Which measures of physical function and motor impairment best predict quality of life in Parkinson's disease?

Lower extremity physical function and quality of life in patients with stroke: a longitudinal cohort study

PURPOSE

Lower extremity physical function (LEPF) is a key component for mobility and is impacted in stroke-related disability. A reduction in LEPF can have a significant impact on an individual's Quality of Life (QoL). The aim of this study is to characterise the relationship between LEPF and QoL.

METHODS

The MOBITEC-Stroke Study is a longitudinal cohort-study including patients with their first occurrence of ischaemic stroke. Using a linear mixed-effects model, the relationship between LEPF (timed up-and-go performance (TUG); predictor) and QoL (Stroke Specific Quality of Life scale (SS-QoL); outcome) at 3 and 12 months post stroke was investigated and adjusted for sex, age, Instrumental Activities of Daily Living (IADL), fear of falling (Falls Efficacy Scale-International Version, FES-I), and stroke severity (National Institute of Stroke Severity scale, NIHSS), accounting for the repeated measurements.

RESULTS

Data of 51 patients (65 % males, 35% females) were analysed. The mean age was 71.1 (SD 10.4) years, median NIHSS score was 2.0. SS-QoL was 201.5 (SD 20.5) at 3 months and 204.2 (SD 17.4) at 12 months; the mean change was 2.7 (95% CI -2.4 to 7.7), p= 0.293. A positive association was found between baseline TUG performance (estimate log score -13.923; 95% CI -27.495 to -0.351; p=0.048) and change in SS-QoL score in multivariate regression analysis.

CONCLUSION

Higher LEPF (i.e better TUG performance) at baseline, was associated with an improvement in QoL from 3- to 12-months post stroke. These results highlight the critical role of physical function, particularly baseline LEPF, in influencing the QoL of stroke survivors.

Correlation between motor function and health-related quality of life in early to mid-stage patients with Parkinson disease: a cross-sectional observational study

Aim

To investigate the correlation between motor function and health-related quality of life (HrQOL) in early to mid-stage patients with Parkinson disease (PwP).

Methods

This cross-sectional study recruited PwP from April 2020 to December 2023 at the outpatient clinic of Peking Union Medical College Hospital in Beijing, China. The motor symptoms were assessed using Movement Disorder Society-sponsored revision of the Unified Parkinson's Disease Rating Scale (MDS-UPDRS) part 3. Balance function was evaluated using the Berg Balance Scale (BBS), and the risk of fall using Timed Up-and-Go test (TUG), and Five Times Sit-to-Stand test (FTSST). Freezing of gait questionnaire (FOGQ) was used to evaluate the severity of gait. The Intelligent Device for Energy Expenditure and Physical Activity (IDEEA) recorded gait cycle parameters, and the isokinetic dynamometer measured muscle strength. The Parkinson's Disease Questionnaire-39 (PDQ-39) was used to measure HrQOL. All assessments were tested during the on state. Spearman correlation was conducted to evaluate the correlation between motor function and HrQOL.

Results

243 patients with mean age of 69.33 years were enrolled. The PDQ-39 score was strongly correlated with FOG in H&Y stage III (r = 0.653, p < 0.001) and moderately correlated in H&Y stage I (r = 0.471, p < 0.001) and H&Y stage II (r = 0.386, p < 0.001). Furthermore, the FOG was strongly correlated with mobility domain at H&Y stage III (r = 0.694, p < 0.001) and moderately correlated at H&Y stage I (r = 0.431, p < 0.001) and H&Y stage II (r = 0.434, p < 0.001). All motor function scores were correlated with PDQ-39 scores at H&Y stage III (p < 0.05).

Conclusion

Motor function correlated with HrQOL in early to mid-stage PwP, and FOG was the main factor, especially affecting mobility, activities of daily life and communication. HrQOL in patients at different disease stages were variously affected by motor function, and HrQOL and multiple dimensions was significantly associated with motor function in patients at H&Y stage III.

Turns while walking among individuals with Parkinson's disease following overground locomotor training: A pilot study

BACKGROUND

Individuals with Parkinson's disease are challenged in making turns while walking, evidenced by reduced intersegmental coordination and reduced dynamic postural stability. Although overground locomotor training previously improved ambulation among people with Parkinson's disease, its effect on walking turns remained unknown. We sought to understand the effects of overground locomotor training on walking turns among individuals with mild-Parkinson's disease.

METHODS

Twelve participants with Parkinson's (7 Males/5 Females; Age: 68.5 ± 6.4 years) completed twenty-four sessions lasting approximately 60 min and over 12-15 weeks. Baseline and follow-up assessments included the ten-minute walk test using wearable sensors. Primary outcomes included changes to intersegmental coordination, measured by peak rotation and normalized peak rotation, and dynamic postural stability, measured by peak turn velocities in the frontal and transverse planes. Statistical analysis included one-tailed paired t-tests and Cohen's d effect sizes with α = 0.05.

FINDINGS

No effects of overground locomotor training on mean peak thoracic rotation (+0.23 ± 4.24°; Cohen's d = 0.05; P = 0.45) or mean normalized peak thoracic rotation (-0.59 ± 5.52 (unitless); Cohen's d = 0.10; P = 0.45) were observed. Moderate and small effects of overground locomotor training were observed on mean peak turn velocities in the frontal (+1.59 ± 2.18°/s; Cohen's d = 0.43; P = 0.01) and transverse planes (+0.88 ± 3.18°/s; Cohen's d = 0.25; P = 0.18).

INTERPRETATION

This pilot study provides preliminary evidence suggesting that individuals with mild-Parkinson's moderately improved frontal plane dynamic postural stability after overground locomotor training, likely attenuating the perturbations experienced while turning.

CLINICAL TRIAL REGISTRATION

NCT03864393.

Exercise-Induced Functional Changes in People with Parkinson's Disease following External Cueing and Task-Based Intervention

Introduction

The purpose of this study was to evaluate change in motor function, gait speed, dynamic balance, balance confidence, and quality of life (QoL) in nine participants with Parkinson's disease (PwPD) completing Lee Silverman Voice Treatment BIG (LSVT-BIG), an external cueing and task-based intervention. Although supported as an efficacious treatment in PwPD, there is limited research examining clinically meaningful change in outcome measures related to external cueing and task-based interventions.

Materials and Methods

This was a case series of nine PwPD (age range 64-76 years, 55% male) who completed the LSVT-BIG protocol. Disease duration ranged from 1 to 17 years and was classified as moderate in all participants (Hoehn and Yahr = 2 or 3). Outcome measures included motor function (MDS-UPDRS Part III Motor), gait speed, dynamic balance (MiniBEST), Activities-specific Balance Confidence (ABC), and Summary Index for PD Quality of Life 39 (PDQ-SI). Assessments were completed at baseline (BASE), end of treatment (EOT), and 4 weeks after EOT (EOT+4).

Results

Minimal detectable change (MDC) or minimal clinical important difference (MCID) was observed in one or more outcome measures in 8 of 9 participants at EOT and EOT+4 across domains of motor function (67%, 78%), gait speed (78%, 67%), balance confidence (44%, 33%), quality of life (44%, 78%), and dynamic balance (22%, 22%). Discussion. In this case series, 8 of 9 participants showed MDC or MCID changes across multiple functional domains. Improvements were observed immediately post (EOT) and 4-week post-treatment (EOT+4) suggesting a temporal component of the LSVT-BIG impact on functional change. Future research should include clinical trials to examine additional external cueing and task-based intervention efficacy with consideration of intensity, frequency, and mode of delivery across disease severity.

Cross-Spatiotemporal Graph Convolution Networks for Skeleton-Based Parkinsonian Gait MDS-UPDRS Score Estimation

Gait impairment in Parkinson's Disease (PD) is quantitatively assessed using the Movement Disorder Society Unified Parkinson's Disease Rating Scale (MDS-UPDRS), a well-established clinical tool. Objective and efficient PD gait assessment is crucial for developing interventions to slow or halt its advancement. Skeleton-based PD gait MDS-UPDRS score estimation has attracted increasing interest in improving diagnostic efficiency and objectivity. However, previous works ignore the important cross-spacetime dependencies between joints in PD gait. Moreover, existing PD gait skeleton datasets are very small, which is a big issue in deep learning-based gait studies. In this work, we collect a sizable PD gait skeleton dataset by multi-view Azure Kinect sensors. The collected dataset contains 102 PD patients and 30 healthy older adults. In addition, gait data from 16 young adults (aged 24-50 years) are collected to further examine the effect of age on PD gait assessment. For skeleton-based automatic PD gait analysis, we propose a novel cross-spatiotemporal graph convolution network (CST-GCN) to learn complex features of gait patterns. Specifically, a gait graph labeling strategy is designed to assemble and group cross-spacetime neighbors of the root node according to the spatiotemporal semantics of the gait skeleton. Based on this strategy, the CST-GCN module explicitly models the cross-spacetime dependencies among joints. Finally, a dual-path model is presented to realize the modeling and fusion of spatial, temporal, and cross-spacetime gait features. Extensive experiments validate the effectiveness of our method on the collected dataset.

