Planning for Prevention of Parkinson Disease: Now Is the Time

A systematic review of the factors associated with the psychological wellbeing of people with Parkinson's in the COVID-19 pandemic

PURPOSE

The lockdown and social distancing measures introduced as a result of the COVID-19 pandemic impacted the ability of people with Parkinson's to engage in normal health management practices. This led to documented reductions in psychological wellbeing. The aim of the present review was to identify factors associated with the psychological wellbeing of people with Parkinson's during the acute stage of the pandemic.

MATERIALS AND METHODS

Five academic databases (PsycINFO, MEDLINE, Embase, CINAHL, and Web of Science) were searched and 23 articles were identified using pre-defined inclusion and exclusion criteria. The findings are stratified by risk factor and analysed using a narrative synthesis.

RESULTS

Worsening of motor symptoms, poor motor-related daily living experiences and motor symptoms during "off time" (when symptom suppressing medication has worn off) as well as less physical activity emerged as the most consistent risk factors of worsened or poorer psychological wellbeing. A deviation from pre-pandemic risk factors was identified, with age and gender not identified as consistent risk factors.

CONCLUSIONS

The implications of this review are not limited to preparing for future pandemics but can also be applied to more common concerns with comparable contextual characteristics such as yearly flu outbreaks, social isolation, and economic uncertainty.

Preparing for Parkinson's disease prevention trials: Current progress and future directions

In recent decades, numerous clinical trials have aimed to delay or prevent Parkinson's disease (PD) progression. Despite the theoretical promise and encouraging preclinical data, none have shown clear efficacy in slowing or preventing PD progression, related to several key limitations. Conventional motor and non-motor scales often fall short in detecting early disease changes, while the heterogeneity of PD phenotypes complicates treatment efficacy. The timing of interventions is also critical, as most trials target patients already in advanced stages of neurodegeneration. A deeper understanding of the preclinical phase and the emergence of new pathological frameworks have shifted the focus toward preventing the onset of clinical PD. Recent advances in biomarker research, including tissue, fluid, and imaging markers, are poised to transform PD research by improving patient selection, stratification, and disease progression monitoring. New biologically grounded frameworks for classifying synucleinopathies aim to distinguish biological subtypes from clinical phenotypes, enabling more targeted prevention trials. Successful PD prevention trials will require early enrollment of individuals at the highest risk, employing low-risk personalized interventions, with biomarkers or sensitive clinical markers as endpoints. Early involvement of key stakeholders will be essential to ensure that trials are timely, ethically sound, and aligned with the needs of the PD community.

Evidence for alpha-synuclein aggregation in older individuals with hyposmia: a cross-sectional study

BACKGROUND

Synuclein pathology in neurodegenerative diseases, such as Parkinson's disease (PD) and Dementia with Lewy bodies (DLB), begins years before motor or cognitive symptoms arise. Alpha-Synuclein seed amplification assays (α-syn SAA) may detect aggregated synuclein before symptoms occur.

METHODS

Data from the Parkinson Associated Risk Syndrome Study (PARS) have shown that individuals with hyposmia, without motor or cognitive symptoms, are enriched for dopamine transporter imaging (DAT) deficit and are at high risk to develop clinical parkinsonism or related synucleinopathies. α-syn aggregates in CSF were measured in 100 PARS participants using α-syn SAA.

FINDINGS

CSF α-syn SAA was positive in 48% (34/71) of hyposmic compared to 4% (1/25) of normosmic PARS participants (relative risk, 11.97; 95% CI, 1.73-82.95). Among α-syn SAA positive hyposmics 65% remained without a DAT deficit for up to four years follow-up. α-syn SAA positive hyposmics were at higher risk of having DAT deficit (12 of 34) compared to α-syn SAA negative hyposmics (4 of 37; relative risk, 3.26; 95% CI, 1.16-9.16), and 7 of 12 α-syn SAA positive hyposmics with DAT deficit developed symptoms consistent with synucleinopathy.

INTERPRETATION

Approximately fifty percent of PARS participants with hyposmia, easily detected using simple, widely available tests, have synuclein pathology detected by α-syn SAA. Approximately, one third (12 of 34) α-syn SAA positive hyposmic individuals also demonstrate DAT deficit. This study suggests a framework to investigate screening paradigms for synuclein pathology that could lead to design of therapeutic prevention studies in individuals without symptoms.

FUNDING

The study was funded by the U.S. Department of Defense, the Helen Graham Foundation and the Michael J. Fox Foundation for Parkinson's Research.

