Prolonged-release melatonin in Parkinson's disease patients with a poor sleep quality: A randomized trial

Insomnia in Parkinson's Disease: Causes, Consequences, and Therapeutic Approaches

Sleep disorders represent prevalent non-motor symptoms in Parkinson's disease (PD), affecting over 90% of the PD population. Insomnia, characterized by difficulties in initiating and maintaining sleep, emerges as the most frequently reported sleep disorder in PD, with prevalence rates reported from 27 to 80% across studies. Insomnia not only significantly impacts the quality of life of PD patients but is also associated with cognitive impairment, motor disabilities, and emotional deterioration. This comprehensive review aims to delve into the mechanisms underlying insomnia in PD, including neurodegenerative changes, basal ganglia beta oscillations, and circadian rhythms, to gain insights into the neural pathways involved. Additionally, the review explores the risk factors and comorbidities associated with insomnia in PD, providing valuable insights into its management. Special attention is given to the challenges faced by healthcare providers in delivering care to PD patients and the impact of caregiving roles on patients' quality of life. Overall, this review provides a comprehensive understanding of insomnia in PD and highlights the importance of addressing this common sleep disorder in PD patients.

A scoping review of over-the-counter products for depression, anxiety and insomnia in older people

BACKGROUND

Depression, anxiety, and insomnia are prevalent in older people and are associated with increased risk of mortality, dependency, falls and reduced quality of life. Prior to or whilst seeking treatment, older people often manage these symptoms or conditions using products purchased over the counter (OTC), such as medication or herbal products. This review aims to map the evidence available for OTC medications, herbal medicines and dietary supplements for depression, anxiety and insomnia in older adults.

METHODOLOGY

We carried out a scoping review, including searches of five databases to identify relevant randomised controlled trials (inception-Dec 2022). We took an inclusive approach to products to represent the wide range that may be available online. Trials were summarised according to condition and product.

RESULTS

We included 47 trials and 10 ongoing trial protocols. Most targeted insomnia (n = 25), followed by depression (n = 20), and mixed conditions (n = 2). None evaluated products targeted at anxiety alone. Where reported, most products appeared to be safe for use, but studies rarely included people with multiple comorbidities or taking concomitant medication. Some types of melatonin for insomnia (n = 19) and omega-3 fatty acids for depression (n = 7) had more substantive evidence compared to the other products.

CONCLUSION

There is a substantial gap in evidence for OTC products for anxiety in older people. This should be addressed in future trials. Research should also focus on products that are widely used, and these need to be tested in older populations that are similar to those who would use them in practice.

The Vital Role of Melatonin and Its Metabolites in the Neuroprotection and Retardation of Brain Aging

While primarily produced in the pineal gland, melatonin's influence goes beyond its well-known role in regulating sleep, nighttime metabolism, and circadian rhythms, in the field of chronobiology. A plethora of new data demonstrates melatonin to be a very powerful molecule, being a potent ROS/RNS scavenger with anti-inflammatory, immunoregulatory, and oncostatic properties. Melatonin and its metabolites exert multiple beneficial effects in cutaneous and systemic aging. This review is focused on the neuroprotective role of melatonin during aging. Melatonin has an anti-aging capacity, retarding the rate of healthy brain aging and the development of age-related neurodegenerative diseases, such as Alzheimer's disease, Parkinson's disease, Huntington's disease, multiple sclerosis, amyotrophic lateral sclerosis, etc. Melatonin, as well as its metabolites, N1-acetyl-N2-formyl-5-methoxykynuramine (AFMK) and N1-acetyl-5-methoxykynuramine (AMK), can reduce oxidative brain damage by shielding mitochondria from dysfunction during the aging process. Melatonin could also be implicated in the treatment of neurodegenerative conditions, by modifying their characteristic low-grade neuroinflammation. It can either prevent the initiation of inflammatory responses or attenuate the ongoing inflammation. Drawing on the current knowledge, this review discusses the potential benefits of melatonin supplementation in preventing and managing cognitive impairment and neurodegenerative diseases.

