Modernizing Daily Function Assessment in Parkinson's Disease Using Capacity, Perception, and Performance Measures.

Many disease symptoms restrict the quality of life of the affected. This usually occurs indirectly, at least in most neurological diseases. Here, impaired daily function is interposed between the symptoms and the reduced quality of life. This is reflected in the International Classification of Function, Disability and Health model published by the World Health Organization in 2001. This correlation between symptom, daily function, and quality of life makes it clear that to evaluate the success of a therapy and develop new therapies, daily function must also be evaluated as accurately as possible. However, daily function is a complex construct and therefore difficult to quantify. To date, daily function has been measured primarily by capacity (clinical assessments) and perception (surveys and patient-reported outcomes) assessment approaches. Now, daily function can be captured in a new dimension, that is, performance, through new digital technologies that can be used in the home environment of patients. This viewpoint discusses the differences and interdependencies of capacity, perception, and performance assessment types using the example of Parkinson's disease. Options regarding how future study protocols should be designed to get the most comprehensive and validated picture of daily function in patients are presented. © 2020 The Authors. Movement Disorders published by Wiley Periodicals LLC on behalf of International Parkinson and Movement Disorder Society.

New methods for the assessment of Parkinson's disease (2005 to 2015): A systematic review.

BACKGROUND: The past decade has witnessed a highly dynamic and growing expansion of novel methods aimed at improving the assessment of Parkinson's disease with technology (NAM-PD) in laboratory, clinical, and home environments. However, the current state of NAM-PD regarding their maturity, feasibility, and usefulness in assessing the main PD features has not been systematically evaluated. METHODS: A systematic review of articles published in the field from 2005 to 2015 was performed. Of 9,503 publications identified in PubMed and the Web of Science, 848 full papers were evaluated, and 588 original articles were assessed to evaluate the technological, demographic, clinimetric, and technology transfer readiness parameters of NAM-PD. RESULTS: Of the studies, 65% included fewer than 30 patients, < 50% employed a standard methodology to validate diagnostic tests, 8% confirmed their results in a different dataset, and 87% occurred in a clinic or lab. The axial features domain was the most frequently studied, followed by bradykinesia. Rigidity and nonmotor domains were rarely investigated. Only 6% of the systems reached a technology level that justified the hope of being included in clinical assessments in a useful time period. CONCLUSIONS: This systematic evaluation provides an overview of the current options for quantitative assessment of PD and what can be expected in the near future. There is a particular need for standardized and collaborative studies to confirm the results of preliminary initiatives, assess domains that are currently underinvestigated, and better validate the existing and upcoming NAM-PD. © 2016 International Parkinson and Movement Disorder Society.

Quantitative home-based assessment of Parkinson's symptoms: the SENSE-PARK feasibility and usability study.

BACKGROUND: Currently, assessment of symptoms associated with Parkinson's disease is mainly performed in the clinic. However, these assessments have limitations because they provide only a snapshot of the condition. METHODS: The feasibility and usability of an objective, continuous and relatively unobtrusive system (SENSE-PARK System), which consists of wearable sensors (three worn during the day and one worn at night), a smartphone-based App, a balance board and computer software, was tested 24/7 over 12 weeks in a study including 22 PD patients. During the first four weeks of the study, patients did not get feedback about their performance, during the last eight weeks they did. The study included seven clinical visits with standardized interviews, and regular phone contact. The primary outcome was the number of drop-outs during the study. As secondary outcomes, the Post-Study System Usability Questionnaire (PSSUQ), score and information obtained from the standardized interviews were used to evaluate the usability of the system. RESULTS: All patients completed the study. The participants rated the usability of the SENSE-PARK System with a mean score of 2.67 (±0.49) on the PSSUQ. The interviews revealed that most participants liked using the system and appreciated that it signaled changes in their health condition. CONCLUSIONS: This 12 week controlled study demonstrates that the acceptance level of PD patients using the SENSE-PARK System as a home-based 24/7 assessment is very good. Particular emphasis should be given to a user-friendly design. Motivation to wear such a system can be increased by providing direct feedback about the individual health condition.

Autonomic Symptoms in Older Adults Are Common and Associated With Health-Related Quality of Life.

