Sleep, physical activity, and psychological outcomes in children and adolescents with pediatric onset multiple sclerosis.

BACKGROUND: Sleep, physical activity (PA) and sedentary behavior (SED) have bidirectional associations with mental health in children. The relationships among sleep, PA, SED, with depressive and fatigue symptoms have not been investigated in Pediatric Onset Multiple Sclerosis (POMS) but are needed to inform sleep and PA behavior change interventions. OBJECTIVES: (1) To describe sleep quality including: sleep efficiency, latency, total sleep time, number of awakenings, time in bed, and wake after sleep onset using actigraphy in children and adolescents ages 11 to 18 diagnosed with POMS, and to compare these sleep metrics to those of an age- and sex-matched non-MS group (2) To examine the relationship between time spent in sedentary, light (LIPA), moderate and vigorous PA (MVPA), sleep quality, with depression, fatigue, and quality of life in children and adolescents with POMS and an age and sex matched non-MS group. METHODS: A cross-sectional study recruited children and adolescents with POMS ages 11 to 18 years followed at a tertiary pediatric hospital (Toronto, Canada) and an age and sex matched non-MS group from the general population. Participants were consented prior to initiation of study procedures. Participants wore an Actiwatch monitor and GT3X accelerometer and completed standardized questionnaires validated to capture data on sleep disturbances, depression, fatigue, and quality of life. Objective sleep data were collected using an Actiwatch including sleep efficiency, total sleep time, number of awakenings, wake after sleep onset (WASO), and sleep latency. A GT3X accelerometer was used to collect PA data including time spent in SED, light (LPA), and moderate to vigorous (MVPA) PA. Correlational analyses and tests of difference were used to compare the groups. RESULTS: 25 POMS (21F; 16.6 years ±1.1 yrs., median Expanded Disability Status Scale (EDSS) =1.5, IQR=1) and 25 Non-MS (22 F; 16±1.3 yrs.) took part. POMS had higher BMI (T= -5.1, P<0.001) compared to Non-MS. No differences in sleep efficiency (MS mean = 87%, vs. 88%) sleep time (MS Mean = 7.3 hrs. vs. 7.4 hrs.,), WASO (MS mean=37 mins. vs. 36 mins), latency (MS mean=15 mins vs. 11 mins), SED (MS mean =763 mins. vs. 730 mins) or PA (MS, mean LPA = 68 mins. vs 60 mins; MS mean MVPA = 12.7 mins. vs. 12.4 mins). Within POMS, higher sleep efficiency was associated with more SED (SR= 0.4, p = 0.05), while higher sleep efficiency was associated with less SED in Non-MS (SR = -0.7, p< 0.0). In children with POMS, less sleep time, shorter sleep onset latency and more WASO was associated with more SED (SR range = -0.45 to -0.58, P< 0.01). Higher sleep efficiency was associated with less fatigue. Less WASO was associated with lower depression, lower fatigue (SR = 0.67, p<0.01) and better quality of life (SR= -0.6, p<0.01). Greater LPA was associated with lower sleep onset latency (-0.45, p<0.05). CONCLUSIONS: Children with POMS did not differ in Actiwatch monitored sleep quality metrics. However, within the POMS group sleep quality was associated with better fatigue, depression and QOL. Further, total sleep time, WASO and latency associated with time spent SED and LPA, which independently associate with mental health outcome. Longitudinal work should determine the temporal associations between WASO, sleep latency, sleep time, PA, and mental health outcomes and whether reallocation of specific sleep or PA behaviors (time to sleep, total sleep time, sedentary to MVPA) result in improved depression fatigue, or quality of life in children and adolescents with POMS.

Profiling cognitive-motor interference in a large sample of persons with progressive multiple sclerosis and impaired processing speed: results from the CogEx study.

