Non-motor Parkinson disease: new concepts and personalised management

Motor dysfunction in Parkinson's patients: depression differences in a latent growth model

Objective

This study aims to utilize latent growth model (LGM) to explore the developmental trajectory of motor dysfunction in Parkinson's disease (PD) patients and investigate the relationship between depression and motor dysfunction.

Methods

Four-year follow-up data from 389 PD patients were collected through the Parkinson's Progression Marker Initiative (PPMI). Firstly, a univariate LGM was employed to examine the developmental trajectory of motor dysfunction in PD patients. Subsequently, depression levels were introduced as covariates into the model, and depression was further treated as a parallel growth latent variable to study the longitudinal relationship between motor dysfunction and depression.

Results

In the trajectory analysis of motor dysfunction, the fit indices for the quadratic growth LGM model were χ2 = 7.419, df = 6, CFI = 0.998, TLI = 0.997, SRMR = 0.019, and RMSEA = 0.025, indicating that the growth trend of motor dysfunction follows a quadratic curve rather than a simple linear pattern. Introducing depression symptoms as time-varying covariates to explore their effect on motor dysfunction revealed significant positive correlations (β = 0.383, p = 0.026; β = 0.675, p < 0.001; β = 0.385, p = 0.019; β = 0.415, p = 0.014; β = 0.614, p = 0.003), suggesting that as depression levels increase, motor dysfunction scores also increase. Treating depression as a parallel developmental process in the LGM, the regression coefficients for depression intercept on motor dysfunction intercept, depression slope on motor dysfunction slope, and depression quadratic factor on motor dysfunction quadratic factor were 0.448 (p = 0.046), 1.316 (p = 0.003), and 1.496 (p = 0.038), respectively. These significant regression coefficients indicate a complex relationship between depression and motor dysfunction, involving not only initial level associations but also growth trends over time and possible quadratic effects.

Conclusion

This study indicates a quadratic growth trajectory for motor dysfunction in PD, suggesting a continuous increase in severity with a gradual deceleration in growth rate. The relationship between depression and motor dysfunction is complex, involving initial associations, evolving trends over time, and potential quadratic effects. Exacerbation of depressive symptoms may coincide with motor function deterioration.

Evaluation of the effect of bilateral subthalamic nucleus deep brain stimulation on fatigue in Parkinson's Disease as measured by the non-motor symptoms scale

BACKGROUND

Fatigue is a common and disabling non-motor symptom (NMS) in Parkinson's disease (PD) patients. However, the effect of subthalamic nucleus (STN) deep brain stimulation (DBS) on fatigue has not been widely studied.

OBJECTIVE

To determine the effect of STN DBS on fatigue in PD patients, measured by the Non-motor symptoms scale (NMSS).

METHODS

Cross-sectional analysis of 50 patients with PD who underwent STN DBS at King's College Hospital and Salford Royal Hospital with fatigue scores (measured by question number 4 from domain 2 (sleep/fatigue) of the NMSS as the primary outcome measure. Secondary outcome measures included the PD Sleep Scale (PDSS), Scales for Outcome in PD (SCOPA)-motor examination, activities of daily living, motor complications, Hoehn and Yahr (HY) stage and changes in Levodopa Equivalent Daily Dose (LEDD).

RESULTS

50 patients with a mean follow-up period of 1.98 ± 1.36 years were studied. Significant improvement in median fatigue scores (4.00 (0.75-9.00) to 1.00 (0.00-4.50); p = .001) was observed. In addition, improvements in question 5 (sleep maintenance and fragmentation; 8.00 (4.00-12.00) to 0.00 (0.00-4.00); p < .001) and in domain 2 total score (sleep/fatigue; 20.00 (8.75-27.25) to 6.00 (0.75-16.00); p < .001) were also significant, together with improvements in NMSS total score, SCOPA scores and HY stage (p ≤ .02). Moreover, LEDD but especially dopamine agonists LEDD was significantly reduced after DBS (310.00 (0.00-480.00) to 150.00 (0.00-300.00); p < .020).

CONCLUSIONS

Even though open label and not using a validated fatigue scale, this observational analysis suggest that fatigue improves significantly after STN DBS with persisting benefits at two years follow-up.

Depression is associated with the nonmotor symptoms of Parkinson's disease: A comparative analysis

Background and aims

The nonmotor symptoms (NMS) of Parkinson's disease (PD) and their potential role in early diagnosis are recent debates. Herein, we aimed to investigate the association between depression and NMS of PD including sleep disorders, hyposexuality, hyposmia, constipation, and orthostatic hypotension.

Methods

A total of 93 PD patients with depression and 67 PD patients without depression were included in the study, and NMS were compared between the two groups. Furthermore, the possible associations between depression severity measured by Beck Depression Inventory (BDI) and NMS were investigated using linear regression or binary logistic regression models controlled for possible confounders. Eventually, we performed a subgroup analysis in each mild, moderate, and severe depression group.

Results

Orthostatic hypotension, constipation, and hyposexuality showed a significant difference between PD patients with and without depression (p < 0.001, p = 0.029, and p < 0.001, respectively). The BDI score was significantly associated with hyposexuality, Montreal cognitive assessment (MoCA), and Pittsburgh Sleep Quality (p = 0.016, p = 0.010, and p = 0.011, respectively); however, after adjustments for possible confounders, the associations of the BDI score with the MoCA score and hyposexuality remained significant (p = 0.015 and p = 0.019, respectively). Considering subgroup analysis, a similar pattern of significant results was observed particularly in the severe group.

Conclusions

This study suggests a possible association between depression in PD patients and some NMS observed in the course of PD. These findings could be beneficial for early diagnosis of the disease, which eventually could make a considerable difference in the management of PD patients. Additional interventional longitudinal studies are warranted to explore how controlling depression could impact the NMS of patients with PD.

A systematic review of the associations between sedentary behavior, physical inactivity, and non-motor symptoms of Parkinson's disease

BACKGROUND

Parkinson's disease (PD), known for motor symptoms, often presents early non-motor issues that significantly affect patients' quality of life. While effective treatments are limited, physical activity and exercise offer potential benefits. However, an overlooked aspect of the movement intensity continuum is prolonged sitting or sedentary behavior, and physical inactivity. Thus, this study aimed to conduct a systematic review investigating the associations between sedentary behavior, physical inactivity, and non-motor symptoms, specifically cognitive impairment, depression, and poor sleep in PD.

METHODS

Conforming to PRISMA guidelines, a systematic search of the literature was conducted via electronic databases including MEDLINE, CINAHL, Scopus, PubMed and PsycINFO up to February 28, 2023. Studies were included if they investigated associations between sedentary behavior or physical inactivity and at least one non-motor symptom such as depression, poor sleep, and/or cognitive impairment, in adults aged 18 years or older with PD. Quality assessment of the studies was performed using the Newcastle-Ottawa scale for cross-sectional and cohort studies.

RESULTS

Of the 463 publications found, 7 studies met the inclusion criteria (n = 980 unique participants). Sample sizes ranged from 17 to 487 participants, and all studies were observational, conducted in home or community settings. Collectively, these studies show that higher amounts of both objectively-measured and self-reported sedentary time are associated with worse scores on standardized measures of cognition and the Parkinson's Disease Questionnaire (PDQ) summary index and its subscales, such as cognition (memory and concentration). Additionally, longitudinal cohort studies suggest that physical inactivity and higher sedentary behavior are associated with depression and cognitive impairment in PD. Less sleep was associated with higher sedentary behavior.

CONCLUSION

Associations observed between physical inactivity, sedentary behavior, and non-motor symptoms in PD underscore the need to address these factors for enhanced well-being. Further well-designed studies are essential to assess the impact of reducing sedentary behavior and physical inactivity on non-motor symptoms in PD. Prospero registration number: PROSPERO (ID: CRD42023405422) on April 11, 2023.

