Effects of Endurance Training on Motor Signs of Parkinson's Disease: A Systematic Review and Meta-Analysis

Exercise as medicine in Parkinson's disease

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

Exercise training effect on skeletal muscle motor drive in older adults: A systematic review with meta-analysis of randomized controlled trials

The meta-analysis aimed to determine whether exercise training can positively change indices of motor drive, i.e., the input from the central nervous system to the muscle, and how training characteristics, motor drive assessment, assessed muscle, and testing specificity could modulate the changes in motor drive in older adults. A random-effect meta-analysis model using standardized mean differences (Hedges' g) determined treatment effects. Moderators (e.g., training type and intensity) and meta-regressors (e.g., number of sessions) were performed using mixed- and fixed-effect models. A significant Q-test, followed by pairwise post hoc comparisons, determined differences between levels of the categorical moderators. Methodological quality was assessed using the Cochrane risk of bias tool. Ten randomized controlled trials, 290 older adults, met the inclusion criteria. Only strength and power exercise training were retrieved from the search and included in the analysis. Strength (g = 0.60, 95 % CI 0.24 to 0.96) and power training (g = 0.51, 95 % CI 0.02 to 1.00) increased motor drive compared with a control condition. High (g = 0.66; 95 % CI 0.34 to 0.97) and low-high (g = 1.23; 95 % CI 0.19 to 2.27) combinations of training intensities increased motor drive compared to the control condition. The multi-joint training and testing exercise structure (g = 1.23; 95 % CI 0.79 to 1.67) was more effective in increasing motor drive (Qdf=2 = 14.15; p = 0.001) than the multi-single joint structure (g = 0.46; 95 % CI 0.06 to 0.85). Therefore, strength and power training with high volume and intensity associated with multi-joint training and testing combination of exercises seem to improve skeletal muscle motor drive in older adults effectively.

Effectiveness of Balance Exercise and Brisk Walking on Alleviating Nonmotor and Motor Symptoms in People With Mild-to-Moderate Parkinson Disease: A Randomized Clinical Trial With 6-Month Follow-up

OBJECTIVE

To investigate the effects of balance exercise and brisk walking on nonmotor and motor symptoms, balance and gait functions, walking capacity, and balance confidence in Parkinson disease (PD) at posttraining and 6-month follow-up.

DESIGN

Two-arm, assessor-blinded randomized controlled trial SETTING: University research laboratory and the community PARTICIPANTS: Ninety-nine eligible individuals with mild-to-moderate PD INTERVENTIONS: Participants were randomized to balance and brisk walking group (B&B, n=49) or active control group (n=50). B&B received ten 90-minute sessions of balance exercises and brisk walking supervised by physical therapists for 6 months (week 1-6: weekly, week 7-26: monthly), whereas control practiced whole-body flexibility and upper limb strength exercise at same dosage (180 min/wk). Both groups performed unsupervised home exercises 2-3 times/wk during intervention and continued at follow-up.

MAIN OUTCOME MEASURES

Primary outcomes were Movement Disorder Society Unified Parkinson Disease Rating Scale nonmotor (MDS-UPDRS-I) and motor (MDS-UPRDS-III) scores. Secondary outcomes were mini-Balance Evaluation Systems Test (mini-BEST) score, comfortable gait speed (CGS), 6-minute walk test (6MWT), dual-task timed-Up-and-Go (DTUG) time, and Activities-Specific Balance Confidence Scale score.

RESULTS

Eighty-three individuals completed the 6-month intervention with no severe adverse effects. The mean between-group (95% CI) difference for the MDS-UPDRS nonmotor score was 1.50 (0.19-2.81) at 6 months and 1.09 (-0.66 to 2.85) at 12 months. The mean between-group (95% CI) difference for the MDS-UPDRS motor score was 3.75 (0.69-6.80) at 6 months and 4.57 (1.05-8.01) at 12 months. At 6 and 12 months, there were significant between-group improvements of the B&B group in mini-BEST score, CGS, 6MWT, and DTUG time.

CONCLUSIONS

This combined balance and brisk walking exercise program alleviates nonmotor and motor symptoms and improves walking capacity, balance, and gait functions posttraining, with positive carryover effects for all except nonmotor outcomes, at 6-month follow-up in mild-to-moderate PD.

