Unmet needs in Parkinson disease: Motor and non-motor

Demyelination in psychiatric and neurological disorders: Mechanisms, clinical impact, and novel therapeutic strategies

Demyelination, defined as the loss of myelin sheaths around neuronal axons, is increasingly recognized as a key factor in a broad range of psychiatric and neurological disorders, including schizophrenia, major depressive disorder, bipolar disorder, post-traumatic stress disorder, autism spectrum disorder, substance use disorders, Alzheimer's disease, Parkinson's disease, and multiple sclerosis. This review investigates the core mechanisms driving demyelination, its clinical impact, and emerging therapeutic strategies aimed at maintaining or restoring myelin integrity. Disruption of myelin impairs crucial neural communication pathways, resulting in cognitive, motor, and behavioral deficits that substantially reduce quality of life and create significant economic and social challenges. Key contributors to demyelination include genetic predisposition, environmental triggers, immune dysregulation, neuroinflammation, and alterations in the gut-brain axis mediated by the vagus nerve. Promising therapies include sphingosine 1-phosphate receptor modulators and muscarinic acetylcholine receptor antagonists, both of which diminish immune-related myelin damage and may enhance neuroprotection. In addition, the novel antidepressant arketamine appears to boost myelination through transforming growth factor-β1 signaling pathways. Approaches targeting the gut-brain axis, such as noninvasive transcutaneous auricular vagus nerve stimulation and fecal microbiota transplantation, may also help reduce inflammation and support myelin repair. Future research should center on clarifying the precise molecular mechanisms of demyelination, developing targeted therapies, and leveraging advanced neuroimaging for earlier detection and personalized treatment. By combining immunomodulatory and neuroprotective strategies, there is potential to significantly improve outcomes for individuals affected by demyelinating psychiatric and neurological disorders.

The spectrum of embodied intersubjective synchrony in empathy: from fully embodied to externally oriented engagement in Parkinson's disease

Background

Parkinson's disease is a prevalent neurodegenerative disorder that not only affects motor function but also impairs empathy. While the neurobiological changes underlying these deficits are known, the impact of PD on the lived experience of empathy remains poorly understood. This study investigates the lived experience of empathy for pain in individuals with PD, with a specific focus on embodied intersubjective synchrony.

Method

Forty-five patients with mild to moderate PD were exposed to videos of athletes suffering falls during extreme sports. Following exposure, participants underwent phenomenological interviews to explore their embodied experiences in connection with the other's suffering. Data were analyzed through an iterative process involving three independent analyses, triangulation, and the application of advanced analytical techniques (CAQDAS, inter-rater agreement index, interactive dashboards, spider graphs) to enhance the depth of the phenomenological analysis.

Results

This study provides a nuanced view of empathy for pain in Parkinson's disease, uncovering a spectrum of embodied intersubjective synchrony. Two primary empathic structures emerged: Embodied Resonance Empathy, marked by strong bodily and emotional connections with temporal synchronization to others' suffering through internal sensations, and Marginal Embodied Resonance Empathy, where bodily and emotional resonance is reduced or absent, relying mainly on external visual cues. Substructures of Embodied Resonance Empathy include Other-Centered Empathy, driven by a motivation to help, and Self-Centered Empathy, focused on personal discomfort. For Marginal Embodied Resonance Empathy, substructures range from Transparent Resonance Empathy, involving emotional responses without bodily sensations, to Non-Resonance Empathy, characterized by a complete absence of bodily and emotional resonance.

Conclusion

This study uncovers a spectrum of embodied intersubjective synchrony in empathy among individuals with PD, ranging from fully embodied synchrony, characterized by internal bodily and emotional resonance, temporally attuned to the other's suffering, to externally oriented synchrony, characterized by diminished or absent bodily and emotional resonance, relying primarily on external visual alignment with the other's suffering. These findings highlight the importance of embodied intersubjective synchrony in empathy, suggesting that targeted interventions could be essential for enhancing social cognition in PD.

The device-aided intrajejunal delivery of levodopa-entacapone-carbidopa intestinal gel the treatment of Parkinson's disease: overview of efficacy and safety

INTRODUCTION

Device-aided therapies (DATs) have been developed to provide continuous drug delivery (CDD) to people with advanced Parkinson's disease (PD) whose symptoms can no longer be effectively managed with oral or transdermal therapy. Intrajejunal infusion of levodopa-carbidopa intestinal gel (LCIG), delivered via the CADD Legacy 1400 pump, is an established CDD option, while levodopa-entacapone-carbidopa intestinal gel (LECIG), delivered via the Crono LECIG pump, is a more recent addition to the range of DAT options in Europe.

AREAS COVERED

This article explores the rationale for the development of LECIG infusion, the role of entacapone in the formulation, and the attributes and specifications of the LECIG infusion pump device. Clinical and real-world data reporting its efficacy, safety and tolerability of LECIG in advanced PD patients from a range of European centers are reviewed, with a focus on the practical benefits that a smaller, lighter and quieter device can provide for patients who wish to start treatment with intrajejunal levodopa infusion.

EXPERT OPINION

LECIG infusion delivered via the LECIG infusion pump offers another valuable DAT option to consider for suitable people with advanced PD providing both good long-term clinical benefits and a favorable treatment experience for patients.

Neuroadaptation in neurodegenerative diseases: compensatory mechanisms and therapeutic approaches

Progressive neuronal loss is a hallmark of neurodegenerative diseases including Alzheimer's, Parkinson's, Huntington's, and Amyotrophic Lateral Sclerosis (ALS), which cause cognitive and motor impairment. Delaying the onset and course of symptoms is largely dependent on neuroadaptation, the brain's ability to restructure in response to damage. The molecular, cellular, and systemic processes that underlie neuroadaptation are examined in this study. These mechanisms include gliosis, neurogenesis, synaptic plasticity, and changes in neurotrophic factors. Axonal sprouting, dendritic remodelling, and compensatory alterations in neurotransmitter systems are important adaptations observed in NDDs; nevertheless, these processes may shift to maladaptive plasticity, which would aid in the advancement of the illness. Amyloid and tau pathology-induced synaptic alterations in Alzheimer's disease emphasize compensatory network reconfiguration. Dopamine depletion causes a major remodelling of the basal ganglia in Parkinson's disease, and non-dopaminergic systems compensate. Both ALS and Huntington's disease rely on motor circuit rearrangement and transcriptional dysregulation to slow down functional deterioration. Neuroadaptation is, however, constrained by oxidative stress, compromised autophagy, and neuroinflammation, particularly in elderly populations. The goal of emerging therapy strategies is to improve neuroadaptation by pharmacologically modifying neurotrophic factors, neuroinflammation, and synaptic plasticity. Neurostimulation, cognitive training, and physical rehabilitation are instances of non-pharmacological therapies that support neuroplasticity. Restoring compensating systems may be possible with the use of stem cell techniques and new gene treatments. The goal of future research is to combine biomarkers and individualized medicines to maximize neuroadaptive responses and decrease the course of illness. In order to reduce neurodegeneration and enhance patient outcomes, this review highlights the dual function of neuroadaptation in NDDs and its potential as a therapeutic target.

Optimized use of safinamide as an add-on therapy in Asian patients with Parkinson's disease: a narrative review and expert opinion

Parkinson's disease (PD) imposes a large burden on Asian countries and threatens to grow rapidly as Asian populations age. PD phenotypes in Asian patients differ from those reported in the West, yet management generally follows a similar approach. Levodopa (l-dopa) is a mainstay of therapy and is typically followed by the addition of a catechol-O-methyltransferase inhibitor or a monoamine oxidase-B (MAO-B) inhibitor to address the wearing-off effect. There is little guidance on switching between MAO-B inhibitors or other adjunct therapies that consider the newer evidence for safinamide as an add-on PD therapy in Asian patients. Therefore, a group of PD experts in Asia evaluated the evidence supporting safinamide for the treatment of PD with a focus on integrating this treatment option into local clinical practice. A narrative review was conducted to identify supportive evidence for the formulation of summary statements on key topics. The efficacy and safety of safinamide added to l-dopa in Asian patients with PD are supported by both clinical trials and observational data, including two randomized trials enrolling exclusively Asian patients (n = 406; n = 307) and an Asian subpopulation analysis from another randomized trial (n = 173). Safinamide reduces wear-off duration and has beneficial effects on motor symptoms of PD, with good tolerability outcomes. Safinamide may also have beneficial effects on non-motor symptoms of PD such as urinary symptoms, apathy and sleep disturbances, and it is a suitable treatment for older patients. Overall, safinamide is an effective and well-tolerated treatment for the wear-off effect of l-dopa in Asian patients and, during long-term treatment, might reduce the risk of dyskinesia in patients without pre-existing dyskinesia. Additional research is needed to better understand the role of safinamide for patients with fluctuating pain, the dose-effect relationship of safinamide in Asian patients and the efficacy of safinamide in Asian patients with early-onset PD.