Brazilian dance self-perceived impacts on quality of life of people with Parkinson's

Background

Parkinson's disease (PD) causes several motor and non-motor symptoms, resulting in negative impacts on physical, mental, emotional, and social aspects of people with PD quality of life. Dance has been considered as a potential non-pharmacological intervention to improve people with PD motor and non-motor symptoms, thereby enhancing quality of life.

Purpose

To analyze the self-perceive impacts of Brazilian Dance on the quality of life (physical, mental, emotional, and social) of PwPD, both before and during the COVID-19 pandemic.

Methods

Fourteen participants from the "Dança & Parkinson" project were included in this qualitative study. Data collection instruments consisted of a profile and personal data sheet; assessment of accessibility to the online dance classes; Telephone Montreal Cognitive Assessment by phone call; and semi-structured interview conducted through ZOOM video call. The participants characterization data were calculated using mean, standard deviation, and percentages with the Excel Program version 2013. Qualitative data was analyzed using the Thematic Analysis technique in the Nvivo, version 8.0, qualitative analysis of text, sound, and video program.

Results

The participants reported facing various challenges in dealing with PD, which negatively impact their quality of life. However, their resilience, acceptance, and dedication to treatment play an important role in coping with the issues related to the disease. Brazilian dance, both in-person before the COVID-19 pandemic and online during the pandemic, led the participants to perceive improvements in physical, mental, emotional, and social aspects of quality of life.

Conclusion

The Brazilian dance appears to have a positive impact on the physical, mental, emotional, and social aspects of the participants' quality of life, both before and during the COVID-19 pandemic.

ParkinSong Online: Feasibility of Telehealth Delivery and Remote Data Collection for a Therapeutic Group Singing Study in Parkinson's

BACKGROUND

Parkinson's disease can negatively affect vocal functioning and social wellbeing, particularly in the latter stages of disease progression. Face-to-face group singing interventions can improve communication and wellbeing outcomes, yet not all people can access in-person sessions. To help overcome barriers to participation, exploration of the feasibility and utility of online therapeutic singing programs is needed.

OBJECTIVES

To evaluate the feasibility, acceptability, and preliminary efficacy of a 12-week ParkinSong Online intervention on speech and wellbeing for people with Parkinson's disease.

METHODS

A total of 28 participants with idiopathic Parkinson's disease were recruited to a single-arm feasibility study. Weekly 90-minute online sessions were co-facilitated by a music therapist and speech pathologist. Speech and wellbeing assessments were conducted pre and post intervention. Participant and facilitator surveys were administered after each session, with focus group interviews at the end of the program.

RESULTS

The recruitment rate was high (90%) with no attrition, adverse events, or safety issues. There was good intervention fidelity, attendance (average 89%), and positive participant experience. Feasibility was good, with technology reported as the main challenge (connecting and navigating Zoom). No improvements were seen in voice measures or wellbeing outcomes in this small trial. The online format used in this study did not provide the same benefits as in-person ParkinSong sessions.

CONCLUSIONS

ParkinSong Online is feasible for recreational purposes and social engagement provided that people have adequate technological knowledge or support. The optimal online delivery format to achieve communication improvements in Parkinson's awaits confirmation.

Trends and hotspots in non-motor symptoms of Parkinson's disease: a 10-year bibliometric analysis

Non-motor symptoms are prevalent among individuals with Parkinson's disease (PD) and seriously affect patient quality of life, even more so than motor symptoms. In the past decade, an increasing number of studies have investigated non-motor symptoms in PD. The present study aimed to comprehensively analyze the global literature, trends, and hotspots of research investigating non-motor symptoms in PD through bibliometric methods. Studies addressing non-motor symptoms in the Web of Science Core Collection (WoSCC), published between January 2013 and December 2022, were retrieved. Bibliometric methods, including the R package "Bibliometrix," VOS viewer, and CiteSpace software, were used to investigate and visualize parameters, including yearly publications, country/region, institution, and authors, to collate and quantify information. Analysis of keywords and co-cited references explored trends and hotspots. There was a significant increase in the number of publications addressing the non-motor symptoms of PD, with a total of 3,521 articles retrieved. The United States was ranked first in terms of publications (n = 763) and citations (n = 11,269), maintaining its leadership position among all countries. King's College London (United Kingdom) was the most active institution among all publications (n = 133) and K Ray Chaudhuri was the author with the most publications (n = 131). Parkinsonism & Related Disorders published the most articles, while Movement Disorders was the most cited journal. Reference explosions have shown that early diagnosis, biomarkers, novel magnetic resonance imaging techniques, and deep brain stimulation have become research "hotspots" in recent years. Keyword clustering revealed that alpha-synuclein is the largest cluster for PD. The keyword heatmap revealed that non-motor symptoms appeared most frequently (n = 1,104), followed by quality of life (n = 502), dementia (n = 403), and depression (n = 397). Results of the present study provide an objective, comprehensive, and systematic analysis of these publications, and identifies trends and "hot" developments in this field of research. This work will inform investigators worldwide to help them conduct further research and develop new therapies.

Future Directions for Developing Non-dopaminergic Strategies for the Treatment of Parkinson's Disease

The symptomatic treatment of Parkinson's disease (PD) has been dominated by the use of dopaminergic medication, but significant unmet need remains, much of which is related to non-motor symptoms and the involvement of non-dopaminergic transmitter systems. As such, little has changed in the past decades that has led to milestone advances in therapy and significantly improved treatment paradigms and patient outcomes, particularly in relation to symptoms unresponsive to levodopa. This review has looked at how pharmacological approaches to treatment are likely to develop in the near and distant future and will focus on two areas: 1) novel non-dopaminergic pharmacological strategies to control motor symptoms; and 2) novel non-dopaminergic approaches for the treatment of non-motor symptoms. The overall objective of this review is to use a 'crystal ball' approach to the future of drug discovery in PD and move away from the more traditional dopamine-based treatments. Here, we discuss promising non-dopaminergic and 'dirty drugs' that have the potential to become new key players in the field of Parkinson's disease treatment.

Long-term efficacy of hydrotherapy on balance function in patients with Parkinson's disease: a systematic review and meta-analysis

Background

Hydrotherapy can improve the motor and non-motor symptoms of Parkinson's disease (PD), but the long-term effects of hydrotherapy on PD are still unclear.

Objective

The purpose of this systematic evaluation and meta-analysis was to explore the long-term effects of hydrotherapy on balance function in PD patients.

Methods

A systematic search of five databases was conducted to identify appropriate randomized controlled trials (RCTs) according to the established inclusion and exclusion criteria. The general characteristics and outcome data (balance, exercise, mobility, quality of life, etc.) of the included studies were extracted, and the quality of the included studies was evaluated using the Cochrane risk of bias assessment tool. Finally, the outcome data were integrated for meta-analysis.

Results

A total of 149 articles were screened, and 5 high-quality RCTs involving 135 PD patients were included. The results of the meta-analysis showed positive long-term effects of hydrotherapy on balance function compared to the control group (SMD = 0.69; 95% CI = 0.21, 1.17; p = 0.005; I2 = 44%), However, there were no significant long-term effects of hydrotherapy on motor function (SMD = 0.06; 95% CI = -0.33, 0.44; p = 0.77; I2 = 0%), mobility and quality of life (SMD = -0.21; 95% CI = -0.98, 0.57; p = 0.6; I2 = 71%). Interestingly, the results of the sensitivity analysis performed on mobility showed a clear continuation effect of hydrotherapy on mobility compared to the control group (SMD = -0.80; 95% CI = -1.23, -0.37; p < 0.001; I2 = 0%).

Conclusion

The long-term effects of hydrotherapy on PD patients mainly focus on balance function, and the continuous effects on motor function, mobility, and quality of life are not obvious.