Exercise, Neuroprotective Exerkines, and Parkinson's Disease: A Narrative Review

Parkinson's disease (PD) is a prevalent neurodegenerative disease in which treatment often includes an exercise regimen. Exercise is neuroprotective in animal models of PD, and, more recently, human clinical studies have verified exercise's disease-modifying effect. Aerobic exercise and resistance training improve many of PD's motor and non-motor symptoms, while neuromotor therapy and stretching/flexibility exercises positively contribute to the quality of life in people with PD. Therefore, understanding the role of exercise in managing this complex disorder is crucial. Exerkines are bioactive substances that are synthesized and released during exercise and have been implicated in several positive health outcomes, including neuroprotection. Exerkines protect neuronal cells in vitro and rodent PD models in vivo. Aerobic exercise and resistance training both increase exerkine levels in the blood, suggesting a role for exerkines in the neuroprotective theory. Many exerkines demonstrate the potential for protecting the brain against pathological missteps caused by PD. Every person (people) with Parkinson's (PwP) needs a comprehensive exercise plan tailored to their unique needs and abilities. Here, we provide an exercise template to help PwP understand the importance of exercise for treating PD, describe barriers confronting many PwP in their attempt to exercise, provide suggestions for overcoming these barriers, and explore the role of exerkines in managing PD. In conclusion, exercise and exerkines together create a powerful neuroprotective system that should contribute to slowing the chronic progression of PD.

Update: Protective and risk factors for Parkinson disease

We review the epidemiologic literature on potential protective and risk factors in Parkinson's Disease (PD). Prior research identified numerous possible protective and risk factors. Potential protective factors include tobacco abuse, physical activity, urate levels, NSAID use, calcium channel blocker use, statin use, and use of some α1-adrenergic antagonists. Some potential protective factors could be products of reverse causation, including increased serum urate, tobacco abuse, and coffee-tea-caffeine consumption. Potential risk factors include traumatic brain injury, pesticide exposure, organic solvent exposure, lead exposure, air pollution, Type 2 Diabetes, some dairy products, cardiovascular disease, and some infections including Hepatitis C, H. pylori, and COVID-19. Potential non-environmental risk factors include bipolar disorder, essential tremor, bullous pemphigoid, and inflammatory bowel disease. There is an inverse relationship with PD and risk of most cancers. Though many potential protective and risk factors for PD were identified, research has not yet led to unique, rigorous prevention trials or successful disease-modifying interventions. While efforts to reduce exposure to some industrial toxicants are well justified, PD incidence might be most effectively reduced by mitigation of risks, such as Type 2 Diabetes, air pollution, traumatic brain injury, or physical inactivity, that are general public health intervention targets.

Telerehabilitation by Videoconferencing for Balance and Gait in People with Parkinson's Disease: A Scoping Review

Although supervised and real-time telerehabilitation by videoconferencing is now becoming common for people with Parkinson's disease (PD), its efficacy for balance and gait is still unclear. This paper uses a scoping approach to review the current evidence on the effects of telerehabilitation by videoconferencing on balance and gait for patients with PD. We also explored whether studies have used wearable technology during telerehabilitation to assess and treat balance and gait via videoconferencing. Literature searches were conducted using PubMed, ISI's Web of Knowledge, Cochrane's Library, and Embase. The data were extracted for study design, treatment, and outcomes. Fourteen studies were included in this review. Of these, seven studies investigated the effects of telerehabilitation (e.g., tele-yoga and adapted physiotherapy exercises) on balance and gait measures (e.g., self-reported balance, balance scale, walking speed, mobility, and motor symptoms) using videoconferencing in both assessment and treatment. The telerehabilitation programs by videoconferencing were feasible and safe for people with PD; however, the efficacy still needs to be determined, as only four studies had a parallel group. In addition, no study used wearable technology. Robust evidence of the effects of telerehabilitation by videoconferencing on balance and gait for patients with PD was not found, suggesting that future powered, prospective, and robust clinical trials are needed.