6-Shogaol, a neuro-nutraceutical derived from ginger, alleviates motor symptoms and depression-like behaviors and modulates the release of monoamine neurotransmitters in Parkinson's disease mice

PURPOSE

Parkinson's disease (PD) disrupts the regulation of neurotransmitters in the brain, causing patients to experience not only motor symptoms but also non-motor symptoms such as depression. 6-shogaol (6S) is a potential neuro-nutraceutical derived from ginger, and is known to ameliorate motor symptoms by suppressing inflammation in PD mice. In this study, we investigated whether 6S can attenuate motor symptoms and depression-like behaviors through neurotransmitter regulation and to elucidate which neurotransmitters are intimately correlated with these effects.

METHODS

C57BL/6 J mice were injected with 30 mg/kg of 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine (MPTP) for 5 d to induce PD. 6S was administered via oral gavage for 11 d, including the MPTP injection period.

RESULTS

6S alleviated MPTP-induced motor symptoms and depression-like behaviors. MPTP injection decreased the levels of seven neurotransmitters in the striatum and four neurotransmitters in the hippocampus. Administration of 6S increased striatal dopamine, serotonin, and norepinephrine levels and hippocampal dopamine, norepinephrine, serotonin, and γ-aminobutyric acid levels. Moreover, correlation analysis shown that the motor symptom improvement effect of 6S was associated with striatal dopamine, norepinephrine, serotonin, and 5-hydroxyindoleacetic acid levels. The effect of 6S on depressive-like behavior was significantly correlated with striatal dopamine metabolites and serotonin and hippocampal dopamine, norepinephrine, and serotonin. Immunohistochemistry showed that 6S upregulated the expression of the vesicular monoamine transporter 2, which was reduced by MPTP in the striatum and hippocampus.

CONCLUSION

This study demonstrated that 6S improved motor symptoms and depression-like behaviors by regulating the release of monoamine neurotransmitters.

Management of Osteoporosis in Parkinson's Disease: A Systematic Review of Clinical Practice Guidelines

BACKGROUND

Parkinson's disease (PD) is the fastest-growing neurological disorder globally. Defining features include tremor, muscular rigidity, bradykinesia, and postural instability, which in combination with nonmotor symptoms such as cognitive impairment and orthostatic hypotension increase the risk of falls. Along with low bone mineral density, fracture risk is high in PD.

OBJECTIVES

The aims were to identify and appraise clinical practice guidelines, consensus statements, and treatment algorithms containing recommendations for bone health in people with PD (PwP).

METHODS

We systematically searched 4 electroninc databases (MEDLINE, Embase, Emcare, and Web of Science) (n = 78), in addition to the websites of organizations, societies, and professional bodies focused on PD or osteoporosis (n = 28), up to April 22, 2024.

RESULTS

After duplicate removal, screening, and full-text review, 6 records were included. Included records were appraised using the AGREE II (Appraisal of Guidelines for Research and Evaluation) tool. All records recognized bone health as a concern in PD, yet recommendations for fracture-risk screening were inconsistent. Two of six records grouped PD under the broad category of neurological diseases. The acceptability and tolerance of anti-osteoporosis medications in PwP was discussed only in 1 record, which incorporated national osteoporosis guidelines into a PD-specific treatment algorithm.

CONCLUSIONS

This review highlights that despite the documented high fracture rates of PwP, health professionals do not always have adequate resources to support them when considering how to manage osteoporosis. Osteoporosis screening and management needs to be incorporated into PD treatment guidelines, and equally providing specific recommendations for PwP related to bone health in national osteoporosis guidelines should be a priority given the high burden of fracture in the patient population.

Is Mat pilates effective in lower limb strength and hand grip strength of people with Parkinson's? A randomized clinical trial with follow-up

INTRODUCTION

Parkinson's disease can contribute to the loss of muscle strength, and physical exercise such as Mat Pilates can be effective in improving this, core stability, flexibility, and muscle control.

OBJECTIVE

To analyze the effects of a 12-week intervention with Mat Pilates in the short and long term, on lower limb and hand grip strength in people with Parkinson's.

METHODS

The study included 23 people (61.7 ± 7.5 years) of both sexes, diagnosed with Parkinson's disease who were selected according to inclusion criteria and divided into intervention and control groups.

RESULTS

The hand grip variable showed improvement in the intervention group intragroup only in the right hand (p = 0.003) in the post-intervention period. In the lower limb strength variable, there was significance in the extension of the left leg both in the intervention intragroup (p = 0.042), and in the control group (p = 0.001) the result in the flexion of the left leg in the intervention group (p = 0.032). The follow-up data showed significance in the strength of extension of the right leg in the intervention group (p = 0.049) and in the control group (p = 0.024) and in the extension of the left leg in the intervention group (p = 0.021).

CONCLUSION

Mat Pilates classes for people with Parkinson's with mild and moderate degrees proved to be effective in the short term in the hand grip strength of the right hand, and in the extension and flexion of the left legs, and positive effects in the long term in the strength of extension of the right also left legs.

Updated MDSGene review on the clinical and genetic spectrum of LRRK2 variants in Parkinson´s disease

Pathogenic variants in the LRRK2 gene are one of the most commonly identifiable monogenic causes of Parkinson´s disease (PD, PARK-LRRK2). This systematic MDSGene literature review comprehensively summarizes published demographic, clinical, and genetic findings related to LRRK2 variants ( https://www.mdsgene.org/ ). Data on 4660 individuals with 283 different variants were curated. The median age at onset in the PD patients with available information was 56 years, notably, with approximately one-third having PD onset <50 years. Tremor was the most frequently reported initial symptom and more common than reported in other dominantly inherited forms of PD. Of the 211 potentially PD-causing variants, 25 were classified as pathogenic or likely pathogenic, and the remaining 186 (88.2%) were variants of uncertain significance. p.G2019S was the most frequently reported pathogenic variant, followed by p.R1441G and p.R1441C. This systematic review represents the most extensive database on PARK-LRRK2 to date and provides a vital resource to improve precision medicine.

Associations between Thyroid Hormones and Cognitive Impairment in Patients with Parkinson's Disease

This study aims to explore the correlation of serum thyroid hormone levels to cognitive impairments in Parkinson's disease (PD) patients. In this retrospective study, 106 Chinese patients without cognitive impairments and 94 patients with cognitive impairments, including 55 with mild cognitive impairment (PD-MCI) and 39 with PD dementia (PDD), were analyzed. Clinical data regarding the PD assessments, including disease duration, Unified Parkinson's Disease Rating Scale (UPDRS) Part 3 scores, and Hoehn and Yahr (H-Y) staging, were analyzed. Cognitive functions were evaluated using the Montreal Cognitive Assessment score. Serum levels of thyroid-stimulating hormone (TSH), free thyroxine (FT4), and free triiodothyronine (FT3), were measured using ELISA. Significantly altered H-Y staging, disease duration, and UPDRS Part 3 scores were observed in PD patients with cognitive impairment compared with those without. Serum levels of FT3 were significantly decreased, while FT4 and TSH levels were significantly elevated in PD patients with cognitive impairment compared with those without. Combined detection of TSH, FT3, and FT4 showed value in distinguishing PD patients with and without cognitive impairment. Furthermore, a comparison of serum levels between PD-MCI and PDD patients revealed significant association between thyroid hormone levels and the degree of cognitive impairment in PD patients. Our findings suggest a relationship between changes in serum thyroid hormone levels and cognitive impairments in PD patients. Thyroid hormone levels, particularly FT3, may serve as potential markers for cognitive dysfunction in PD.

