognition rate was reliable in both MS (ICC 0.91) and controls (ICC 0.84). A learning effect between sessions was observed for DT velocity in both groups and for DTC cadence in people with MS. SIGNIFICANCE: ST and DT gait measures as well as DT cognition rate are reliable outcomes for repeated testing, while DTC and CV variables may not be suitable for long-term monitoring.

Vigorous cool room treadmill training to improve walking ability in people with multiple sclerosis who use ambulatory assistive devices: a feasibility study.

BACKGROUND: Aerobic training has the potential to restore function, stimulate brain repair, and reduce inflammation in people with Multiple Sclerosis (MS). However, disability, fatigue, and heat sensitivity are major barriers to exercise for people with MS. We aimed to determine the feasibility of conducting vigorous harness-supported treadmill training in a room cooled to 16 °C (10 weeks; 3times/week) and examine the longer-term effects on markers of function, brain repair, and inflammation among those using ambulatory aids. METHODS: Ten participants (9 females) aged 29 to 74 years with an Expanded Disability Status Scale ranging from 6 to 7 underwent training (40 to 65% heart rate reserve) starting at 80% self-selected walking speed. Feasibility of conducting vigorous training was assessed using a checklist, which included attendance rates, number of missed appointments, reasons for not attending, adverse events, safety hazards during training, reasons for dropout, tolerance to training load, subjective reporting of symptom worsening during and after exercise, and physiological responses to exercise. Functional outcomes were assessed before, after, and 3 months after training. Walking ability was measured using Timed 25 Foot Walk test and on an instrumented walkway at both fast and self-selected speeds. Fatigue was measured using fatigue/energy/vitality sub-scale of 36-Item Short-Form (SF-36) Health Survey, Fatigue Severity Scale, modified Fatigue Impact Scale. Aerobic fitness (maximal oxygen consumption) was measured using maximal graded exercise test (GXT). Quality-of-life was measured using SF-36 Health Survey. Serum levels of neurotrophin (brain-derived neurotrophic factor) and cytokine (interleukin-6) were assessed before and after GXT. RESULTS: Eight of the ten participants completed training (attendance rates ≥ 80%). No adverse events were observed. Fast walking speed (cm/s), gait quality (double-support (%)) while walking at self-selected speed, fatigue (modified Fatigue Impact Scale), fitness (maximal workload achieved during GXT), and quality-of-life (physical functioning sub-scale of SF-36) improved significantly after training, and improvements were sustained after 3-months. Improvements in fitness (maximal respiratory exchange ratio and maximal oxygen consumption during GXT) were associated with increased brain-derived neurotrophic factor and decreased interleukin-6. CONCLUSION: Vigorous cool room training is feasible and can potentially improve walking, fatigue, fitness, and quality-of-life among people with moderate to severe MS-related disability. TRIAL REGISTRATION: The study was approved by the Newfoundland and Labrador Health Research Ethics Board (reference number: 2018.088) on 11/07/2018 prior to the enrollment of first participant (retrospectively registered at ClinicalTrials.gov: NCT04066972. Registered on 26 August 2019.

Under-treated depression negatively impacts lifestyle behaviors, participation and health-related quality of life among older people with multiple sclerosis.

PURPOSE: To what extent depression may negatively impact successful aging with multiple sclerosis (MS) is not known. We examined the impact of depression/depressive symptoms on lifestyle choices (diet, exercise, smoking and alcohol), participation and health-related quality of life (HRQoL) among older people living with MS (n = 742). METHODS: Based on self-reported depression diagnosis and scores on the Hospital Anxiety and Depression Scale, we divided the sample into four groups: 1. No depression diagnosis and low symptoms (n = 412), 2. Diagnosed with depression and low symptoms (n = 103), 3. Diagnosed with depression and high symptoms (n = 87), and 4. No depression diagnosis and high symptoms (n = 140). We used regression modelling to predict outcomes, controlling for age, MS disease duration, type of MS at initial diagnosis and disability. RESULTS: A high proportion (44.5%) reported either being diagnosed with depression, having high levels of symptoms or both. Only 12.1% reported that they were prescribed anti-depressants and 13.6% utilized psychosocial services. Compared to those with depression who had low symptoms, respondents who had high depressive symptoms (n = 227) were more likely to be non-exercisers (OR 1.85, 95%CI 1.02-3.34, p = 0.042), consume a poor diet (OR 2.12, 95%CI 1.27-3.52, p = 0.004), have the lowest levels of participation (OR 3.36, 95%CI 1.74-6.49, p = 0.0003) and report the poorest HRQoL (OR 1.95, 95%CI 1.17-3.26, p = 0.011). Men and people experiencing higher levels of disability and fatigue were at greater risk of having high symptoms and being undiagnosed. CONCLUSION: Undiagnosed and under-treated depression is common among older people living with MS and adversely impacts health choices.

