Validity and reliability of linear encoder muscle power testing in persons with Parkinson's disease

OBJECTIVE

To investigate the construct validity ON medication and the reliability both ON and OFF medication of linear encoder muscle power testing in persons with Parkinson's disease (pwPD).

DESIGN

A study using baseline data from one randomized controlled trial (study 1) and one cohort study (study 2).

SETTING

University exercise lab.

PARTICIPANTS

Study 1: 35 healthy controls and 70 pwPD. Study 2: 20 pwPD.

INTERVENTION

Study 1: baseline data. Study 2: 4 chair rise tests (2 ON and 2 OFF medication), in a randomized order, separated by 4 to 16 days.

MAIN MEASURES

Linear encoder data were collected from a chair rise test. Known groups validity and convergent validity (i.e., construct validity) were assessed by comparing peak power between pwPD and healthy controls and associations between peak power and functional performance (i.e., 6-Min Walk Test, Timed Up and Go Test, Six-Spot Step Test), respectively. Reliability was assessed as day-to-day variation and by intraclass correlation coefficients.

RESULTS

Peak power was comparable between pwPD and healthy controls (-7.2%, p = 0.17), but lower in moderately impaired pwPD compared to mildly impaired pwPD (-27%, p < 0.01) and healthy controls (-23%, p < 0.01). Moderate to strong associations were observed between peak power and functional performance (r2 = 0.44-0.51). Day-to-day variation ON and OFF medication were 1.0 and 1.3 W/kg, respectively, while intraclass correlation coefficients were 0.95 (0.87;0.98) and 0.93 (0.82;0.97), respectively.

CONCLUSION

Linear encoder muscle power testing shows inconsistent known groups validity, acceptable convergent validity ON medication, and excellent day-to-day reliability ON and OFF medication in pwPD.

Are physical activity levels, cardiorespiratory fitness and peak power associated with Parkinson's disease severity?

INTRODUCTION

Increased physical activity (PA) may slow Parkinson's disease (PD) progression. Associations between markers of PA and PD severity could justify further studies evaluating interventions increasing PA levels in PD. The objectives of the present study were to assess associations between PA, cardiorespiratory fitness (VO2-max), and muscle peak power and measures of the Movement Disorder Society-sponsored revision of the Unified Parkinson's Disease Rating Scale (MDS-UPDRS), the Parkinson's disease questionnaire-39 (PDQ-39), and the four PD hallmark motor symptoms (rigidity, bradykinesia, postural instability, and tremor).

METHODS

Data from 105 people with PD were used. PA was measured for seven consecutive days using accelerometers. Peak power was measured with a linear encoder during a chair rise test, while VO2-max was directly assessed during a graded bicycle test. Analyses included simple and multiple linear regression and hurdle exponential regression.

RESULTS

PA was weakly to moderately associated with MDS-UPDRS II + III, rigidity, bradykinesia, and postural instability, as well as PDQ-39 mobility and activities of daily living sub-scores. VO2-max and peak power were weakly to moderately associated with MDS-UPDRS III, bradykinesia, and postural instability, while peak power was further weakly associated with the MDS-UPDRS II. Lastly, VO2-max was associated with PDQ-39 mobility and activities of daily living sub-scores.

CONCLUSION

PA, VO2-max, and peak power were associated with PD severity, thus highlighting the potential benefits of a physically active lifestyle. Furthermore, PA and VO2-max were associated with PDQ-39 sub-scores. This calls for confirmation of the potential effect of PA on quality of life in PD.

Exercise as medicine in Parkinson's disease

Parkinson's disease (PD) is an incurable and progressive neurological disorder leading to deleterious motor and non-motor consequences. Presently, no pharmacological agents can prevent PD evolution or progression, while pharmacological symptomatic treatments have limited effects in certain domains and cause side effects. Identification of interventions that prevent, slow, halt or mitigate the disease is therefore pivotal. Exercise is safe and represents a cornerstone in PD rehabilitation, but exercise may have even more fundamental benefits that could change clinical practice. In PD, the existing knowledge base supports exercise as (1) a protective lifestyle factor preventing the disease (ie, primary prevention), (2) a potential disease-modifying therapy (ie, secondary prevention) and (3) an effective symptomatic treatment (ie, tertiary prevention). Based on current evidence, a paradigm shift is proposed, stating that exercise should be individually prescribed as medicine to persons with PD at an early disease stage, alongside conventional medical treatment.