Setting the clinical context to non-motor symptoms reflected by Park-pain, Park-sleep, and Park-autonomic subtypes of Parkinson's disease

Non-motor symptoms (NMS) of Parkinson's disease (PD) are well described in both clinical practice and the literature, enabling their management and enhancing our understanding of PD. NMS can dominate the clinical pictures and NMS subtypes have recently been proposed, initially based on clinical observations, and later confirmed in data driven analyses of large datasets and in biomarker-based studies. In this chapter, we provide an update on what is known about three common subtypes of NMS in PD. The pain (Park-pain), sleep dysfunction (Park-sleep), and autonomic dysfunction (Park-autonomic), providing an overview of their individual classification, clinical manifestation, pathophysiology, diagnosis, and potential treatments.

New horizons in Parkinson's disease in older populations

Parkinson's disease (PD) is the second most common neurodegenerative disorder after Alzheimer's disease. Ageing is considered to be the greatest risk factor for PD, with a complex interplay between genetics and the environment. With population ageing, the prevalence of PD is expected to escalate worldwide; thus, it is of utmost importance to reduce the burden of PD. To date, there are no therapies to cure the disease, and current treatment strategies focus on the management of symptoms. Older adults often have multiple chronic diseases and geriatric syndromes, which further complicates the management of PD. Healthcare systems and care models necessary to address the broad needs of older PD patients are largely unavailable. In this New Horizon article, we discuss various aspects of PD from an ageing perspective, including disease management. We highlight recent advancements in PD therapies and discuss new care models with the potential to improve patient's quality of life.

The Park Sleep subtype in Parkinson's disease: from concept to clinic

INTRODUCTION

The heterogeneity of Parkinson's disease (PD) is evident from descriptions of non-motor (NMS) subtypes and Park Sleep, originally identified by Sauerbier et al. 2016, is one such clinical subtype associated with the predominant clinical presentation of sleep dysfunctions including excessive daytime sleepiness (EDS), along with insomnia.

AREAS COVERED

A literature search was conducted using the PubMed, Medline, Embase, and Web of Science databases, accessed between 1 February 2023 and 28 March 2023. In this review, we describe the clinical subtype of Park Sleep and related 'tests' ranging from polysomnography to investigational neuromelanin MRI brain scans and some tissue-based biological markers.

EXPERT OPINION

Cholinergic, noradrenergic, and serotonergic systems are dominantly affected in PD. Park Sleep subtype is hypothesized to be associated primarily with serotonergic deficit, clinically manifesting as somnolence and narcoleptic events (sleep attacks), with or without rapid eye movement behavior disorder (RBD). In clinic, Park Sleep recognition may drive lifestyle changes (e.g. driving) along with therapy adjustments as Park Sleep patients may be sensitive to dopamine D3 active agonists, such as ropinirole and pramipexole. Specific dashboard scores based personalized management options need to be implemented and include pharmacological, non-pharmacological, and lifestyle linked advice.

(HIIT-The Track) High-Intensity Interval Training for People with Parkinson's Disease: Individual Response Patterns of (Non-)Motor Symptoms and Blood-Based Biomarkers-A Crossover Single-Case Experimental Design

INTRODUCTION

Physical exercise is receiving increasing interest as an augmentative non-pharmacological intervention in Parkinson's disease (PD). This pilot study primarily aimed to quantify individual response patterns of motor symptoms to alternating exercise modalities, along with non-motor functioning and blood biomarkers of neuroplasticity and neurodegeneration.

MATERIALS & METHODS

People with PD performed high-intensity interval training (HIIT) and continuous aerobic exercise (CAE) using a crossover single-case experimental design. A repeated assessment of outcome measures was conducted. The trajectories of outcome measures were visualized in time series plots and interpreted relative to the minimal clinically important difference (MCID) and smallest detectable change (SDC) or as a change in the positive or negative direction using trend lines.

RESULTS

Data of three participants were analyzed and engaging in physical exercise seemed beneficial for reducing motor symptoms. Participant 1 demonstrated improvement in motor function, independent of exercise modality; while for participant 2, such a clinically relevant (positive) change in motor function was only observed in response to CAE. Participant 3 showed improved motor function after HIIT, but no comparison could be made with CAE because of drop-out. Heterogeneous responses on secondary outcome measures were found, not only between exercise modalities but also among participants.

CONCLUSION

Though this study underpins the positive impact of physical exercise in the management of PD, large variability in individual response patterns to the interventions among participants makes it difficult to identify clear exercise-induced adaptations in functioning and blood biomarkers. Further research is needed to overcome methodological challenges in measuring individual response patterns.

Melatonin as a Chronobiotic/Cytoprotective Agent in REM Sleep Behavior Disorder

Dream-enactment behavior that emerges during episodes of rapid eye movement (REM) sleep without muscle atonia is a parasomnia known as REM sleep behavior disorder (RBD). RBD constitutes a prodromal marker of α-synucleinopathies and serves as one of the best biomarkers available to predict diseases such as Parkinson disease, multiple system atrophy and dementia with Lewy bodies. Most patients showing RBD will convert to an α-synucleinopathy about 10 years after diagnosis. The diagnostic advantage of RBD relies on the prolonged prodromal time, its predictive power and the absence of disease-related treatments that could act as confounders. Therefore, patients with RBD are candidates for neuroprotection trials that delay or prevent conversion to a pathology with abnormal α-synuclein metabolism. The administration of melatonin in doses exhibiting a chronobiotic/hypnotic effect (less than 10 mg daily) is commonly used as a first line treatment (together with clonazepam) of RBD. At a higher dose, melatonin may also be an effective cytoprotector to halt α-synucleinopathy progression. However, allometric conversion doses derived from animal studies (in the 100 mg/day range) are rarely employed clinically regardless of the demonstrated absence of toxicity of melatonin in phase 1 pharmacological studies with doses up to 100 mg in normal volunteers. This review discusses the application of melatonin in RBD: (a) as a symptomatic treatment in RBD; (b) as a possible disease-modifying treatment in α-synucleinopathies. To what degree melatonin has therapeutic efficacy in the prevention of α-synucleinopathies awaits further investigation, in particular multicenter double-blind trials.

Common and distinct roles of amygdala subregional functional connectivity in non-motor symptoms of Parkinson's disease

Neuroimaging studies suggest a pivotal role of amygdala dysfunction in non-motor symptoms (NMS) of Parkinson's disease (PD). However, the relationship between amygdala subregions (the centromedial (CMA), basolateral (BLA) and superficial amygdala (SFA)) and NMS has not been delineated. We used resting-state functional MRI to examine the PD-related alterations in functional connectivity for amygdala subregions. The left three subregions and right BLA exhibited between-group differences, and were commonly hypo-connected with the frontal, temporal, insular cortex, and putamen in PD. Each subregion displayed distinct hypoconnectivity with the limbic systems. Partial least-squares analysis revealed distinct amygdala subregional involvement in diverse NMS. Hypo-connectivity of all four subregions was associated with emotion, pain, olfaction, and cognition. Hypo-connectivity of the left SFA was associated with sleepiness. Our findings highlight the hypofunction of the amygdala subregions in PD and their preliminary associations with NMS, providing new insights into the pathogenesis of NMS.

