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.
Cross-sectional descriptive.
A rehabilitation research laboratory.
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).
Participants performed 5 mobility tasks (rolling in bed, lying to sitting, sitting to standing, walking, climbing steps) wearing a portable metabolic cart.
Oxygen consumption (V˙o
) during mobility tasks, maximal V˙o
during graded maximal exercise test, perceived exertion, and task-induced fatigue were measured on a visual analog scale before and after mobility tasks.
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).
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.
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, r
2
= 0.23). Higher fluid intelligence predicted greater brain-derived neurotrophic factor response to exercise (p = 0.01, r
2
= 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.
•Single-task and dual-task gait variables are reliable outcome measures.•Cognition rate is a reliable dual-task measure of cognition.•Calculated gait dual-task cost and coefficient of variability ...have low reliability.•A learning effect may occur from repeated dual-task testing.
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.
To evaluate the reliability of ST and DT measures of gait and cognition over three test sessions.
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.
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.
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.
•Atypical brain excitability asymmetry in MS may indicate neuroinflammation-mediated hyperexcitability.•Shifting excitability asymmetry significantly predicted more severe physical MS symptoms and ...cognitive processing.•Asymmetry ratio may be a useful biomarker of MS progression and measure benefit of treatments.
Investigate whether asymmetrical corticospinal excitability exists in Multiple Sclerosis (MS) and its association with MS symptoms.
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.
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.
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.
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.
•Brain lesions and atrophy in multiple sclerosis (MS) compromise neural resources.•Completing two tasks at once (dual-tasking) may reveal reduced network capacity.•Walking causes errors in working ...memory among people with MS but not controls.•The error rate was correlated with neurologist-scored MS-related disability level.
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.
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.
Randomized cross-over trial.
Research laboratory in a tertiary rehabilitation hospital.
Convenience sample of 12 chronic stroke survivors.
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).
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,
= 0.01) but not MICE (pre: 25.49 ± 1.10 ms, and post: 25.28 ± 1.0 ms,
= 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,
= 0.02) but not after HIIT (pre: 8.83 ± 2.0 kg vs. post: 8.65 ± 2.2 kg,
= 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 (
= 0.31,
= 0.04) and decreases in pinch strength of the less affected hand (
= 0.26
= 0.02).
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.
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.
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.
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.
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.
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.
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.
Celotno besedilo
Dostopno za:
DOBA, IZUM, KILJ, NUK, PILJ, PNG, SAZU, SIK, UILJ, UKNU, UL, UM, UPUK
Multiple sclerosis (MS) can create significant financial burden, with cost of living rising consistently with increasing age and disability. We aimed to determine the prevalence and predictors of ...financial strain among a large sample of older Canadians with MS. A binomial logistic regression, which estimates the probability of an event happening (financial strain—yes/no), was performed. Participants were 64.6 (SD ± 6.2) years old and reported living with MS symptoms 32.8 (SD ± 9.4) years. In total, 22% of participants experienced financial strain. Predictors of financial strain (from greatest to least) were not having private health insurance, job loss due to MS, having moderate to high stress, greater physical impact of MS, not having home adaptations, not having social support, and living alone. These findings point to insufficiencies in Canada’s health and social systems when it comes to the provision of universal care to those living with disabling neurological chronic illness.
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 ...textO
R) for ≥20 min) without the use of ergometer-based exercise.
Cross-sectional study using convenience sampling.
Research laboratory in a tertiary rehabilitation hospital.
Chronic hemiparetic stroke survivors (>6-months) who could provide consent and walk with or without assistance.
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.
Attainment of indicators for moderate intensity aerobic exercise. Oxygen uptake (Formula: see textO
), carbon dioxide production (Formula: see textCO
), and HR were recorded throughout the 30 min IFT protocol. Values were reported as percentage of Formula: see textO
R, HR reserve (HRR) and HRR calculated from predicted maximum HR (HRR
), which were determined from a prior maximal graded exercise test.
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 textO
(Δ 820 ± 290 ml min
,
< 0.001), HR (Δ 42 ± 14 bpm,
< 0.001), and energy expenditure (EE; Δ 4.0 ± 1.4 kcal min
,
< 0.001). Also, mean values for percentage of Formula: see textO
R (62 ± 19), HRR (55 ± 14), and HRR
(52 ± 18) were significantly higher than the minimum threshold (40%) indicating achievement of moderate intensity aerobic exercise (
= 0.004, 0.016, and 0.043, respectively).
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.
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