The predictive relationships between advanced dynamic balance and physical activity/quality of life in Parkinson's disease

Gait and balance problems commonly occur in Parkinson's disease (PD). However, balance tasks with only one performance objective (e.g., sit-to-stand) may not be sufficient, compared to dual motor tasks (e.g., carrying a tray while walking), to be applied to the assessments and interventions which are designed to promote PD patients' balance functioning, physical activity (PA) and health-related quality of life (HQoL). The aim of this study, therefore, was to determine whether advanced dynamic balance, measured by a demanding motor-motor dual task, is a significant predictor of PA/HQoL in older adults with and without PD. Participants with (n = 22) and without (n = 23) PD were assessed using the Berg Balance Scale (BBS), the single leg hop and stick series task (SLHS), the Physical Activity Scale for the Elderly (PASE), and the Parkinson's Disease Questionnaire-39 (PDQ39). We calculated the R² change, namely the incremental validity, between the multiple regression models before and after adding the scores on the BBS/SLHS. While controlling for biological and socioeconomic covariates, competence in the SLHS task provided moderate and large levels of incremental validity to PA (ΔR² = 0.08, Cohen's f² = 0.25, p = .035) and HQoL (ΔR² = 0.13, Cohen's f² = 0.65, p < .001), respectively. In particular for participants with PD, the SLHS explained significantly more variance in HQoL in relation to psychosocial functioning (ΔR² = 0.25, Cohen's f² = 0.42, p = .028) compared to the BBS (p = .296). Assessing advanced dynamic balance by means of a highly demanding dual-task paradigm was not only strongly associated with PA but also covered a wider spectrum of HQoL components. This approach is recommended for use in evaluations and interventions carried out in clinical and research settings in order to promote healthy living.

Determinants of 6-minute walk test in people with Parkinson's disease

BACKGROUND

Most of the previous studies, investigating determinants of 6-minute walk test (6MWT), were conducted on small sample sizes and/or have not explored different aspects such as freezing of gait, physical activity, gender, dual-task cost, and/or have not been able to explain large portion of variation in 6MWT in people with Parkinson's disease.

AIMS

This study aimed to investigate the determinants of 6MWT, including aspects that previous studies have not explored.

METHODS

In this descriptive cross-sectional study, 6MWT determinants were investigated upon 42 people with Parkinson's disease. After recording participants' demographic data, walking capacity, disease stage, severity of motor symptoms, freezing of gait, balance, physical activity, fear of falling, functional balance, and dual-task cost values were evaluated and grouped into modifiable and unmodifiable variables to investigate possible therapeutic benefits aiming improvement in walking capacity.

RESULTS

The mean distance for 6MWT was 401.7 ± 92.7 m. Significant differences between women and men were found for height, walking capacity and speed, fear of falling, and functional balance (p<0.05). Hierarchical regression analysis showed that gender, age, and time since diagnosis significantly explained 52.4% of the variance in 6MWT and disease stage, freezing of gait, dual-task cost, and functional balance added an extra 35.6% to the explained variance.

CONCLUSIONS

These results showed that gender, age, disease stage, freezing of gait, dual-task cost, and functional balance values are significant contributors to the variance in 6MWT. Therefore, while planning rehabilitation strategies to improve walking capacity, one should focus on these aspects in people with Parkinson's disease.

Effects of LSVT-BIG via telerehabilitation on non-motor and motor symptoms and quality of life in Parkinson's disease

BACKGROUND

Parkinson's disease (PD) is a neurodegenerative disease with motor and non-motor symptoms affecting the quality of life. This study aimed to investigate the effects of the Lee Silverman Voice Therapy (LSVT)-BIG rehabilitation program via telerehabilitation on quality of life, motor and non-motor symptoms in people with Parkinson's disease (PwPD), and their correlation with each other.

METHODS

Fifteen patients with mild-to-moderate PD (Hoehn and Yahr stages 1-3) were included in the LSVT-BIG exercise program with remote access for 16 sessions over four weeks. Motor and non-motor experiences before and after the program were evaluated with MDS-UPDRS parts 1, 2, and 3 and quality of life with PDQ-39. The correlation between MDS-UPDRS parts and PDQ-39 subgroups was examined.

RESULTS

Following the application of the LSVT-BIG rehabilitation program with remote access, MDS-UPDRS parts 1, 2, and 3 scores and PDQ-39 summary index (PDQ-39 SI) and subgroup scores (excluding social support) were improved. A moderate-strong correlation was determined between MDS-UPDRS parts 1 and 2 and the PDQ-39 parameters of the patients.

CONCLUSION

Both motor and non-motor symptoms may be associated with the quality of life in PD. We have concluded that LSVT-BIG treatment via telerehabilitation can improve motor and non-motor symptoms along with the quality of life in PwPD.

Gait alterations in Parkinson’s disease at the stage of hemiparkinsonism—A longitudinal study

Background

Progressive gait impairment in Parkinson’s disease (PD) leads to significant disability. Quantitative gait parameters analysis provides valuable information about fine gait alterations.

Objectives

To analyse change of gait parameters in patients with early PD at the stage of hemiparkinsonism and after 1 year of follow up, taking into account clinical asymmetry.

Methods

Consecutive early PD outpatients with strictly unilateral motor features underwent clinical and neuropsychological assessment at the study entry and after 1 year of follow up. Gait was assessed with GAITRite walkway using dual-task methodology. Spatiotemporal gait parameters (step time and length, swing time and double support time) and their coefficients of variation (CV), gait velocity and heel-to-heel base support were evaluated.

Results

We included 42 PD patients with disease duration of 1.3 years (±1.13). Progression of motor and non-motor symptoms, without significant cognitive worsening, was observed after 1 year of follow up. Significant shortening of the swing time, prolongation of the double support and increase of their CVs were observed during all task conditions similarly for most parameters on symptomatic and asymptomatic bodysides, except for CV for the swing time under the combined task.

Conclusion

Alterations of the swing time and double support time are already present even at the asymptomatic body side, and progress similarly, or even at faster pace, at this side, despite dopaminergic treatment These parameters deserve further investigation in larger, prospective studies to address their potential to serve as markers of progression in interventional disease modifying trials with early PD patients.

Measures of motor segmentation from rapid isometric force pulses are reliable and differentiate Parkinson's disease from age-related slowing

Some people with Parkinson's disease (PD) have disruptions in motor output during rapid isometric muscle contractions. Measures of such disruptions (motor segmentation) may help clarify disease subtype, progression, or effects of therapeutic interventions. We investigated the potential utility of segmentation measures by testing two hypotheses that are fundamental to measurement and evaluation. First, measures of motor segmentation are reliable from day to day (intraclass correlation coefficient > 0.8). Second, that measures of motor segmentation have the sensitivity to differentiate between people with PD and older adults. 10 subjects with PD had a mean age of 70.1 years, Hoehn-Yahr stage < 3, and median levodopa equivalent daily dose of 350 mg. Older adult (mean age 81.9 years) reference data are from a previously published study. Each subject provided approximately 87 rapid isometric index finger abduction force pulses up to 65% of their maximal isometric force for calculation of force pulse measures. Measures were computed for the excitation, transition, and relaxation phases of each force pulse. Measures of motor segmentation had high reliability and presented large (Cohen's D > 0.8) and significant (p < 0.05) group differences. In bivariate plots of selected measures, motor segmentation marked a departure of PD from age-related slowing. Across all subjects, greater segmentation was associated with greater impairments in rate control and a longer time to reach peak force (all Spearman's ρ > 0.8). These results support the potential utility of the motor segmentation measures by satisfying requirements for reliability and the sensitivity to indicate deviations from age-related slowing in motor output.