Pharmacokinetics and Dose Proportionality Study of a Novel Antiparkinsonian Agent, a 1H-1,2,4-Triazol-3-ylthio-conjugate of Prottremine

The novel antiparkinsonian agent PA-96 is the focus of our research. PA-96 supported the survival of cultured naïve dopamine neurons, alleviated motor deficits in MPTP and haloperidol-based mice models of Parkinson's disease, and increased the density of tyrosine hydroxylase positive neurons and dopamine concentration in the midbrain of an MPTP-damaged brain. In this work, an HPLC-MS/MS method was developed and validated, and the pharmacokinetics of the agent was investigated in mice after a single or multiple oral administration (p.o.) and intravenous injection (i.v.) at various doses. The dose proportionality was also evaluated after a single p.o. administration of three ascending doses (1, 5, and 10 mg/kg) and a single i.v. injection of two doses (1 and 10 mg/kg); also, the bioavailability was estimated. The disproportionality of pharmacokinetic parameters could be explained by the saturation of active centres of enzymes or receptors binding the substance: at low doses, part of the compound is bound, leaving a small amount circulating in blood, and rapidly metabolised and/or bound too. The bioavailability of PA-96 was c.a. 7 and 35% for the doses of 5 and 10 mg/kg, correspondingly.

Vestibular Neurostimulation for Parkinson's Disease: A Novel Device-Aided Non-Invasive Therapeutic Option

Dopaminergic replacement therapy remains the mainstay of symptomatic treatment for Parkinson's disease (PD), but many unmet needs and gaps remain. Device-based treatments or device-aided non-oral therapies are typically used in the advanced stages of PD, ranging from stereotactic deep brain stimulation to levodopa or apomorphine infusion therapies. But there are concerns associated with these late-stage therapies due to a number of procedural, hardware, or long-term treatment-related side effects of these treatments, and their limited nonmotor benefit in PD. Therefore, there is an urgent unmet need for low-risk adjuvants or standalone therapies which can address the range of burdensome motor and nonmotor symptoms that occur in PD. Recent studies suggest that non-invasive neurostimulation of the vestibular system may be able to address these gaps through the stimulation of the vestibular brainstem sensory network which extensively innervates brain regions, regulating both motor and a range of nonmotor functions. Therapeutic non-invasive vestibular stimulation is a relatively modern concept that may potentially improve a broad range of motor and nonmotor symptoms of PD, even at early stages of the disease. Here, we review previous studies supporting the therapeutic potential of vestibular stimulation for the treatment of PD and discuss ongoing clinical trials and potential areas for future investigations.

Blunted Melatonin Circadian Rhythm in Parkinson's Disease: Express Bewilderment

Melatonin (MTN) is a neuro-hormone released from the pineal gland. MTN secretion is regulated by different neuronal circuits, including the retinohypothalamic tract and suprachiasmatic nucleus (SCN), which are affected by light. MTN is neuroprotective in various neurodegenerative diseases, including Parkinson's disease (PD). MTN circulating level is highly blunted in PD. However, the underlying causes were not fully clarified. Thus, the present review aims to discuss the potential causes of blunted MTN levels in PD. Distortion of MTN circadian rhythmicity in PD patients causies extreme daytime sleepiness. The underlying mechanism for blunted MTN response may be due to reduction for light exposure, impairment of retinal light transmission, degeneration of circadian pacemaker and dysautonomia. In conclusion, degeneration of SCN and associated neurodegeneration together with neuroinflammation and activation of NF-κB and NLRP3 inflammasome, induce dysregulation of MTN secretion. Therefore, low serum MTN level reflects PD severity and could be potential biomarkers. Preclinical and clinical studies are suggested to clarify the underlying causes of low MTN in PD.

Subcutaneous Levodopa: A New Engine for the Vintage Molecule

The management of Parkinson's disease (PD) continues to evolve with advancements in non-oral levodopa-based therapies aiming to provide continuous drug delivery (CDD). Such therapies address the challenges posed by the emergence of motor fluctuations, dyskinesias, and non-motor fluctuations (NMF) associated with oral levodopa administration and contributing to define the advanced stage of PD. The key focus of this review is placed on subcutaneous foslevodopa/foscarbidopa (Foslevodopa/foscarbidopa) infusion, showcasing its recent clinical availability and efficacy in providing continuous levodopa delivery. While providing an overview of the other non-oral levodopa-based CDD systems, such as intrajejunal levodopa-carbidopa infusion and levodopa-entacapone-carbidopa infusion, we highlight the current promising evidence for Foslevodopa/foscarbidopa to improve, for example, "on time" without troublesome dyskinesia and reducing "off time" in people with advanced PD. Additionally, Foslevodopa/foscarbidopa demonstrates potential in managing early morning off periods, sleep quality and other motor and non-motor symptoms. Moreover, other non-oral CDD options such as ND0612 and DIZ102/DIZ101 are discussed, with focus on their pharmacokinetics/pharmacodynamics, efficacy, and safety profiles. While these advancements present new therapeutic avenues, long-term observational studies are warranted to elucidate their impact on existing PD therapies. Overall, this review provides insights into the evolving landscape of non-oral CDD therapies and offers a pragmatic approach for their integration into clinical practice.

Mouse Model of Parkinson's Disease with Bilateral Dorsal Striatum Lesion with 6-Hydroxydopamine Exhibits Cognitive Apathy-like Behavior

Among the symptoms of Parkinson's disease (PD), apathy comprises a set of behavioral, affective, and cognitive features that can be classified into several subtypes. However, the pathophysiology and brain regions that are involved in these different apathy subtypes are still poorly characterized. We examined which subtype of apathy is elicited in a mouse model of PD with 6-hydroxydopamine (6-OHDA) lesions and the behavioral symptoms that are exhibited. Male C57/BL6J mice were allocated to sham (n = 8) and 6-OHDA (n = 13) groups and locally injected with saline or 4 µg 6-OHDA bilaterally in the dorsal striatum. We then conducted motor performance tests and apathy-related behavioral experiments. We then pathologically evaluated tyrosine hydroxylase (TH) immunostaining. The 6-OHDA group exhibited significant impairments in motor function. In the behavioral tests of apathy, significant differences were observed between the sham and 6-OHDA groups in the hole-board test and novelty-suppressed feeding test. The 6-OHDA group exhibited impairments in inanimate novel object preference, whereas social preference was maintained in the three-chamber test. The number of TH+ pixels in the caudate putamen and substantia nigra compacta was significantly reduced in the 6-OHDA group. The present mouse model of PD predominantly showed dorsal striatum dopaminergic neuronal loss and a decrease in novelty seeking as a symptom that is related to the cognitive apathy component.

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.

Experiences of Living With the Nonmotor Symptoms of Parkinson's Disease: A Photovoice Study

BACKGROUND

Nonmotor symptoms (NMSs) are frequently experienced by people with Parkinson's disease (PD) and are often perceived as their most bothersome symptoms. However, these remain poorly understood with suboptimal clinical management. These unmet needs are an important determinant of health-related quality of life (QoL) in PD.

OBJECTIVE

The aim of this study was to gain insights into the experience of living with the NMS of PD in real-time using participatory action methodology.

METHOD

Using the photovoice method, 14 people with PD took photographs to document their experiences of living with the NMS of PD. They composed corresponding written narratives to capture the impact of NMS on their daily activities and QoL. In total, 152 photographs and corresponding narratives were analysed using thematic analysis with an inductive approach.

RESULTS

Four interrelated themes were identified. Emotional well-being and sense of self encompassed a process of adjustment to living with PD. Engaging in valued activities, adopting a positive mindset and utilising coping strategies were thought to enhance confidence and self-esteem. Social support and societal awareness highlighted the importance of supportive relationships and socialising to aid participation and avoid isolation. Barriers to social engagement included the unpredictability of NMS and nonvisible NMS being neglected or misunderstood.

CONCLUSION

Findings demonstrated the far-reaching impact of nonmotor aspects of PD on emotional, occupational and social dimensions. These needs could be addressed through person-centred and comprehensive approaches to care.

PATIENT OR PUBLIC CONTRIBUTION

This study utilised a participatory research approach allowing participants to choose the subjects that mattered to them and how to present their results. Additionally, a group workshop was held with people with PD, their family members and healthcare professionals to guide theme development.