Plumbagin's Healing Effect on Motor Impairment in Rotenone-toxified Rodents

BACKGROUND

Parkinson's disease is an illness marked by a gradual mitigation of dopamine neurons within the substantia nigra, which eventually leads to a deficiency of dopamine that further gives rise to mobility as well as cognitive impairments. Through long-established traditions, a wide array of Traditional Chinese Medicines (TCM) have undergone testing and are employed to avoid neurodegenerative disorders. Plumbagin is the primary active component of a medication called Baihua Dan or Plumbago zeylanica L., which is clinically used in China.

OBJECTIVES

This study investigated plumbagin-induced alterations in a Parkinson's disease rat model instigated by subcutaneous rotenone injection.

METHODS

Male rats were administered subcutaneous injections of rotenone at a dosage of 1.5 mg/kg, followed by the treatment with varying doses of plumbagin (10, 20, and 40 mg/kg) through the oral route. The rats underwent various motor ability tests, including the actophotometer, rotarod, open field, beam walk, gait evaluation, ability to grip, and catalepsy bar tests. Furthermore, the brain dopamine level was then estimated for the extracted tissues. Also, through molecular docking, the binding effectiveness of plumbagin was assessed for human MAO-B. After that, plumbagin was put through 100 ns of molecular dynamic simulations to examine the stability of its conformational binding to the target protein. Furthermore, ADMET tests were used to verify Plumbagin's druggability.

RESULTS

Plumbagin was found to alleviate rotenone-induced motor abnormalities and restore brain dopamine levels. Furthermore, plumbagin showed excellent interactions with MAO-B (monoamine oxidase-B) when compared with selegiline (a standard drug for Parkinson's disease).

CONCLUSION

These findings underscore the potential therapeutic efficacy of plumbagin in mitigating behavioural deficits in rotenone-induced rodents. Considering this, plumbagin might be a feasible pharmacological strategy for the control of rotenone-triggered behavioural impairment in rats (in vivo), and it might display interesting interactions with MAO-B (in silico).

Circadian disruption promotes the neurotoxicity of oligomeric alpha-synuclein in mice

Circadian disruption often arises prior to the onset of typical motor deficits in patients with Parkinson's disease (PD). It remains unclear whether such a prevalent non-motor manifestation would contribute to the progression of PD. Diffusible oligomeric alpha-synuclein (O-αSyn) is perceived as the most toxic and rapid-transmitted species in the early stages of PD. Exploring the factors that influence the spread and toxicity of O-αSyn should be helpful for developing effective interventions for the disease. The aim of this study was to explore the effects of circadian disruption on PD pathology and parkinsonism-like behaviors in a novel mouse model induced by O-αSyn. We discovered that O-αSyn could enter the brain rapidly following intranasal administration, resulting in the formation of nitrated-αSyn pathology and non-motor symptoms of the mice. Meanwhile, circadian disruption exacerbated the burden of nitrated-αSyn pathology and accelerated the loss of dopaminergic neurons in O-αSyn-treated mice. Subsequent experiments demonstrated that circadian disruption might act via promoting nitrative stress and neuroinflammation. These findings could highlight the circadian rhythms as a potential diagnostic and therapeutic target in early-stage PD.

The rise of Parkinson's disease is a global challenge, but efforts to tackle this must begin at a national level: a protocol for national digital screening and "eat, move, sleep" lifestyle interventions to prevent or slow the rise of non-communicable diseases in Thailand

The rising prevalence of Parkinson's disease (PD) globally presents a significant public health challenge for national healthcare systems, particularly in low-to-middle income countries, such as Thailand, which may have insufficient resources to meet these escalating healthcare needs. There are also many undiagnosed cases of early-stage PD, a period when therapeutic interventions would have the most value and least cost. The traditional "passive" approach, whereby clinicians wait for patients with symptomatic PD to seek treatment, is inadequate. Proactive, early identification of PD will allow timely therapeutic interventions, and digital health technologies can be scaled up in the identification and early diagnosis of cases. The Parkinson's disease risk survey (TCTR20231025005) aims to evaluate a digital population screening platform to identify undiagnosed PD cases in the Thai population. Recognizing the long prodromal phase of PD, the target demographic for screening is people aged ≥ 40 years, approximately 20 years before the usual emergence of motor symptoms. Thailand has a highly rated healthcare system with an established universal healthcare program for citizens, making it ideal for deploying a national screening program using digital technology. Designed by a multidisciplinary group of PD experts, the digital platform comprises a 20-item questionnaire about PD symptoms along with objective tests of eight digital markers: voice vowel, voice sentences, resting and postural tremor, alternate finger tapping, a "pinch-to-size" test, gait and balance, with performance recorded using a mobile application and smartphone's sensors. Machine learning tools use the collected data to identify subjects at risk of developing, or with early signs of, PD. This article describes the selection and validation of questionnaire items and digital markers, with results showing the chosen parameters and data analysis methods to be robust, reliable, and reproducible. This digital platform could serve as a model for similar screening strategies for other non-communicable diseases in Thailand.