Association of Motor and Nonmotor Symptoms With Health-Related Quality of Life in a Large Online Cohort of People With Parkinson Disease

Background and Objectives

There is growing interest in health-related quality of life (HRQOL) as a comprehensive view of the patient's well-being, guiding concept for the treating clinician, and therapeutic trial outcome measure for patients with Parkinson disease (PwPD). The key determinants of HRQOL have not been investigated in large populations of PwPD. Our objective was to evaluate correlates of HRQOL in a large, online cohort of PwPD.

Methods

As part of an ongoing online cohort study, we performed a cross-sectional analysis at enrollment of 23,058 PwPD. We conducted univariate and stepwise multivariate linear regression analyses of HRQOL as measured by the EQ-5D-5L tool. In addition, we performed an interaction analysis to evaluate heterogeneity of the effect of motor symptoms on HRQOL and Spearman correlation analysis to evaluate the association of nonmotor symptoms with HRQOL.

Results

In the multivariate linear regression model, participants with moderate or severe depression, more severe motor symptoms, and a higher burden of medical comorbidities had the most substantially decreased HRQOL as measured by the EQ index (β −0.11, −0.18, −0.02, −0.01, respectively; p < 0.001 for all). An interaction analysis showed that more severe motor symptoms had a higher effect on individuals with female sex, lower educational level, lower income, more severe depression, or more severe cognitive impairment (p ≤ 0.01 for interaction terms). Neuropsychiatric symptoms and falls had the most negative associations with HRQOL (ρ −0.31 to 0.37; p < 0.0001).

Discussion

Potentially treatable motor and nonmotor symptoms, particularly neuropsychiatric symptoms, account for a large amount of the variation in HRQOL in PwPD. Motor symptoms may have differential effects on HRQOL in different demographic and clinical subpopulations, highlighting important areas for future health disparities research. Our findings provide targets for clinician intervention and future research on symptom management to optimize HRQOL in PD.

Classification of Evidence

This study provides Class II evidence that motor and neuropsychiatric symptoms are associated with HRQOL in PwPD.

Outcomes Impacting Quality of Life in Advanced Parkinson’s Disease Patients Treated with Levodopa-Carbidopa Intestinal Gel

Background:

It is believed that motor symptoms, including dyskinesia, and non-motor symptoms impact health-related quality of life (HRQoL) in patients with Parkinson’s disease (PD), and that improvements in these metrics are correlated.

Objective:

Investigate the relationship between HRQoL and measures of PD severity and treatment efficacy, including motor and non-motor symptoms.

Methods:

This was a planned investigation of an international, prospective, single-arm, post-marketing observational study of the long-term effectiveness of levodopa-carbidopa intestinal gel (LCIG) in patients with advanced PD. Pearson correlation coefficients (PCC) were calculated for baseline and change from baseline at 12 months between HRQoL and motor and non-motor symptoms.

Results:

A total of 195 patients were included. At baseline, HRQoL was moderately positively correlated with Activities of Daily Living (UPDRS II, PCC = 0.44), non-motor symptoms (0.48), and measures of sleep (0.50 and 0.40); all p < 0.001. After 12 months of treatment with LCIG, improvements in HRQoL were moderately positively correlated with improvement from baseline in non-motor symptoms (PCC = 0.42), sleep (0.54), and daytime sleepiness (0.40; all p < 0.001), and weakly correlated with improvement in dyskinesia signs and symptoms (PCC = 0.23; p = 0.011). Improvement in HRQoL was not correlated with improvements in OFF time or dyskinesia time.

Conclusion:

Both at baseline and for change from baseline at 12 months, HRQoL was correlated with baseline and change from baseline in dyskinesia, Activities of Daily Living, and non-motor symptoms, including sleep; but not with baseline or change in OFF time.

Leveraging the Potential of Digital Technology for Better Individualized Treatment of Parkinson's Disease

Recent years have witnessed a strongly increasing interest in digital technology within medicine (sensor devices, specific smartphone apps) and specifically also neurology. Quantitative measures derived from digital technology could provide Digital Biomarkers (DMs) enabling a quantitative and continuous monitoring of disease symptoms, also outside clinics. This includes the possibility to continuously and sensitively monitor the response to treatment, hence opening the opportunity to adapt medication pathways quickly. In addition, DMs may in the future allow early diagnosis, stratification of patient subgroups and prediction of clinical outcomes. Thus, DMs could complement or in certain cases even replace classical examiner-based outcome measures and molecular biomarkers measured in cerebral spinal fluid, blood, urine, saliva, or other body liquids. Altogether, DMs could play a prominent role in the emerging field of precision medicine. However, realizing this vision requires dedicated research. First, advanced data analytical methods need to be developed and applied, which extract candidate DMs from raw signals. Second, these candidate DMs need to be validated by (a) showing their correlation to established clinical outcome measures, and (b) demonstrating their diagnostic and/or prognostic value compared to established biomarkers. These points again require the use of advanced data analytical methods, including machine learning. In addition, the arising ethical, legal and social questions associated with the collection and processing of sensitive patient data and the use of machine learning methods to analyze these data for better individualized treatment of the disease, must be considered thoroughly. Using Parkinson's Disease (PD) as a prime example of a complex multifactorial disorder, the purpose of this article is to critically review the current state of research regarding the use of DMs, discuss open challenges and highlight emerging new directions.

Dependence of Piezoelectric Discs Electrical Impedance on Mechanical Loading Condition

The piezoelectric effect, along with its associated materials, fascinated researchers in all areas of basic sciences and engineering due to its interesting properties and promising potentials. Sensing, actuation, and energy harvesting are major implementations of piezoelectric structures in structural health monitoring, wearable devices, and self-powered systems, to name only a few. The electrical or mechanical impedance of its structure plays an important role in deriving its equivalent model, which in turn helps to predict its behavior for any system-level application, such as with respect to the rectifiers containing diodes and switches, which represent a nonlinear electrical load. In this paper, we study the electrical impedance response of different sizes of commercial piezoelectric discs for a wide range of frequencies (without and with mechanical load for 0.1–1000 kHz with resolution 20 Hz). It shows significant changes in the position of resonant frequency and amplitude of resonant peaks for different diameters of discs and under varying mechanical load conditions, implying variations in the mechanical boundary conditions on the structure. The highlight of our work is the proposed electrical equivalent circuit model for varying mechanically loaded conditions with the help of impedance technique. Our approach is simple and reliable, such that it is suitable for any structure whose accurate material properties and dimensions are unknown.

Behavioural and neuroplastic effects of a double-blind randomised controlled balance exercise trial in people with Parkinson's disease

Balance dysfunction is a disabling symptom in people with Parkinson's disease (PD). Evidence suggests that exercise can improve balance performance and induce neuroplastic effects. We hypothesised that a 10-week balance intervention (HiBalance) would improve balance, other motor and cognitive symptoms, and alter task-evoked brain activity in people with PD. We performed a double-blind randomised controlled trial (RCT) where 95 participants with PD were randomised to either HiBalance (n = 48) or a control group (n = 47). We found no significant group by time effect on balance performance (b = 0.4 95% CI [-1, 1.9], p = 0.57) or on our secondary outcomes, including the measures of task-evoked brain activity. The findings of this well-powered, double-blind RCT contrast previous studies of the HiBalance programme but are congruent with other double-blind RCTs of physical exercise in PD. The divergent results raise important questions on how to optimise physical exercise interventions for people with PD.Preregistration clinicaltrials.gov: NCT03213873.

Rates of neuromuscular excitation during cycling in Parkinson's disease compared to healthy young and older adults

BACKGROUND

Bradykinesia affects mobility in some people with Parkinson's. Fall risk makes the neural control of maximal speed ambulatory movements difficult to study in Parkinson's. Stationary recumbent bicycling favors the use of electromyography at high movement speeds, and may better reveal neuromuscular rate limiters.

METHODS

Subjects were 18 adults with Parkinson's, 14 older adults and 14 young adults. Electromyograms were recorded from two muscles during stationary recumbent bicycling at 60, 80, 100, 120 RPM and peak voluntary cadence. Rate of electromyogram rise was calculated. Subjects performed the timed up and go and four square step test. Parkinson's sub-groups were formed based on whether they could pedal ≥120 RPM. Mixed models were used to compare groups and spearman's correlations quantified relationships.