Octogenarians with Multiple Sclerosis: Lessons for Aging in Place.

Les facteurs de protection retrouvés chez des octogénaires atteints de sclérose en plaques (SP) vivant à domicile ont été comparés à ceux d'individus sans SP du même groupe d'âge et de personnes moins âgées atteintes de SP. Les données provenant des octogénaires atteints de SP (n = 23) et d'un groupe de répondants plus jeunes avec cette maladie (n = 61) ont été tirées d'une enquête canadienne sur le vieillissement avec SP. Les données des groupes avec SP ont été comparées aux statistiques nationales d'octogénaires de la population générale. Les octogénaires avec SP présentaient plus d'incapacités et une prévalence plus élevée de troubles de l'humeur, mais étaient physiquement plus actifs que la population d'octogénaires de l'enquête canadienne. Les octogénaires avec SP ont déclaré éprouver moins de stress et de fatigue que le groupe d'individus plus jeunes avec SP. Bien que la différence d'âge entre les deux groupes avec SP soit d'une dizaine d'années, ces groupes ont rapporté des niveaux similaires de soutien social, d'aisance financière, d'incapacité physique et de participation. Le maintien d'appuis solides (sociaux et financiers), d'une attitude positive, la pratique d'activité physique et la participation aux activités quotidiennes peuvent contribuer au vieillissement dans la collectivité chez les individus avec SP, malgré les défis amenés par cette maladie.We aimed to determine protective factors distinguishing octogenarians with multiple sclerosis (MS) living at home from others their age and younger people with MS. Data from MS octogenarians (n = 23) and a matched group of MS young-old respondents (n = 61) were extracted from a Canadian MS aging survey. The MS groups were compared, along with a group of octogenarians from the general population, using national statistics. MS octogenarians lived with greater disability and higher prevalence of mood disorders but were more physically active than Canadian octogenarians without MS. MS octogenarians reported less stress and fatigue than the MS young-old group, and despite being more than a decade older, they reported similar levels of social support, financial flexibility, physical disability, and participation. Even when challenged by MS, maintenance of strong supports (social and financial), positive attitude, and participation in physical activity and life roles may contribute to aging in place.

Oxygen Cost During Mobility Tasks and Its Relationship to Fatigue in Progressive Multiple Sclerosis.

OBJECTIVE: To compare the oxygen costs of mobility tasks between individuals with progressive multiple sclerosis (MS) using walking aids and matched controls and to determine whether oxygen cost predicted fatigue. DESIGN: Cross-sectional descriptive. SETTING: A rehabilitation research laboratory. PARTICIPANTS: A total of 14 adults with progressive MS (mean age ± SD [y], 54.07±8.46) using walking aids and 8 age- and sex-matched controls without MS (N=22). INTERVENTIONS: Participants performed 5 mobility tasks (rolling in bed, lying to sitting, sitting to standing, walking, climbing steps) wearing a portable metabolic cart. MAIN OUTCOME MEASURES: Oxygen consumption (V˙o2) during mobility tasks, maximal V˙o2 during graded maximal exercise test, perceived exertion, and task-induced fatigue were measured on a visual analog scale before and after mobility tasks. RESULTS: People with progressive MS had significantly higher oxygen cost in all tasks compared to controls (P<.05): climbing steps (3.60 times more in MS), rolling in bed (3.53), walking (3.10), lying to sitting (2.50), and sitting to standing (1.82). There was a strong, positive correlation between task-induced fatigue and oxygen cost of walking, (ρ [13]=0.626, P=.022). CONCLUSIONS: People with progressive MS used 2.81 times more energy on average for mobility tasks compared to controls. People with progressive MS experienced accumulation of oxygen cost, fatigue, and exertion when repeating tasks and higher oxygen cost during walking was related to greater perception of fatigue. Our findings suggest that rehabilitation interventions that increase endurance during functional tasks could help reduce fatigue in people with progressive MS who use walking aids.