Circadian neurogenetics and its implications in neurophysiology, behavior, and chronomedicine

The circadian rhythm affects multiple physiological processes, and disruption of the circadian system can be involved in a range of disease-related pathways. The genetic underpinnings of the circadian rhythm have been well-studied in model organisms. Significant progress has been made in understanding how clock genes affect the physiological functions of the nervous system. In addition, circadian timing is becoming a key factor in improving drug efficacy and reducing drug toxicity. The circadian biology of the target cell determines how the organ responds to the drug at a specific time of day, thus regulating pharmacodynamics. The current review brings together recent advances that have begun to unravel the molecular mechanisms of how the circadian clock affects neurophysiological and behavioral processes associated with human brain diseases. We start with a brief description of how the ubiquitous circadian rhythms are regulated at the genetic, cellular, and neural circuit levels, based on knowledge derived from extensive research on model organisms. We then summarize the latest findings from genetic studies of human brain disorders, focusing on the role of human clock gene variants in these diseases. Lastly, we discuss the impact of common dietary factors and medications on human circadian rhythms and advocate for a broader application of the concept of chronomedicine.

Fine-tuning the circadian system with light treatment for Parkinson's disease: an in-depth, critical review

Late in the twentieth century, interest intensified regarding the involvement of the circadian system in the aetiology and treatment of Parkinson's disease (PD). It has been envisaged that this approach might provide relief beyond the limited benefits and severe side effects achieved by dopamine (DA) replacement. In the first clinical article, published in 1996, polychromatic light was used to shift the circadian clock as it is considered to be the most powerful zeitgeber (time keeper) that can be implemented to realign circadian phase. Since that time, 11 additional articles have implemented light treatment (LT) in various forms as an adjuvant to DA replacement. In spite of the growing interest in this area, the systematic exploration of LT in PD has been stymied by several methodological factors. Such factors include time of LT presentation, duration of studies undertaken, frequency of light employed, dose of light prescribed and relevance of experimental design to the prolonged course of the illness. On this basis, it is the purpose of this review to provide an in-depth examination of these papers, and the underlying preclinical work, to provide critique, thereby giving direction for future studies in therapeutic applications of LT for PD. Consideration of this collective work may serve to carve a path for future research and thereby improve the lives of those suffering from this debilitating disorder.

Medical, surgical, and physical treatments for Parkinson's disease

Although dopamine replacement therapy remains a core component of Parkinson's disease treatment, the onset of motor fluctuations and dyskinetic movements might require a range of medical and surgical approaches from a multidisciplinary team, and important new approaches in the delivery of dopamine replacement are becoming available. The more challenging, wide range of non-motor symptoms can also have a major impact on the quality of life of a patient with Parkinson's disease, and requires careful multidisciplinary management using evidence-based knowledge, as well as appropriately tailored strategies according to the individual patient's needs. Disease-modifying therapies are urgently needed to prevent the development of the most disabling refractory symptoms, including gait and balance difficulties, cognitive impairment and dementia, and speech and swallowing impairments. In the third paper in this Series, we present the latest evidence supporting the optimal treatment of Parkinson's disease, and describe an expert approach to many aspects of treatment choice where an evidence base is insufficient.

Neuroprotective Potential of Melatonin: Evaluating Therapeutic Efficacy in Alzheimer's and Parkinson's Diseases

Decreased melatonin levels have been linked to both Alzheimer's disease (AD) and Parkinson's disease (PD), which are the two most prevalent neurodegenerative disorders. The development of sleep disorders is widespread in patients diagnosed with AD or PD. In this regard, calcification of the pineal gland, typically seen in the third decade, has been associated with a reduction in melatonin production. Recent studies have suggested that exogenous melatonin application can be utilized to treat sleep disorders in patients with neurodegenerative diseases. Furthermore, research has shown that deficiencies in melatonin levels in patients with AD or PD begin before a diagnosis of either disease is made. These findings could encourage further research on melatonin as a potential biomarker for the diagnosis or a possible area for the early treatment of these diseases. Many clinical studies have also produced data denoting melatonin treatment as a method to reduce the detrimental neurocognitive effects of these diseases. Further research on the role of melatonin in neurodegenerative diseases could expand symptomatic and prophylactic treatment options for diseases such as AD and PD. This review investigates melatonin's physiological properties, its role in AD and PD, and current findings on its potential therapeutic benefits in AD and PD patients.