BACKGROUND: Performing cognitive-motor dual tasks (DTs) may result in reduced walking speed and cognitive performance. The effect in persons with progressive multiple sclerosis (pwPMS) having cognitive dysfunction is unknown. OBJECTIVE: To profile DT-performance during walking in cognitively impaired pwPMS and examine DT-performance by disability level. METHODS: Secondary analyses were conducted on baseline data from the CogEx-study. Participants, enrolled with Symbol Digit Modalities Test 1.282 standard deviations below normative value, performed a cognitive single task ([ST], alternating alphabet), motor ST (walking) and DT (both). Outcomes were number of correct answers on the alternating alphabet task, walking speed, and DT-cost (DTC: decline in performance relative to the ST). Outcomes were compared between EDSS subgroups (≤ 4, 4.5-5.5, ≥ 6). Spearman correlations were conducted between the DTCmotor with clinical measures. Adjusted significance level was 0.01. RESULTS: Overall, participants (n = 307) walked slower and had fewer correct answers on the DT versus ST (both p < 0.001), with a DTCmotor of 15.8% and DTCcognitive of 2.7%. All three subgroups walked slower during the DT versus ST, with DTCmotor different from zero (p's < 0.001). Only the EDSS ≥ 6 group had fewer correct answers on the DT versus ST (p < 0.001), but the DTCcognitive did not differ from zero for any of the groups (p ≥ 0.039). CONCLUSION: Dual tasking substantially affects walking performance in cognitively impaired pwPMS, to a similar degree for EDSS subgroups.

Feasibility of social cognitive theory-based fall prevention intervention for people with intellectual disabilities living in group-home.

BACKGROUND: Adults with intellectual disability (ID) have a higher rate of fall events than the general population. Consequently, interventions for reducing fall events and improving health are highly required for individuals with ID. One essential step towards effectively delivering fall prevention interventions among adults with ID involves evaluating their feasibility. This study examined the feasibility of a home-based exercise intervention, supplemented with behavioural change strategies, among individuals with ID living in residential settings. METHOD: This study provided an 8-week intervention, consisting of a workshop for support workers and sessions for participants with ID, focusing on behavioural reward/s, education regarding fall prevention/exercise and exercise training. One week prior to and 1 week following such an intervention, such participants underwent measurements for (1) physical performance, (2) fall efficacy, (3) self-efficacy for activity and (4) social support. RESULTS: Participants having ID (n = 33), support workers (n = 11) and one administrator participated in this study. There were no adverse events during the intervention, and the mean adherence rate was 70.8 ± 19.5%. Two participants with ID dropped out of the programme due to a lack of interest. The participants with ID significantly improved individual physical performance, self-efficacy for activity, fall efficacy and support from friends and support workers. CONCLUSIONS: Fall prevention interventions for adults with ID living in group-homes were highly promising for eventual large-scale implementation within such communities.

Calibration of hip accelerometers for measuring physical activity and sedentary behaviours in adults with Down syndrome.

BACKGROUND: The knowledge base on physical activity and sedentary behaviour in adults with Down syndrome (DS) may advance by accelerometer calibration studies. This study aimed to develop cut-points for sedentary behaviour and moderate-to-vigorous physical activity (MVPA) for adults with DS based on output from accelerometers worn on the dominant and non-dominant hips. METHODS: Sixteen adults with DS (10 men; age 31 ± 15 years) performed 12 tasks including sedentary behaviours and physical activities. We obtained metabolic equivalents (METs) with indirect calorimetry and vector magnitude (VM) output from triaxial accelerometers (wGT3X-BT, ActiGraph) worn on the dominant and non-dominant hips. Receiver operating characteristic curves were used to identify optimal VM cut-points that maximised sensitivity and specificity. RESULTS: Overall classification accuracy was very high (area under the ROC curve: 0.95 and 0.92 for sedentary and MVPA models, respectively). For the non-dominant hip, the optimal VM cut-points were (1) sedentary behaviour ≤236 counts·min-1 and (2) MVPA ≥2167 counts·min-1 . For the dominant hip, optimal cut-points were (1) sedentary behaviour ≤243 counts·min-1 and (2) MVPA ≥2092 counts·min-1 . CONCLUSIONS: The presented VM cut-points for sedentary behaviour and MVPA for adults with DS had high classification accuracy. There were small differences in accelerometer cut-points between the dominant and non-dominant hip.

Accelerometer-based estimation of oxygen uptake in adults with Down syndrome: vector magnitude vs. vertical axis.