FINDINGS

Eight people with Parkinson's and four older adults could not complete the 120 RPM condition. Faster people with Parkinson's (n = 10) had greater maximum cadence (F = 42.85, P < 0.05), higher rates of electromyogram rise in both muscles (F > 16.9, P < 0.05), and faster mobility test times (F > 6.5, P < 0.05) than slower people with Parkinson's (n = 8). In Parkinson's, correlations between vastus lateralis rate of electromyogram rise and four square step test (ρ = -0.62), timed up and go (ρ = -0.53), and peak cadence (ρ = 0.76) were significant (all P < 0.05).

INTERPRETATION

People with Parkinson's with slower peak pedaling cadence had slower mobility performance and lower vastus lateralis excitation rates at higher cadences. Vastus lateralis excitation rates had moderate to strong relationships with peak cadence and mobility. Exercise interventions may seek to improve peak cadence or excitation rates in people with Parkinson's.

Effective detection of abnormal gait patterns in Parkinson's disease patients using kinematics, nonlinear, and stability gait features

BACKGROUND AND OBJECTIVES

Parkinson's disease (PD) is a neurodegenerative disease that produces movement disorders and it is the second most common neurodegenerative disease after Alzheimer's. Among other symptoms, PD affects gait patterns and produces bradykinesia, abnormal changes in posture, and shortened strides. In this study we present a comprehensive analysis of three different feature sets to model those abnormal gait patterns. The proposed approach is evaluated upon three groups of subjects: PD patients, young healthy controls (YHC), and elderly healthy controls (EHC).

METHODS

Three feature sets are created: (1) kinematic measures including those that allow modeling time, distance and velocity of the strides, (2) nonlinear dynamics including different measures extracted from embedded attractors resulting from the time-series of the gait signals, and (3) different stability measures extracted in the time and frequency-domains. Support Vector Machine, Random Forest and XGBoost classifiers are trained to automatically discriminate between PD patients and healthy subjects.

RESULTS

Among the considered feature sets, three individual measures emerge as the ones that yield accurate detection of PD and could potentially be used in clinical practice. Accuracies of up to 87.0% and 90.0% are found for the classification between PD vs. YHC and PD vs. EHC, respectively, considering individual measures.

CONCLUSIONS

This study contributes to a better understanding of abnormal gait patterns observed in PD patients. Particularly the introduced approach shows good results that could be potentially used in clinical practice as a tool to support the diagnosis and follow-up of the patients.

Quantifying Parkinson's disease motor severity under uncertainty using MDS-UPDRS videos

Parkinson's disease (PD) is a brain disorder that primarily affects motor function, leading to slow movement, tremor, and stiffness, as well as postural instability and difficulty with walking/balance. The severity of PD motor impairments is clinically assessed by part III of the Movement Disorder Society Unified Parkinson's Disease Rating Scale (MDS-UPDRS), a universally-accepted rating scale. However, experts often disagree on the exact scoring of individuals. In the presence of label noise, training a machine learning model using only scores from a single rater may introduce bias, while training models with multiple noisy ratings is a challenging task due to the inter-rater variabilities. In this paper, we introduce an ordinal focal neural network to estimate the MDS-UPDRS scores from input videos, to leverage the ordinal nature of MDS-UPDRS scores and combat class imbalance. To handle multiple noisy labels per exam, the training of the network is regularized via rater confusion estimation (RCE), which encodes the rating habits and skills of raters via a confusion matrix. We apply our pipeline to estimate MDS-UPDRS test scores from their video recordings including gait (with multiple Raters, R=3) and finger tapping scores (single rater). On a sizable clinical dataset for the gait test (N=55), we obtained a classification accuracy of 72% with majority vote as ground-truth, and an accuracy of ∼84% of our model predicting at least one of the raters' scores. Our work demonstrates how computer-assisted technologies can be used to track patients and their motor impairments, even when there is uncertainty in the clinical ratings. The latest version of the code will be available at https://github.com/mlu355/PD-Motor-Severity-Estimation.

Gutenberg Gait Database, a ground reaction force database of level overground walking in healthy individuals

The Gutenberg Gait Database comprises data of 350 healthy individuals recorded in our laboratory over the past seven years. The database contains ground reaction force (GRF) and center of pressure (COP) data of two consecutive steps measured - by two force plates embedded in the ground - during level overground walking at self-selected walking speed. The database includes participants of varying ages, from 11 to 64 years. For each participant, up to eight gait analysis sessions were recorded, with each session comprising at least eight gait trials. The database provides unprocessed (raw) and processed (ready-to-use) data, including three-dimensional GRF and two-dimensional COP signals during the stance phase. These data records offer new possibilities for future studies on human gait, e.g., the application as a reference set for the analysis of pathological gait patterns, or for automatic classification using machine learning. In the future, the database will be expanded continuously to obtain an even larger and well-balanced database with respect to age, sex, and other gait-specific factors.

Pilot trial of a mouthpiece as treatment for signs and symptoms of Parkinson disease

PURPOSE

Several case studies and anecdotal reports have shown assorted motor and quality of life benefits from use of a dental mouthpiece among people with Parkinson disease (PD). A larger exploratory study is necessary to assess potential efficacy and feasibility of this treatment strategy. If shown to be effective and feasible in a larger sample of people with PD, mechanistic studies may be warranted to examine a potential relationship between orofacial sensory input and motor function in people with PD.

MATERIALS AND METHODS

This study was registered on clinicaltrials.gov (NCT: 04082663). Twenty people with PD, Hoehn and Yahr stages I-III, participated in this study. Each participant completed various baseline motor and quality of life assessments before being fitted with a custom mouthpiece. Motor assessments were completed a second time after 25 min of mouthpiece wear. Participants were asked to wear the mouthpiece for 1 month before completing follow-up quality of life assessments and providing feedback about the mouthpiece. Wilcoxon signed-rank tests were used to compare results across conditions.

RESULTS

Gait velocity and cadence showed significant (p < .05) improvement while wearing the mouthpiece. However, these changes were not significant after correcting for multiple comparisons. Thirteen participants indicated they would be unlikely to continue wearing the mouthpiece.

CONCLUSIONS

These results do not provide adequate evidence to pursue further this type of mouthpiece as a treatment strategy for motor signs and symptoms or quality of life in people with PD.

Prevalence of freezing of gait in Parkinson's disease: a systematic review and meta-analysis

BACKGROUND

Freezing of gait (FOG) is considered one of the most disturbing and least understood symptoms in Parkinson's disease (PD). The reported prevalence rates of FOG in PD vary widely, ranging from 5 to 85.9%.

OBJECTIVE

We conducted a systematic review and meta-analysis to provide a reliable estimate of the average point prevalence of FOG in PD, and we further investigated the study characteristics that might have influenced the estimate.

METHODS

We searched different databases to identify studies that report the prevalence of FOG in PD or include relevant raw data for further calculation. The last inclusion date was February 20, 2020. The modified Quality Assessment of Diagnostic Accuracy Studies (QUADAS) tool was used for the quality assessment, and articles that met the predefined criteria were included in the quantitative analysis.

RESULTS

Sixty-six studies were selected from 3392 references. A weighted prevalence of 50.6% in 9072 PD patients experienced FOG based on the special questionnaires (the FOG-Q and NFOG-Q), which was about twice as high as that assessed by the specific items of the clinical rating scales (UPDRS item2.14 and MDS-UPDRS item3.11) (23.2%) or simple clinical questions (25.4%). The weighted prevalence was 37.9% for early stage (≤ 5 years) and 64.6% for advanced stage (≥ 9 years). Moreover, a higher prevalence was calculated from the population-based studies than that in multicenter and single-center studies (47.3% vs. 33.5% and 37.1%, respectively).

CONCLUSION

The result from this systematic review confirms that FOG is very common in PD and its prevalence is usually underestimated in hospital settings. Importantly, a more accurate assessment of FOG in future clinical researches would involve the use of special FOG scale rather than a single item on a scale or a general clinical inquiry.