Sleep disorders in Lewy body dementia: Mechanisms, clinical relevance, and unanswered questions

In Lewy body dementia (LBD), disturbances of sleep and/or arousal including insomnia, excessive daytime sleepiness, rapid eye movement (REM) sleep behavior disorder, obstructive sleep apnea, and restless leg syndrome are common. These disorders can each exert a significant negative impact on both patient and caregiver quality of life; however, their etiology is poorly understood. Little guidance is available for assessing and managing sleep disorders in LBD, and they remain under-diagnosed and under-treated. This review aims to (1) describe the specific sleep disorders which occur in LBD, considering their putative or potential mechanisms; (2) describe the history and diagnostic process for these disorders in LBD; and (3) summarize current evidence for their management in LBD and consider some of the ongoing and unanswered questions in this field and future research directions.

Significant potential of melatonin therapy in Parkinson's disease - a meta-analysis of randomized controlled trials

Objective

Since its discovery as an antioxidant, melatonin has been increasingly recognized for its therapeutic potential beyond sleep disturbances in neurodegenerative disorders. This study aims to evaluate efficacy of various melatonin doses, treatment durations, and formulations, in alleviating motor symptoms and sleep disturbances in Parkinson's disease, the second most common neurodegenerative disorder worldwide.

Methods

PubMed, Cochrane Library, ClinicalTrials.gov and other databases were systematically searched to retrieve randomized controlled trials (RCTs) administrating melatonin to Parkinson's disease patients until June 10th, 2023. Outcomes including Unified Parkinson Disease Rating Scale (UPDRS) scores and Pittsburgh Sleep Quality Index (PSQI) scores, were pooled and reported as mean differences (MD) with 95% confidence intervals (CIs). Meta-analysis was performed using an inverse variance random-effects model in Review Manager 5.4 software. Trial Sequential Analysis was performed to avoid false-positive results from random errors.

Results

Five RCTs with a total of 155 patients were included. Statistically significant reductions in UPDRS total scores were observed in groups receiving Melatonin ≥10 mg/day (MD = -11.35, 95% CI: -22.35 to -0.35, I2 = 0%, p = 0.04) and immediate release formulations (MD = -11.35, 95% CI: -22.35 to -0.35, I2 = 0%, p = 0.04). No significant effects on individual UPDRS II, III, and IV scores were observed, regardless of melatonin dosage and treatment duration. Moreover, significant improvements in PSQI scores were observed with only immediate-release melatonin formulations (MD = -2.86, 95% CI: -4.74 to -0.97, I2 = 0%, p = 0.003).

Conclusion

Melatonin ≥10 mg/day for a minimum duration of ≥12 weeks in immediate-release formulations consistently demonstrated significant therapeutic potential in improving motor symptom and sleep disturbances in Parkinson disease. However, further trials are warranted to investigate its impact when initiated early in the disease course to fully explore its true therapeutic potential.

Systematic review registration

Unique identifier: CRD42023427491 (PROSPERO).

Parkinson's Disease: A Narrative Review on Potential Molecular Mechanisms of Sleep Disturbances, REM Behavior Disorder, and Melatonin

Parkinson's disease (PD) is one of the most common neurodegenerative diseases. There is a wide range of sleep disturbances in patients with PD, such as insomnia and rapid eye movement (REM) sleep behavior disorder (or REM behavior disorder (RBD)). RBD is a sleep disorder in which a patient acts out his/her dreams and includes abnormal behaviors during the REM phase of sleep. On the other hand, melatonin is the principal hormone that is secreted by the pineal gland and significantly modulates the circadian clock and mood state. Furthermore, melatonin has a wide range of regulatory effects and is a safe treatment for sleep disturbances such as RBD in PD. However, the molecular mechanisms of melatonin involved in the treatment or control of RBD are unknown. In this study, we reviewed the pathophysiology of PD and sleep disturbances, including RBD. We also discussed the potential molecular mechanisms of melatonin involved in its therapeutic effect. It was concluded that disruption of crucial neurotransmitter systems that mediate sleep, including norepinephrine, serotonin, dopamine, and GABA, and important neurotransmitter systems that mediate the REM phase, including acetylcholine, serotonin, and norepinephrine, are significantly involved in the induction of sleep disturbances, including RBD in PD. It was also concluded that accumulation of α-synuclein in sleep-related brain regions can disrupt sleep processes and the circadian rhythm. We suggested that new treatment strategies for sleep disturbances in PD may focus on the modulation of α-synuclein aggregation or expression.