BACKGROUND: Triaxial accelerometer output [vector magnitude (VM) counts] may better estimate physical activity intensity as reflected in the rate of oxygen uptake (V̇O2 ) than the traditional vertical axis (VA) counts in adults with Down syndrome (DS). This study examined the accuracy of VM vs. VA counts in estimating V̇O2 in adults with and without DS across different physical activities and sedentary behaviours. METHODS: Sixteen adults with DS (10 men and 6 women; 31 ± 15 years) and 19 adults without DS (10 men and 9 women; 24 ± 5 years) performed 12 tasks. V̇O2 was measured by portable spirometer (K4b2 , Cosmed) and VM and VA with an accelerometer (wGT3X-BT, Actigraph). RESULTS: Vector magnitude and VA were significant predictors of V̇O2 in adults with DS (P < 0.001; R2  = 0.74 and 0.65, respectively) and adults without DS (P < 0.001; P < 0.001; R2  = 0.75 and 0.61, respectively). Absolute error of prediction was significantly smaller for VM than VA for sitting, playing app, drawing, sweeping, standing and basketball (P ≤ 0.005), but smaller for VA than VM for walking at 0.8 m·s-1 (P = 0.005). Bland-Altman plots for adults with and without DS indicated narrower limits of agreement for VM than VA (-5.57 to 5.57 and -6.44 to 6.44 mL·kg-1 ·min-1 ; -6.21 to 6.17 and -7.75 to 7.74 mL·kg-1 ·min-1 , respectively). CONCLUSIONS: Vector magnitude and VA are significant predictors of V̇O2 in adults with and without DS, yet VM more accurately estimated V̇O2 than VA for most tasks. Development of accelerometer-based prediction of physical activity levels in adults with and without DS may improve by utilising VM counts.

Safety of exercise training in multiple sclerosis: a protocol for an updated systematic review and meta-analysis.

BACKGROUND: There has been an exponential growth in the number of clinical research studies regarding exercise training in multiple sclerosis, and literature reviews and meta-analyses have documented the many benefits of exercise training. This research further requires careful review for documenting the safety of exercise training in multiple sclerosis, as clarity on safety represents a major hurdle in the clinical prescription of exercise behaviour. OBJECTIVES: To enhance understanding of the feasibility of exercise in multiple sclerosis, we (1) provide a protocol of a systematic review and meta-analysis that summarises rates and risks of clinical relapse, adverse events (i.e., an unfavourable outcome that occurs during the intervention delivery time period), and serious adverse events (i.e., an untoward occurrence that results in death or is life threatening, requires hospitalisation, or results in disability during the intervention delivery time period), as well as retention, adherence, and compliance, from randomised controlled trials of exercise training in persons with multiple sclerosis; and (2) identify moderators of relapse, adverse events, and serious adverse event rates. METHODS: Eight field-relevant databases will be searched electronically. Studies that involve a randomised controlled trial of exercise training (with non-exercise, non-pharmacological, comparator), report on safety outcomes, and include adults with multiple sclerosis will be included. Rates and relative risks of the three primary outcomes (relapse, adverse event, and serious adverse event) will be calculated and reported each with standard error and 95% confidence interval. Random-effects meta-analysis will estimate mean population relative risk for outcomes. Potential sources of variability, including participant characteristics, features of the exercise stimulus, and comparison condition, will be examined with random-effects meta-regression with maximum likelihood estimation. DISCUSSION: The results from this systematic review and meta-analysis will inform and guide healthcare practitioners, researchers, and policymakers on the safety of exercise training in persons with multiple sclerosis. Where possible, we will identify the impact of exercise type, exercise delivery style, participant disability level, and the prescription of exercise guidelines, on the safety of exercise training. The result will identify critical information on the safety of exercise in persons with multiple sclerosis, while also identifying gaps in research and setting priorities for future enquiries. SYSTEMATIC REVIEW REGISTRATION: PROSPERO 2020 CRD42020190544.

Effects of exercise training on multiple sclerosis biomarkers of central nervous system and disease status: a systematic review of intervention studies.