Synergistic Benefits of Combined Aerobic and Cognitive Training on Fluid Intelligence and the Role of IGF-1 in Chronic Stroke.

BACKGROUND: Paired exercise and cognitive training have the potential to enhance cognition by "priming" the brain and upregulating neurotrophins. METHODS: Two-site randomized controlled trial. Fifty-two patients >6 months poststroke with concerns about cognitive impairment trained 50 to 70 minutes, 3× week for 10 weeks with 12-week follow-up. Participants were randomized to 1 of 2 physical interventions: Aerobic (>60% VO2peak using <10% body weight-supported treadmill) or Activity (range of movement and functional tasks). Exercise was paired with 1 of 2 cognitive interventions (computerized dual working memory training [COG] or control computer games [Games]). The primary outcome for the 4 groups (Aerobic + COG, Aerobic + Games, Activity + COG, and Activity + Games) was fluid intelligence measured using Raven's Progressive Matrices Test administered at baseline, posttraining, and 3-month follow-up. Serum neurotrophins collected at one site (N = 30) included brain-derived neurotrophic factor (BDNF) at rest (BDNFresting) and after a graded exercise test (BDNFresponse) and insulin-like growth factor-1 at the same timepoints (IGF-1rest, IGF-1response). RESULTS: At follow-up, fluid intelligence scores significantly improved compared to baseline in the Aerobic + COG and Activity + COG groups; however, only the Aerobic + COG group was significantly different (+47.8%) from control (Activity + Games -8.5%). Greater IGF-1response at baseline predicted 40% of the variance in cognitive improvement. There was no effect of the interventions on BDNFresting or BDNFresponse; nor was BDNF predictive of the outcome. CONCLUSIONS: Aerobic exercise combined with cognitive training improved fluid intelligence by almost 50% in patients >6 months poststroke. Participants with more robust improvements in cognition were able to upregulate higher levels of serum IGF-1 suggesting that this neurotrophin may be involved in behaviorally induced plasticity.

Serum levels of insulin-like growth factor-1 and brain-derived neurotrophic factor as potential recovery biomarkers in stroke.

OBJECTIVES: Our objectives were: 1) to determine whether maximal aerobic exercise increased serum neurotrophins in chronic stroke and 2) to determine the factors that predict resting and exercise-dependent levels. METHODS: We investigated the potential predictors of resting and exercise-dependent serum insulin-like growth factor-1 and brain-derived neurotrophic factor among 35 chronic stroke patients. Predictors from three domains (demographic, disease burden, and cardiometabolic) were entered into 4 separate stepwise linear regression models with outcome variables: resting insulin-like growth factor, resting brain-derived neurotrophic factor, exercise-dependent change in insulin-like growth factor, and exercise-dependent change brain-derived neurotrophic factor. RESULTS: Insulin-like growth factor decreased after exercise (p = 0.001) while brain-derived neurotrophic factor did not change (p = 0.38). Greater lower extremity impairment predicted higher resting brain-derived neurotrophic factor (p = 0.004, r2 = 0.23). Higher fluid intelligence predicted greater brain-derived neurotrophic factor response to exercise (p = 0.01, r2 = 0.18). There were no significant predictors of resting or percent change insulin-like growth factor-1. DISCUSSION: Biomarkers have the potential to characterize an individual's potential for recovery from stroke. Neurotrophins such as insulin-like growth factor-1 and brain-derived neurotrophic factor are thought to be important in neurorehabilitation; however, the factors that modulate these biomarkers are not well understood. Resting brain-derived neurotrophic factor and percent change in brain-derived neurotrophic factor were related to physical and cognitive recovery in chronic stroke, albeit weakly. Insulin-like growth factor-1 was not an informative biomarker among chronic stroke patients. The novel finding that fluid intelligence positively correlated with exercise-induced change in brain-derived neurotrophic factor warrants further research.

Asymmetry of Brain Excitability: A New Biomarker that Predicts Objective and Subjective Symptoms in Multiple Sclerosis.