Circadian disruption and sleep disorders in neurodegeneration

Disruptions of circadian rhythms and sleep cycles are common among neurodegenerative diseases and can occur at multiple levels. Accumulating evidence reveals a bidirectional relationship between disruptions of circadian rhythms and sleep cycles and neurodegenerative diseases. Circadian disruption and sleep disorders aggravate neurodegeneration and neurodegenerative diseases can in turn disrupt circadian rhythms and sleep. Importantly, circadian disruption and various sleep disorders can increase the risk of neurodegenerative diseases. Thus, harnessing the circadian biology findings from preclinical and translational research in neurodegenerative diseases is of importance for reducing risk of neurodegeneration and improving symptoms and quality of life of individuals with neurodegenerative disorders via approaches that normalize circadian in the context of precision medicine. In this review, we discuss the implications of circadian disruption and sleep disorders in neurodegenerative diseases by summarizing evidence from both human and animal studies, focusing on the bidirectional links of sleep and circadian rhythms with prevalent forms of neurodegeneration. These findings provide valuable insights into the pathogenesis of neurodegenerative diseases and suggest a promising role of circadian-based interventions.

Premotor, nonmotor and motor symptoms of Parkinson's Disease: A new clinical state of the art

Parkinson's Disease (PD) is a neurodegenerative disorder that affects dopaminergic neurons in the mesencephalic substantia nigra, causing a progressive clinical course characterized by pre-motor, non-motor and motor symptoms, which negatively impact the quality of life of patients and cause high health care costs. Therefore, the present study aims to discuss the clinical manifestations of PD and to make a correlation with the gut-brain (GB) axis, approaching epidemiology and therapeutic perspectives, to better understand its clinical progression and identify symptoms early. A literature review was performed regarding the association between clinical progression, the gut-brain axis, epidemiology, and therapeutic perspectives, in addition to detailing pre-motor, non-motor symptoms (neuropsychiatric, cognitive, autonomic, sleep disorders, sensory abnormalities) and cardinal motor symptoms. Therefore, this article addresses a topic of extreme relevance, since the previously mentioned clinical manifestations (pre-motor and non-motor) can often act as prodromal markers for the early diagnosis of PD and may precede it by up to 20 years.

Effects of Music-Based Interventions on Motor and Non-Motor Symptoms in Patients with Parkinson's Disease: A Systematic Review and Meta-Analysis

This systematic review and meta-analysis examined previous studies on music-based interventions for individuals with Parkinson’s disease (PD). The effectiveness of the interventions on various motor and non-motor outcomes was evaluated. This review was conducted by searching PubMed, CINAHL, PsycINFO, and Cochrane Library CENTRAL prior to June 2022 for randomized controlled trial (RCT) and controlled clinical trial (CCT) studies published in English. Data were expressed as weighted/standardized mean difference (MD/SMD) with 95% confidence intervals (CI). I2 index was used for heterogeneity. The initial search identified 745 studies, and 13 studies involving 417 participants with PD which met the inclusion criteria included in this review. The results of the meta-analysis revealed that music-based interventions can significantly improve walking velocity (MD = 0.12, 95% CI = 0.07~0.16, p < 0.00001), stride length (MD = 0.04, 95% CI = 0.02~0.07, p = 0.002), and mobility (MD = −1.05, 95% CI = −1.53~−0.57, p < 0.0001). However, the results did not support significant effects for music-based interventions on cadence (MD = 3.21, 95% CI = −4.15~10.57, p = 0.39), cognitive flexibility (MD = 20.91, 95% CI = −10.62~52.44, p = 0.19), inhibition (SMD = 0.07, 95% CI = −0.40~0.55, p = 0.76), and quality of life (SMD = −0.68, 95% CI= −1.68~0.32, p = 0.18). The findings suggest that music-based interventions are effective for the improvement of some motor symptoms, but evidence for non-motor symptoms is limited. Further high-quality studies with a larger sample size are required to obtain the robust effects of music-based interventions on various outcomes among patients with PD.

Advances in the Pharmacological and Non-pharmacological Management of Non-motor Symptoms in Parkinson's Disease: An Update Since 2017

BACKGROUND

Non-motor symptoms (NMS) are an important and ubiquitous determinant of quality of life in Parkinson's disease (PD). However, robust evidence for their treatment is still a major unmet need.

OBJECTIVE

This study aimed to provide an updated review on advances in pharmacological, nonpharmacological, and exercise-based interventions for NMS in PD, covering the period since the publication of the MDS Task Force Recommendations.

METHODS

We performed a literature search to identify pharmacological, non-pharmacological, and exercise-based interventions for NMS in PD. As there are recent reviews on the subject, we have only included studies from the 1st of January 2017 to the 1st of December 2021 and limited our search to randomised and non-randomised (including open-label) clinical trials.

RESULTS

We discuss new strategies to manage NMS based on data that have become available since 2017, for instance, on the treatment of orthostatic hypotension with droxidopa, several dopaminergic treatment options for insomnia, and a range of non-pharmacological and exercise-based interventions for cognitive and neuropsychiatric symptoms, pain, and insomnia and excessive sleepiness.

CONCLUSION

Recent evidence suggests that targeted non-pharmacological treatments, as well as some other NMS management options, may have a significant beneficial effect on the quality of life and need to be considered in the pathways of treatment of PD.

Therapeutic Approaches to Non-Motor Symptoms of Parkinson's Disease: A Current Update on Preclinical Evidence

Despite being classified as a movement disorder, Parkinson's disease (PD) is characterized by a wide range of non-motor symptoms that significantly affect the patients' quality of life. However, clear evidence-based therapy recommendations for non-motor symptoms of PD are uncommon. Animal models of PD have previously been shown to be useful for advancing the knowledge and treatment of motor symptoms. However, these models may provide insight into and assess therapies for non-motor symptoms in PD. This paper highlights non-motor symptoms in preclinical models of PD and the current position regarding preclinical therapeutic approaches for these non-motor symptoms. This information may be relevant for designing future preclinical investigations of therapies for nonmotor symptoms in PD.

Impact of Off-Time on Quality of Life in Parkinson's Patients and Their Caregivers: Insights from Social Media

Introduction

In Parkinson's disease (PD), the quality of life of both patients and caregivers is affected. While key issues relating to quality of life may not emerge in conversations with healthcare professionals (HCPs), unguarded social media conversations can provide insight into how people with Parkinson's disease (PwPD) and their caregivers are affected. We conducted a qualitative and quantitative netnographic study of PD conversations posted on social media sites over a 12-month period.

Objective

To identify key themes and issues for PwPD.

Methods

Using predefined and piloted search terms, we identified 392,962 social media posts (between March 31, 2020, and March 31, 2021, for the UK and France, and between September 30, 2019, and March 31, 2021, for Italy, Spain, and Germany). A random sample of these posts was then analyzed using natural language processing (NLP), and quantitative, qualitative,in-depth contextual analysis was also performed.

Results

Key themes that emerged in the PD conversation related to the changing experience of symptoms over time are the physical, emotional, and cognitive impact of symptoms, the management and treatment of PD, disease awareness among the general public, and the caregiver burden. The emotional impact of motor symptoms on PwPD is significant, particularly when symptoms increase and PwPD lose their independence, which may exacerbate existing anxiety and depression. Nonmotor symptoms can also compound the difficulties with managing the physical impact of motor symptoms. The burden of nonmotor symptoms is felt by both PwPD and their caregivers, with the impact of nonmotor symptoms on cognitive processes particularly frustrating for caregivers. The experience of off-time was also featured in the online conversation. Some PwPD believe there is a lack of adequate management from healthcare professionals, who may not appreciate their concerns or take sufficient time to discuss their needs.

Conclusion

This study identified key themes that PwPD and their caregivers discuss online. These findings help signpost issues of importance to PwPD and areas in which their care may be improved.