"Advanced" Parkinson's disease: A review

There is no consensus driven definition of "advanced" Parkinson's disease (APD) currently. APD has been described in terms of emergence of specific clinical features and clinical milestones of the disease e.g., motor fluctuations, time to increasing falls, emergence of cognitive decline, etc. The pathological burden of disease has been used to characterize various stages of the disease. Imaging markers have been associated with various motor and nonmotor symptoms of advancing disease. In this review, we present an overview of clinical, pathologic, and imaging markers of APD. We also propose a model of disease definition involving longitudinal assessments of these markers as well as quality of life metrics to better understand and predict disease progression in those with Parkinson's disease.

Remotely prescribed, monitored, and tailored home-based gait-and-balance exergaming using augmented reality glasses: a clinical feasibility study in people with Parkinson's disease

Background

Exergaming has the potential to increase adherence to exercise through play, individually tailored training, and (online) remote monitoring. Reality Digital Therapeutics (Reality DTx®) is a digital therapeutic software platform for augmented reality (AR) glasses that enables a home-based gait-and-balance exergaming intervention specifically designed for people with Parkinson's disease (pwPD).

Objective

The primary objective was to evaluate the feasibility and potential efficacy of Reality DTx® AR exergaming intervention for improving gait, balance, and walking-adaptability fall-risk indicators. The secondary objective was to evaluate the potential superiority of AR glasses [Magic Leap 2 (ML2) vs. HoloLens 2 (HL2)].

Methods

This waitlist-controlled clinical feasibility study comprised three laboratory visits (baseline; pre-intervention; and post-intervention), a home visit, and a 6-week AR exergaming intervention. Five complementary gait-and-balance exergames were remotely prescribed (default five sessions/week of 30 active minutes/session), monitored, and tailored. Feasibility was assessed in terms of safety, adherence, and user experience. During laboratory visits, gait-and-balance capacity was assessed using standard clinical gait-and-balance tests and advanced walking-adaptability fall-risk assessments.

Results

In total, 24 pwPD participated. No falls and four near falls were reported. Session adherence was 104%. The User Experience Questionnaire scores for Reality DTx® ranged from above average to excellent, with superior scores for HL2 over ML2 for Perspicuity and Dependability. Intervention effects were observed for the Timed Up and Go test (albeit small), the Five Times Sit to Stand test, and walking speed. Walking-adaptability fall-risk indicators all improved post-intervention.

Conclusion

Reality DTx® is a safe, adherable, usable, well-accepted, and potentially effective intervention in pwPD. These promising results warrant future randomized controlled trials on the (cost-)effectiveness of home-based AR exergaming interventions for improving gait, balance, and fall risk.

Clinical trial registration

ClinicalTrials.gov, identifier NCT05605249.

Real-world Chinese herbal medicine for Parkinson's disease: a hospital-based retrospective analysis of electronic medical records

Background

Parkinson's disease (PD) is a progressive neurodegenerative condition. Chinese medicine therapies have demonstrated effectiveness for PD in controlled settings. However, the utilization of Chinese medicine therapies for PD in real-world clinical practice and the characteristics of patients seeking these therapies have not been thoroughly summarized.

Method

The study retrospectively analyzed initial patient encounters (PEs) with a first-listed diagnosis of PD, based on electronic medical records from Guangdong Provincial Hospital of Chinese Medicine between July 2018 and July 2023.

Results

A total of 3,206 PEs, each corresponding to an individual patient, were eligible for analyses. Approximately 60% of patients made initial visits to the Chinese medicine hospital after receiving a PD diagnosis, around 4.59 years after the onset of motor symptoms. Over 75% of the patients visited the Internal Medicine Outpatient Clinic at their initial visits, while a mere 13.85% visited PD Chronic Care Clinic. Rest tremor (61.98%) and bradykinesia (52.34%) are the most commonly reported motor symptoms, followed by rigidity (40.70%). The most commonly recorded non-motor symptoms included constipation (31.88%) and sleep disturbance (25.27%). Integration of Chinese medicine and conventional medicine therapies was the most common treatment method (39.15%), followed by single use of Chinese herbal medicine (27.14%). The most frequently prescribed herbs for PD included Glycyrrhiza uralensis Fisch. (gan cao), Astragalus mongholicus Bunge (huang qi), Atractylodes macrocephala Koidz. (bai zhu), Angelica sinensis (Oliv.) Diels (dang gui), Rehmannia glutinosa (Gaertn.) DC. (di huang), Paeonia lactiflora Pall. (bai shao), Bupleurum chinense DC. (chai hu), Citrus aurantium L. (zhi qiao/zhi shi/chen pi), Panax ginseng C. A. Mey. (ren shen), and Poria cocos (Schw.) Wolf (fu ling). These herbs contribute to formulation of Bu zhong yi qi tang (BZYQT).

Conclusion

Patients typically initiated Chinese medical care after the establishment of PD diagnosis, ~4.59 years post-onset of motor symptoms. The prevalent utilization of CHM decoctions and patented Chinese herbal medicine products, underscores its potential in addressing both motor and non-motor symptoms. Despite available evidence, rigorous clinical trials are needed to validate and optimize the integration of CHM, particularly BZYQT, into therapeutic strategies for PD.

Effects of acupuncture on sleep quality in patients with Parkinson's disease: A systematic review and meta-analysis

OBJECTIVE

To systematically evaluate the evidence relating to acupuncture on the sleep quality of patients with Parkinson's disease.

DATA SOURCES

Six English-language (PubMed, Cochrane Library, EBSCOhost, Embase, OVID MEDLINE, and Web of Science) and four Chinese-language (China National Knowledge Infrastructure, SinoMed, China Scientific Journals Database, and Wanfang) databases were searched for pertinent studies published from database inception to 11 October 2023.

METHODS

Two researchers independently screened eligible studies and extracted relevant data using custom data extraction tables. Methodological quality assessment of the included studies was performed using Cochrane Handbook 5.1.0. Meta-analysis was performed using Cochrane Review Manager version 5.4.

RESULTS

Twenty-four studies (1701 participants) met inclusion criteria. The meta-analysis showed that acupuncture improved the Parkinson's Disease Sleep Scale, Pittsburgh Sleep Quality Index, Hamilton Anxiety Scale, Hamilton Depression Scale, Self-Rating Depression Scale, and Parkinson's Disease Questionnaire 39 scores compared with controls (all P < 0.05).

CONCLUSION

This review showed that acupuncture improved sleep quality, anxiety and depressive symptoms, and quality of life of patients with Parkinson's disease relative to controls.

Significance of non-motor symptoms and development of a screening tool for osteoporosis in Parkinson's disease

BACKGROUND AND PURPOSE

Parkinson's disease (PD) patients have a higher likelihood of having osteoporosis compared to controls, therefore deserving special attention. This study was to 1) investigate the association of non-motor symptoms with osteoporosis amongst PD patients, and 2) develop screening tools for osteoporosis.

MATERIALS AND METHODS

PD Patients were included (n = 109). The factors/variables were obtained from clinical records due to the retrospective nature of this study. The bone mineral density (BMD) of the lumbar spine and femoral neck was examined using a dual-energy X-ray absorptiometry machine, according to which they were categorized as either having (T-score ≤ -2.5) or not having osteoporosis (T-score>-2.5) at the two sites. The non-motor symptoms were assessed using clinical scales, including non-motor experiences of daily living, depression, anxiety, cognitive function, and autonomic function. The potential covariates included demographic and clinical factors/variables, such as age and sex. Logistic regression was used to investigate the associations and establish the screening tools.

RESULTS

Patients with autonomic dysfunction had significantly (p = 0.011) higher odds of having femoral neck osteoporosis compared to those with no/minimal dysfunction after adjusting for sex, disease duration, and body mass index, demonstrating a strong association (odds ratio=12.81). Based on the four factors/variables, a screening tool with a good accuracy was established (C-statistic = 0.85).

CONCLUSION

PD patients with autonomic dysfunction had greater odds of having femoral neck osteoporosis compared to those with no/minimal dysfunction. The screening tool may lay a foundation for developing screening models with higher accuracy to identify which PD patients may require a BMD test.