Physical activity and sleep pattern in relation to incident Parkinson's disease: a cohort study

BACKGROUND

How physical activity (PA) and different sleep traits and overall sleep pattern interact in the development of Parkinson's disease (PD) remain unknown.

OBJECTIVE

To prospectively investigate the joint associations of PA and sleep pattern with risk of PD.

METHODS

Included were 339,666 PD-free participants from the UK Biobank. Baseline PA levels were grouped into low (< 600 MET-mins/week), medium (600 to < 3000 MET-mins/week) and high (≥ 3000 MET-mins/week) according to the instructions of the UK Biobank. Healthy sleep traits (chronotype, sleep duration, insomnia, snoring, and daytime sleepiness) were scored from 0 to 5 and were categorized into "ideal sleep pattern" (≥ 3 sleep scores) and "poor sleep pattern" (0-2 sleep scores). Hazard ratios (HRs) and 95% confidence intervals (CIs) of PD were estimated by Cox proportional hazards models.

RESULTS

During a median of 11.8 years of follow-up, 1,966 PD events were identified. The PD risk was lower in participants with high PA (HR = 0.73; 95% CI: 0.64, 0.84), compared to those with low PA; and participants with ideal sleep pattern also had a lower risk of PD (HR = 0.78; 95% CI: 0.69, 0.87), compared to those with poor sleep pattern. When jointly investigating the combined effect, participants with both high PA and ideal sleep pattern had the lowest risk of incident PD (HR = 0.55; 95% CI: 0.44, 0.69), compared to those with low PA and poor sleep pattern; notably, participants with high PA but poor sleep pattern also gained benefit on PD risk reduction (HR = 0.74; 95% CI: 0.55, 0.99).

CONCLUSIONS

Both high PA and ideal sleep pattern were independently associated with lower risk of developing PD, and those with both high PA level and ideal sleep pattern had the lowest risk. Our results suggest that improving PA levels and sleep quality may be promising intervention targets for the prevention of PD.

Pharmacotherapy for Disease Modification in Early Parkinson's Disease: How Early Should We Be?

Slowing or halting progression continues to be a major unmet medical need in Parkinson's disease (PD). Numerous trials over the past decades have tested a broad range of interventions without ultimate success. There are many potential reasons for this failure and much debate has focused on the need to test 'disease-modifying' candidate drugs in the earliest stages of disease. While generally accepted as a rational approach, it is also associated with significant challenges around the selection of trial populations as well as trial outcomes and durations. From a health care perspective, intervening even earlier and before at-risk subjects have gone on to develop overt clinical disease is at the heart of preventive medicine. Recent attempts to develop a framework for a biological definition of PD are aiming to enable 'preclinical' and subtype-specific diagnostic approaches. The present review addresses past efforts towards disease-modification, including drug targets and reasons for failure, as well as novel targets that are currently being explored in disease-modification trials in early established PD. The new biological definitions of PD may offer new opportunities to intervene even earlier. We critically discuss the potential and challenges around planning 'disease-prevention' trials in subjects with biologically defined 'preclinical' or prodromal PD.

Considerations on How to Prevent Parkinson's Disease Through Exercise

The increasing prevalence of people with Parkinson's disease (PD) necessitates a high priority for finding interventions to delay or even prevent the onset of PD. There is converging evidence that exercise may exert disease-modifying effects in people with clinically manifest PD, but whether exercise also has a preventive effect or is able to modify the progression of the pathology in the prodromal phase of PD is unclear. Here we provide some considerations on the design of trials that aim to prevent PD through exercise. First, we discuss the who could benefit from exercise, and potential exercise-related risks. Second, we discuss what specific components of exercise mediate the putative disease-modifying effects. Third, we address how methodological challenges such as blinding, adherence and remote monitoring could be handled and how we can measure the efficacy of exercise as modifier of the course of prodromal PD. We hope that these considerations help in designing exercise prevention trials for persons at risk of developing PD.

Parkinson's Disease Drug Therapies in the Clinical Trial Pipeline: 2023 Update

BACKGROUND

Since 2020, annual reports on the clinical development of new drug-based therapies for the neurodegenerative condition of Parkinson's disease (PD) have been generated. These reviews have followed the progress of both "symptomatic treatments" (ST - improves/reduces symptoms of the condition) and "disease modifying treatments" (DMT - attempts to delay/slow progression by addressing the underlying biology of PD). Additional efforts have been made to further categorize these experimental treatments based on their mechanisms of action and class of drug.

METHODS

A dataset of clinical trials for drug therapies in PD was obtained using trial data downloaded from the ClinicalTrials.gov online registry. A breakdown analysis of all the studies that were active as of January 31st, 2023, was conducted.