A randomised controlled trial on effectiveness and feasibility of sport climbing in Parkinson's disease

Physical activity is of prime importance in non-pharmacological Parkinson's disease (PD) treatment. The current study examines the effectiveness and feasibility of sport climbing in PD patients in a single-centre, randomised controlled, semi-blind trial. A total of 48 PD patients without experience in climbing (average age 64 ± 8 years, Hoehn & Yahr stage 2-3) were assigned either to participate in a 12-week sport climbing course (SC) or to attend an unsupervised physical training group (UT). The primary outcome was the improvement of symptoms on the Movement Disorder Society-Sponsored Revision of the Unified Parkinson's Disease Rating Scale part III (MDS-UPDRS-III). Sport climbing was associated with a significant reduction of the MDS-UPDRS-III (-12.9 points; 95% CI -15.9 to -9.8), while no significant improvement was to be found in the UT (-3.0 points; 95% CI -6.0 to 0.1). Bradykinesia, rigidity and tremor subscales significantly improved in SC, but not in the unsupervised control group. In terms of feasibility, the study showed a 99% adherence of participants to climbing sessions and a drop-out rate of only 8%. No adverse events occurred. This trial provides class III evidence that sport climbing is highly effective and feasible in mildly to moderately affected PD patients.

Intrajejunal Infusion of Levodopa/Carbidopa for Advanced Parkinson's Disease: A Systematic Review

Advanced Parkinson's disease is inconsistently defined, and evidence is lacking in relation to device‐aided therapies. To update existing reviews of intrajejunal infusion of levodopa/carbidopa (LCIG), we performed a literature search for relevant articles (to November 3, 2020) using PubMed supplemented by hand searching. Retrieved articles were categorized by relevance to identified research questions, including motor complications and symptoms; nonmotor symptoms; functioning, quality of life, and caregiver burden; optimal timing of treatment initiation and administration duration; discontinuation; and complications. Most eligible studies (n = 56) were open‐label, observational studies including relatively small patient numbers. LCIG consistently reduces OFF time and increased ON time without troublesome dyskinesia with varying effects regarding ON time with troublesome dyskinesia and the possibility of diphasic dyskinesia. More recent evidence provides some increased support for the benefits of LCIG in relation to nonmotor symptoms, quality of life, activities of daily living, and reduced caregiver burden. Patient age does not appear to significantly impact the effectiveness of LCIG. Discontinuation rates with LCIG (~17%–26%) commonly relate to device‐related issues, although the ability to easily discontinue LCIG may represent a potential benefit. LCIG may be a favorable option for patients with advanced Parkinson's disease who show predominant nonmotor symptoms and vulnerability to complications of other advanced therapy modalities. Larger, well‐controlled studies, including precise investigation of cost effectiveness, would further assist treatment selection. © 2021 The Authors. Movement Disorders published by Wiley Periodicals LLC on behalf of International Parkinson and Movement Disorder Society

Evolution of Quality of Life in Persons with Parkinson's Disease: A Prospective Cohort Study

Parkinson's disease (PD) is a chronic neurodegenerative disorder that results in important functional symptoms, altered mood, and deterioration in quality of life (QoL). This study aimed to determine the evolution of the QoL in persons with PD in the Albacete health district over a two-year period and identify associated sociodemographic, clinical, and socio-health characteristics. A cohort study was conducted of patients at different stages of PD in the Albacete health district. Calculated sample size: 155 patients. Instruments: A purpose-designed questionnaire for data collection and the "Parkinson Disease Questionnaire" (PDQ-39), which measures 8 dimensions and a global index where a higher score indicates worse quality of life. Three measurements were made: baseline, one year, two years. A descriptive and bivariate analysis was conducted. Ethical aspects: informed consent, anonymized data. Results: Mean age 69.51 (standard deviation, SD 8.73) years, 60% male, 75.5% married, and 85.5% lived with family. The most frequent motor symptoms were slow movement (86.23%), postural instability (55.5%), tremor (45.5%), and dyskinesia (24.6%). Among the non-motor symptoms were fatigue (66.2%), pain, daytime somnolence, constipation, and apathy, with approximately 50% each. The mean QoL score at baseline was 27.47 (SD 16.14); 95% CI (confidence interval) 24.91-30.03. At two years, global QoL had slightly worsened (28.3; SD 17.26; 95% CI 25.41-31.18), with a statistically significant worsening in mobility, activities of daily living, and communication, whereas social support improved.

Clinimetrics of the Freezing of Gait Questionnaire for Parkinson Disease During the "off" State

Introduction:

Freezing of gait, a common PD motor symptom, could increase the risk of falling. This study aimed to investigate the clinimetric attributes of the Freezing of Gait Questionnaire (FOGQ) for people with Parkinson disease in the “off” state.

Methods:

A total of 115 patients with Parkinson disease (PD; mean age, 60.25 years) were included. Acceptability, internal consistency (by the Cronbach alpha, and test-retest by Intraclass Correlation [ICC]), and reliability of the Persian-translated version of the FOGQ were examined. Dimensionality was estimated by Exploratory Factor Analysis (EFA). Fall efficacy scale-international, unified Parkinson disease rating scale-II, Berg balance scale, functional reach test, and Parkinson disease questionnaire-39 were applied to determine the convergent validity. Diagnostic accuracy for obtaining optimal cutoff point, separating faller and non-faller groups, was analyzed by Receiver Operating Characteristics (ROC) curve analysis and Area Under the Curve (AUC). All tests were carried out in an “off” state.

Results:

The Cronbach alpha was high (α=0.92). The test-retest showed high reliability (ICC=0.89). The FOGQ was unidimensional according to the EFA and had acceptable convergent validity with moderate to high correlation with other clinical scales. The optimal cutoff point to discriminate fallers from non-fallers during the “off” state was 9/10, with an AUC of 0.92.

Conclusion:

Our results suggest that the FOGQ has appropriate reliability, validity, and discriminative ability for measuring FOG in patients with PD during the “off” state.

The Use of Exergames in the Neurorehabilitation of People with Parkinson Disease: The Impact on Daily Life

Introduction  Parkinson disease (PD) is a progressive degeneration characterized by motor disorders, such as tremor, bradykinesia, stiffness and postural instability. Objective  To evaluate the independence, confidence and balance in the development of daily activities in patients with PD before and after rehabilitation. Methods  A descriptive, retrospective cross-sectional study was carried out with 16 patients (mean 57.6 ± 18.7 years), submitted to anamnesis, otolaryngological evaluation and vestibular assessment. The Vestibular Disorders Activities of Daily Living (VADL) and the Activities-Specific Balance Confidence (ABC) scales were applied before and after rehabilitation with virtual reality. Results  a) The instrumental subscale of the questionnaire showed statistically significant result ( p  = 0.022; 95% CI 1.21; 2.21) between the first and second assessments; b) The correlation between the questionnaires showed statistically significant result in the ambulation subscale ( p  = 0.011; 95% CI -0.85; -0.17) first and ( p  = 0.002, 95% CI -0.88; -0.31) second assessments, and the functional subscale was only verified in the second assessment ( p  = 0.011, 95% CI -0.85; -0.17); and c) The patients presented clinical improvement in the final assessment after rehabilitation with significant result for the tightrope walk ( p  = 0.034, 95% CI -12.5; -0.3) and ski slalom games ( p  = 0.005, 95% CI -34.8; -6.6). Conclusions  Our results showed that the VADL and ABC questionnaires, applied before and after rehabilitation, were important tools to measure the independence, confidence and balance while developing daily activities. The VADL and ABC questionnaires may effectively contribute to quantify the effect of the applied therapeutics and, consequently, its impact on the quality of life of patients with PD.

Protocol for PD SENSORS: Parkinson's Disease Symptom Evaluation in a Naturalistic Setting producing Outcome measuRes using SPHERE technology. An observational feasibility study of multi-modal multi-sensor technology to measure symptoms and activities of daily living in Parkinson's disease

INTRODUCTION

The impact of disease-modifying agents on disease progression in Parkinson's disease is largely assessed in clinical trials using clinical rating scales. These scales have drawbacks in terms of their ability to capture the fluctuating nature of symptoms while living in a naturalistic environment. The SPHERE (Sensor Platform for HEalthcare in a Residential Environment) project has designed a multi-sensor platform with multimodal devices designed to allow continuous, relatively inexpensive, unobtrusive sensing of motor, non-motor and activities of daily living metrics in a home or a home-like environment. The aim of this study is to evaluate how the SPHERE technology can measure aspects of Parkinson's disease.

METHODS AND ANALYSIS

This is a small-scale feasibility and acceptability study during which 12 pairs of participants (comprising a person with Parkinson's and a healthy control participant) will stay and live freely for 5 days in a home-like environment embedded with SPHERE technology including environmental, appliance monitoring, wrist-worn accelerometry and camera sensors. These data will be collected alongside clinical rating scales, participant diary entries and expert clinician annotations of colour video images. Machine learning will be used to look for a signal to discriminate between Parkinson's disease and control, and between Parkinson's disease symptoms 'on' and 'off' medications. Additional outcome measures including bradykinesia, activity level, sleep parameters and some activities of daily living will be explored. Acceptability of the technology will be evaluated qualitatively using semi-structured interviews.