BACKGROUND AND PURPOSE: Multiple sclerosis (MS) is a demyelinating and neurodegenerative disease of the central nervous system (CNS) that can be tracked through biomarkers of disease status. We investigated the effects of exercise on MS biomarkers associated with CNS status including imaging, blood-brain barrier (BBB) function and neurotrophic factors. METHODS: We conducted open-dated searches of Scopus, Medline, EMBASE and the Cochrane Library. We included studies written in English describing interventions of exercise that measured one or more of the biomarkers associated with MS published up to October 2018. RESULTS: We located a total of 3012 citations through searches in electronic databases. Of these, 16 studies were eligible for review; six studies focused on magnetic resonance imaging (MRI) markers, nine studies focused on neurotrophic factors and three studies focused on BBB function markers. It is of note that two studies included both neurotrophic factor and BBB function markers and are therefore included across categories of biomarkers in this review. The existing evidence from MRI studies confirmed that exercise training can improve CNS integrity and function. There is evidence of a positive effect of exercise training on modulation of BBB permeability markers and brain-derived neurotrophic factor. CONCLUSIONS: Exercise successfully improves MRI outcomes and peripheral biomarkers (i.e. brain-derived neurotrophic factor) in people with MS. This suggests that exercise can be recommended as an adjuvant therapy for MS treatment. This conclusion is tempered by some methodological limitations including small sample sizes and high drop-out rates in the reviewed studies.

Body mass index and cardiorespiratory fitness in persons with multiple sclerosis.

OBJECTIVE: This study examined body fatness and its association with cardiorespiratory fitness (CRF) in persons with multiple sclerosis (pwMS) accounting for disability status. MATERIALS AND METHODS: This study involved a secondary data analysis from a previous study of 62 pwMS. Body fatness was indirect measured as body mass index (BMI), and CRF was measured as peak oxygen consumption from an incremental exercise test with spirometry. Participants were allocated into 3 different groups based on established BMI categories (ie, normal, overweight, and obese), and data were analyzed using SPSS. RESULTS: The average BMI was 27.0 (6.7) kg/m2 , and CRF was 19.5 (7.2) mL/kg/min. There was an inverse correlation (pr = -.38 [-.57; -.14]; P = .003) between BMI and CRF controlling for age, sex, disease duration, and disability level. ANCOVA with linear contrast analysis revealed a statistical significant reduction in CRF between groups of different BMI categories; normal weight 20.8 (0.85); overweight 19.8 (1.13); and obese 16.9 (1.73) mL/kg/min; F (2, 55) = 3.33, P = .043; η2  = .11. CONCLUSIONS: The findings suggest that BMI has a negative impact on CRF in pwMS, with a marked reduction in CRF for those classified as obese compared to those in the normal and overweight category.

National estimates of self-reported sitting time in adults with multiple sclerosis.

BACKGROUND: Limited data exist on the prevalence and distribution of sedentary behavior (SB) in multiple sclerosis (MS). OBJECTIVE: The objective of this paper is to describe sitting time as a metric of SB in a large national sample of people with MS. METHODS: A total of 8004 individuals from the North American Research Committee on MS (NARCOMS) Registry completed the sitting time question from the International Physical Activity Questionnaire in spring 2015. We present descriptive data on sitting time for the total sample and across sociodemographic, clinical, and behavioral characteristics. RESULTS: The final sample included 6483 individuals. Of these, 36.7% were classified with mild disability, 24.7% with moderate disability, and 38.6% with severe disability. Median sitting time for the total sample was 480 min/day (P25 = 310 min/day, P75 = 720 min/day). Sitting time was highest for individuals with MS who were male (540 min/day), not married (540 min/day), had a disease duration >30 years (540 min/day), were underweight (540.5 min/day), had an annual income of < $15,000 (585 min/day), presented with a progressive form of MS (600 min/day), were classified as insufficiently active (600 min/day), or presented with severe disability (661 min/day). CONCLUSION: Sitting time is twice as high in individuals with MS compared to the general population (240 min/day).

People with MS are less physically active than healthy controls but as active as those with other chronic diseases: An updated meta-analysis.