OBJECTIVES: Investigate whether asymmetrical corticospinal excitability exists in Multiple Sclerosis (MS) and its association with MS symptoms. METHODS: Bilateral resting and active motor thresholds (RMT, AMT) were gathered using transcranial magnetic stimulation among 82 MS patients. Corticospinal excitability (CSE) asymmetry was expressed as the ratio between weaker and stronger sides' RMT and AMT. Stronger and weaker side was determined by pinch and grip strength. We examined whether CSE asymmetry predicted symptoms. RESULTS: AMT asymmetry ratio revealed atypical CSE asymmetry whereby the hemisphere associated with the weaker hand was more excitable in early MS. After controlling for MS disease demographics, shifting of CSE asymmetry towards greater excitability in the stronger side significantly predicted more severe symptoms including Expanded Disease Severity Scale, nine-hole peg test, cognitive processing speed, walking speed, heat sensitivity, fatigue, and subjective impact of MS. CONCLUSION: CSE asymmetry significantly predicted the severity of MS-related physical and objective cognitive symptoms. The phenomenon may be related to neuroinflammation-mediated hyperexcitability. Shifting of asymmetry toward less excitability on the weaker side may suggest the onset of a more neurodegenerative phase of the disease. SIGNIFICANCE: Shifting of hemispheric excitability, detected using a CSE asymmetry ratio, may be a useful biomarker to track disease progression and understand the benefits of treatments.

A Bout of High Intensity Interval Training Lengthened Nerve Conduction Latency to the Non-exercised Affected Limb in Chronic Stroke.

Objective: Evaluate intensity-dependent effects of a single bout of high intensity interval training (HIIT) compared to moderate intensity constant-load exercise (MICE) on corticospinal excitability (CSE) and effects on upper limb performance in chronic stroke. Design: Randomized cross-over trial. Setting: Research laboratory in a tertiary rehabilitation hospital. Participants: Convenience sample of 12 chronic stroke survivors. Outcome measures: Bilateral CSE measures of intracortical inhibition and facilitation, motor thresholds, and motor evoked potential (MEP) latency using transcranial magnetic stimulation. Upper limb functional measures of dexterity (Box and Blocks Test) and strength (pinch and grip strength). Results: Twelve (10 males; 62.50 ± 9.0 years old) chronic stroke (26.70 ± 23.0 months) survivors with moderate level of residual impairment participated. MEP latency from the ipsilesional hemisphere was lengthened after HIIT (pre: 24.27 ± 1.8 ms, and post: 25.04 ± 1.8 ms, p = 0.01) but not MICE (pre: 25.49 ± 1.10 ms, and post: 25.28 ± 1.0 ms, p = 0.44). There were no significant changes in motor thresholds, intracortical inhibition or facilitation. Pinch strength of the affected hand decreased after MICE (pre: 8.96 ± 1.9 kg vs. post: 8.40 ± 2.0 kg, p = 0.02) but not after HIIT (pre: 8.83 ± 2.0 kg vs. post: 8.65 ± 2.2 kg, p = 0.29). Regardless of type of aerobic exercise, higher total energy expenditure was associated with greater increases in pinch strength in the affected hand after exercise (R2 = 0.31, p = 0.04) and decreases in pinch strength of the less affected hand (R2 = 0.26 p = 0.02). Conclusion: A single bout of HIIT resulted in lengthened nerve conduction latency in the affected hand that was not engaged in the exercise. Longer latency could be related to the cross-over effects of fatiguing exercise or to reduced hand spasticity. Somewhat counterintuitively, pinch strength of the affected hand decreased after MICE but not HIIT. Regardless of the structure of exercise, higher energy expended was associated with pinch strength gains in the affected hand and strength losses in the less affected hand. Since aerobic exercise has acute effects on MEP latency and hand strength, it could be paired with upper limb training to potentiate beneficial effects.

Bipedal hopping timed to a metronome to detect impairments in anticipatory motor control in people with mild multiple sclerosis.