Background: Autonomic symptoms are common in older adults, and a large body of literature focusing on age-related diseases shows that autonomic symptoms in these diseases constrain Health-Related Quality of Life (HRQoL). To our best knowledge, the association between autonomic symptoms in older adults, independent of specific diseases, and HRQoL has not yet been assessed. Aim: To assess the frequency and the effect of autonomic symptoms in general, as well as orthostatic intolerance, vasomotor, secretomotor, gastrointestinal, bladder, and pupillomotor symptoms, on HRQoL in older adults. Methods: Cross-sectional data of the fourth visit of the Tübinger evaluation of Risk factors for Early detection of Neurodegeneration (TREND) study were included. Autonomic symptoms, as assessed with the Composite Autonomic Symptom Score 31 (COMPASS 31), were quantified and compared with HRQoL, as assessed with the EuroQol five-level version (EQ-5D-5L). Statistical analyses included Spearman's rank correlation and multiple linear regression analysis. Results: The analysis included 928 participants with a median of 68 years; 47% were women. Of those, 85% reported at least one autonomic symptom. Gastrointestinal and secretomotor symptoms were most common. The COMPASS 31 total score and all subdomains were significantly associated with reduced HRQoL. Among the subdomains, the strongest correlations with HRQoL were found for gastrointestinal and bladder symptoms. Overall, autonomic symptoms alone explained 20% of the variance of HRQoL; when depressive mood was added, the model explained 32%. Conclusion: Autonomic symptoms are associated with HRQoL and depressive symptoms in older adults.

Walking on common ground: a cross-disciplinary scoping review on the clinical utility of digital mobility outcomes.

Physical mobility is essential to health, and patients often rate it as a high-priority clinical outcome. Digital mobility outcomes (DMOs), such as real-world gait speed or step count, show promise as clinical measures in many medical conditions. However, current research is nascent and fragmented by discipline. This scoping review maps existing evidence on the clinical utility of DMOs, identifying commonalities across traditional disciplinary divides. In November 2019, 11 databases were searched for records investigating the validity and responsiveness of 34 DMOs in four diverse medical conditions (Parkinson's disease, multiple sclerosis, chronic obstructive pulmonary disease, hip fracture). Searches yielded 19,672 unique records. After screening, 855 records representing 775 studies were included and charted in systematic maps. Studies frequently investigated gait speed (70.4% of studies), step length (30.7%), cadence (21.4%), and daily step count (20.7%). They studied differences between healthy and pathological gait (36.4%), associations between DMOs and clinical measures (48.8%) or outcomes (4.3%), and responsiveness to interventions (26.8%). Gait speed, step length, cadence, step time and step count exhibited consistent evidence of validity and responsiveness in multiple conditions, although the evidence was inconsistent or lacking for other DMOs. If DMOs are to be adopted as mainstream tools, further work is needed to establish their predictive validity, responsiveness, and ecological validity. Cross-disciplinary efforts to align methodology and validate DMOs may facilitate their adoption into clinical practice.

The association between objectively measured physical activity, depression, cognition, and health-related quality of life in Parkinson's disease.

BACKGROUND: Lower levels of physical activity are associated with lower Health-Related Quality of Life (HRQoL) in Parkinson's disease (PD). We evaluated the influence of quantitative physical activity parameters among other (disease-related) features representing other domains of the WHO International model for classification of Function, Disability, and Health (ICF) on HRQoL in PD. METHODS: Home-based movement data (DynaPort MiniMod®) was collected in 47 PD patients. Nine stepwise regression models were calculated, with consecutive outcome variables: Parkinson's Disease Questionnaire (PDQ) Summary Index (SI), PDQ-Mobility, PDQ-Activities of Daily Living (ADL). Demographic variables, disease-specific features, and quantitative physical activity parameters, were included as predicting variables in all analyses. The following three physical activity parameters were alternately included for both sedentary and active episodes: 'percentage' of 24 h spent within these episodes, 'number of bouts', and 'mean bout lengths' (MBL). RESULTS: Depression and 'Total Energy Expenditure' were the main predictors of overall HRQoL (PDQ-SI), independent of the permutation of activity parameters. The same parameters predicted the PDQ-Mobility score. However, this result was altered when 'MBL' parameters were included into the model, 'MBL' of sedentary episodes additionally predicted HRQoL-Mobility. The PDQ-ADL score was associated with demographic, motor, and non-motor variables including cognitive status. After exclusion of demented PD patients, older age and cognitive impairment no longer constrained HRQoL-ADL. DISCUSSION: For the first time, we showed the influence of objective, home-based measured physical activity among depression and cognition on HRQoL in PD. This suggests that a multifactorial treatment approach would be most successful to increase HRQoL in PD.

Effect of Fear of Falling on Turning Performance in Parkinson's Disease in the Lab and at Home.