BACKGROUND: There has been remarkable growth in research examining physical activity behavior (any bodily movement produced by skeletal muscle contraction that results in energy expenditure) among people living with multiple sclerosis (MS) over the past decade. The current meta-analysis quantified physical activity participation levels in persons with MS compared with non-diseased and other clinical populations. METHODS: We searched PUBMED, PsycINFO and Web of Science using the keywords physical activity, exercise, and physical fitness in conjunction with MS. We conducted a quantitative synthesis of the difference in physical activity participation levels among persons with MS compared with non-diseased populations and other clinical populations and then examined moderators that might explain variation in the overall effect size (ES). RESULTS: 21 studies were included involving 5303 persons with MS and yielded a mean ES of -0.57 (95% CI=-0.76, 60.37). The weighted mean ES was heterogeneous (Q=443.811, df=31, p<0.001). The magnitude of the mean ES increased when comparing the MS population with non-diseased populations, but decreased when comparing MS with clinical populations. CONCLUSION: The cumulative evidence reinforces that persons with MS are less physically active than non-diseased, but not clinical populations, and this observation supports the need for new efforts on promoting physical activity across the MS community.

Depressive symptomology in multiple sclerosis: Disability, cardiorespiratory fitness and heart rate variability.

OBJECTIVES: This study aimed to investigate whether neurological disability status, heart rate variability (HRV), cardiorespiratory fitness (CRF) explained the variance in depressive symptoms in multiple sclerosis (MS). METHODS: Associations between CRF (via maximal oxygen uptake; VO2peak ), HRV indices of normalized ultra-low (nULF) and very low frequency domains (nVLF), neurological disability status and depressive symptoms (using the Depression subscale of the Hospital Anxiety Depression Scale; HADS-D) were assessed in 53 participants with MS and 17 matched controls. Hierarchical linear regression analysis was conducted within the MS subsample to examine the variance explained by neurological disability alone and CRF. RESULTS: The groups were similar in mean age (MS=52.0 years, Control=51.1 years) and sex (MS=72% female, Control=77% female). Among individuals with MS, HADS-D scores significantly correlated with disability status (sample mean score=4) and VO2peak (r=-.62, P<.001), whereas VO2peak only correlated with nVLF (r=0.29, P<.05), but not nULF (r=0.26, P=.06). The hierarchical linear regression indicated that VO2peak (P<.05) attenuated the effect of disability status on HADS-D scores such that disability was no longer a predictor of depressive symptomology at step 2 (P>.05). CONCLUSION: Heart rate variability does not seem to significantly differ between individuals with MS and healthy controls. When accounting for CRF, disability status no longer explains significant variance in depressive symptoms in MS. Accordingly, targeting CRF might be an effective approach for effectively managing depressive symptoms in individuals with MS.

Virtual street-crossing performance in persons with multiple sclerosis: Feasibility and task performance characteristics.

OBJECTIVES: Multiple sclerosis (MS) is a neurological disease that commonly results in physical and cognitive dysfunction. Accordingly, MS might impact the ability to safely cross the street. The purpose of this study was to examine the feasibility of a simulated street-crossing task in persons with MS and to determine differences in street-crossing performance between persons with MS and non-MS controls. METHODS: 26 participants with MS (median Expanded Disability Status Scale [EDSS] score = 3.5) and 19 controls completed 40 trials of a virtual street-crossing task. There were 2 crossing conditions (i.e., no distraction and phone conversation), and participants performed 20 trials per condition. Participants were instructed that the goal of the task was to cross the street successfully (i.e., without being hit be a vehicle). The primary outcome was task feasibility, assessed as completion and adverse events. Secondary outcomes were measures of street-crossing performance. RESULTS: Overall, the simulated street-crossing task was feasible (i.e., 90% completion, no adverse events) in participants with MS. Participants with MS waited longer and were less attentive to traffic before entering the street compared with controls (all P < .05). Participants with MS also took longer to cross the street and were closer to oncoming vehicles when exiting the street compared to controls (all P < .05). When distracted, all participants took longer to initiate crossing, took longer to cross the street, and made more head turns while crossing (all P < .05). There were no significant group by condition interaction effects (all P > .05). CONCLUSIONS: A virtual street-crossing task is feasible for studying street-crossing behavior in persons with mild MS and most individuals with moderate MS. Virtual street-crossing performance is impaired in persons with MS compared to controls; however, persons with MS do not appear to be more vulnerable to a distracting condition. The virtual reality environment presents a safe and useful setting for understanding pedestrian behavior in persons with MS.