An Exploration of People Living with Parkinson's Experience of Cardio-Drumming; Parkinson's Beats: A Qualitative Phenomenological Study

Research has shown that physical activity has a range of benefits for people living with Parkinson's (PLwP), improving muscle strength, balance, flexibility, and walking, as well as non-motor symptoms such as mood. Parkinson's Beats is a form of cardio-drumming, specifically adapted for PLwP, and requires no previous experience nor skills. Nineteen PLwP (aged between 55 and 80) took part in the regular Parkinson's Beats sessions in-person or online. Focus group discussions took place after twelve weeks to understand the impacts of Parkinson's Beats. Through the framework analysis, six themes and fifteen subthemes were generated. Participants reported a range of benefits of cardio-drumming, including improved fitness and movement, positive mood, the flow experience, and enhanced social wellbeing. A few barriers to participation were also reported. Future research is justified, and best practice guidelines are needed to inform healthcare professionals, PLwP and their care givers.

Effects of physical exercise interventions on balance, postural stability and general mobility in Parkinson's disease: a network meta-analysis

OBJECTIVE

To assess which type of physical exercise intervention has the most beneficial effects on balance, postural stability and general mobility in patients with Parkinson's disease. These parameters were assessed using the Activities-specific Balance Confidence (ABC) scale, Berg Balance Scale (BBS), Mini-Balance Evaluation Systems Test (MiniBESTest) and Timed Up and Go Test (TUG).

DESIGN

Network meta-analysis.

METHODS

The PubMed, Cochrane Central Register of Controlled Trials, and Web of Science databases were searched up to August 2022 to identify randomized controlled trials on the effects of physical exercise interventions on balance, postural stability, and general mobility. The network meta-analysis included pairwise and indirect comparisons of results on the ABC scale, BBS, MiniBESTest, and TUG across 8 categories of physical exercise.

RESULTS

Eighty-six studies with a total of 4,693 patients were included. For the ABC scale, the indirect comparison showed that the highest effect size was observed for balance vs sensorimotor training without including endurance interventions (0.62; 95% confidence interval (95% CI) 0.06, 1.17). The highest effect sizes for BBS were observed for alternative exercises (1.21; 95% CI 0.62, 1.81), body-weight supported (BWS) interventions (1.31; 95% CI 0.57, 2.05), dance (1.18; 95% CI 0.33, 2.03) and sensorimotor training, including endurance interventions (1.10; 95% CI 0.46, 1.75) vs control groups. Indirect comparisons showed that the highest effect size for the MiniBESTest were observed for balance (0.75; 95% CI 0.46, 1.04) and resistance (0.58; 95% CI 0.10, 1.07) vs control groups. For the TUG, comparisons showed a significant effect size for alternative exercises (-0.54; 95% CI -0.82, -0.26), balance (-0.42; 95% CI -0.75, -0.08), resistance (-0.60; 95% CI -0.89, -0.31), and sensorimotor training including endurance interventions (-0.61; 95% CI -0.95, -0.27) vs control comparisons.

CONCLUSION

Balance interventions improve balance, postural stability, and general mobility in people with Parkinson's disease. Moreover, alternative exercises, dance, BWS interventions, resistance, and sensorimotor training, including and not including endurance interventions, are also effective.

Advice to People with Parkinson's in My Clinic: Exercise

There is compelling evidence that exercise must be part of main line therapy for people with Parkinson's disease. In this viewpoint, we outline the four key components of exercise: aerobic exercise, resistance exercise, flexibility exercise, and neuromotor exercises (posture, gait, balance, and agility) that can improve both motor and non-motor symptoms of the disease and, in the case of aerobic exercise, may delay the disease. We outline guidelines on how to change and optimize the exercise prescription at different stages of the disease.

The effect of home-based exercise on motor symptoms, quality of life and functional performance in Parkinson's disease: a systematic review and meta-analysis

BACKGROUND

Faced with the lack of physical activity caused by mandatory home isolation during special periods and patients' inconvenience in carrying out professionally supervised exercise, many home-based exercise programs have been developed. This systematic review and meta-analysis aimed to examine the effects of home-based exercise on measures of motor symptoms, quality of life and functional performance in Parkinson's disease (PD) patients.