Background: Parkinson's disease (PD) is a neurodegenerative movement disorder associated with gait and balance problems and a substantially increased risk of falling. Falls occur often during complex movements, such as turns. Both fear of falling (FOF) and previous falls are relevant risk factors for future falls. Based on recent studies indicating that lab-based and home assessment of similar movements show different results, we hypothesized that FOF and a positive fall history would influence the quantitative turning parameters differently in the laboratory and home. Methods: Fifty-five PD patients (43 underwent a standardized lab assessment; 40 were assessed over a mean of 12 days at home with approximately 10,000 turns per participant; and 28 contributed to both assessments) were classified regarding FOF and previous falls as "vigorous" (no FOF, negative fall history), "anxious" (FOF, negative fall history), "stoic" (no FOF, positive fall history) and "aware" (FOF, positive fall history). During the assessments, each participant wore a sensor on the lower back. Results: In the lab assessment, FOF was associated with a longer turning duration and lowered maximum and middle angular velocities of turns. In the home evaluations, a lack of FOF was associated with lowered maximum and average angular velocities of turns. Positive falls history was not significantly associated with turning parameters, neither in the lab nor in the home. Conclusion: FOF but not a positive fall history influences turning metrics in PD patients in both supervised and unsupervised environments, and this association is different between lab and home assessments. Our findings underline the relevance of comprehensive assessments including home-based data collection strategies for fall risk evaluation.

No relevant association of kinematic gait parameters with Health-related Quality of Life in Parkinson's disease.

BACKGROUND: Health-related Quality of Life (HrQoL) is probably the most important outcome parameter for the evaluation and management of chronic diseases. As this parameter is subjective and prone to bias, there is an urgent need to identify objective surrogate markers. Gait velocity has been shown to be associated with HrQoL in numerous chronic diseases, such as Parkinson's disease (PD). With the development and wide availability of simple-to-use wearable sensors and sophisticated gait algorithms, kinematic gait parameters may soon be implemented in clinical routine management. However, the association of such kinematic gait parameters with HrQoL in PD has not been assessed to date. METHODS: Kinematic gait parameters from a 20-meter walk from 43 PD patients were extracted using a validated wearable sensor system. They were compared with the Visual Analogue Scale of the Euro-Qol-5D (EQ-5D VAS) by performing a multiple regression analysis, with the International Classification of Functioning, Disability and Health (ICF) model as a framework. RESULTS: Use of assistive gait equipment, but no kinematic gait parameter, was significantly associated with HrQoL. CONCLUSION: The widely accepted concept of a positive association between gait velocity and HrQoL may, at least in PD, be driven by relatively independent parameters, such as assistive gait equipment.

A Viewpoint on Wearable Technology-Enabled Measurement of Wellbeing and Health-Related Quality of Life in Parkinson's Disease.

In this viewpoint, we discuss how several aspects of Parkinson's disease (PD) - known to be correlated with wellbeing and health-related quality of life-could be measured using wearable devices ('wearables'). Moreover, three people with PD (PwP) having exhaustive experience with using such devices write about their personal understanding of wellbeing and health-related quality of life, building a bridge between the true needs defined by PwP and the available methods of data collection. Rapidly evolving new technologies develop wearables that probe function and behaviour in domestic environments of people with chronic conditions such as PD and have the potential to serve their needs. Gathered data can serve to inform patient-driven management changes, enabling greater control by PwP and enhancing likelihood of improvements in wellbeing and health-related quality of life. Data can also be used to quantify wellbeing and health-related quality of life. Additionally these techniques can uncover novel more sensitive and more ecologically valid disease-related endpoints. Active involvement of PwP in data collection and interpretation stands to provide personally and clinically meaningful endpoints and milestones to inform advances in research and relevance of translational efforts in PD.

Health-Related Quality of Life in patients with Parkinson's disease--A systematic review based on the ICF model.

We analyzed features associated with a reduction in Health-Related Quality of Life (HRQoL) in people with idiopathic Parkinson's disease (PD). As a new approach, features were embedded in the WHO framework for measuring health and disability, the ICF model. From 609 articles screened, 114 articles were included. Features aligned with the ICF's body functions and structures domain (BFS) were investigated more often than personal features, activities of daily living, environmental factors, and participation in societal roles (95, 42, 35, 29 and 14 times, respectively). The strongest associations were found for the relationships between HRQoL and "psychosocial functioning" from the participation domain and HRQoL, and "mobility limitations" from the activities domain. For the BFS, non-motor symptoms were more closely associated with reduced HRQoL than motor symptoms. In conclusion, this systematic review (i) provides entirely new insights in the association of HRQoL with PD features, (ii) shows an imbalance between most extensively investigated and most relevant features for HRQoL, and (iii) demonstrates the usefulness of the ICF model for such an approach.

Continuous leg dyskinesia assessment in Parkinson's disease -clinical validity and ecological effect.