Fitness and its association with fatigue in persons with multiple sclerosis.

This study compared physical fitness components between fatigued and non-fatigued persons with MS and examined those components as correlates of fatigue. Sixty-two ambulatory persons with MS completed the Modified Fatigue Impact Scale (MFIS) and underwent assessments of cardiorespiratory capacity, lower extremity muscle strength (i.e., peak torque and asymmetry), body composition, and static balance over two different sessions 7 days apart. Participants were allocated into fatigue groups based on MFIS scores (non-fatigued group (i.e., MFIS ≤38), n = 26; and fatigued group (MFIS >38), n = 36). The fatigued group had significantly (P < 0.05) lower cardiorespiratory capacity (VO2peak ) and muscular strength (i.e., knee flexion peak torque) than the non-fatigued group. VO2peak and knee extension peak torque were the two physical fitness components significantly correlated with fatigue scores in the fatigued group (P < 0.05), and follow-up stepwise linear regression revealed that VO2peak was a significant predictor of fatigue scores (R2  = 0.13). Discriminant function analysis further identified VO2peak as a significant (P < 0.05) correlate of fatigue status. This model explained 21% of variance in group status (i.e., fatigued vs non-fatigued) and correctly classified approximately 76% of cases into fatigue status groups. The improvement of cardiorespiratory capacity should be considered in rehabilitation programs for persons with MS, especially those presenting with elevated fatigue.

Effects of a DVD-delivered exercise program on patterns of sedentary behavior in older adults: a randomized controlled trial.

INTRODUCTION: In the present study, we examined the influence of a home-based, DVD-delivered exercise intervention on daily sedentary time and breaks in sedentary time in older adults. METHODS: Between 2010 and 2012, older adults (i.e., aged 65 or older) residing in Illinois (N = 307) were randomized into a 6-month home-based, DVD-delivered exercise program (i.e., FlexToBa; FTB) or a waitlist control. Participants completed measurements prior to the first week (baseline), following the intervention period (month 6), and after a 6 month no-contact follow-up (month 12). Sedentary behavior was measured objectively using accelerometers for 7 consecutive days at each time point. Differences in daily sedentary time and breaks between groups and across the three time points were examined using mixed-factor analysis of variance (mixed ANOVA) and analysis of covariance (ANCOVA). RESULTS: Mixed ANOVA models revealed that daily minutes of sedentary time did not differ by group or time. The FTB condition, however, demonstrated a greater number of daily breaks in sedentary time relative to the control condition (p = .02). ANCOVA models revealed a non-significant effect favoring FTB at month 6, and a significant difference between groups at month 12 (p = .02). CONCLUSIONS: While overall sedentary time did not differ between groups, the DVD-delivered exercise intervention was effective for maintaining a greater number of breaks when compared with the control condition. Given the accumulating evidence emphasizing the importance of breaking up sedentary time, these findings have important implications for the design of future health behavior interventions.

Accelerometer output and its association with energy expenditure during manual wheelchair propulsion.

STUDY DESIGN: This is an experimental design. OBJECTIVES: This study examined the association between rates of energy expenditure (that is, oxygen consumption (VO2)) and accelerometer counts (that is, vector magnitude (VM)) across a range of speeds during manual wheelchair propulsion on a motor-driven treadmill. Such an association allows for the generation of cutoff points for quantifying the time spent in moderate-to-vigorous physical activity (MVPA) during manual wheelchair propulsion. SETTING: The study was conducted in the University Laboratory. METHODS: Twenty-four manual wheelchair users completed a 6-min period of seated rest and three 6-min periods of manual wheelchair propulsion on a motor-driven wheelchair treadmill. The 6-min periods of wheelchair propulsion corresponded with three treadmill speeds (1.5, 3.0 and 4.5 mph) that elicited a range of physical activity intensities. Participants wore a portable metabolic unit and accelerometers on both wrists. Primary outcome measures included steady-state VO2 and VM, and the strength of association between VO2 and VM was based on the multiple correlation and squared multiple correlation coefficients from linear regression analyses. RESULTS: Strong linear associations were established between VO2 and VM for the left (R=0.93±0.44; R2=0.87±0.19), right (R=0.95±0.37; R2=0.90±0.14) and combined (R=0.94±0.38; R2=0.88±0.15) accelerometers. The linear relationship between VO2 and VM for the left, right and combined wrists yielded cutoff points for MVPA of 3659 ±1302, 3630±1403 and 3644±1339 counts min(-1), respectively. CONCLUSION: We provide cutoff points based on the linear association between energy expenditure and accelerometer counts for estimating time spent in MVPA during manual wheelchair propulsion using wrist-worn accelerometry. The similarity across wrist location permits flexibility in selecting a location for wrist accelerometry placement.