METHODS

We performed a systematic review and meta-analysis, and searched PubMed, MEDLINE, Embase, Cochrane library, and Web of Science from their inception date to April 1, 2023. The quality of the literature was assessed using PEDro's quality scale. The data was pooled using R software. Results are presented as pooled standardized mean difference (SMD) with 95% confidence interval (CI).

RESULTS

A total of 20 studies involving 1885 PD patients were included. Meta-analysis results showed that home-based exercise had a small effect in relieving overall motor symptoms in PD patients (SMD = -0.29 [-0.45, -0.13]; P < 0.0001), improving quality of life (SMD = 0.20 [0.08, 0.32]; P < 0.0001), walking speed (SMD = 0.26 [0.05, 0.48]; P = 0.005), balance ability (SMD = 0.23 [0.10, 0.36]; P < 0.0001), finger dexterity (SMD = 0.28 [0.10, 0.46]; P = 0.003) and decreasing fear of falling (SMD = -0.29 [-0.49, -0.08]; P = 0.001). However, home-based exercise did not significantly relieve the overall motor symptoms of PD patients when the training period was less than 8 weeks and the total number of sessions was less than 30.

CONCLUSION

During times of limited physical activity due to pandemics such as COVID-19, home-based exercise is an alternative to maintain and improve motor symptoms in PD patients. In addition, for the minimum dose of home-based exercise, we recommend that the exercise period is no less than 8 weeks and the total number of sessions is no less than 30 times.

TRIAL REGISTRATION

PROSPERO registration number: CRD42022329780.

Physical exercise and its effects on people with Parkinson's disease: Umbrella review

INTRODUCTION

Parkinson's disease is neurodegenerative, complex and progressive, manifesting in a slow and irreversible way. Physical exercise has been proposed as therapeutic alternative to people with Parkinson´s disease.

OBJECTIVE

To synthesize knowledge about the effects of physical exercise on people with Parkinson´s Disease as presented by published systematic reviews.

METHODS

Nine electronic databases and two grey literature databases were searched for systematic reviews reporting the effects of physical exercises on people with Parkinson´s Disease. Searches involved a two-phase process, by, at least, two independent reviewers. Methodological quality of the included systematic reviews was assessed using AMSTAR-2.

RESULTS

From 2,122 systematic reviews, 139 were included. Motor outcomes were assessed in 91% of the studies, with balance being the most studied. Non-motor outcomes were assessed in 68% of the studies, with emphasis on quality of life. Physical exercises were classified into five categories: aerobic exercises, strength, combined, sensorimotor activities and other activity protocols. Findings of the systematic reviews suggest that all exercise categories can be prescribed to improve balance and mobility, while combined exercises, strength, and specific activities improve both motor and non-motor outcomes, and aerobic exercise and sensorimotor activities improve motor outcomes.

CONCLUSION

Current evidence from systematic reviews suggests that physical exercises impacts both motor and non-motor outcomes in people with Parkinson´s Disease. Limits in evidence provided by the systematic reviews were related to methodological issues and to the description of the interventions and must be considered to improve decision-making and clinical application.

The effects of exercise dose on patients with Parkinson's disease: a systematic review and meta-analysis of randomized controlled trials

OBJECTIVE

The effects of different exercise doses on motor function, balance, mobility, and quality of life (QOL) in patients with Parkinson's disease (PD) were evaluated.

METHOD

The exercise intervention dose was evaluated based on the recommendations of the American College of Sports Medicine (ACSM) for developing and maintaining cardiorespiratory health, muscle strength, and physical function for PD patients and classified into high ACSM compliance and low or uncertain ACSM compliance. The impact of ACSM compliance on Unified Parkinson's Disease Rating Scale, Part III (UPDRS-III), Berg Balance Scale (BBS), Timed Up and Go (TUG), and 39-item Parkinson's Disease Questionnaire (PDQ-39) in patients with PD was compared using the standardized mean difference (SMD) along with the corresponding 95% confidence interval (95% CI).

RESULTS

A total of 26 articles were included, comprising 32 studies. Twenty-one studies were classified as high ACSM compliance, and 11 studies were classified as low or uncertain ACSM compliance. For the four outcome measures, the SMD ratio of exercise interventions with high ACSM compliance to those with low or uncertain ACSM compliance was as follows: UPDRS-III (- 0.74: - 0.17), TUG (- 0.62: - 0.17), PDQ-39 (- 0.58: - 0.31), and BBS (0.51: 0.52).