Changes in the Secretion of Melatonin and Selected Adipokines during the Progression of Parkinson's Disease-Preliminary Studies

Parkinson's disease (PD) is one of the most common neurodegenerative diseases affecting elderly people. Considering the gap in the literature on melatonin and adipokine levels in PD patients at various stages of the disease, we conducted a study to investigate the levels of selected parameters in PD patients at the disease's early (ES) and advanced (AS) stages. Melatonin, leptin, adiponectin, and resistin concentrations were measured in the blood serum of 20 PD patients without dyskinesia (ES), 24 PD patients with dyskinesia (AS), and 20 healthy volunteers as a control group (CG). The data were analyzed using ANOVA. Melatonin was significantly lower in ES (p < 0.05) and higher in AS patients (p < 0.05) compared to CG. The level of leptin was increased both in ES (p < 0.001) and AS (p < 0.001) versus CG, while resistin was increased only in patients with dyskinesia (p < 0.05). Higher melatonin (p < 0.001) and resistin (p < 0.05) and lower leptin (p < 0.05) levels were found in AS versus ES. The main findings of the study include the changes in inflammatory markers' levels during PD and a surprising increase in melatonin level in dyskinesia patients. Further research is necessary, which will be aimed at modulating the secretion of melatonin and adipokines as a treatment target for PD.

Clinical Evaluation of Sleep Disorders in Parkinson’s Disease

The paradigm of the framing of Parkinson’s disease (PD) has undergone significant revision in recent years, making this neurodegenerative disease a multi-behavioral disorder rather than a purely motor disease. PD affects not only the “classic” substantia nigra at the subthalamic nuclei level but also the nerve nuclei, which are responsible for sleep regulation. Sleep disturbances are the clinical manifestations of Parkinson’s disease that most negatively affect the quality of life of patients and their caregivers. First-choice treatments for Parkinson’s disease determine amazing effects on improving motor functions. However, it is still little known whether they can affect the quantity and quality of sleep in these patients. In this perspective article, we will analyze the treatments available for this specific clinical setting, hypothesizing a therapeutic approach in relation to neurodegenerative disease state.

Neuroprotective effects of melatonin in neurodegenerative and autoimmune central nervous system diseases

The suprachiasmatic nucleus (SCN) in the anterior hypothalamus is the major circadian pacemaker in humans. Melatonin is a key hormone secreted by the pineal gland in response to darkness. Light-induced stimuli are transmitted along the retinohypothalamic tract to the SCN. Activation of the SCN inhibits the production of melatonin by the pineal gland through a complex neural pathway passing through the superior cervical ganglion. Accordingly, when light is unavailable, the pineal gland secretes melatonin. The circadian rhythm modulates sleep-wake cycles as well as many physiological functions of the endocrine system, including core body temperature, pulse rate, oxygen consumption, hormone levels, metabolism, and gastrointestinal function. In neurodegenerative disorders, the sleep-wake cycle is disrupted and circadian regulation is altered, which accelerates disease progression, further disrupting circadian regulation and setting up a vicious cycle. Melatonin plays a critical role in the regulation of circadian rhythms and is a multifunctional pleiotropic agent with broad neuroprotective effects in neurodegenerative disorders, viral or autoimmune diseases, and cancer. In this review, I discuss the neuroprotective functions of melatonin in circadian regulation and its roles in promoting anti-inflammatory activity, enhancing immune system functions, and preventing alterations in glucose metabolism and mitochondrial dysfunction in neurodegenerative disorders and autoimmune central nervous system diseases.

Circadian disruption and sleep disorders in neurodegeneration

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

Neuroprotective Effect of Melatonin on Sleep Disorders Associated with Parkinson's Disease

Parkinson's disease (PD) is a complex, multisystem disorder with both neurologic and systemic manifestations, which is usually associated with non-motor symptoms, including sleep disorders. Such associated sleep disorders are commonly observed as REM sleep behavior disorder, insomnia, sleep-related breathing disorders, excessive daytime sleepiness, restless legs syndrome and periodic limb movements. Melatonin has a wide range of regulatory effects, such as synchronizing circadian rhythm, and is expected to be a potential new circadian treatment of sleep disorders in PD patients. In fact, ongoing clinical trials with melatonin in PD highlight melatonin's therapeutic effects in this disease. Mechanistically, melatonin plays its antioxidant, anti-inflammatory, anti-excitotoxity, anti-synaptic dysfunction and anti-apoptotic activities. In addition, melatonin attenuates the effects of genetic variation in the clock genes of Baml1 and Per1 to restore the circadian rhythm. Together, melatonin exerts various therapeutic effects in PD but their specific mechanisms require further investigations.