Cardiorespiratory fitness (V̇O2peak) across the adult lifespan in persons with multiple sclerosis and matched healthy controls

OBJECTIVES

Cardiorespiratory fitness (measured as peak oxygen uptake; V̇O2peak) is a well-established health predictor in the general population and in persons with multiple sclerosis (pwMS). We aimed to investigate differences in V̇O2peak between age groups and the prevalence of V̇O2peak impairments across the adult lifespan in pwMS compared to age- and sex-matched healthy controls (HC).

DESIGN

Cross-sectional study.

METHODS

Data from 469 pwMS (EDSS range 1.0-7.0), who carried out graded cardiopulmonary exercise testing during their rehabilitation stay at the Valens clinic from 07/2010 to 10/2022, were retrospectively analyzed. Data from 21,063 HC were extracted from previously published studies containing normative reference values.

RESULTS

With advanced age (i.e., across age groups), a continuous deterioration of V̇O2peak was observed in both pwMS and HC. Within all age groups, V̇O2peak was reduced in pwMS compared to HC with deficits ranging from 29 % to 40 % for females (p < .05), and from 30 % to 41 % for males (p < .05). However, no age ∗ group interaction was observed in neither males (p = .626) nor females (p = .557). With V̇O2peak impairments defined as values below the 5th percentile of HC, a high prevalence was observed in pwMS, with values ranging from 48 % to 100 % across age groups.

CONCLUSIONS

The present data provide evidence for a parallel deterioration of V̇O2peak in pwMS and matched controls with advancing age, coinciding with a high prevalence of impairments in V̇O2peak already present in young adulthood in pwMS. Understanding the extent of impairments as well as the age trajectories of cardiorespiratory fitness in pwMS is crucial for designing optimal rehabilitative and preventive interventions.

Validity and reliability of VO2-max testing in persons with Parkinson's disease

INTRODUCTION

Direct whole body assessment of maximal oxygen consumption (VO₂-max test) is considered the gold standard when assessing cardiorespiratory fitness (VO₂-max) in healthy people. VO₂-max is also an important health and performance indicator for persons with Parkinson's disease (pwPD) and is often used when prescribing exercise and evaluating aerobic exercise interventions. However, no study has examined the content validity of the VO₂-max test in pwPD as well as the test-retest reliability (i.e., day-to-day variation) in both the ON and OFF medication state. Therefore, the present study investigated the content validity and test-retest reliability of the VO₂-max test in pwPD both ON and OFF medication.

METHODS

Twenty pwPD completed four VO₂-max tests (two tests ON and two tests OFF medication), in a randomized order, separated by four to sixteen days. The first tests ON and OFF medication were used to assess content validity based on attainment of five pre-defined end-criteria (one primary and four secondary). Reliability was examined by intraclass correlation coefficients (ICC) and the day-to-day variation of the two ON and OFF medication tests.

RESULTS

In pwPD, 50% and 60% attained the primary end-criterion ON and OFF medication, respectively. A higher proportion (i.e., 70-90%) attained the secondary end-criteria both ON and OFF medication with no difference between medication states. Day-to-day variations were 1.2 and 1.8 ml O₂/kg/min, while ICC_2.1 were 0.97 (95%-CI: 0.92; 0.99) and 0.96 (95%-CI: 0.90; 0.98) ON and OFF medication, respectively.

CONCLUSION

The VO₂-max test has an acceptable content validity and excellent day-to-day reliability ON and OFF medication in pwPD.

Cortical diffusion kurtosis imaging and thalamic volume are associated with cognitive and walking performance in relapsing-remitting multiple sclerosis

BACKGROUND

In multiple sclerosis (MS), pronounced neurodegeneration manifests itself as cerebral gray matter (GM) atrophy, which is associated with cognitive and physical impairments. Microstructural changes in GM estimated by diffusion kurtosis imaging (DKI) may reveal neurodegeneration that is undetectable by conventional structural MRI and thus serve as a more sensitive marker of disease progression.

OBJECTIVE

The primary objective was to investigate the relationships between morphological and diffusional properties in cerebral GM and physical and cognitive performance in relapsing-remitting MS (RRMS) patients. A secondary objective was to investigate the relationship between GM microstructure and white matter (WM) injury, estimated by the volume of WM lesions.

METHODS

Sixty-seven RRMS patients performed the brief repeatable battery of neuropsychological tests (BRB-N), the 6-minute walk test (6MWT), the six spot step test (SSST), and underwent MRI scans using structural and DKI protocols. GM volumetrics and DKI measurements were analyzed in the cortex and deep GM structures using a general linear model with demographics, physical- and cognitive performance as covariates.