Clinical trajectories and biomarkers for weight variability in early Parkinson’s disease

Unexplained weight changes that occur in Parkinson’s disease (PD), are often neglected and remain a poorly understood non-motor feature in patients with PD. A specific ‘Park-weight’ phenotype with low body weight has been described, and our aim was to evaluate the clinical and prognostic trajectories and biomarkers of weight variability in PD. We evaluated body weight-related biomarkers in 405 de novo PD patients and 187 healthy controls (HC) over a 5-year follow-up period from the PPMI database. Body-weight variability was defined as intra-individual variability in body weight between visits. PD patients were categorized as weight losers, gainers, or patients with stable weight. The differential progression of motor and non-motor clinical variables between groups was explored using linear mixed-effects models. Finally, we estimated longitudinal changes in weight as a function of baseline and longitudinal striatal presynaptic dopaminergic transporter imaging. PD patients presented a greater weight variability compared to HC (p = 0.003). Patients who developed weight loss had lower CSF amyloid-beta 1–42 (p = 0.009) at baseline. In addition, patients with weight loss showed a faster cognitive decline (p = 0.001), whereas patients with weight gain showed a slower motor progression (p = 0.001), compared to patients with stable weight. Baseline right striatal denervation was a predictor of weight variability in both PD patients and HC (p < 0.001). Similarly, weight variability in PD patients was associated with the progression of right striatal denervation (p < 0.001). Weight variability and specifically weight loss are more frequent in PD compared to HC, and are associated with specific motor, non-motor and cognitive progression patterns. A greater CSF amyloid burden was present at baseline in patients with subsequent weight loss. Presynaptic dopaminergic imaging in the right striatum may serve as a predictor of future weight changes in PD and HC.

Evaluation of the Dementia Apraxia Test in Parkinson's Disease Patients

INTRODUCTION

Ideomotor apraxia, a disorder of skilled movements affecting limbs and/or face, can be seen in patients with Parkinson's disease (PD), yet tests of apraxia in PD are rare. The aim of this project was to evaluate the psychometric properties and validity of the Dementia Apraxia Test (DATE) in a PD sample.

METHODS

118 PD patients were included. Besides DATE performance, motor and non-motor burden, cognition, and activity of daily living (ADL) function were assessed. Patients were classified as cognitively impaired (n = 41) or non-cognitively impaired (n = 77).

RESULTS

Interrater reliability of the DATE (sub-)scores between video ratings and on-site ratings by the investigator was good (0.81 ≤ rk ≤ 0.87). Items were mostly easy to perform, especially the buccofacial apraxia items, which had also low discriminatory power. DATE scores were associated with cognition and ADL function. DATE performance was confounded by motor impairment and patients' age; however, when analysed for both cognitive groups separately, the correlation between DATE and motor performance was not significant.

DISCUSSION/CONCLUSION

The DATE seems to be an objective and predominantly valid apraxia screening tool for PD patients, with a few items needing revision. Due to the potential effect of motor impairment and age, standardized scores adjusting for these confounders are needed.

High rates of blood transfusion associated with Parkinson’s disease

Background

As evidence continues to accumulate regarding the multi-organ dysfunction associated with Parkinson’s disease (PD), it is still unclear as to whether PD increases the risk of hematological pathology. In this study, the authors investigate the association between PD and hematological pathology risk factors.

Methods

This retrospective cohort analysis was conducted using 8 years of the National Readmission Database. All individuals diagnosed with PD were queried at the time of primary admission. Readmissions, complications, and risk factors were analyzed at 30-, 90-, 180-, and 300-day intervals. Statistical analysis included multivariate Gaussian-fitted modeling using age, sex, comorbidities, and discharge weights as covariates. Coefficients of model variables were exponentiated and interpreted as odds ratios.

Results

The database query yielded 1,765,800 PD patients (mean age: 76.3 ± 10.4; 44.1% female). Rates of percutaneous blood transfusion in readmitted patients at 30, 90, 180, and 300 days were found to be 8.7%, 8.6%, 8.3%, and 8.3% respectively. Those with anti-parkinsonism medication side effects at the primary admission had increased rates of gastrointestinal (GI) hemorrhage (OR: 1.02; 95%CI: 1.01–1.03, p < 0.0001) and blood transfusion (OR: 1.06; 95%CI: 1.05–1.08, p < 0.0001) at all timepoints after readmission. PD patients who experienced GI hemorrhage of any etiology, including as a side effect of anti-parkinsonism medication, were found to have significantly higher rates of blood transfusion at all timepoints (OR: 1.14; 95%CI: 1.13–1.16, p < 0.0001).

Conclusions

Blood transfusions were found to be significantly associated with anti-parkinsonism drug side effects and GI hemorrhage of any etiology.

Synthesis and Biological Evaluation of a Series of Novel 1-(3-((6-Fluoropyridin-3-yl)oxy)propyl)piperazines as Dopamine/Serotonin Receptor Agonists

Evidence suggested that the use of partial dopamine D2/D3 receptor agonists may be a better choice for the treatment of Parkinson's disease (PD), and the stimulation of 5-HT1A receptors (mainly via nondopaminergic mechanisms) alleviates motor and nonmotor disorders of PD, implying that the multitarget approach may provide a double bonus for the treatment of the disease. In this study, 20 novel 1-(3-((6-fluoropyridin-3-yl)oxy)propyl)piperazine derivatives were designed and synthesized using a bioisosterism approach, and their activities for D2/D3/5-HT1A receptors were further tested. The results showed that several compounds exhibited a multitarget combination of D2/5-HT1A agonism. Compounds 7b and 34c showed agonistic activities on D2/D3/5-HT1A receptor. The EC50 value of 7b for D2/D3/5-HT1A receptor were 0.9/19/2.3 nmol/L, respectively; and the EC50 value of 34c for D2/D3/5-HT1A receptor were 3.3/10/1.4 nmol/L, respectively. In addition, 34c exhibited good metabolic stability (the half-life T 1/2 = 159.7 minutes) in vitro, which is of great significance for the further exploration of multitarget anti-PD drugs.

Effect of Pillbox Organizers with Alarms on Adherence to Pharmacotherapy in Parkinson Disease Patients Taking Three and More Daily Doses of Dopaminergic Medications

Improvement of adherence to pharmacotherapy in patients with Parkinson’s disease (PD) is a challenge in routine clinical practice. Our study was aimed at the effect of pillbox organizers with alarms improving adherence to pharmacotherapy and its impact on clinical outcomes. Forty nonadherent patients with PD being treated with ≥ 3 daily doses of levodopa and/or dopamine agonists were pseudorandomized and consecutively ranked to groups A (early-start intervention) and B (delayed-start intervention). We used the following validated diagnostic instruments: MMAS-8 (adherence), PDQ-8 (quality of life, QoL), GDS (depression), NMSS (non-motor symptoms), MDS-UPDRS III (motor involvement), MDS-UPDRS IV, and WOQ-9 (motor and non-motor fluctuations and dyskinesias). We proved a significantly improved rate of adherence with the use of pillbox organizers with alarms. Moreover, after only four weeks of using the pillbox organizer, we detected an improvement in QoL scores, motor involvement, motor-, and non-motor fluctuations. Our study showed that pillbox organizers with alarms are efficient in improving adherence to pharmacotherapy in PD. It also could contribute to better motor states, less severe fluctuations, and improved QoL.

Caregiver Burden in Late-Stage Parkinsonism and Its Associations

BACKGROUND

Patients in the late stages of parkinsonism are highly dependent on others in their self-care and activities of daily living. However, few studies have assessed the physical, psychological and social consequences of caring for a person with late-stage parkinsonism.

PATIENTS AND METHODS

Five hundred and six patients and their caregivers from the Care of Late Stage Parkinsonism (CLaSP) study were included. Patients' motor and non-motor symptoms were assessed using the UPDRS and Non-motor symptom scale (NMSS), Neuropsychiatric inventory (NPI-12), and caregivers' health status using the EQ-5D-3 L. Caregiver burden was assessed by the Zarit Burden Interview (ZBI).