Remotely prescribed and monitored home-based gait-and-balance therapeutic exergaming using augmented reality (AR) glasses: protocol for a clinical feasibility study in people with Parkinson's disease

BACKGROUND

Clinical guidelines for people with Parkinson's disease (pwPD) stress that, complementary to pharmacological treatment, exercise and physiotherapy should be given a central role in disease management. Adhering to regular exercise of the right type, and with high repetition, remains a challenge for pwPD. Exergaming has the potential to increase adherence through play and personalised interventions, both in clinic and at home. Reality DTx® is an augmented-reality (AR) home-based gait-and-balance exergaming intervention specifically designed for pwPD as an extension of supervised physiotherapy. The primary objective of this study is to evaluate the feasibility and potential efficacy of Reality DTx®.

METHODS

Twenty-four pwPD (Hoehn and Yahr stages 2-4) with self-reported gait and/or balance impairments will participate in this study. The study comprises a 6-week waitlist-controlled AR home-based therapeutic gait-and-balance exergaming intervention. Reality DTx® will initially be prescribed remotely for a minimum of 5 days a week for 30 min per day. We will remotely set and adjust the frequency, difficulty, type of games, and/or duration weekly, based on objective and subjective data from the AR glasses and participant, respectively. In addition to the home-based gait-and-balance exergaming intervention, the study comprises three laboratory visits: before the 6-week waitlist period (t0; baseline), before the 6-week intervention period (t1; pre-intervention), and after the 6-week intervention period (t2; post-intervention). The primary study parameters are feasibility (in terms of safety, adherence, and user experience) and potential efficacy for improving gait and balance (using standard clinical gait-and-balance tests and a targeted walking-related fall-risk assessment). Recruitment started in December 2022 and the final post-intervention assessment will be according to planning in July 2023.

CONCLUSIONS

This clinical feasibility trial is the first remotely prescribed and monitored home-based AR gait-and-balance exergaming intervention for pwPD. The results in terms of clinical feasibility (i.e. safety, adherence, and user experience) and potential efficacy (gait, balance, and fall-risk outcomes) form the basis for future randomised controlled studies on the effectiveness of home-based AR gait-and-balance exergaming interventions for pwPD.

TRIAL REGISTRATION

ClinicalTrials.gov, NCT05605249 . Registered on 4 November 2022.

Ageing with Parkinson's: Identification of Personal Needs in the Northern Spanish Context

As individuals diagnosed with Parkinson's disease enter older age, the myriad challenges and complications associated with this condition tend to escalate. Hence, there is a critical necessity to comprehensively discern the perceived needs of these individuals, along with their proposed remedies and essential support requisites. Additionally, understanding the perspectives of their families becomes imperative to formulate tailored interventions aimed at enhancing their overall development, progression, and quality of life. The study's main objective is to assess the perceived needs of individuals with PD and their family members, propose necessary solutions, and suggest future perspectives. The study encompassed a cohort of 268 participants, comprising 179 individuals diagnosed with Parkinson's disease and 89 of their relatives. A meticulously designed structured interview instrument consisting of 93 items was employed to assess various domains encompassing perceived needs, institutional support mechanisms, essential solutions, and future anticipations. Results: Statistically significant differences were found in health resources, social services resources, obstacles, solutions, and future outlook, with higher mean values from the relatives. Conclusions: The results highlight the most concerning needs in this context. Specifically, those needs related to health resources, social services resources, and future outlook present the greatest differences between the two subsamples, with the family members perceiving more needs. This alignment extended to both the categorization of unmet needs and the requisite solutions envisioned to address them. Suggested improvements include a sociosanitary strategy, stakeholder involvement, and prioritizing flexible home assistance to support older individuals with PD and their families.

Relationships Between Rapid Eye Movement Sleep Behavior Disorder and Parkinson's Disease: Indication from Gut Microbiota Alterations

Rapid eye movement sleep behavior disorder (RBD) has a close relationship with Parkinson's disease (PD) and was even regarded as the most reliable hallmark of prodromal PD. RBD might have similar changes in gut dysbiosis to PD, but the relationship between RBD and PD in gut microbial alterations is rarely studied. In this study, we aim to investigate whether there were consistent changes between RBD and PD in gut microbiota, and found some specific biomarkers in RBD that might indicate phenoconversion to PD. Alpha-diversity showed no remarkable difference and beta-diversity showed significant differences based on the unweighted (R = 0.035, P = 0.037) and weighted (R = 0.0045, P = 0.008) UniFrac analysis among idiopathic RBD (iRBD), PD with RBD, PD without RBD and normal controls (NC). Enterotype distribution indicated iRBD, PD with RBD and PD without RBD were Ruminococcus-dominant while NC were Bacteroides-dominant. 7 genera (4 increased: Aerococcus, Eubacterium, Gordonibacter and Stenotrophomonas, 3 decreased: Butyricicoccus, Faecalibacterium and Haemophilus) were consistently changed in iRBD and PD with RBD. Among them, 4 genera (Aerococcus, Eubacterium, Butyricicoccus, Faecalibacterium) remained distinctive in the comparison between PD with RBD and PD without RBD. Through clinical correlation analysis, Butyricicoccus and Faecalibacterium were found negatively correlated with the severity of RBD (RBD-HK). Functional analysis showed iRBD had similarly increased staurosporine biosynthesis to PD with RBD. Our study indicates that RBD had similar gut microbial changes to PD. Decreased Butyricicoccus and Faecalibacterium might be potential hallmarks of phenoconversion of RBD to PD.

The classical and non-classical axes of renin-angiotensin system in Parkinson disease: The bright and dark side of the moon

Parkinson disease (PD) is a common brain neurodegenerative disease due to progressive degeneration of the dopaminergic neurons in the substantia nigra pars compacta (SNpc). Of note, the cardio-metabolic disorders such as hypertension are adversely affect PD neuropathology through exaggeration of renin-angiotensin system (RAS). The RAS affects the stability of dopaminergic neurons in the SNpc, and exaggeration of angiotensin II (AngII) is implicated in the development and progression of PD. RAS has two axes classical including angiotensin converting enzyme (ACE)/AngII/AT1R, and the non-classical axis which include ACE2/Ang1-7/Mas receptor, AngIII, AngIV, AT2R, and AT4R. It has been shown that brain RAS is differs from that of systemic RAS that produce specific neuronal effects. As well, there is an association between brain RAS and PD. Therefore, this review aims to revise from published articles the role of brain RAS in the pathogenesis of PD focusing on the non-classical pathway, and how targeting of this axis can modulate PD neuropathology.

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.

The PD-Ballet study: study protocol for a randomised controlled single-blind hybrid type 2 clinical trial evaluating the effects of ballet dancing on motor and non-motor symptoms in Parkinson's disease

BACKGROUND

To date, beneficial effects of multimodal exercise programmes on Parkinson's disease (PD) have focused on motor symptoms and little attention has been paid to the potential effects of such programmes on the non-motor symptoms of PD, which are now universally known as one of the key drivers of quality of life and a key unmet need. We aim to explore clinical effectiveness of a ballet-based dance programme in addressing non-motor and motor symptoms of Parkinson's disease across all stages of progression.

METHODS

A randomised, single-blind, controlled trial of 160 people with Parkinson's across all motor stages (Participants will be stratified into three groups of motor advancement: Hoehn and Yahr (HY) stages I and II being Mild Group, HY Stage III being Moderate Group and HY Stages IV and V being Severe Group) will be randomly allocated to either an intervention or a control group using an independent randomisation body. The primary outcome is an improvement in non-motor symptoms as measured by the Movement Disorders Society Non-Motor Scale (MDS-NMS). The intervention protocol consists of 12 one-weekly dance sessions led by English National Ballet. Each session is followed by a 'tea and biscuit' social time. Control group follows standard clinical pathway and joins the 'tea and biscuit' to control for any positive effects of social interactions. All participants are assessed at baseline, immediately after completion of the intervention and 3-6 months later to explore any potential longitudinal effects.

DISCUSSION

To our knowledge, no adequately powered study has explored the effects of a dance-based intervention on non-motor symptoms of Parkinson's disease, assessing these on both holistic and granular levels. We also aim to stratify participants in accordance with their motor state as assessed by. HY staging to explore specific effects on the symptoms at the initial, moderate and complex stages of the disease. If successful, this trial provides first evidence on clinical effectiveness of a ballet-based dance intervention for symptoms of Parkinson's disease, assessed in a robust, rigorous manner.

TRIAL REGISTRATION

NCT04719468.