CONCLUSION

The results suggest that compared with exercise interventions with low or uncertain ACSM compliance, exercise interventions with high ACSM compliance had a more significant improvement effect on motor function, mobility, and QOL in PD patients. However, the effect on balance was not as pronounced, and further research is needed to validate these findings.

Design of the STEPS trial: a phase II randomized controlled trial evaluating eHealth-supported motor-cognitive home training for Parkinson's disease

BACKGROUND

Electronic health (eHealth) technology offers the potential to support and motivate physical activity for symptom management in Parkinson's disease (PD). It is also recommended that motor exercise in PD be complemented with cognitive training aimed at attentional or executive functions. This paper describes the protocol for a double-blind randomized controlled trial to evaluate the effects of motor-cognitive training in the home environment, supported by eHealth.

METHODS/DESIGN

The Support for home Training using Ehealth in Parkinsons diseaSe (STEPS) is a double-blind single center randomized controlled trial. Two parallel groups will include in total 120 participants with mild to moderate PD who will receive either (i) the intervention (a progressive 10-week individualized motor-cognitive eHealth training with cognitive behavioral elements to increase physical activity levels) or (ii) an active control group (an individualized 10-week paper-based home exercise program). The active control group will not receive motor-cognitive exercises or cognitive behavioral approaches to increase physical activity level. The primary outcome is walking capacity assessed by the six-minute walk test (6MWT). Secondary outcomes will include gait performance during single and dual task conditions, gait speed, functional mobility and lower limb strength, balance, physical activity behavior and a range of patient reported outcome measures relevant in PD.

DISCUSSION

The STEPS trial will answer the question whether 10 weeks of eHealth supported motor-cognitive exercise in the home environment can improve walking capacity in PD when compared to a standard paper exercise program. Findings from this study will also strengthen the evidence concerning the efficacy of PD-specific eHealth interventions with a view meeting future health care demands by addressing issues of inaccessibility to specialized neurological rehabilitation in PD.

TRIAL REGISTRATION

ClinicalTrials.gov August 2022, NCT05510739.

Split-Belt Treadmill Training to Improve Gait Adaptation in Parkinson's Disease

BACKGROUND

Gait deficits in people with Parkinson's disease (PD) are triggered by circumstances requiring gait adaptation. The effects of gait adaptation training on a split-belt treadmill (SBT) are unknown in PD.

OBJECTIVE

We investigated the effects of repeated SBT versus tied-belt treadmill (TBT) training on retention and automaticity of gait adaptation and its transfer to over-ground walking and turning.

METHODS

We recruited 52 individuals with PD, of whom 22 were freezers, in a multi-center randomized single-blind controlled study. Training consisted of 4 weeks of supervised treadmill training delivered three times per week. Tests were conducted pre- and post-training and at 4-weeks follow-up. Turning (primary outcome) and gait were assessed over-ground and during a gait adaptation protocol on the treadmill. All tasks were performed with and without a cognitive task.

RESULTS

We found that SBT-training improved gait adaptation with moderate to large effects sizes (P < 0.02) compared to TBT, effects that were sustained at follow-up and during dual tasking. However, better gait adaptation did not transfer to over-ground turning speed. In both SBT- and TBT-arms, over-ground walking and Movement Disorder Society-Unified Parkinson's Disease Rating Scale III (MDS-UPDRS-III scores were improved, the latter of which reached clinically meaningful effects in the SBT-group only. No impact was found on freezing of gait.

CONCLUSION

People with PD are able to learn and retain the ability to overcome asymmetric gait-speed perturbations on a treadmill remarkably well, but seem unable to generalize these skills to asymmetric gait off-treadmill. Future study is warranted into gait adaptation training to boost the transfer of complex walking skills. © 2022 The Authors. Movement Disorders published by Wiley Periodicals LLC on behalf of International Parkinson and Movement Disorder Society.