BACKGROUND: People with mild multiple sclerosis (MS) often report subtle deficits in balance and cognition but display no measurable impairment on clinical assessments. We examined whether hopping to a metronome beat had the potential to detect anticipatory motor control deficits among people with mild MS (Expanded Disability Status Scale ≤ 3.5). METHODS: Participants with MS (n = 13), matched controls (n = 9), and elderly subjects (n = 13) completed tests of cognition (Montreal Cognitive Assessment (MoCA)) and motor performance (Timed 25 Foot Walk Test (T25FWT)). Participants performed two bipedal hopping tasks: at 40 beats/min (bpm) and 60-bpm in random order. Hop characteristics (length, symmetry, variability) and delay from the metronome beat were extracted from an instrumented walkway and compared between groups. RESULTS: The MS group became more delayed from the metronome beat over time whereas elderly subjects tended to hop closer to the beat (F = 4.52, p = 0.02). Delay of the first hop during 60-bpm predicted cognition in people with MS (R = 0.55, ß = 4.64 (SD 4.63), F = 4.85, p = 0.05) but not among control (R = 0.07, p = 0.86) or elderly subjects (R = 0.17, p = 0.57). In terms of hopping characteristics, at 60-bpm, people with MS and matched controls were significantly different from the elderly group. However, at 40-bpm, the MS group was no longer significantly different from the elderly group, even though matched controls and elderly still differed significantly. CONCLUSIONS: This new timed hopping test may be able to detect both physical ability, and feed-forward anticipatory control impairments in people with mild MS. Hopping at a frequency of 40-bpm seemed more challenging. Several aspects of anticipatory motor control can be measured: including reaction time to the first metronome cue and the ability to adapt and anticipate the beat over time.

Telegerontology as a Novel Approach to Address Health and Safety by Supporting Community-Based Rural Dementia Care Triads: Randomized Controlled Trial Protocol.

BACKGROUND: Telegerontology is an approach using videoconferencing to connect an interdisciplinary team in a regional specialty center to patients in rural communities, which is becoming increasingly practical for addressing current limitations in rural community-based dementia care. OBJECTIVE: Using the remotely-delivered expertise of the Telegerontology dementia care team, we aim to enhance the caregiver/patient/physician triad and thereby provide the necessary support for the person with dementia to "age in place." METHODS: This is a cluster randomized feasibility trial with four rural regions in the province of Newfoundland and Labrador, Canada (2 regions randomly assigned to "intervention" and 2 to "control"). The study population includes 22 "dementia triads" that consist of a community-dwelling older Canadian with moderate to late dementia, their family caregivers, and their Primary Care Physician (PCP). Over the 6-month active study period, all participants will be provided an iPad. The intervention is intended as an adjunct to existing PCP care, consisting of weekly Skype-based videoconferencing calls with the Telegerontology physician, and other team members as needed (occupational therapist, physical therapist etc). Control participants receive usual community-based dementia care with their PCP. A baseline (pre-) assessment will be performed during a home visit with the study team. Post intervention, 6- and 12-month follow-up assessments will be collected remotely using specialized dementia monitoring applications and Skype calls. Primary outcomes include admission to long-term care, falls, emergency room visits, hospital stays, and caregiver burden. RESULTS: Results will be available in March of 2018. CONCLUSIONS: Results from this study will demonstrate a novel approach to dementia care that has the potential to impact both rural PCPs, family caregivers, and people with dementia, as well as provide evidence for the utility of Telegerontology in models of eHealth-based care.

Intensifying Functional Task Practice to Meet Aerobic Training Guidelines in Stroke Survivors.

Objective: To determine whether stroke survivors could maintain workloads during functional task practice that can reach moderate levels of cardiometabolic stress (i.e., ≥40% oxygen uptake reserve ([Formula: see text]O2R) for ≥20 min) without the use of ergometer-based exercise. Design: Cross-sectional study using convenience sampling. Setting: Research laboratory in a tertiary rehabilitation hospital. Participants: Chronic hemiparetic stroke survivors (>6-months) who could provide consent and walk with or without assistance. Intervention: A single bout of intermittent functional training (IFT). The IFT protocol lasted 30 min and involved performing impairment specific multi-joint task-oriented movements structured into circuits lasting ~3 min and allowing 30-45 s recovery between circuits. The aim was to achieve an average heart rate (HR) 30-50 beats above resting without using traditional ergometer-based aerobic exercise. Outcome measures: Attainment of indicators for moderate intensity aerobic exercise. Oxygen uptake ([Formula: see text]O2), carbon dioxide production ([Formula: see text]CO2), and HR were recorded throughout the 30 min IFT protocol. Values were reported as percentage of [Formula: see text]O2R, HR reserve (HRR) and HRR calculated from predicted maximum HR (HRRpred), which were determined from a prior maximal graded exercise test. Results: Ten (3-female) chronic (38 ± 33 months) stroke survivors (70% ischemic) with significant residual impairments (NIHSS: 3 ± 2) and a high prevalence of comorbid conditions (80% ≥ 1) participated. IFT significantly increased all measures of exercise intensity compared to resting levels: [Formula: see text]O2 (Δ 820 ± 290 ml min-1, p < 0.001), HR (Δ 42 ± 14 bpm, p < 0.001), and energy expenditure (EE; Δ 4.0 ± 1.4 kcal min-1, p < 0.001). Also, mean values for percentage of [Formula: see text]O2R (62 ± 19), HRR (55 ± 14), and HRRpred (52 ± 18) were significantly higher than the minimum threshold (40%) indicating achievement of moderate intensity aerobic exercise (p = 0.004, 0.016, and 0.043, respectively). Conclusion: Sufficient workloads to achieve moderate levels of cardiometabolic stress can be maintained in chronic stroke survivors using impairment-focused functional movements that are not dependent on ergometers or other specialized equipment.