ETHICS AND DISSEMINATION

Ethical approval has been given to commence this study; the results will be disseminated as widely as appropriate.

Effects of Subthalamic Nucleus Deep Brain Stimulation and Levodopa on Balance in People with Parkinson's Disease: A Cross Sectional Study

Subthalamic nucleus deep brain stimulation (STN-DBS) and levodopa are common treatment strategies for Parkinson’s disease (PD). However, the specific effects of these treatment strategies on balance and its components remain unclear. This cross-sectional study of people with PD and STN-DBS compared balance in the treated state (ON-medication/ON-stimulation) and untreated state (OFF-medication/OFF-stimulation) using the Balance Evaluation Systems Test (BESTest). Total BESTest scores from the treated and untreated states were compared to assess overall balance. Scores for the six sections of the BESTest were further compared to assess differences in specific components of balance between treatment conditions. Twenty-nine participants were included (Male: 21, Female: 8, Mean Age ± SD: 65.0 ± 6.9). Total BESTest scores showed improved balance in the treated state compared to the untreated state (Treated: 67.56 ± 10.92; Untreated: 59.23 ± 16.51, p < 0.001). Four sections (Stability Limits/Verticality, Anticipatory Postural Reactions, Sensory Orientation, Stability in Gait) of the BESTest significantly improved in the treated state relative to the untreated state, after correcting for multiple comparisons (p < 0.05). These results demonstrate that STN-DBS and levodopa improve overall balance and provide a first step toward understanding the effects of these treatment strategies on specific components of balance.

Microprocessor Controlled Knee Ankle Foot Orthosis (KAFO) vs Stance Control vs Locked KAFO: A Randomized Controlled Trial

OBJECTIVE

To evaluate the potential of a microprocessor swing and stance controlled knee-ankle-foot orthosis (MPO) to improve balance, functional mobility, and quality of life in individuals with lower-extremity impairments as compared to a stance-control-orthosis (SCO) and conventional knee-ankle-foot orthosis (KAFO) over a use-period of a month.

DESIGN

Randomized crossover study.

SETTING

Ambulatory research laboratory and home and community for community-dwelling adults.

PARTICIPANTS

Persons (N=18) who actively used a unilateral KAFO or SCO for impairments due to neurologic or neuromuscular disease, orthopedic disease, or trauma.

INTERVENTION

Participants were trained to acclimate and use SCO and MPO.

MAIN OUTCOME MEASURES

The 6-minute walk test (6MWT), 10-m walk test, Berg Balance Scale (BBS), functional gait assessment (FGA), hill assessment index, stair assessment index (SAI), Five Times Sit to Stand Test, crosswalk test, Modified Falls Efficacy Scale, Orthotic and Prosthetic User's Survey (OPUS), and World Health Organization Quality of Life (WHQOL)-BREF Scale.

RESULTS

Significant changes were observed in participants' self-selected gait speed (P=.023), BBS (P=.01), FGA (P=.002), and SAI (P<.001) between baseline and post-MPO assessment. Similar significant differences were seen when comparing post-MPO with post-SCO data. During the 6MWT, persons using the MPO walked significantly longer (P=.013) than when using their baseline device. Participants reported higher quality of life scores in the OPUS (P=.02) and physical health domain of the WHOQOL-BREF (P=.037) after using the MPO. Participants reported fewer falls when wearing the MPO (5) versus an SCO (38) or locked KAFO (15).

CONCLUSIONS

The MPO may contribute to improved quality of life and health status of persons with lower-extremity impairments by providing the ability to have better walking speed, endurance, and functional balance.

Determinants of Quality of Life According to Cognitive Status in Parkinson's Disease

Background

Quality of life (QoL) was worse in Parkinson’s disease patients with mild cognitive impairment (PD-MCI) or dementia (PDD) than PD patients with normal cognition (PD-NC). The aim of this study was to investigate and compare the potential heterogeneous determinants of QoL in PD patients with different cognitive statuses.

Methods

We recruited 600 PD patients, including 185 PD-NC patients, 336 PD-MCI patients and 79 PDD patients, in this cross-sectional study. All patients completed the QoL assessment by the 39-item Parkinson’s Disease Questionnaire (PDQ-39), as well as clinical evaluations and neuropsychological tests. The determinants of the QoL were analyzed by multiple stepwise regression analysis.

Results

QoL was more impaired across the three groups (PD-NC < PD-MCI < PDD). The Unified Parkinson’s Disease Rating Scale part III (UPDRS-III) score, Geriatric Depression Rating Scale (GDS) score and daily levodopa equivalent dose (LED) were independent variables of PDQ-39 in PD-NC patients. The GDS score, disease duration, UPDRS-III score, Epworth Sleepiness Score (ESS) and sex were independent variables of PDQ-39 in PD-MCI patients. The GDS score and disease duration were independent variables of PDQ-39 in PDD patients.

Conclusion

The determinants of QoL in PD-NC, PD-MCI and PDD patients were heterogeneous. Motor function was considered to be the most crucial determinant for QoL in PD-NC, while depression was indicated to be the most vital determinant for PD-MCI and PDD. For QoL improvement, clinicians might need to focus more on motor function in PD-NC patients and on depression in PD-MCI and PDD patients.

Impact of lower limb muscle strength on walking function beyond aging and diabetes

Objective

This study was performed to investigate the influence of lower limb muscle strength on the walking function of advanced-age patients with diabetes.

Methods

In this cross-sectional descriptive study, data were collected from 202 advanced-age patients with diabetes. All patients completed questionnaires, the one-leg stance test, the timed up-and-go test, the 30-s sit-to-stand test, and plantar pressure platform measurements. The patients were divided in two groups according to their lower limb muscle strength: those with declining muscle strength and those with normal muscle strength.

Results

Walking function was significantly abnormal in the patients with declining lower limb muscle strength. The gait trajectories were abnormal, mainly with respect to a shortage of driving force.

Conclusion

The lower limb muscle strength can affect the static balance and dynamic balance in advanced-age patients with declining lower limb muscle strength.

Motor activity and Becker's muscular dystrophy: lights and shadows

Becker's disease is an inherited muscular dystrophy caused by mutations in the gene coding for the dystrophin protein that leads to quantitative and/or qualitative protein dysfunction and consequent muscle degeneration. Studies in animal models demonstrate that, while eccentric or high-intensity training are deleterious for dystrophic muscles, low-intensity aerobic training may slowdown the disease process and progression. Based on these preclinical data, the available studies in patients with Becker's muscular dystrophy undergoing workout on a cycle ergometer or on a treadmill, at a heart rate ≤65% of their maximal oxygen uptake, showed that aerobic exercise counteracts physical deterioration and loss of functional abilities. These findings suggest an improvement of physical performance through an increase of muscle strength, fatigue resistance, and dexterity capacities, without substantial evidence of acceleration of muscular damage progression. Therefore, individually tailored mild-to-moderate intensity aerobic exercise should be considered as part of the management of these patients. However, further research is necessary to define specific and standardized guidelines for the prescription of type, intensity, frequency, and duration of motor activities. In this review, we provided a summary of the impact of physical activity both in animal models and in patients with Becker's muscular dystrophy, with the intent to identify trends and gaps in knowledge. The potential therapeutic implications and future research directions have been also highlighted.

A comparison of the relationship between manual dexterity and postural control in young and older individuals with Parkinson's disease

The motor symptoms of Parkinson's disease (PD) cause deterioration in manual dexterity. This deterioration affects independence in activities of daily living negatively. The loss of postural control, which occurs more frequently with disease progression, restricts physical functions and reduces mobility in patients with PD. Impaired postural control may affect distal mobility of an individual. The aim of this study was to investigate postural control and manual dexterity in individuals ≤ 65 and >65 years with PD and analyze the relationship between these variables according to age. Sixty-six individuals with PD participated in the study. The participants were categorized according to age (n = 29 for 65 years of age or younger and n = 37 for older). Manual dexterity (Dominant and Non-dominant hand) was assessed by the Nine Hole Peg Test (NHPT). Postural control was evaluated by the Limit of Stability Test (LoS) using a computerized balance measuring instrument. There was no statistically significant difference between the age groups on the combined dependent variables after controlling for disability, gender, weight, and height; F(7, 54) = 0.804, p = 0.587. Only LoS-Maximum Excursion was higher in the individuals ≤ 65 years (p = 0.035). Significant correlations were found between NHPT-Dominant and LoS-Reaction Time, LoS-Maximum Excursion; NHPT-Non-dominant and LoS-Reaction Time, LoS-Endpoint Excursion, LoS-Maximum Excursion in the older group (p < 0.05). There was no difference manual dexterity and postural control according to age except for LoS-Maximum Excursion. LoS-Maximum Excursion was higher in the young group. The manual dexterity was associated with postural control in individuals over 65 years of age with PD; however, not associated in younger individuals.