RESULTS

The majority of caregivers were the spouse or life partner (71.2%), and were living with the patient at home (67%). Approximately half of caregivers reported anxiety/depression and pain/discomfort (45% and 59% respectively). The factors most strongly associated with caregiver burden were patients' neuropsychiatric features on the total NPI score (r = 0.38, p < 0.0001), total NMSS score (r = 0.28, p < 0.0001), caring for male patients and patients living at home. Being the spouse, the hours per day assisting and supervising the patient as well as caregivers' EQ-5D mood and pain scores were also associated with higher ZBI scores (all p < 0.001).

CONCLUSION

The care of patients with late stage parkinsonism is associated with significant caregiver burden, particularly when patients manifest many neuropsychiatric and non-motor features and when caring for a male patient at home.

Effect of onset age on the levodopa threshold dosage for dyskinesia in Parkinson's disease

INTRODUCTION

With the levodopa threshold effect for dyskinesia observed, threshold dosage of levodopa was identified in the general Parkinson's disease (PD) population. While early-onset PD (EOPD) and late-onset PD (LOPD) differ in the pathogenesis and clinical manifestations, threshold dosage of levodopa for individualized treatment remains unestablished. The objective of this study was to propose threshold dosage of levodopa in EOPD and LOPD patients, respectively.

METHODS

Data on demographic and clinical and treatment measures were collected in 539 PD patients. Patients were divided into different onset groups using 50 as the cut-off age. We used univariable and multivariable analysis to screen for risk factors for dyskinesia. Receiver operating characteristic curve was used to determine the levodopa threshold dosages for dyskinesia.

RESULTS

The prevalence of dyskinesia was 47.7% (53/111) in the EOPD group and 24.1% (103/428) in the LOPD group. Risk factors identified for dyskinesia include high levodopa daily dose and levodopa responsiveness for EOPD patients and high levodopa daily dose, long levodopa treatment duration, low body weight, use of entacapone, and high Hoehn-Yahr stage in off state for LOPD patients. The daily levodopa threshold dosages were 400 mg or 5.9 mg/kg for EOPD and 450 mg or 7.2 mg/kg for LOPD.

CONCLUSION

EOPD patients had lower levodopa threshold dosage comparing with LOPD patients. Treatment of EOPD requires stricter levodopa dose control to delay the onset of dyskinesia.

Circadian rhythms in neurodegenerative disorders

Endogenous biological clocks, orchestrated by the suprachiasmatic nucleus, time the circadian rhythms that synchronize physiological and behavioural functions in humans. The circadian system influences most physiological processes, including sleep, alertness and cognitive performance. Disruption of circadian homeostasis has deleterious effects on human health. Neurodegenerative disorders involve a wide range of symptoms, many of which exhibit diurnal variations in frequency and intensity. These disorders also disrupt circadian homeostasis, which in turn has negative effects on symptoms and quality of life. Emerging evidence points to a bidirectional relationship between circadian homeostasis and neurodegeneration, suggesting that circadian function might have an important role in the progression of neurodegenerative disorders. Therefore, the circadian system has become an attractive target for research and clinical care innovations. Studying circadian disruption in neurodegenerative disorders could expand our understanding of the pathophysiology of neurodegeneration and facilitate the development of novel, circadian-based interventions for these disabling disorders. In this Review, we discuss the alterations to the circadian system that occur in movement (Parkinson disease and Huntington disease) and cognitive (Alzheimer disease and frontotemporal dementia) neurodegenerative disorders and provide directions for future investigations in this field.

Cholinergic Receptor Modulation as a Target for Preventing Dementia in Parkinson's Disease

Parkinson’s disease (PD) is a neurodegenerative condition characterized by the loss of dopaminergic neurons in the substantia nigra pars compacta (SNpc) in the midbrain resulting in progressive impairment in cognitive and motor abilities. The physiological and molecular mechanisms triggering dopaminergic neuronal loss are not entirely defined. PD occurrence is associated with various genetic and environmental factors causing inflammation and mitochondrial dysfunction in the brain, leading to oxidative stress, proteinopathy, and reduced viability of dopaminergic neurons. Oxidative stress affects the conformation and function of ions, proteins, and lipids, provoking mitochondrial DNA (mtDNA) mutation and dysfunction. The disruption of protein homeostasis induces the aggregation of alpha-synuclein (α-SYN) and parkin and a deficit in proteasome degradation. Also, oxidative stress affects dopamine release by activating ATP-sensitive potassium channels. The cholinergic system is essential in modulating the striatal cells regulating cognitive and motor functions. Several muscarinic acetylcholine receptors (mAChR) and nicotinic acetylcholine receptors (nAChRs) are expressed in the striatum. The nAChRs signaling reduces neuroinflammation and facilitates neuronal survival, neurotransmitter release, and synaptic plasticity. Since there is a deficit in the nAChRs in PD, inhibiting nAChRs loss in the striatum may help prevent dopaminergic neurons loss in the striatum and its pathological consequences. The nAChRs can also stimulate other brain cells supporting cognitive and motor functions. This review discusses the cholinergic system as a therapeutic target of cotinine to prevent cognitive symptoms and transition to dementia in PD.

Personalised Advanced Therapies in Parkinson's Disease: The Role of Non-Motor Symptoms Profile

Device-aided therapies, including levodopa-carbidopa intestinal gel infusion, apomorphine subcutaneous infusion, and deep brain stimulation, are available in many countries for the management of the advanced stage of Parkinson’s disease (PD). Currently, selection of device-aided therapies is mainly focused on patients’ motor profile while non-motor symptoms play a role limited to being regarded as possible exclusion criteria in the decision-making process for the delivery and sustenance of a successful treatment. Differential beneficial effects on specific non-motor symptoms of the currently available device-aided therapies for PD are emerging and these could hold relevant clinical implications. In this viewpoint, we suggest that specific non-motor symptoms could be used as an additional anchor to motor symptoms and not merely as exclusion criteria to deliver bespoke and patient-specific personalised therapy for advanced PD.

Improvements in clinical signs of Parkinson's disease using photobiomodulation: a prospective proof-of-concept study

Background

Parkinson’s disease (PD) is a progressive neurodegenerative disease with no cure and few treatment options. Its incidence is increasing due to aging populations, longer disease duration and potentially as a COVID-19 sequela. Photobiomodulation (PBM) has been successfully used in animal models to reduce the signs of PD and to protect dopaminergic neurons.

Objective

To assess the effectiveness of PBM to mitigate clinical signs of PD in a prospective proof-of-concept study, using a combination of transcranial and remote treatment, in order to inform on best practice for a larger randomized placebo-controlled trial (RCT).

Methods

Twelve participants with idiopathic PD were recruited. Six were randomly chosen to begin 12 weeks of transcranial, intranasal, neck and abdominal PBM. The remaining 6 were waitlisted for 14 weeks before commencing the same treatment. After the 12-week treatment period, all participants were supplied with PBM devices to continue home treatment. Participants were assessed for mobility, fine motor skills, balance and cognition before treatment began, after 4 weeks of treatment, after 12 weeks of treatment and the end of the home treatment period. A Wilcoxon Signed Ranks test was used to assess treatment effectiveness at a significance level of 5%.

Results

Measures of mobility, cognition, dynamic balance and fine motor skill were significantly improved (p < 0.05) with PBM treatment for 12 weeks and up to one year. Many individual improvements were above the minimal clinically important difference, the threshold judged to be meaningful for participants. Individual improvements varied but many continued for up to one year with sustained home treatment. There was a demonstrable Hawthorne Effect that was below the treatment effect. No side effects of the treatment were observed.

Conclusions

PBM was shown to be a safe and potentially effective treatment for a range of clinical signs and symptoms of PD. Improvements were maintained for as long as treatment continued, for up to one year in a neurodegenerative disease where decline is typically expected. Home treatment of PD by the person themselves or with the help of a carer might be an effective therapy option. The results of this study indicate that a large RCT is warranted.