Women's and Men's Differing Experiences of Health, Lifestyle, and Aging with Multiple Sclerosis.

BACKGROUND: The growing population of older people with multiple sclerosis (MS) has led to more interest in understanding factors associated with healthy aging. We aimed to determine whether older women and men with MS have different health and lifestyle behaviors and whether there are sex differences in contributors to perceived health. METHODS: Data were obtained from a postal survey involving 743 Canadians older than 55 years with MS for at least 20 years. Sex differences in health, lifestyle, mood, and socioeconomics were examined using analysis of variance. Multiple regression was used to build explanatory models of health perception. RESULTS: Despite no differences in age, years with MS, disability, fatigue, or social support, older men (n = 166) experienced lower perceived health and lower resilience and participated less in life roles than older women (n = 577). Men experienced more depressive symptoms, and women reported more anxiety. Depression was the strongest predictor of health perception in both women and men (ß = -2.40 and -5.19, respectively, for each 3-point increase in depressive symptoms). Other contributors included household participation, fatigue, resilience, and disability in women and physical activity, financial flexibility, and alcohol use in men. CONCLUSIONS: Older men exhibit poorer adaptation to aging with MS than older women.

Bipedal Hopping Reveals Evidence of Advanced Neuromuscular Aging Among People With Mild Multiple Sclerosis.

Measures of walking such as the timed 25-ft walk test (T25FWT) may not be able to detect subtle impairment in lower limb function among people with multiple sclerosis (MS). We examined bipedal hopping to determine to what extent people with mild (Expanded Disease Severity Scale ≤ 3.5) MS (n = 13) would differ compared to age-, gender-, and education-matched controls (n = 9) and elderly participants (n = 13; ≥ 70 years old). We estimated lower limb power (e.g., hop length, velocity), consistency (e.g., variability of hop length, time), and symmetry (ratio of left to right foot). Participants completed the T25FWT and, after a rest, they then hopped using both feet 4 times along the walkway. We found that although all groups scored below the 6 -s cutoff for T25FWT, the elderly group had significantly shorter hop lengths, more variability, and more asymmetry than the controls. The results of the MS group were not significantly different from the elderly or controls in most measures and most of their values fell between the control and elderly groups. Hop length, but not measures of walking predicted Expanded Disease Severity Scale score (R2 = .38, p = .02). Bipedal hopping is a potentially useful measure of lower limb neuromuscular performance.

Healthy Aging from the Perspectives of 683 Older People with Multiple Sclerosis.

Purpose. The aim of this study was to determine what factors most greatly contributed to healthy aging with multiple sclerosis (MS) from the perspective of a large sample of older people with MS. Design and Methods. Participants (n = 683; >55 years of age with symptoms >20 years) provided answers to an open-ended question regarding healthy aging and were categorized into three groups, 55-64 (young), 65-74 (middle), and 75 and over (oldest old). Sociodemographic actors were compared using ANOVA. Two independent raters used the framework method of analyzing qualitative data. Results. Participants averaged 64 years of age (±6.2) with MS symptoms for 32.9 years (±9.4). 531 participants were female (78%). The majority of participants lived in their own home (n = 657) with a spouse or partner (n = 483). Participants described seven themes: social connections, attitude and outlook on life, lifestyle choices and habits, health care system, spirituality and religion, independence, and finances. These themes had two shared characteristics, multidimensionality and interdependence. Implications. Learning from the experiences of older adults with MS can help young and middle aged people with MS plan to age in their own homes and communities. Our data suggests that older people with MS prioritize factors that are modifiable through targeted self-management strategies.

Walking impairs cognitive performance among people with multiple sclerosis but not controls.