Generalised cognitive motor interference in multiple sclerosis.

Researchers have examined cognitive motor interference (CMI) for lower extremity function in MS, but have not examined this in the upper extremity. This study examined CMI for both lower and upper extremity motor tasks in persons with MS and without MS. Eighty-two persons walked on a GAITRite electronic walkway (velocity) and performed the nine-hole peg test (NHPT, seconds) without (single task) and with a cognitive challenge (dual task). The data were analysed with mixed-factor ANOVA and Pearson correlations. When comparing MS and controls, there were statistical significant and exceptionally large Task main effects on gait velocity (ηp(2)=.41; F1,60=55.78; p<.005) and NHPT performance (ηp(2)=.62; F1,60=127.8; p<.005). When considering disability status among those with MS, there were statistically significant and large Task main effects on velocity (ηp(2)=.38; F1,60=37.3; p<.005) and NHPT test (ηp(2)=.62; F1,60=95.7; p<.005). The dual task cost of walking and performing the NHPT were significantly correlated in the entire sample, those with MS and controls, and in those with MS who had mild, moderate, and severe disability (all |r|>.450). CMI occurs in both the lower and upper extremities, and is comparable between persons with and without MS and across MS disability level.

Descriptive epidemiology of physical activity rates in multiple sclerosis.

BACKGROUND: Persons with multiple sclerosis (MS) engage in substantially less overall physical activity than healthy controls, but there is little information on public health rates of physical activity necessary for health benefits. PURPOSE: This study examined the rates of insufficient, moderate, and sufficient physical activity in persons with MS compared with healthy controls. METHOD: Secondary analysis of data from participants with MS (n = 1521) and healthy controls (n = 162) who completed the Godin Leisure-Time Exercise Questionnaire (GLTEQ) as part of a questionnaire battery in 14 previous investigations. RESULTS: There were statistically significant differences in overall GLTEQ scores (F1,1666 = 96.8, P < 0.001, d = 0.83) and rates of physical activity (χ(2) (2, N = 1683) = 94.2, P < 0.001) between MS and control groups. The rates of insufficient, moderate, and sufficient physical activity in the MS group were 58.0%, 15.2%, and 26.8%, respectively. Those with MS were 2.5 times more likely to report insufficient physical activity and 2.3 times less likely to report sufficient physical activity than controls. CONCLUSION: The majority of persons with MS were insufficiently physically active, and this segment represents the largest opportunity for successful behavior change and accumulation of associated health benefits.

Psychometric properties of quality of life and health-related quality of life assessments in people with multiple sclerosis.