Trial registration

Australian New Zealand Clinical Trials Registry, registration number: ACTRN12618000038291p, registered on 12/01/2018.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12883-021-02248-y.

Is there a special relationship between complex I activity and nigral neuronal loss in Parkinson's disease? A critical reappraisal

Parkinson’s disease (PD) is a progressive neurodegenerative disease manifesting both motor and non-motor symptoms. The motor features are generally ascribed to the selective loss of dopamine neurons within the substantia nigra pars compacta. While the precise etiology of PD remains elusive, multiple genetic and environmental elements have emerged as contributing factors. The discovery of MPTP-induced parkinsonism directed intense inquiry towards mitochondrial pathways, with a specific focus on mitochondrial complex I. Consisting of more than 40 subunits, complex I is the first enzyme of the electron transport chain that is required for mitochondrial ATP production. In this review, we present a critical analysis of studies assessing the prevalence and specificity of mitochondrial complex I deficiency in PD. In addition, we take the novel view of incorporating the features of genetically-defined bona fide complex I disorders and the prevalence of nigral involvement in such cases. Through this innovative bi-directional view, we consider both complex I changes in a disease of the substantia nigra and nigral changes in diseases of complex I. We assess the strength of association between nigral cell loss and complex I deficits, as well as the oft under-appreciated heterogeneity of complex I deficiency disorders and the variability of the PD data.

Non-motor complications in late stage Parkinson's disease: recognition, management and unmet needs

Introduction: The burden of non-motor symptoms (NMS) is a major determinant of health-related quality of life in Parkinson's disease (PD), particularly at its late stage.Areas covered: The late stage is usually defined as the period from unstable advanced to the palliative stage, characterized by a combination of emerging treatment-resistant axial motor symptoms (freezing of gait, postural instability, falls and dysphagia), as well as both non-dopaminergic and dopaminergic NMS: cognitive decline, neuropsychiatric symptoms, aspects of dysautonomia, pain and sleep disturbances (insomnia and excessive day-time sleepiness). Here, the authors summarize the current knowledge on NMS dominating the late stage of PD and propose a pragmatic and clinically focused approach for their recognition and treatment.Expert opinion: The NMS progression pattern is complex and remains under-researched. While dopamine-dependent NMS may improve with dopamine replacement therapy, non-dopamine dependent NMS worsen progressively and culminate at the late stages of PD. Furthermore, some PD specific features could interact negatively with other comorbidities, multiple medication use and frailty - the evaluation of these aspects is important in the creation of personalized management plans in the late stage of PD.

Does Depression Contribute to the Bladder and Bowel Complaint in Parkinson's Disease Patients?

Background

The question of whether depression contributes to the bladder and bowel complaint in Parkinson's disease (PD) has not been addressed.

Objectives

We studied bladder, bowel and sexual symptoms in PD patients with/without depression.

Methods

We had 267 referred PD patients: age 68.3 ± 7.7 years, 150 men, 117 women. We divided them into those with/without depression and performed the pelvic function questionnaires including bladder, bowel and sexual items; for example, OABSS, IPSS, and a pelvic organ questionnaire).

Results

The patient age, sex ratio, disease duration, Hoehn-Yahr motor grade, and cognitive score were not significantly different between the PD with depression (n = 35, 13.1%) and PD without depression (n = 232, 86.9%) groups. Regarding bladder, bowel and sexual complaints, significant difference was noted in constipation (P = 0.000854) and sensation of residual urine (P = 0.04820) items.

Conclusions

Our PD patients with depression showed significantly more common constipation and sensation of residual urine compared to the patients with PD alone, suggesting that depression contributes to the bladder and bowel complaint in PD patients.

Rotigotine Transdermal Patch for Motor and Non-motor Parkinson's Disease: A Review of 12 Years' Clinical Experience

Motor and non-motor symptoms (NMS) have a substantial effect on the health-related quality of life (QoL) of patients with Parkinson's disease (PD). Transdermal therapy has emerged as a time-tested practical treatment option, and the rotigotine patch has been used worldwide as an alternative to conventional oral treatment for PD. The efficacy of rotigotine on motor aspects of PD, as well as its safety and tolerability profile, are well-established, whereas its effects on a wide range of NMS have been described and studied but are not widely appreciated. In this review, we present our overall experience with rotigotine and its tolerability and make recommendations for its use in PD and restless legs syndrome, with a specific focus on NMS, underpinned by level 1-4 evidence. We believe that the effective use of the rotigotine transdermal patch can address motor symptoms and a wide range of NMS, improving health-related QoL for patients with PD. More specifically, the positive effects of rotigotine on non-motor fluctuations are also relevant. We also discuss the additional advantages of the transdermal application of rotigotine when oral therapy cannot be used, for instance in acute medical emergencies or nil-by-mouth or pre/post-surgical scenarios. We highlight evidence to support the use of rotigotine in selected cases (in addition to general use for motor benefit) in the context of personalised medicine.

Unmet needs in Parkinson disease: Motor and non-motor

Compared to other neurodegenerative diseases, Parkinson's disease (PD) is distinctive in terms of marked symptomatic variability and prognosis, as well as for the wide variety of symptomatic treatment options. Despite several decades of advances in medications and neurosurgical approaches, there remains an unmet need for symptomatic motor control. Better control of tremor, gait and balance, posture, dexterity, and communication skills are major challenges for better therapeutics of the PD movement disorder. Non-motor symptoms (NMS), which often precede motor impairments, add complexity to the burden of PD and its management. Recognized by James Parkinson MD two centuries ago, and despite 21st century neurological advances, a range of NMS plague the patient's journey, from prodromal to palliative stages. Characterizing the clinical phenotype of the entire non-motor profile of PD is challenging. Further research and understanding are needed for discovering biomarkers of certain NMS, such as dementia, fatigue, pain, sleep, and apathy. More work is needed to gather a robust evidence base for guiding treatment of troubling NMS, which exert a major impact on quality of life for people with PD and their caregivers.

High-Intensity Interval Cycle Ergometer Training in Parkinson's Disease: Protocol for Identifying Individual Response Patterns Using a Single-Subject Research Design

Background: People with Parkinson's disease (PD) experience not only motor problems but also non-motor problems that seriously impede their daily functioning and quality of life. The current pharmacologic treatment of PD is symptomatic, and alternative rehabilitation treatments, which preferably also have a disease-modifying effect and promote neuroplasticity, are needed. Recent studies suggest that high-intensity interval training (HIIT) is promising for promoting neuroplasticity in human PD, with short training time and reduced burden. Biomarkers for neuroplasticity such as brain-derived neurotrophic factor (BDNF) and neurodegeneration (including neurofilament NfL and α-synuclein) may play a role, but their response to HIIT is not well-investigated.

Objectives: The aims of this study were (1) to study the effects of 4 weeks of HIIT compared with 4 weeks of continuous aerobic exercise on motor and non-motor outcomes of PD and (2) to investigate the association between HIIT, motor/non-motor performances changes, and blood biomarker levels for neuroplasticity and neurodegeneration.

Study Design: Single-subject research design with alternating treatment setup (ABACA) and frequent repeated measurements was used. Each participant received different intervention conditions (B/C) interspersed with baseline periods (A, i.e., ABACA or ACABA), and frequent repeated assessment of outcome measures is done to quantify within-subject, individual response patterns with sufficient power for data analysis. Blood samples were collected once a week in the baseline and training phases (A1 and B/C) and once every 2 weeks in the washout phases (A2 and A3).

Intervention: Four subjects with PD on stable dopaminergic medication, two in Hoehn–Yahr stage 1–2, and two in Hoehn–Yahr stage 2.5–3 followed an ABACA or ACABA schedule, consisting of blocks with 30-min sessions of “B” (HIIT) or 50-min sessions of “C” [continuous aerobic exercise (CAE)] 3×/week for 4 weeks, separated by baseline “A” periods of 8 weeks for a total duration of 28 weeks.