People with multiple sclerosis (MS) complain of problems completing two tasks simultaneously; sometimes called 'dual-tasking' (DT). Previous research in DT among people with MS has focused on how adding a cognitive task interferes with gait and few have measured how adding a motor task could interfere with cognition. We aimed to determine the extent to which walking affects a concurrent working memory task in people with MS compared to healthy controls. We recruited MS participants (n=13) and controls (n=10) matched by age (±3years), education (±3years) and gender. Participants first completed the cognitive task (subtracting 7's from the previous number) and then again while walking on an instrumented walkway. Although there were no baseline differences in cognition or walking between MS participants and controls, MS participants demonstrated a 52% decrease in number of correct answers during DT (p<0.001). Mental Tracking Rate (% correct answers/min) correlated strongly with MS-related disability measured using the Expanded Disability Status Scale (EDSS; r(11)=-0.68, p<0.01). We propose that compromised mental tracking during walking could be related to limited neural resource capacity and could be a potentially useful outcome measure to detect ecologically valid dual tasking impairments.

Comparing Three Dual-Task Methods and the Relationship to Physical and Cognitive Impairment in People with Multiple Sclerosis and Controls.

Dual-tasking (DT) is a measure to detect impairments in people with multiple sclerosis (MS). We compared three DT methods to determine whether cognitive (Montreal Cognitive Assessment (MoCA)) or physical disability (Expanded Disease Severity Scale; EDSS) was related to DT performance. We recruited MS participants with low disability (<3 EDSS, n = 13) and high disability (≥3 EDSS, n = 9) and matched controls (n = 13). Participants walked at self-selected (SS) speed on an instrumented walkway (Protokinetics, Havertown, USA), followed by DT walks in randomized order: DT ABC (reciting every second letter of the alphabet), DT 7 (serially subtracting 7's from 100), and DT 3 (counting upwards, leaving out multiples and numbers that include 3). DT 7 resulted in the most consistent changes in performance. Both MS and control groups reduced velocity and cadence and shortened step length during DT with no significant differences between groups. Control subjects widened stride width by about 1 cm while MS subjects (collapsed as one group) did not. MS subjects with higher disability significantly increased percentage time in double support during DT compared to SS (F = 12.95, p < 0.001). The change in DS was related to cognitive and not physical disability (r = 0.54, p < 0.05).

Predictors of exercise participation in ambulatory and non-ambulatory older people with multiple sclerosis.

Background. Exercise at moderate intensity may confer neuroprotective benefits in multiple sclerosis (MS), however it has been reported that people with MS (PwMS) exercise less than national guideline recommendations. We aimed to determine predictors of moderate to vigorous exercise among a sample of older Canadians with MS who were divided into ambulatory (less disabled) and non-ambulatory (more disabled) groups. Methods. We analysed data collected as part of a national survey of health, lifestyle and aging with MS. Participants (n = 743) were Canadians over 55 years of age with MS for 20 or more years. We identified 'a priori' variables (demographic, personal, socioeconomic, physical health, exercise history and health care support) that may predict exercise at moderate to vigorous intensity (>6.75 metabolic equivalent hours/week). Predictive variables were entered into stepwise logistic regression until best fit was achieved. Results. There was no difference in explanatory models between ambulatory and non-ambulatory groups. The model predicting exercise included the ability to walk independently (OR 1.90, 95% CI [1.24-2.91]); low disability (OR 1.50, 95% CI [1.34-1.68] for each 10 point difference in Barthel Index score), perseverance (OR 1.17, 95% CI [1.08-1.26] for each additional point on the scale of 0-14), less fatigue (OR 2.01, 95% CI [1.32-3.07] for those in the lowest quartile), fewer years since MS diagnosis (OR 1.58, 95% CI [1.11-2.23] below the median of 23 years) and fewer cardiovascular comorbidities (OR 1.55 95% CI [1.02-2.35] one or no comorbidities). It was also notable that the factors, age, gender, social support, health care support and financial status were not predictive of exercise. Conclusions. This is the first examination of exercise and exercise predictors among older, more disabled PwMS. Disability is a major predictor of exercise participation (at moderate to vigorous levels) in both ambulatory and non-ambulatory groups suggesting that more exercise options must be developed for people with greater disability. Perseverance, fatigue, and cardiovascular comorbidities are predictors that are modifiable and potential targets for exercise adherence interventions.