INTRODUCTION: Dyskinesias in Parkinson's disease (PD) patients are a common side effect of long-term dopaminergic therapy and are associated with motor dysfunctions, including gait and balance deficits. Although promising compounds have been developed to treat these symptoms, clinical trials have failed. This failure may, at least partly, be explained by the lack of objective and continuous assessment strategies. This study tested the clinical validity and ecological effect of an algorithm that detects and quantifies dyskinesias of the legs using a single ankle-worn sensor. METHODS: Twenty-three PD patients (seven with leg dyskinesias) and 13 control subjects were investigated in the lab. Participants performed purposeful daily activity-like tasks while being video-taped. Clinical evaluation was performed using the leg dyskinesia item of the Unified Dyskinesia Rating Scale. The ecological effect of the developed algorithm was investigated in a multi-center, 12-week, home-based sub-study that included three patients with and seven without dyskinesias. RESULTS: In the lab-based sub-study, the sensor-based algorithm exhibited a specificity of 98%, a sensitivity of 85%, and an accuracy of 0.96 for the detection of dyskinesias and a correlation level of 0.61 (p < 0.001) with the clinical severity score. In the home-based sub-study, all patients could be correctly classified regarding the presence or absence of leg dyskinesias, supporting the ecological relevance of the algorithm. CONCLUSION: This study provides evidence of clinical validity and ecological effect of an algorithm derived from a single sensor on the ankle for detecting leg dyskinesias in PD patients. These results should motivate the investigation of leg dyskinesias in larger studies using wearable sensors.

Quantitative Timed-Up-and-Go Parameters in Relation to Cognitive Parameters and Health-Related Quality of Life in Mild-to-Moderate Parkinson's Disease.

INTRODUCTION: The instrumented-Timed-Up-and-Go test (iTUG) provides detailed information about the following movement patterns: sit-to-walk (siwa), straight walking, turning and walk-to-sit (wasi). We were interested in the relative contributions of respective iTUG sub-phases to specific clinical deficits most relevant for daily life in Parkinson's disease (PD). More specifically, we investigated which condition-fast speed (FS) or convenient speed (CS)-differentiates best between mild- to moderate-stage PD patients and controls, which parameters of the iTUG sub-phases are significantly different between PD patients and controls, and how the iTUG parameters associate with cognitive parameters (with particular focus on cognitive flexibility and working memory) and Health-Related-Quality of Life (HRQoL). METHODS: Twenty-eight PD participants (65.1 ± 7.1 years, H&Y stage 1-3, medication OFF state) and 20 controls (66.1 ± 7.5 years) performed an iTUG (DynaPort®, McRoberts BV, The Netherlands) under CS and FS conditions. The PD Questionnaire 39 (PDQ-39) was employed to assess HRQoL. General cognitive and executive functions were assessed using the Montreal Cognitive Assessment and the Trail Making Test. RESULTS: The total iTUG duration and sub-phases durations under FS condition differentiated PD patients slightly better from controls, compared to the CS condition. The following sub-phases were responsible for the observed longer total duration PD patients needed to perform the iTUG: siwa, turn and wasi. None of the iTUG parameters correlated relevantly with general cognitive function. Turning duration and wasi maximum flexion velocity correlated strongest with executive function. Walking back duration correlated strongest with HRQoL. DISCUSSION: This study confirms that mild- to moderate-stage PD patients need more time to perform the iTUG than controls, and adds the following aspects to current literature: FS may be more powerful than CS to delineate subtle movement deficits in mild- to moderate-stage PD patients; correlation levels of intra-individual siwa and wasi parameters may be interesting surrogate markers for the level of automaticity of performed movements; and sub-phases and kinematic parameters of the iTUG may have the potential to reflect executive functioning and HRQoL aspects of PD patients.

The end-state comfort effect facilitates joint action.

Motor experts can accurately predict the future actions of others by observing their movements. This report describes three experiments that investigate such predictions in everyday object manipulations and test whether these predictions facilitate responses to the actions of others. Observing video excerpts showing an actor reaching for a vertically mounted dial, participants in Experiment 1 needed to predict how the actor would rotate it. Their predictions were specific to the direction and extent of the dial rotation and improved proportionate to the length of the video clip shown. Testing whether such predictions facilitate responses, in the subsequent experiments responders had to undo an actor's actions, back-rotating a dial (Exp 2) and a bar (Exp 3). The responders' actions were initiated faster when the actors' movements obeyed the so-called end-state comfort principle than when they did not. Our experiments show that humans exploit the end-state comfort effect to tweak their predictions of the future actions of others. The results moreover suggest that the precision of these predictions is mediated by perceptual learning rather than by motor simulation.