The New Freezing of Gait Questionnaire: Unsuitable as an Outcome in Clinical Trials?

BACKGROUND

Freezing of gait (FOG) is a common gait deficit in Parkinson's disease. The New Freezing of Gait Questionnaire (NFOG-Q) is a widely used and valid tool to quantify freezing of gait severity. However, its test-retest reliability and minimal detectable change remain unknown.

OBJECTIVE

To determine the test-retest reliability and responsiveness of the NFOG-Q.

METHODS

Two groups of freezers, involved in 2 previous rehabilitation trials, completed the NFOG-Q at 2 time points (T1 and T2), separated by a 6-week control period without active intervention. Sample 1 (N = 57) was measured in ON and sample 2 (N = 14) in OFF. We calculated various reliability statistics for the NFOG-Q scores between T1 and T2 as well as correlation coefficients with clinical descriptors to explain the variability between time points.

RESULTS

In sample 1 the NFOG-Q showed modest reliability (intraclass correlation coefficient = 0.68 [0.52-0.80]) without differences between T1 and T2. However, a minimal detectable change of 9.95 (7.90-12.27) points emerged for the total score (range 28 points, relative minimal detectable change of 35.5%). Sample 2 showed largely similar results. We found no associations between cognitive-related or disease severity-related outcomes and variability in NFOG-Q scores.

CONCLUSIONS

We conclude that the NFOG-Q is insufficiently reliable or responsive to detect small effect sizes, as changes need to go beyond 35% to surpass measurement error. Therefore, we warrant caution in using the NFOG-Q as a primary outcome in clinical trials. These results emphasize the need for robust and objective freezing of gait outcome measures.

Increased gait variability during robot-assisted walking is accompanied by increased sensorimotor brain activity in healthy people

BACKGROUND

Gait disorders are major symptoms of neurological diseases affecting the quality of life. Interventions that restore walking and allow patients to maintain safe and independent mobility are essential. Robot-assisted gait training (RAGT) proved to be a promising treatment for restoring and improving the ability to walk. Due to heterogenuous study designs and fragmentary knowlegde about the neural correlates associated with RAGT and the relation to motor recovery, guidelines for an individually optimized therapy can hardly be derived. To optimize robotic rehabilitation, it is crucial to understand how robotic assistance affect locomotor control and its underlying brain activity. Thus, this study aimed to investigate the effects of robotic assistance (RA) during treadmill walking (TW) on cortical activity and the relationship between RA-related changes of cortical activity and biomechanical gait characteristics.

METHODS

Twelve healthy, right-handed volunteers (9 females; M = 25 ± 4 years) performed unassisted walking (UAW) and robot-assisted walking (RAW) trials on a treadmill, at 2.8 km/h, in a randomized, within-subject design. Ground reaction forces (GRFs) provided information regarding the individual gait patterns, while brain activity was examined by measuring cerebral hemodynamic changes in brain regions associated with the cortical locomotor network, including the sensorimotor cortex (SMC), premotor cortex (PMC) and supplementary motor area (SMA), using functional near-infrared spectroscopy (fNIRS).

RESULTS

A statistically significant increase in brain activity was observed in the SMC compared with the PMC and SMA (p < 0.05), and a classical double bump in the vertical GRF was observed during both UAW and RAW throughout the stance phase. However, intraindividual gait variability increased significantly with RA and was correlated with increased brain activity in the SMC (p = 0.05; r = 0.57).

CONCLUSIONS

On the one hand, robotic guidance could generate sensory feedback that promotes active participation, leading to increased gait variability and somatosensory brain activity. On the other hand, changes in brain activity and biomechanical gait characteristics may also be due to the sensory feedback of the robot, which disrupts the cortical network of automated walking in healthy individuals. More comprehensive neurophysiological studies both in laboratory and in clinical settings are necessary to investigate the entire brain network associated with RAW.

Electroskip auditory biofeedback in a patient with Parkinson disease: a case report

The purpose of this case study was to observe the effects of a rehabilitation program with an audio-biofeedback technology device called Electroskip in a patient with Parkinson disease. The patient was a 61-year-old man with moderate Parkinson disease (Hoehn and Yahr Parkinson’s scale stage III) and dementia who had progressive episodes of freezing of gait. The patient also had a history of recent falls. The patient completed a 6-week rehabilitation program focused on functional tasks, balance and gait training while using Electroskip technology, which is a wireless, wearable device that sends a discrete real-time generative audio-biofeedback signal when the user steps on either the heel or toe force sensors positioned under the innersoles. The outcome measures included the Timed Up and Go test, the modified Gait Abnormality Rating Scale, the modified Parkinson’s Activity Scale, and the Freezing of Gait Questionnaire. The patient completed 17 of the 18 scheduled training sessions and all testing sessions; no adverse events occurred during the rehabilitation program and high satisfaction levels were reported by the patient and family after completion of the 6-week rehabilitation program. Clinically significant improvements were seen in all measures at 6 weeks. The results of this report suggest that a rehabilitation program focused on functional tasks, balance, and gait training using the Electroskip technology may be beneficial for improving gait and balance in a patient with moderate Parkinson disease. Future work is needed to determine the effectiveness of Electroskip technology by means of randomized controlled trials.

Associations of Motor Symptom Severity and Quality of Life to Motor Task Performance in Upper and Lower Extremities Across Task Complexity in Parkinson's Disease

The authors examined the associations between the performance of upper- and lower-extremity motor tasks across task complexity and motor symptom severity, overall disease severity, and the physical aspects of quality of life in persons with Parkinson's disease. The performance was assessed for three lower-extremity tasks and two upper-extremity tasks of different levels of complexity. The motor symptoms and overall disease severity correlated significantly with all motor tasks with higher correlation coefficients in the complex tasks. Thus, the strength of the association between disease severity or severity of motor symptoms and motor performance is task-specific, with higher values in complex motor tasks than in simpler motor tasks. Mobility-related and activity-of-daily-living-related quality of life correlated with lower-extremity tasks of low and medium complexity and with the complex upper-extremity task, respectively; this suggests that Parkinson's Disease Questionnaire-39 is capable of differentiating between the impact of gross and fine motor function on quality of life.

Using wearables to assess bradykinesia and rigidity in patients with Parkinson's disease: a focused, narrative review of the literature

The potential of using wearable technologies for the objective assessment of motor symptoms in Parkinson's disease (PD) has gained prominence recently. Nonetheless, compared to tremor and gait impairment, less emphasis has been placed on the quantification of bradykinesia and rigidity. This review aimed to consolidate the existing research on objective measurement of bradykinesia and rigidity in PD through the use of wearables, focusing on the continuous monitoring of these two symptoms in free-living environments. A search of PubMed was conducted through a combination of keyword and MeSH searches. We also searched the IEEE, Google Scholar, Embase, and Scopus databases to ensure thorough results and to minimize the chances of missing relevant studies. Papers published after the year 2000 with sample sizes greater than five were included. Studies were assessed for quality and information was extracted regarding the devices used and their location on the body, the setting and duration of the study, the "gold standard" used as a reference for validation, the metrics used, and the results of each paper. Thirty-one and eight studies met the search criteria and evaluated bradykinesia and rigidity, respectively. Several studies reported strong associations between wearable-based measures and the gold-standard references for bradykinesia, and, to a lesser extent, rigidity. Only a few, pilot studies investigated the measurement of bradykinesia and rigidity in the home and free-living settings. While the current results are promising for the future of wearables, additional work is needed on their validation and adaptation in ecological, free-living settings. Doing so has the potential to improve the assessment and treatment of motor fluctuations and symptoms of PD more generally through real-time objective monitoring of bradykinesia and rigidity.