Architecture of the subthalamic nucleus

The subthalamic nucleus (STN) is a major neuromodulation target for the alleviation of neurological and neuropsychiatric symptoms using deep brain stimulation (DBS). STN-DBS is today applied as treatment in Parkinson´s disease, dystonia, essential tremor, and obsessive-compulsive disorder (OCD). STN-DBS also shows promise as a treatment for refractory Tourette syndrome. However, the internal organization of the STN has remained elusive and challenges researchers and clinicians: How can this small brain structure engage in the multitude of functions that renders it a key hub for therapeutic intervention of a variety of brain disorders ranging from motor to affective to cognitive? Based on recent gene expression studies of the STN, a comprehensive view of the anatomical and cellular organization, including revelations of spatio-molecular heterogeneity, is now possible to outline. In this review, we focus attention to the neurobiological architecture of the STN with specific emphasis on molecular patterns discovered within this complex brain area. Studies from human, non-human primate, and rodent brains now reveal anatomically defined distribution of specific molecular markers. Together their spatial patterns indicate a heterogeneous molecular architecture within the STN. Considering the translational capacity of targeting the STN in severe brain disorders, the addition of molecular profiling of the STN will allow for advancement in precision of clinical STN-based interventions.

Subthalamic stimulation has acute psychotropic effects and improves neuropsychiatric fluctuations in Parkinson's disease

Background

Subthalamic nucleus deep brain stimulation (STN-DBS) is a well-established treatment for motor complications in Parkinson's disease (PD). However, its effects on neuropsychiatric symptoms remain disputed. The aim of this study was to evaluate the effects of STN-DBS on neuropsychiatric symptoms in PD.

Methods

We retrospectively assessed 26 patients with PD who underwent a preoperative levodopa challenge and postoperative levodopa and stimulation challenges 1 year after STN-DBS. Based on the Neuropsychiatric Fluctuations Scale, Neuropsychiatric State Scores and Neuropsychiatric Fluctuation Indices (NFIs) were calculated. Mixed-effects models with random effects for intercept were used to examine the association of Neuropsychiatric State Score and NFI with the different assessment conditions.

Results

In acute challenge conditions, there was an estimated increase of 15.9 points in the Neuropsychiatric State Score in stimulation ON conditions (95% CI 11.4 to 20.6, p<0.001) and 7.6 points in medication ON conditions (95% CI 3.3 to 11.9, p<0.001). Neuropsychiatric fluctuations induced by levodopa, quantified with NFI, decreased by 35.54% (95% CI 49.3 to 21.8, p<0.001) 1 year after STN-DBS.

Conclusions

Bilateral STN-DBS at therapeutic parameters has acute psychotropic effects similar to levodopa and can modulate and decrease levodopa-induced neuropsychiatric fluctuations.

Non-Motor Symptom Management: Insights into Adherence to Treatment Guidelines in Parkinson's Disease Patients

Background

Non-motor symptoms (NMS) reduce quality of life in Parkinson's disease (PD) patients, who experience three times more NMS than individuals without PD. While there are international and national NMS treatment guidelines, their implication in clinical practice remains unclear.

Objective

This study aimed to investigate the adherence to pharmacological NMS treatment guidelines in patients with mild to moderately severe PD.

Methods

220 PD patients with ≥1 NMS based on the Non-Motor Symptom Questionnaire and a Hoehn and Yahr stage ≤4 were randomly selected from the Swedish Parkinson registry and screened for inclusion. NMS were evaluated using the International Parkinson and Movement Disorder Society-Non-Motor Rating Scale (MDS-NMS), Parkinson's Disease Sleep Scale 2, Epworth Sleepiness Scale, and Hospital Anxiety and Depression Scale. Treatment was compared with Swedish national guidelines and international guidelines from the MDS Evidence-Based Medicine Committee.

Results

Among 165 included patients, the median number of NMS was 14, and in median 7 symptoms were estimated to require treatment. The most common NMS requiring treatment were pain (69%) and urinary problems (56%). Treatment of depression and constipation demonstrated the highest adherence to guidelines (79% and 77%), while dysphagia and excessive daytime sleepiness exhibited the lowest adherence (0% and 4%). On average, only 32% of NMS were treated in accordance with guidelines.

Conclusions

Adherence to pharmacological guidelines for NMS in patients with mild to severe PD was low. This study highlights the need for improved evaluation and treatment of NMS to enhance symptom management and quality of life among PD patients.

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.

Targeting Nrf2 signaling pathway by quercetin in the prevention and treatment of neurological disorders: An overview and update on new developments

BACKGROUND

Neurological disorders (NLDs) are widely acknowledged as a significant public health concern worldwide. Stroke, Alzheimer's disease (AD), and traumatic brain injury (TBI) are three of these disorders that have sparked major study attention. Neurological dysfunction, protein buildup, oxidation and neuronal injury, and aberrant mitochondria are all prevalent neuropathological hallmarks of these disorders. The signaling cascade of nuclear factor erythroid 2 related factor 2 (Nrf2) shares all of them as a common target. Several studies have found that overexpression of Nrf2 is a promising treatment method in NLDs. Effective treatment of these disorders continues to be a universal concern regardless of various medicines. In order to treat a variety of neurological problems, organic remedies may provide an alternative treatment. It has been demonstrated that polyphenols like quercetin (Que) offer considerable capabilities for treating NLDs. One of Que's greatest key targets, Nrf2, has the capacity to control the production of a number of cytoprotective enzymes that exhibit neuroprotective, detoxifying, and antioxidative effects. Additionally, Que enhanced the expression of Nrf2 and inhibited alterations in the shape and death of neurons in the hippocampus.

OBJECTIVE

In this review, we have focused on Que's medicinal prospects as a neuroprotective drug.

METHODS

PubMed, Scopus, Science Direct, and Google Scholar were used to search articles for this study.

RESULTS

The findings of this research demonstrate that (1) Que protected the blood-brain barrier via stimulating Nrf2 in animal stroke, which alleviated ischemic reperfusion and motor dysfunction. (2) By triggering the Nrf2 pathway, Que reduced the neuroinflammation and oxidative damage brought on by TBI in the cortex. (3) In an experimental model of AD, Que enhanced cognitive function by decreasing A1-4, antioxidant activity, and Nrf2 levels in the brain.

CONCLUSION

We discuss recent research on Que-mediated Nrf2 expression in the management of several NLDs in this paper.

Impact of Safinamide on Patient-Reported Outcomes in Parkinson's Disease

Introduction

Parkinson's disease (PD) is a chronic and progressive neurodegenerative condition due to the degeneration of nigral dopaminergic cells. Both motor and non-motor symptoms (NMS) of PD produce a marked impairment in PD patients' quality of life (QoL), but contrary to motor features, NMS do not improve with dopamine replacement. Novel therapeutic interventions for PD have successfully controlled most motor manifestations of PD, but the management of NMS is still challenging. Since NMS have a negative impact on the QoL of PD patients, researchers are currently looking for drugs that can modulate the activity of neurotransmitter systems other than dopamine in the hope that can alleviate NMS in PD. Among the recently approved drugs for patients experiencing fluctuations in motor symptoms, safinamide stands out as an effective add-on therapy to levodopa. Safinamide is a monoamine oxidase type-B inhibitor (MAOB-I), with proven efficacy in reducing motor fluctuations. Its distinctive mechanism of action impacts dopaminergic pathways via MAOB inhibition and glutamatergic pathways by blocking sodium and calcium channels. Findings from Phase III clinical trials, meta-analysis, post-hoc analysis, and real-life experiences indicate that safinamide benefits motor symptoms such as tremor, bradykinesia, rigidity, and gait. Additionally, it shows promise for improving NMS like fatigue, pain, mood, and sleep disturbances in patients with PD.

Areas Covered

In this article, the authors explore the impact of safinamide on patient-reported outcomes in PD. A thorough search was conducted on PubMed focusing on studies published between 2018 and 2023 in English. The inclusion criteria encompassed clinical trials, randomized controlled trials, systematic reviews, meta-analyses, and reviews. The search strategy revolved around the implementation of MeSH terms related to safinamide and its impact on the quality of life in PD.

Conclusion

Our data strongly support the improving effect on QoL, reducing the disabling NMS reported in patients with PD.