RESULTS

Mean diffusivity (MD) in the cortex was associated with the SSST, 6MWT, information processing, global cognitive performance, and volume of WM lesions. In addition, thalamic volume was associated with SSST (r² = 0.21, 6MWT (r² = 0.18), information processing (r² = 0.21), and WM lesion volume (r² = 0.60).

CONCLUSION

Cortical diffusion and thalamic volume are associated with walking and cognitive performance in RRMS patients and are highly affected by the presence of WM lesions.

Efficacy of High-Intensity Aerobic Exercise on Brain MRI Measures in Multiple Sclerosis

OBJECTIVE

To determine whether 24 weeks of high-intensity progressive aerobic exercise (PAE) affects brain MRI measures in people with multiple sclerosis (MS).

METHODS

We conducted a randomized, controlled, phase 2 trial (with a crossover follow-up) including an exercise group (supervised PAE followed by self-guided physical activity) and a waitlist group (habitual lifestyle followed by supervised PAE). Mildly to severely impaired patients with MS aged 18-65 years were randomized (1:1). The primary outcome was percentage brain volume change (PBVC) after 24 weeks, analyzed using the intention-to-treat principle.

RESULTS

Eighty-six participants were recruited. PBVC did not change over the intervention period (mean between-group change +0.12%, 95% confidence interval [CI] -0.27 to 0.51, p = 0.55). In contrast, cardiorespiratory fitness (+3.5 mL O₂/min/kg, 2.0 to 5.1, p < 0.01) and annualized relapse rate (0.00, 0.00-0.07 vs +0.45, 0.28 to 0.61, p < 0.01) improved in the exercise group.

CONCLUSION

These findings do not support a neuroprotective effect of PAE in terms of total brain atrophy in people with MS and it did not lead to a statistically significant difference in gray matter parenchymal fraction. PAE led to improvements in cardiorespiratory fitness and a lower relapse rate. While these exploratory findings cautiously support PAE as a potential adjunct disease-modifying treatment in MS, further investigations are warranted.

CLINICALTRIALSGOV IDENTIFIER

NCT02661555.

CLASSIFICATION OF EVIDENCE

This study provides Level I evidence that 24 weeks of high-intensity PAE did not elicit disease-modifying effects in PBVC in people with MS. Exploratory analyses showed that PAE may reduce relapse rate.

Efficacy of high-intensity aerobic exercise on cognitive performance in people with multiple sclerosis: A randomized controlled trial

BACKGROUND

Cognitive impairment is highly prevalent in multiple sclerosis (MS). Progressive aerobic exercise (PAE) represents a promising approach toward preservation or even improvement of cognitive performance in people with MS (pwMS).

OBJECTIVE

To investigate the effects of PAE on the cognitive domains of information processing, learning and memory, and verbal fluency in pwMS.

METHODS

This randomized controlled trial included an exercise (n = 43, 24 weeks of supervised PAE, followed by self-guided physical activity) and a waitlist group (n = 43, 24 weeks of habitual lifestyle, followed by supervised PAE). Assessments included the Brief Repeatable Battery of Neuropsychological tests (BRB-N), self-reported mood, and cardiorespiratory fitness. Published reference data were used to compute Z-scores for BRB-N scores. Cognitive impairment was defined as one or more Z-scores ⩽ -1.5SD.

RESULTS

No between-group changes in the total group were observed in BRB-N scores following PAE. In the cognitively impaired subgroup (43% of the total group) the between-group point estimate suggested a potential clinical relevant improvement in the Symbol Digit Modalities Test (95% CI overlapping zero). Cardiorespiratory fitness increased in the total group and the cognitively impaired subgroup.

CONCLUSION

In the present representative MS group, 24 weeks of supervised PAE had no effect on any cognitive domain in the total group but potentially improved processing speed in the cognitively impaired subgroup.

Aerobic Capacity Is Not Associated with Most Cognitive Domains in Patients with Multiple Sclerosis-A Cross-Sectional Investigation