RESULTS

There was a total of 139 clinical trials registered on the ClinicalTrials.gov website as active (with 35 trials newly registered since our last report). Of these trials, 76 (55%) were considered ST and 63 (45%) were designated DMT. Similar to previous years, approximately a third of the studies were in Phase 1 (n = 47; 34%), half (n = 72, 52%) were in Phase 2 and there were 20 (14%) studies in Phase 3. Novel therapies again represented the most dominant group of experimental treatments in this year's report with 58 (42%) trials testing new agents. Repurposed drugs are present in a third (n = 49, 35%) of trials, with reformulations and new claims representing 19% and 4% of studies, respectively.

CONCLUSIONS

Our fourth annual review of active clinical trials evaluating ST and DMT therapeutics for PD demonstrates that the drug development pipeline is dynamic and evolving. The slow progress and lack of agents transitioning from Phase 2 to Phase 3 is concerning, but collective efforts by various stakeholders are being made to accelerate the clinical trial process, with the aim of bringing new therapies to the PD community sooner.

Therapeutic implications of crocin in Parkinson's disease: A review of preclinical research

Parkinson's disease is among the most common forms of neurodegenerative illness, with present treatment being primarily symptomatic and frequently coming with substantial adverse effects. Neuronal degeneration may arise due to a variety of pathological events, like inflammatory responses, neurotransmitter dysregulation, oxidative damage, mitochondrial malfunction, apoptosis, and genetic factors. The health issue and financial burden brought on by Parkinson's disease can worsen as the population ages. In the search for new and secure therapeutic agents for Parkinson's disease, several natural compounds have been shown to exert considerable neuroprotective benefits. Crocin, a naturally occurring carotenoid molecule, was found to have neuroprotective potential in the therapy of this disorder. Taking into account, the outcomes of various studies and the restorative actions of crocin, the present study emphasized the protective ability of crocin in this disease. Given the strong evidence supporting the neuroprotective ability of crocin, it is inferred that crocin inhibits inflammatory, apoptotic, and antioxidant processes through multiple mechanisms. Therefore, this compound is considered a safe and effective therapeutic choice for neurodegenerative illnesses like Parkinson's disease. However, more research on its efficacy as a treatment of Parkinson's disease is needed, specifically examining its mechanisms and the results obtained in clinical trials.

Co-administration of Nanowired DL-3-n-Butylphthalide (DL-NBP) Together with Mesenchymal Stem Cells, Monoclonal Antibodies to Alpha Synuclein and TDP-43 (TAR DNA-Binding Protein 43) Enhance Superior Neuroprotection in Parkinson's Disease Following Concussive Head Injury

dl-3-n-butylphthalide (dl-NBP) is one of the potent antioxidant compounds that induces profound neuroprotection in stroke and traumatic brain injury. Our previous studies show that dl-NBP reduces brain pathology in Parkinson's disease (PD) following its nanowired delivery together with mesenchymal stem cells (MSCs) exacerbated by concussive head injury (CHI). CHI alone elevates alpha synuclein (ASNC) in brain or cerebrospinal fluid (CSF) associated with elevated TAR DNA-binding protein 43 (TDP-43). TDP-43 protein is also responsible for the pathologies of PD. Thus, it is likely that exacerbation of brain pathology in PD following brain injury may be thwarted using nanowired delivery of monoclonal antibodies (mAb) to ASNC and/or TDP-43. In this review, the co-administration of dl-NBP with MSCs and mAb to ASNC and/or TDP-43 using nanowired delivery in PD and CHI-induced brain pathology is discussed based on our own investigations. Our observations show that co-administration of TiO2 nanowired dl-NBP with MSCs and mAb to ASNC with TDP-43 induced superior neuroprotection in CHI induced exacerbation of brain pathology in PD, not reported earlier.

What to Test in Parkinson Disease Prevention Trials? Repurposed, Low-Risk, and Gene-Targeted Drugs

Despite the sound epidemiologic and basic science rationales underpinning numerous "disease modification" trials in manifest Parkinson disease (PD), none has convincingly demonstrated that a treatment slows progression. Rapidly expanding knowledge of the genetic determinants and prodromal features of PD now allows realistic planning of prevention trials with initiation of putatively neuroprotective therapies earlier in the disease. In this article, we outline the principles of drug selection for PD prevention trials, focused on proof-of-concept opportunities that will help establish a methodological foundation for this fledgling field. We describe prototypical, relatively low-risk drug candidates for such trials (e.g., albuterol, ambroxol, caffeine, ibuprofen), tailored to specific at-risk populations ranging from pathogenic LRRK2 or GBA gene variant carriers to those defined by prodromal PD and α-synucleinopathy. Finally, we review gene-targeted approaches currently in development targeting clinically manifest PD for their potential in future prevention trials.