The multimodal effect of circadian interventions in Parkinson's disease: A narrative review

BACKGROUND

The circadian system and its dysfunction in persons with Parkinson's disease (PwP) has a clear impact on both motor and non-motor symptoms. Examples include circadian patterns in motor disability, with worsening of symptoms throughout the day, but also the existence of similar patterns in non-motor symptoms.

OBJECTIVE

In this narrative review, we discuss the role of the circadian system, we address the role of dopamine in this system, and we summarise the evidence that supports the use of circadian system treatments for motor and non-motor symptoms in PwP.

METHODS

A systematic search in PubMed and Web of Science database was performed and the final search was performed in November 2021. We included articles whose primary aim was to investigate the effect of melatonin, melatonin agonists, and light therapy in PwP.

RESULTS

In total 25 articles were retrieved. Of these, 12 were related to bright light therapy and 13 to melatonin or/and melatonin agonists. Most, but not all, studies showed that melatonin and melatonin agonists and light therapy induced improvements in measures of sleep, depression, motor function, and some also cognitive function and other non-motor symptoms. For some of these outcomes, including daytime sleepiness, depressive symptoms, and some motor symptoms, there is level 2 B evidence for the use of circadian treatments in PwP.

CONCLUSIONS

Treatment with bright light therapy, exogenous melatonin and melatonin agonists seems to have not only positive effects on sleep quality and depression but also on motor function in PwP. Drawbacks in earlier work include the relatively small number of participants and the heterogeneity of outcome measures. Further large and well-designed trials are needed to address these shortcomings and to confirm or refute the possible merits of the circadian system as a treatment target in PwP.

Glymphatic System Dysfunction and Sleep Disturbance May Contribute to the Pathogenesis and Progression of Parkinson’s Disease

Parkinson’s disease (PD) is a multisystem alpha-synucleinopathic neurodegenerative disease and the most prevalent neurodegenerative disorder after Alzheimer’s disease with a high incidence rate in the elderly population. PD is highly multifactorial in etiology and has complex and wide-ranging pathogenic mechanisms. Environmental exposures and genetic predisposition are prominent risk factors. However, current evidence suggests that an intimate link may exist between the risk factor of sleep disturbance and PD pathogenesis. PD is characterized by the pathological hallmarks of alpha-synuclein aggregations and dopaminergic neuron degeneration in the substantia nigra. The loss of dopamine-producing neurons results in both motor and non-motor symptoms, most commonly, bradykinesia, tremor, rigidity, psychiatric disorders, sleep disorders and gastrointestinal problems. Factors that may exacerbate alpha-synuclein accumulation and dopamine neuron loss include neuroinflammation and glymphatic system impairment. Extracellular alpha-synuclein can induce an inflammatory response which can lead to neural cell death and inhibition of neurogenesis. The glymphatic system functions most optimally to remove extracellular brain solutes during sleep and therefore sleep disruption may be a crucial progression factor as well as a risk factor. This literature review interprets and analyses data from experimental and epidemiological studies to determine the recent advances in establishing a relationship between glymphatic system dysfunction, sleep disturbance, and PD pathogenesis and progression. This review addresses current limitations surrounding the ability to affirm a causal link between improved glymphatic clearance by increased sleep quality in PD prevention and management. Furthermore, this review proposes potential therapeutic approaches that could utilize the protective mechanism of sleep, to promote glymphatic clearance that therefore may reduce disease progression as well as symptom severity in PD patients.

Effect of melatonin on quality of life and symptoms in patients with cancer: a systematic review and meta-analysis of randomised controlled trials

OBJECTIVE

This study systematically reviewed the effect of melatonin (MLT) on quality of life (QoL) and symptoms among patients with cancer.

DESIGN

Systematic review and meta-analysis.

DATA SOURCES

Cochrane Library, PubMed, Embase, Web of Science, Medline, CINAHL, Scopus, ClinicalTrials.gov, China Biology Medicine (CBM), ProQuest and Open Grey were searched from inception to November 2021.

ELIGIBILITY CRITERIA

We included randomised controlled trials (RCTs) assessing the effects of MLT on QoL, sleep quality, fatigue, depression, pain, stomatitis rate and stomatitis severity in adult patients with cancer, without language restrictions. Studies that reported the effects of MLT along with other interventions and had incomplete or absent outcome data were excluded.