Effects of Tiliroside and Lisuride Co-Treatment on the PI3K/Akt Signal Pathway: Modulating Neuroinflammation and Apoptosis in Parkinson's Disease

Researchers are actively exploring potential bioactive compounds to enhance the effectiveness of Lisuride (Lis) in treating Parkinson's disease (PD) over the long term, aiming to mitigate the serious side effects associated with its extended use. A recent study found that combining the dietary flavonoid Tiliroside (Til) with Lis has potential anti-Parkinson's benefits. The study showed significant improvements in PD symptoms induced by 1-Methyl-4-phenyl-1,2,3,6-tetrahydropyridine (MPTP) when Til and Lis were given together, based on various behavioral tests. This combined treatment significantly improved motor function and protected dopaminergic neurons in rats with PD induced by MPTP. It also activated important molecular pathways related to cell survival and apoptosis control, as indicated by the increased pAkt/Akt ratio. Til and Lis together increased B-cell lymphoma 2 (Bcl-2), decreased caspase 3 activity, and prevented brain cell decay. Co-administration also reduced tumor necrosis factor alpha (TNF-α) and Interleukin-1 (IL-1). Antioxidant markers such as superoxide dismutase (SOD), catalase, and reduced glutathione significantly improved compared to the MPTP-induced control group. This study shows that using Til and Lis together effectively treats MPTP-induced PD in rats, yielding results comparable to an 8 mg/kg dose of levodopa, highlighting their potential as promising Parkinson's treatments.

Effect of Physiotherapy Interventions on Motor Symptoms in People With Parkinson's Disease: A Systematic Review and Meta-Analysis

OBJECTIVE

To evaluate the effectiveness of different types of physiotherapy interventions in people with Parkinson's disease (PD).

DESIGN

Systematic review and meta-analysis of randomized controlled trials (RCTs).

METHODS

Five databases (PubMed, Embase, Cochrane Library, CINAHL and Web of Science Core Collection) were searched for relevant RCTs published from database inception to July 14, 2022. Reviewers independently screened the literature, extracted data, and assessed the literature quality according to the Cochrane Collaboration Risk of Bias Tool and PEDro Scale. This meta-analysis was conducted using RevMan 5.4.1 and reported in compliance with the PRISMA statement.

RESULTS

Forty-two RCTs with 2,530 participants were included. Across all types of physiotherapy, strength training, mind-body exercise, aerobic exercise, and non-invasive brain stimulation (NiBS) were effective in improving motor symptoms as measured by the (Movement Disorders Society-) Unified PD Scale, whereas balance and gait training (BGT) and acupuncture were not. The pooled results showed that the change in mind-body exercise (MD = -5.36, 95% CI [-7.97 to -2.74], p < .01, I2 = 68%) and NiBS (MD = -4.59, 95% CI [-8.59 to -0.59], p = .02, I2 = 78%) reached clinical threshold, indicating clinically meaningful improvements. Considering the effectiveness of the interventions on motor symptoms, balance, gait and functional mobility, mind-body exercise was recommended the most.

CONCLUSIONS

Exercise appears to be a better form of physiotherapy than NiBS and acupuncture for improving motor function. Mind-body exercise showed beneficial effects on motor symptoms, balance, gait and functional mobility in people with PD, and is worthy of being promoted.

Patient-specific models link neurotransmitter receptor mechanisms with motor and visuospatial axes of Parkinson's disease

Parkinson's disease involves multiple neurotransmitter systems beyond the classical dopaminergic circuit, but their influence on structural and functional alterations is not well understood. Here, we use patient-specific causal brain modeling to identify latent neurotransmitter receptor-mediated mechanisms contributing to Parkinson's disease progression. Combining the spatial distribution of 15 receptors from post-mortem autoradiography with 6 neuroimaging-derived pathological factors, we detect a diverse set of receptors influencing gray matter atrophy, functional activity dysregulation, microstructural degeneration, and dendrite and dopaminergic transporter loss. Inter-individual variability in receptor mechanisms correlates with symptom severity along two distinct axes, representing motor and psychomotor symptoms with large GABAergic and glutamatergic contributions, and cholinergically-dominant visuospatial, psychiatric and memory dysfunction. Our work demonstrates that receptor architecture helps explain multi-factorial brain re-organization, and suggests that distinct, co-existing receptor-mediated processes underlie Parkinson's disease.

Nanotechnology-empowered therapeutics targeting neurodegenerative diseases

Neurodegenerative diseases are posing pressing health issues due to the high prevalence among aging populations in the 21st century. They are evidenced by the progressive loss of neuronal function, often associated with neuronal necrosis and many related devastating complications. Nevertheless, effective therapeutical strategies to treat neurodegenerative diseases remain a tremendous challenge due to the multisystemic nature and limited drug delivery to the central nervous system. As a result, there is a pressing need to develop effective alternative therapeutics to manage the progression of neurodegenerative diseases. By utilizing the functional reconstructive materials and technologies with specific targeting ability at the nanoscale level, nanotechnology-empowered medicines can transform the therapeutic paradigms of neurodegenerative diseases with minimal systemic side effects. This review outlines the current applications and progresses of the nanotechnology-enabled drug delivery systems to enhance the therapeutic efficacy in treating neurodegenerative diseases. This article is categorized under: Therapeutic Approaches and Drug Discovery > Nanomedicine for Neurological Disease Therapeutic Approaches and Drug Discovery > Emerging Technologies.

Barriers and facilitators for healthcare providers to implement family-centered care in Parkinson's disease: a scoping review

Aims

This study aimed to identify and synthesize the barriers and facilitators to the implementation of family-centered care in Parkinson's disease (PD) and to provide a reference for evidence-based Parkinson's disease nursing practice.

Methods

This scoping review follows the methodology framework proposed by Arksey and O'Malley. Four databases including PubMed, Web of Science, Embase, and Cochrane Library were searched. Barriers and facilitators were summarized based on the ecological family-centered model.

Results

Through a comprehensive literature search, 35 studies were found for this scoping review. Barriers and facilitators to implementing family-centered care in PD included physiological factors, environmental factors, culturally based conflicts, living arrangements, education or skills training, group experiences, and individual and family consultations.

Conclusion

Implementing family-centered care in Parkinson's disease is essential to providing comprehensive care that improves outcomes for both PD patients and their family members.

In vivo effects of the alpha-synuclein misfolding inhibitor minzasolmin supports clinical development in Parkinson's disease

Direct targeting of alpha-synuclein (ASYN) has emerged as a disease-modifying strategy for Parkinson's disease and other synucleinopathies which is being approached using both small molecule compounds and ASYN-targeted biologics. Minzasolmin (UCB0599) is an orally bioavailable and brain-penetrant small molecule ASYN misfolding inhibitor in clinical development as a disease-modifying therapeutic for Parkinson's disease. Herein the results of preclinical evaluations of minzasolmin that formed the basis for subsequent clinical development are described. Pharmacokinetic evaluations of intraperitoneal 1 and 5 mg/kg minzasolmin in wildtype mice revealed parallel and dose-proportional exposures in brain and plasma. Three-month administration studies in the Line 61 transgenic mouse model of PD were conducted to measure ASYN pathology and other PD-relevant endpoints including markers of CNS inflammation, striatal DAT labeling and gait. Reductions in ASYN pathology were correlated with improved aspects of gait and balance, reductions in CNS inflammation marker abundance, and normalized striatal DAT levels. These findings provide support for human dose determinations and have informed the translational strategy for clinical trial design and biomarker selection for the ongoing clinical studies of minzasolmin in patients living with early-stage Parkinson's disease (ClinicalTrials.gov ID: NCT04658186; EudraCT Number 2020-003265).