Outcome Measures: Outcome measures include disease status [Movement Disorder Society-sponsored revision of the Unified Parkinson's Disease Rating Scale (MDS-UPDRS)], blood biomarkers (BDNF, Nfl, and α-synuclein), measures for functional mobility (including an activity tracker), and activities of daily living, as well as cognition, mood, biorhythm (sleeping problems), and quality of life.

Data Analysis: Visual analysis of trends in level, slope, and variability in response patterns was carried out, confirmed by longitudinal regression analysis with phase (ABACA) as the independent variable.

'Dopamine agonist Phobia' in Parkinson's disease: when does it matter? Implications for non-motor symptoms and personalized medicine

INTRODUCTION

Dopamine agonists have been widely used to treat patients with Parkinson's disease, but concerns related to their well-known side effects might prevent their use even when indicated. In this review, the authors describe for the first time the concept of 'Dopamine Agonist Phobia', a pharmacophobia that the authors believe might affect clinicians, and they provide evidence of the benefits of dopamine agonists, focusing on non-motor symptoms.

AREAS COVERED

The authors performed an extensive literature research, including studies exploring the use of dopamine agonists for the treatment of non-motor symptoms. The authors indicate the highest level of evidence in each section.

EXPERT OPINION

'Dopamine Agonist Phobia' may preclude valid therapeutic options in selected cases, specifically for the treatment of non-motor symptoms. Thus, the authors propose a personalized approach in Parkinson's disease treatment, and encourage a thoughtful use of dopamine agonists, rather than an overall nihilism.

Screening of Parkinsonian subtle fine-motor impairment from touchscreen typing via deep learning

Fine-motor impairment (FMI) is progressively expressed in early Parkinson’s Disease (PD) patients and is now known to be evident in the immediate prodromal stage of the condition. The clinical techniques for detecting FMI may not be robust enough and here, we show that the subtle FMI of early PD patients can be effectively estimated from the analysis of natural smartphone touchscreen typing via deep learning networks, trained in stages of initialization and fine-tuning. In a validation dataset of 36,000 typing sessions from 39 subjects (17 healthy/22 PD patients with medically validated UPDRS Part III single-item scores), the proposed approach achieved values of area under the receiver operating characteristic curve (AUC) of 0.89 (95% confidence interval: 0.80–0.96) with sensitivity/specificity: 0.90/0.83. The derived estimations result in statistically significant (\documentclass[12pt]{minimal} \usepackage{amsmath} \usepackage{wasysym} \usepackage{amsfonts} \usepackage{amssymb} \usepackage{amsbsy} \usepackage{mathrsfs} \usepackage{upgreek} \setlength{\oddsidemargin}{-69pt} \begin{document}$$p<0.05$$\end{document}p<0.05) correlation of 0.66/0.73/0.58 with the clinical standard UPDRS Part III items 22/23/31, respectively. Further validation analysis on 9 de novo PD patients vs. 17 healthy controls classification resulted in AUC of 0.97 (0.93–1.00) with 0.93/0.90. For 253 remote study participants, with self-reported health status providing 252.000 typing sessions via a touchscreen typing data acquisition mobile app (iPrognosis), the proposed approach predicted 0.79 AUC (0.66–0.91) with 0.76/0.71. Remote and unobtrusive screening of subtle FMI via natural smartphone usage, may assist in consolidating early and accurate diagnosis of PD.

Clinically relevant connectivity features define three subtypes of Parkinson's disease patients

Parkinson's disease (PD) is characterized by complex clinical symptoms, including classic motor and nonmotor disturbances. Patients with PD vary in clinical manifestations and prognosis, which point to the existence of subtypes. This study aimed to find the fiber connectivity correlations with several crucial clinical symptoms and identify PD subtypes using unsupervised clustering analysis. One hundred and thirty-four PD patients and 77 normal controls were enrolled. Canonical correlation analysis (CCA) was performed to define the clinically relevant connectivity features, which were then used in the hierarchical clustering analysis to identify the distinct subtypes of PD patients. Multimodal neuroimaging analyses were further used to explore the neurophysiological basis of these subtypes. The methodology was validated in an independent data set. CCA revealed two significant clinically relevant patterns (motor-related pattern and depression-related pattern; r = .94, p < .001 and r = .926, p = .001, respectively) among PD patients, and hierarchical clustering analysis identified three neurophysiological subtypes ("mild" subtype, "severe depression-dominant" subtype and "severe motor-dominant" subtype). Multimodal neuroimaging analyses suggested that the patients in the "severe depression-dominant" subtype exhibited widespread disruptions both in function and structure, while the other two subtypes exhibited relatively mild abnormalities in brain function. In the independent validation, three similar subtypes were identified. In conclusion, we revealed heterogeneous subtypes of PD patients according to their distinct clinically relevant connectivity features. Importantly, depression symptoms have a considerable impact on brain damage in patients with PD.

A Wearable System to Objectify Assessment of Motor Tasks for Supporting Parkinson's Disease Diagnosis

Objective assessment of the motor evaluation test for Parkinson’s disease (PD) diagnosis is an open issue both for clinical and technical experts since it could improve current clinical practice with benefits both for patients and healthcare systems. In this work, a wearable system composed of four inertial devices (two SensHand and two SensFoot), and related processing algorithms for extracting parameters from limbs motion was tested on 40 healthy subjects and 40 PD patients. Seventy-eight and 96 kinematic parameters were measured from lower and upper limbs, respectively. Statistical and correlation analysis allowed to define four datasets that were used to train and test five supervised learning classifiers. Excellent discrimination between the two groups was obtained with all the classifiers (average accuracy ranging from 0.936 to 0.960) and all the datasets (average accuracy ranging from 0.953 to 0.966), over three conditions that included parameters derived from lower, upper or all limbs. The best performances (accuracy = 1.00) were obtained when classifying all the limbs with linear support vector machine (SVM) or gaussian SVM. Even if further studies should be done, the current results are strongly promising to improve this system as a support tool for clinicians in objectifying PD diagnosis and monitoring.

Mitochondrial Dysfunction and Parkinson's Disease-Near-Infrared Photobiomodulation as a Potential Therapeutic Strategy

As the main driver of energy production in eukaryotes, mitochondria are invariably implicated in disorders of cellular bioenergetics. Given that dopaminergic neurons affected in Parkinson's disease (PD) are particularly susceptible to energy fluctuations by their high basal energy demand, it is not surprising to note that mitochondrial dysfunction has emerged as a compelling candidate underlying PD. A recent approach towards forestalling dopaminergic neurodegeneration in PD involves near-infrared (NIR) photobiomodulation (PBM), which is thought to enhance mitochondrial function of stimulated cells through augmenting the activity of cytochrome C oxidase. Notwithstanding this, our understanding of the neuroprotective mechanism of PBM remains far from complete. For example, studies focusing on the effects of PBM on gene transcription are limited, and the mechanism through which PBM exerts its effects on distant sites (i.e., its "abscopal effect") remains unclear. Also, the clinical application of NIR in PD proves to be challenging. Efficacious delivery of NIR light to the substantia nigra pars compacta (SNpc), the primary site of disease pathology in PD, is fraught with technical challenges. Concerted efforts focused on understanding the biological effects of PBM and improving the efficiency of intracranial NIR delivery are therefore essential for its successful clinical translation. Nonetheless, PBM represents a potential novel therapy for PD. In this review, we provide an update on the role of mitochondrial dysfunction in PD and how PBM may help mitigate the neurodegenerative process. We also discussed clinical translation aspects of this treatment modality using intracranially implanted NIR delivery devices.