(1) Background: Cognitive impairment is highly prevalent in multiple sclerosis (MS). Staying physically fit may be associated with preservation of cognitive performance in persons with MS (pwMS); (2) Objective: To investigate the association between aerobic capacity and the cognitive domains of information processing, learning and memory, and verbal fluency as well as single and composite z-scores of the Brief Repeatable Battery of Neuropsychological tests (BRBNT) in pwMS; (3) Methods: All subjects first performed the BRBNT and then a maximal oxygen consumption (VO₂-max) test on a bicycle ergometer as a measure of aerobic capacity. Simple and multiple (adjusting for age, sex, and education level) regression analyses were performed to evaluate the relationship between aerobic capacity and cognitive performance in different domains. Published international norms were used to compute z-scores for each individual and composite BRBNT score. Furthermore, cognitive impairment was defined as one or more z-scores ≤−1.5 standard deviation (SD) of healthy controls; (4) Results: Eighty-four subjects were included (44.9 ± 9 years, 16.3 ± 2 education years, Expanded Disability Status Scale (EDSS): 2.6 ± 1.4, MS-type (relapsing-remitting, primary progressive, or secondary progressive): 73/6/5, disease duration: 9.9 ± 7 years, VO₂-max: 28.4 ± 7.0 mL O₂/min/kg). No significant associations between aerobic capacity and cognitive performance in the individual BRBNT tests were found, except that a weak relationship was found between aerobic capacity and the composite processing speed z-score (R² = 0.06, p = 0.02). The average global BRBNT z-score (−0.2 ± 0.66) was not associated with aerobic capacity. Comparison of the cognitively impaired group (34.5%) with the nonimpaired group (65.5%) showed lower aerobic capacity in the impaired group (25.9 ± 1 vs. 29.7 ± 1 mLO₂/min/kg, p = 0.02); (5) Conclusions: Limited support was found for an association between performance in most cognitive domains and aerobic capacity in the present MS group with a third of patients showing signs of cognitive impairments.

Pain, activities of daily living and sport function at different time points after hip arthroscopy in patients with femoroacetabular impingement: a systematic review with meta-analysis

AIM

To investigate pain, activities of daily living (ADL) function, sport function, quality of life and satisfaction at different time points after hip arthroscopy in patients with femoroacetabular impingement (FAI).

DESIGN

Systematic review with meta-analysis. Weighted mean differences between preoperative and postoperative outcomes were calculated and used for meta-analysis.

DATA SOURCES

EMBASE, MEDLINE, SportsDiscus, CINAHL, Cochrane Library, and PEDro.

ELIGIBILITY CRITERIA FOR SELECTING STUDIES

Studies that evaluated hip pain, ADL function, sport function and quality of life before and after hip arthroscopy and postoperative satisfaction in patients with symptomatic FAI.

RESULTS

Twenty-six studies (22 case series, 3 cohort studies, 1 randomised controlled trial (RCT)) were included in the systematic review and 19 in the meta-analysis. Clinically relevant pain and ADL function improvements were first reported between 3 and 6 months, and sport function improvements between 6 months and 1 year after surgery. It is not clear when quality of life improvements were first achieved. On average, residual mild pain and ADL and sport function scores lower than their healthy counterparts were reported by patients following surgery. Postoperative patient satisfaction ranged from 68% to 100%.

CONCLUSIONS

On average, patients reported earlier pain and ADL function improvements, and slower sport function improvements after hip arthroscopy for FAI. However, average scores from patients indicate residual mild hip pain and/or hip function lower than their healthy counterparts after surgery. Owing to the current low level of evidence, future RCTs and cohort studies should investigate the effectiveness of hip arthroscopy in patients with FAI.

TRIAL REGISTRATION NUMBER

CRD42015019649.

Cardiopulmonary fitness is related to disease severity in multiple sclerosis

BACKGROUND

In persons with MS (pwMS), a lower cardiopulmonary fitness has been associated with a higher risk for secondary disorders, decreased functional capacity, symptom worsening and reduced health-related quality of life.

OBJECTIVE

To investigate the association between disease severity and cardiopulmonary fitness.

METHODS

Data from cardiopulmonary exercise tests, previously conducted in three different countries, were pooled. The association between disease severity (Expanded Disability Status Scale (EDSS)) and cardiopulmonary fitness (peak oxygen uptake (VO2peak)) was adjusted for age, sex and the country of origin.

RESULTS

The combined sample comprised 116 ambulant pwMS having a mean (± SD) EDSS score of 2.7 ± 1.3. There was a significant correlation (r = -0.418, p < .01) between VO2peak and EDSS. A multiple regression model (R(2) = 0.520, p < .01) was constructed to describe VO2peak (mL∙kg(-1)∙min(-1)); VO2peak = 36.622 - 5.433 (Sex (1=men)) - 0.124 (Age) - 2.082 (EDSS) + 2.737 (Belgium) + 8.674 (Denmark).

CONCLUSION

There was a significant association between disease severity and cardiopulmonary fitness. The close relation between cardiopulmonary fitness and chronic conditions associated with physical inactivity, suggest a progressive increase in risk of secondary health conditions in pwMS.