Prediction of Freezing of Gait in Parkinson's Disease Using Statistical Inference and Lower-Limb Acceleration Data

The freezing of gait (FoG) is a common type of motor dysfunction in advanced Parkinson's disease (PD) associated with falls. Over the last decade, a significant amount of studies has been focused on detecting FoG episodes in clinical and home environments. Yet, there remains a paucity of techniques regarding real-time prediction of FoG before its occurrence. In this paper, a new algorithm was employed to define the best combination of sensor position, axis, sampling window length, and features to predict FoG. We hypothesized that gait deterioration before FoG onsets can be discriminated from normal gait using statistical analysis of features from successive windows of data collected from lower-limb accelerometers. We defined a new performance measure, "predictivity", to compare the number of correctly predicted FoG events among different combinations. We characterized the system performance using data from 10 PD patients, who experienced FoG while performing several walking tasks in a lab environment. The analysis of 120 different combinations revealed that prediction of FoG can be realized by using an individual shank sensor and sample entropy calculated from the horizontal forward axis with window length of 2 s (88.8%, 92.5%, and 89.0% for average predictivity, sensitivity, and specificity, respectively).

Explaining the unique nature of individual gait patterns with deep learning

Machine learning (ML) techniques such as (deep) artificial neural networks (DNN) are solving very successfully a plethora of tasks and provide new predictive models for complex physical, chemical, biological and social systems. However, in most cases this comes with the disadvantage of acting as a black box, rarely providing information about what made them arrive at a particular prediction. This black box aspect of ML techniques can be problematic especially in medical diagnoses, so far hampering a clinical acceptance. The present paper studies the uniqueness of individual gait patterns in clinical biomechanics using DNNs. By attributing portions of the model predictions back to the input variables (ground reaction forces and full-body joint angles), the Layer-Wise Relevance Propagation (LRP) technique reliably demonstrates which variables at what time windows of the gait cycle are most relevant for the characterisation of gait patterns from a certain individual. By measuring the time-resolved contribution of each input variable to the prediction of ML techniques such as DNNs, our method describes the first general framework that enables to understand and interpret non-linear ML methods in (biomechanical) gait analysis and thereby supplies a powerful tool for analysis, diagnosis and treatment of human gait.

Antidepressants for Depression, Apathy, and Gait Instability in Parkinson's Disease: A Multicenter Randomized Study

Objective Depression, apathy, and gait instability are cardinal symptoms in patients with Parkinson's disease (PD). Selective serotonin reuptake inhibitors (SSRIs) and serotonin and norepinephrine reuptake inhibitors (SNRIs) are used for treating the psychiatric symptoms of PD. This is the first prospective randomized study to compare the efficacy of an SNRI (duloxetine) with SSRIs (paroxetine, escitalopram) in improving depressive symptoms and apathy (primary) and freezing of gait (FOG; secondary) in patients with PD. Methods In this prospective, multicenter, open-label, randomized study, Japanese PD patients with a Quick Inventory of Depressive Symptomatology-Japanese (QIDS-J) score ≥6 were randomly assigned to receive an SSRI (27 enrolled, 25 analyzed) or duloxetine (28 enrolled, 27 analyzed) and were assessed at 6 and 10 weeks. Results The mean change (SD) in the QIDS J [SSRI -2.4 (3.6), p=0.015; SNRI -2.3 (3.9), p=0.029] and FOG-Questionnaire [SSRI -2.9 (4.2), p=0.012; SNRI -3.4 (4.7), p=0.010] scores (from baseline) at 10 weeks was statistically significant, while the mean change in the Apathy Scale scores was not [SSRI -2.7 (5.4), p=0.054; SNRI -1.5 (3.7), p=0.109]. No significant differences were observed between the SSRI and SNRI groups. The treatments were well-tolerated; however, gastrointestinal events were more common with SSRIs. Two SNRI-treated patients reported an exacerbation of tremor. Conclusion SSRIs and SNRIs improve the depressive symptoms and FOG in PD patients with mild to severe depressive symptoms. However, their effectiveness in treating apathy remains to be elucidated.

Hemodialysis Impact on Motor Function beyond Aging and Diabetes-Objectively Assessing Gait and Balance by Wearable Technology

Motor functions are deteriorated by aging. Some conditions may magnify this deterioration. This study examined whether hemodialysis (HD) process would negatively impact gait and balance beyond diabetes condition among mid-age adults (48–64 years) and older adults (65+ years). One hundred and ninety-six subjects (age = 66.2 ± 9.1 years, body-mass-index = 30.1 ± 6.4 kg/m², female = 56%) in 5 groups were recruited: mid-age adults with diabetes undergoing HD (Mid-age HD+, n = 38) and without HD (Mid-age HD−, n = 40); older adults with diabetes undergoing HD (Older HD+, n = 36) and without HD (Older HD−, n = 37); and non-diabetic older adults (Older DM−, n = 45). Gait parameters (stride velocity, stride length, gait cycle time, and double support) and balance parameters (ankle, hip, and center of mass sways) were quantified using validated wearable platforms. Groups with diabetes had overall poorer gait and balance compared to the non-diabetic group (p < 0.050). Among people with diabetes, HD+ had significantly worsened gait and balance when comparing to HD− (Cohen’s effect size d = 0.63–2.32, p < 0.050). Between-group difference was more pronounced among older adults with the largest effect size observed for stride length (d = 2.32, p < 0.001). Results suggested that deterioration in normalized gait speed among HD+ was negatively correlated with age (r = −0.404, p < 0.001), while this correlation was diminished among HD−. Interestingly, results also suggested that poor gait among Older HD− is related to poor ankle stability, while no correlation was observed between poor ankle stability and poor gait among Older HD+. Using objective assessments, results confirmed that the presence of diabetes can deteriorate gait and balance, and this deterioration can be magnified by HD process. Among HD− people with diabetes, poor ankle stability described poor gait. However, among people with diabetes undergoing HD, age was a dominate factor describing poor gait irrespective of static balance. Results also suggested feasibility of using wearable platforms to quantify motor performance during routine dialysis clinic visit. These objective assessments may assist in identifying early deterioration in motor function, which in turn may promote timely intervention.

Technology-based assessment of motor and nonmotor phenomena in Parkinson disease

INTRODUCTION

The increasing development and availability of portable and wearable technologies is rapidly expanding the field of technology-based objective measures (TOMs) in neurological disorders, including Parkinson disease (PD). Substantial challenges remain in the recognition of disease phenomena relevant to patients and clinicians, as well as in the identification of the most appropriate devices to carry out these measurements. Areas covered: The authors systematically reviewed PubMed for studies employing technology as outcome measures in the assessment of PD-associated motor and nonmotor abnormalities. Expert commentary: TOMs minimize intra- and inter-rater variability in clinical assessments of motor and nonmotor phenomena in PD, improving the accuracy of clinical endpoints. Critical unmet needs for the integration of TOMs into clinical and research practice are the identification and validation of relevant endpoints for individual patients, the capture of motor and nonmotor activities from an ecologically valid environment, the integration of various sensor data into an open-access, common-language platforms, and the definition of a regulatory pathway for approval of TOMs. The current lack of multidomain, multisensor, smart technologies to measure in real time a wide scope of relevant changes remain a significant limitation for the integration of technology into the assessment of PD motor and nonmotor functional disability.

Effect of Group-Based Rehabilitation Combining Action Observation with Physiotherapy on Freezing of Gait in Parkinson's Disease

Freezing of gait (FoG) is among the most disabling symptoms of Parkinson's disease (PD) patients. Recent studies showed that action observation training (AOT) with repetitive practice of the observed actions represents a strategy to induce longer-lasting effects compared with standard physiotherapy. We investigated whether AOT may improve FoG and mobility in PD, when AOT is applied in a group-based setting. Sixty-four participants with PD and FoG were assigned to the experimental (AO) or control groups and underwent a 45-minute training session, twice a week, for 5 weeks. AOT consisted in physical training combined with action observation whereas the control group executed the same physical training combined with landscape-videos observation. Outcome measures (FoG questionnaire, Timed Up and Go test, 10-meter walking test, and Berg balance scale) were evaluated before training, at the end of training, and 4 weeks later (FU-4w). Both groups showed positive changes in all outcome measures at posttraining assessment. Improvements in FoG questionnaire, Timed Up and Go test, and Berg balance scale were retained at FU-4w evaluation only in the AOT group. AOT group-based training is feasible and effective on FoG and motor performance in PD patients and may be introduced as an adjunctive option in PD rehabilitation program.