PURPOSE: There is substantial interest in testing interventions for improving quality of life (QOL) and health-related quality of life (HRQOL) in people with multiple sclerosis (MS). Yet, there is limited research on the psychometric properties of QOL [e.g., Satisfaction with Life Scale (SWLS), Leeds MS Quality of Life Scale (LMSQOL)] and HRQOL [e.g., Short Form 12 Health Survey (SF-12) and Multiple Sclerosis Impact Scale-29 (MSIS-29)] measures in this population. Such research is important for designing and interpreting interventions. We examined the test-retest reliability, measurement error, and interpretability of QOL (i.e., SWLS and LMSQOL) and HRQOL (i.e., SF-12 and MSIS-29) measures over 6 months in people with MS. METHODS: Individuals with MS (n = 274) completed the SWLS, LMSQOL, SF-12 and MSIS-29 on two occasions, 6 months apart. We estimated test-retest reliability [intraclass correlation coefficient (ICC)], measurement error [standard error of measurement (SEM) and coefficient of variation] and interpretability [smallest detectable change (SDC)]. RESULTS: Intraclass correlation coefficient values ranged between moderate and good (ICC range = 0.669-0.883); the MSIS-29 physical component had the best reliability, and the SF-12 mental component had the worst reliability. Measurement error, based on percent SEM, varied among measures; the physical and mental components of the SF-12 (%SEM = 4.6 and 5.3, respectively) had the best measurement error, and the MSIS-29 mental component (%SEM = 13.2) and the SWLS (%SEM = 12.7) had the worst measurement error. Interpretability, based on percent SDC, varied among measures; interpretability was best for the physical and mental components of the SF-12 (%SDC = 12.7 and 14.7, respectively) and worst for the MSIS-29 mental component (%SDC = 36.7) and the SWLS (%SDC = 35). CONCLUSION: We provide novel data for helping researchers and clinicians select and interpret QOL and HRQOL measures and scores for interventions among people with MS. Such information will better inform our understanding of intervention effectiveness.

Mobility and cognitive correlates of dual task cost of walking in persons with multiple sclerosis.

BACKGROUND: Persons with multiple sclerosis (MS) often experience a decrease in walking performance while simultaneously performing a cognitive task. This decrease in walking performance is termed dual task cost (DTC). OBJECTIVE: To examine if mobility and cognitive function are correlates of DTC in persons with MS. METHODS: Participants were 96 persons with MS who had Expanded Disability Status Scale scores that ranged between 2.0 and 6.5. To determine DTC, participants walked at a self-selected pace with and without a cognitive task while gait velocity was recorded. The effect of the cognitive task was quantified as the percent change in walking velocity between conditions. Participants further completed the timed 25-foot walk (T25FW) and Symbol Digit Modalities Test (SDMT). Centered scores for the T25FW and SDMT, and the product of the center scores, were placed into a linear regression to determine the correlates of DTC. RESULTS: DTC averaged 12.5% (SD = 9.3) and ranged between -14.1 and 42.4%. Performance on the T25FW ranged between 3.1 and 24.5 s with an average of 6.8 s (SD = 3.1 s). SDMT scores ranged between 15 and 79 with an average of 45 items (SD = 12). Regression analysis revealed that age, disability, walking and cognitive performance explained 17% of the variance in DTC. The interaction between walking and cognition did not explain additional variance. CONCLUSIONS: Mobility and cognitive impairment were both independent predictors of DTC of walking in persons with MS. This raises the possibility that DTC could be reduced with modifications of either mobility or cognition.

Randomized controlled trial of a behavioral intervention targeting symptoms and physical activity in multiple sclerosis.

BACKGROUND: Exercise training is beneficial, but most persons with multiple sclerosis (MS) are sedentary and physically inactive. This has prompted a new focus on the promotion of lifestyle physical activity in MS. We previously designed, tested, and refined a behavioral intervention delivered through the Internet that successfully increased lifestyle physical activity in MS, but have not evaluated the effects on secondary symptomatic and health-related quality of life (HRQOL) outcomes. OBJECTIVE: We conducted a 6-month randomized controlled trial (RCT) that examined the efficacy of an Internet-delivered, behavioral intervention for improving outcomes of fatigue, depression, anxiety, pain, sleep quality, and HRQOL in 82 ambulatory persons with MS. The secondary aim was to replicate previous results regarding change in free-living physical activity. RESULTS: There was a significant and positive effect of the intervention on fatigue severity (p=.001, η ρ (2)=.15) and its physical impact (p=.008, η ρ (2)=.09), depression (p=.006, η ρ (2)=.10), and anxiety (p=.006, η ρ (2)=.10). There were non-significant improvements in pain (p=.08, η ρ (2)=.04), sleep quality (p=.06, η ρ (2)=.05), and physical HRQOL (p=.06, η ρ (2)=.05). We replicated our previous results by demonstrating an increase in self-reported physical activity (p=.001, η ρ (2)=.13). CONCLUSIONS: Our results support behavioral interventions targeting lifestyle physical activity as an alternative approach for managing symptoms in MS.