Dopamine agonists in Parkinson's disease: Impact of D1-like or D2-like dopamine receptor subtype selectivity and avenues for future treatment

Dopamine agonists (DAs) have demonstrated efficacy for the treatment of Parkinson's disease (PD) but are limited by adverse effects (AEs). DAs can vary considerably in their receptor subtype selectivity and affinity, chemical composition, receptor occupancy, and intrinsic activity on the receptor. Most currently approved DAs for PD treatment primarily target D2/D3 (D2-like) dopamine receptors. However, selective activation of D1/D5 (D1-like) dopamine receptors may enable robust activation of motor function while avoiding AEs related to D2/D3 receptor agonism. Full D1/D5 receptor-selective agonists have been explored in small, early-phase clinical studies, and although their efficacy for motor symptoms was robust, challenges with pharmacokinetics, bioavailability, cardiovascular AEs, and dyskinesia rates similar to levodopa prevented clinical advancement. Generally, repeated dopaminergic stimulation with full DAs is associated with frontostriatal dysfunction and sensitization that may induce plastic changes in the motor system, and neuroadaptations that produce long-term motor and nonmotor complications, respectively. Recent preclinical and clinical studies suggest that a D1/D5 receptor-selective partial agonist may hold promise for providing sustained, predictable, and robust motor control, while reducing risk for motor complications (e.g., levodopa-induced dyskinesia) and nonmotor AEs (e.g., impulse control disorders and excessive daytime sleepiness). Clinical trials are ongoing to evaluate this hypothesis. The potential emerging availability of novel dopamine receptor agonists with selective dopamine receptor pharmacology suggests that the older terminology "dopamine agonist" may need revision to distinguish older-generation D2/D3-selective agonists from D1/D5-selective agonists with distinct efficacy and tolerability characteristics.

How and why the adenosine A2A receptor became a target for Parkinson's disease therapy

Dopaminergic therapy for Parkinson's disease has revolutionised the treatment of the motor symptoms of the illness. However, it does not alleviate all components of the motor deficits and has only limited effects on non-motor symptoms. For this reason, alternative non-dopaminergic approaches to treatment have been sought and the adenosine A2A receptor provided a novel target for symptomatic therapy both within the basal ganglia and elsewhere in the brain. Despite an impressive preclinical profile that would indicate a clear role for adenosine A2A antagonists in the treatment of Parkinson's disease, the road to clinical use has been long and full of difficulties. Some aspects of the drugs preclinical profile have not translated into clinical effectiveness and not all the clinical studies undertaken have had a positive outcome. The reasons for this will be explored and suggestions made for the further development of this drug class in the treatment of Parkinson's disease. However, one adenosine A2A antagonist, namely istradefylline has been introduced successfully for the treatment of late-stage Parkinson's disease in two major areas of the world and has become a commercial success through offering the first non-dopaminergic approach to the treatment of unmet need to be introduced in several decades.

Anti-parkinsonian activity of the adenosine A2A receptor antagonist/inverse agonist KW-6356 as monotherapy in MPTP-treated common marmosets

KW-6356 is a novel adenosine A_2A receptor antagonist/inverse agonist that not only blocks binding of adenosine to adenosine A_2A receptor but also inhibits the constitutive activity of adenosine A_2A receptor. The efficacy of KW-6356 as both monotherapy and an adjunct therapy to L-3,4-dihydroxyphenylalanine (L-DOPA)/decarboxylase inhibitor in Parkinson's disease (PD) patients has been reported. However, the first-generation A_2A antagonist istradefylline, which is approved for use as an adjunct treatment to L-DOPA/decarboxylase inhibitor in adult PD patients experiencing OFF episodes, has not shown statistically significant efficacy as monotherapy. In vitro pharmacological studies have shown that the pharmacological properties of KW-6356 and istradefylline at adenosine A_2A receptor are markedly different. However, the anti-parkinsonian activity and effects on dyskinesia of KW-6356 in PD animal models and the differences in the efficacy between KW-6356 and istradefylline are unknown. The present study investigated the anti-parkinsonian activity of KW-6356 as monotherapy in 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine (MPTP)-treated common marmosets, and its efficacy was directly compared with that of istradefylline. In addition, we investigated whether or not repeated administration of KW-6356 induced dyskinesia. Oral administration of KW-6356 reversed motor disability in a dose-dependent manner up to 1 mg/kg in MPTP-treated common marmosets. The magnitude of anti-parkinsonian activity induced by KW-6356 was significantly greater than that of istradefylline. Repeated administration of KW-6356 induced little dyskinesia in MPTP-treated common marmosets primed to exhibit dyskinesia by prior exposure to L-DOPA. These results indicate that KW-6356 can be a novel non-dopaminergic therapy as monotherapy without inducing dyskinesia in PD patients.

Impact of advanced Parkinson's disease on caregivers: an international real-world study

BACKGROUND

Caring for a partner or family member with Parkinson's disease (PD) negatively affects the caregiver's own physical and emotional well-being, especially those caring for people with advanced PD (APD). This study was designed to examine the impact of APD on caregiver perceived burden, quality of life (QoL), and health status.

METHODS

Dyads of people with PD and their primary caregivers were identified from the Adelphi Parkinson's Disease Specific Program (DSP™) using real-world data from the United States, Japan and five European countries. Questionnaires were used to capture measures of clinical burden (people with PD) and caregiver burden (caregivers).

RESULTS

Data from 721 patient-caregiver dyads in seven countries were captured. Caregivers had a mean age 62.6 years, 71.6% were female, and 70.4% were a spouse. Caregivers for people with APD had a greater perceived burden, were more likely to take medication and had lower caregiver treatment satisfaction than those caring for people with early or intermediate PD; similar findings were observed for caregivers of people with intermediate versus early PD. Caregivers for people with intermediate PD were also less likely to be employed than those with early PD (25.3% vs 42.4%) and spent more time caring (6.6 vs 3.2 h/day).

CONCLUSIONS

This real-world study demonstrates that caregivers of people with APD experience a greater burden than those caring for people with early PD. This highlights the importance of including caregiver-centric measures in future studies, and emphasizes the need for implementing treatments that reduce caregiver burden in APD.

TRIAL REGISTRATION

N/A.

Fecal microbiota transplantation in Parkinson's disease-A randomized repeat-dose, placebo-controlled clinical pilot study

Background and purpose

The intestinal microbiome plays a primary role in the pathogenesis of neurodegenerative disorders and may provide an opportunity for disease modification. We performed a pilot clinical study looking at the safety of fecal microbiota transplantation (FMT), its effect on the microbiome, and improvement of symptoms in Parkinson's disease.

Methods

This was a randomized, double-blind placebo-controlled pilot study, wherein orally administered lyophilized FMT product or matching placebo was given to 12 subjects with mild to moderate Parkinson's disease with constipation twice weekly for 12 weeks. Subjects were followed for safety and clinical improvement for 9 additional months (total study duration 12 months).

Results

Fecal microbiota transplantation caused non-severe transient upper gastrointestinal symptoms. One subject receiving FMT was diagnosed with unrelated metastatic cancer and was removed from the trial. Beta diversity (taxa) of the microbiome, was similar comparing placebo and FMT groups at baseline, however, for subjects randomized to FMT, it increased significantly at 6 weeks (p = 0.008) and 13 weeks (p = 0.0008). After treatment with FMT, proportions of selective families within the phylum Firmicutes increased significantly, while proportion of microbiota belonging to Proteobacteria were significantly reduced. Objective motor findings showed only temporary improvement while subjective symptom improvements were reported compared to baseline in the group receiving FMT. Constipation, gut transient times (NS), and gut motility index (p = 0.0374) were improved in the FMT group.

Conclusions

Subjects with Parkinson's disease tolerated multi-dose-FMT, and experienced increased diversity of the intestinal microbiome that was associated with reduction in constipation and improved gut transit and intestinal motility. Fecal microbiota transplantation administration improved subjective motor and non-motor symptoms.

Clinical trial registration

ClinicalTrial.gov, identifier: NCT03671785.

Supportive care of neurodegenerative patients

Neurodegenerative illnesses are notorious for paucity of treatments and relentless clinical progression. Illness may follow a relatively acute presentation, as is seen with primary brain tumors such as glioblastoma or have a more insidious onset with a slower yet unyielding course, such as that seen in Parkinson's disease. Though disparate in presentation, these neurodegenerative illnesses are universally terminal, and both the patients and their families benefit from the intervention of supportive care in conjunction with primary disease management. Supportive palliative care has been shown to improve quality of life, enhance patient outcomes, and often extend patient life-but such care needs to be tailored. This clinical commentary examines the role of supportive palliative care in the management of neurologic patients, comparing and contrasting glioblastoma patients with idiopathic Parkinson's disease patients. Both patient populations are high utilizers of healthcare resources, require active management of multiple symptoms, and have high caregiver burden which underscores the need for supportive services in conjunction with disease management provided by the primary care team. Review of prognostication, patient and family communication, trust and relationship building, and complementary medicinal approaches are explored for these two diseases which broadly represent two differing poles of incurable neurological illness.