Prevalence of sarcopenia in Parkinson's disease: A systematic review and meta-analysis

We meta-analysed the sarcopenia prevalence among patients with Parkinson´s disease (PD) in comparison to a control group and tested the effects of age, sex, sarcopenia assessments, and PD progression in the sarcopenia prevalence. The literature search was performed using five databases in March 2022. The prevalence of sarcopenia in patients with PD was 3 times higher than in the control group (OR 3.98). Subgroup analyses showed that among individuals aged ≥ 70 years the higher prevalence of sarcopenia in PD compared to controls (OR 5.32, P=0.08) tended to be higher (P=0.08) than the group < 70 years. Regarding PD progression, the prevalence of sarcopenia was not different between individuals scoring < 2.5 and ≥ 2.5 in the Hoehn and Yahr scale. Patients with PD have a higher probability of developing sarcopenia when compared with the control group and older PD patients trended to have even higher chance of sarcopenia than their older controls.

Molecular and Cellular Interactions in Pathogenesis of Sporadic Parkinson Disease

An increasing number of the population all around the world suffer from age-associated neurodegenerative diseases including Parkinson’s disease (PD). This disorder presents different signs of genetic, epigenetic and environmental origin, and molecular, cellular and intracellular dysfunction. At the molecular level, α-synuclein (αSyn) was identified as the principal molecule constituting the Lewy bodies (LB). The gut microbiota participates in the pathogenesis of PD and may contribute to the loss of dopaminergic neurons through mitochondrial dysfunction. The most important pathogenetic link is an imbalance of Ca²⁺ ions, which is associated with redox imbalance in the cells and increased generation of reactive oxygen species (ROS). In this review, genetic, epigenetic and environmental factors that cause these disorders and their cause-and-effect relationships are considered. As a constituent of environmental factors, the example of organophosphates (OPs) is also reviewed. The role of endothelial damage in the pathogenesis of PD is discussed, and a ‘triple hit hypothesis’ is proposed as a modification of Braak’s dual hit one. In the absence of effective therapies for neurodegenerative diseases, more and more evidence is emerging about the positive impact of nutritional structure and healthy lifestyle on the state of blood vessels and the risk of developing these diseases.

Study in Parkinson's disease of exercise phase 3 (SPARX3): study protocol for a randomized controlled trial

BACKGROUND

To date, no medication has slowed the progression of Parkinson's disease (PD). Preclinical, epidemiological, and experimental data on humans all support many benefits of endurance exercise among persons with PD. The key question is whether there is a definitive additional benefit of exercising at high intensity, in terms of slowing disease progression, beyond the well-documented benefit of endurance training on a treadmill for fitness, gait, and functional mobility. This study will determine the efficacy of high-intensity endurance exercise as first-line therapy for persons diagnosed with PD within 3 years, and untreated with symptomatic therapy at baseline.

METHODS

This is a multicenter, randomized, evaluator-blinded study of endurance exercise training. The exercise intervention will be delivered by treadmill at 2 doses over 18 months: moderate intensity (4 days/week for 30 min per session at 60-65% maximum heart rate) and high intensity (4 days/week for 30 min per session at 80-85% maximum heart rate). We will randomize 370 participants and follow them at multiple time points for 24 months. The primary outcome is the Movement Disorders Society-Unified Parkinson's Disease Rating Scale (MDS-UPDRS) motor score (Part III) with the primary analysis assessing the change in MDS-UPDRS motor score (Part III) over 12 months, or until initiation of symptomatic antiparkinsonian treatment if before 12 months. Secondary outcomes are striatal dopamine transporter binding, 6-min walk distance, number of daily steps, cognitive function, physical fitness, quality of life, time to initiate dopaminergic medication, circulating levels of C-reactive protein (CRP), and brain-derived neurotrophic factor (BDNF). Tertiary outcomes are walking stride length and turning velocity.

DISCUSSION

SPARX3 is a Phase 3 clinical trial designed to determine the efficacy of high-intensity, endurance treadmill exercise to slow the progression of PD as measured by the MDS-UPDRS motor score. Establishing whether high-intensity endurance treadmill exercise can slow the progression of PD would mark a significant breakthrough in treating PD. It would have a meaningful impact on the quality of life of people with PD, their caregivers and public health.

TRIAL REGISTRATION

ClinicalTrials.gov NCT04284436 . Registered on February 25, 2020.