DATA EXTRACTION AND SYNTHESIS

Two independent reviewers extracted data, and another two reviewers assessed the risk of bias. The risk of bias for each eligible study was assessed using the Cochrane assessment tool. The mean difference or standard mean difference (SMD) with 95% CIs was used in the computation of continuous variables to synthesise data. The relative risk was used for dichotomous outcomes. Heterogeneity was assessed and quantified (I² statistic).

RESULTS

A total of 19 qualified studies that included 2101 patients with cancer (MLT: 1078, control: 1023) were included in the meta-analysis. The results indicated that MLT had no significant effect on QoL (SMD=-0.01, 95% CI (-0.14 to 0.11), p=0.83), sleep quality (SMD=-0.18, 95% CI (-0.62 to 0.26), p=0.42), fatigue (SMD=-0.34, 95% CI (-0.73 to 0.06), p=0.10), pain (SMD=-0.34, 95% CI (-0.7 to 0.02), p=0.06) or stomatitis severity (RR=0.78, 95% CI (0.47 to 1.30), p=0.35). MLT reduced stomatitis rate among patients with cancer (RR=0.47, 95% CI (0.26 to 0.88), p=0.02), except those with head and neck cancer (RR=1.09, 95% CI (0.92 to 1.29), p=0.35). MLT eased depression in patients who received administration for more than 14 days (SMD=-0.14, 95% CI (-0.27 to -0.01), p=0.03) and those who underwent surgery (SMD=-0.17, 95% CI (-0.32 to -0.03), p=0.02).

CONCLUSION

The findings showed that MLT did not improve the QoL, sleep quality, fatigue, pain or stomatitis severity among patients with cancer. It had a limited effect on decreasing the stomatitis rate and easing depression. Different treatments, durations and cancer types were the main sources of heterogeneity. Further large-scale RCTs are urgently needed. In addition, the effects of different combinations of MLT dosage and duration, administration types and joint measures are worthy of further study.

PROSPERO REGISTRATION NUMBER

CRD42021292855.

Effects of melatonin prolonged-release on both sleep and motor symptoms in Parkinson’s disease: a preliminary evidence

Background

Sleep-related symptoms, especially insomnia, are frequently reported by patients with Parkinson’s disease (PD) and can markedly affect motor symptoms and impair patients’ quality of life. Melatonin has been shown to improve sleep in PD patients. This pilot study aimed at evaluating the effects of a 3-month treatment with 2 mg melatonin prolonged-release (PR) on sleep and motor disability in PD patients.

Materials and methods

Twelve PD patients under stable antiparkinsonian treatment were enrolled in the study. Before treatment (T0), motor dysfunction was assessed with Unified Parkinson’s Disease Rating Scale (UPDRS-III) and sleep architecture with polysomnography. Subjective sleep quality was also assessed through Pittsburgh Sleep Quality Index (PSQI) and daytime somnolence with Epworth Sleepiness Scale (ESS). Patients then started melatonin PR and all measures were repeated at the end of treatment after 3 months (T1).

Results

Sleep latency significantly decreased from T0 to T1, but no other significant differences were found in PSG parameters. Melatonin PR treatment significantly reduced the ESS scores from T0 to T1, while the PSQI scores presented a trend of improvement from T0 to T1. Motor dysfunction was not improved by melatonin PR, although there was a trend in decreasing UPDRS-III. Both clinical global improvement and patient clinical global impression documented an improvement in insomnia symptoms at T1.

Conclusions

These findings suggest that melatonin may improve sleep symptoms in PD patients, although further evidence is needed in larger controlled studies to confirm these results and explore the possible direct and indirect influence of sleep improvement on motor dysfunction.

Melatonin Treatment for Sleep Disorders in Parkinson's Disease: A Meta-Analysis and Systematic Review

Objective

The efficacy of melatonin on sleep disorders in Parkinson's disease (PD) is still unclear. The purpose of this study was to investigate the efficacy of melatonin on sleep disorders in PD by summarizing evidence from randomized clinical trials (RCTs).

Methods

PubMed, Cochrane Library, EMBASE, and Web of Science databases were searched for studies published before 20 August 2021. Results were analyzed using Review Manager 5.2 software. We used Trial Sequential Analysis (TSA) software to avoid false-positive results caused by random errors.

Results

We included 7 studies in this systematic review and meta-analysis. The results of the meta-analysis showed that compared with placebo, the subjective sleep quality of patients with PD significantly improved after melatonin treatment (MD = −2.19, 95% CI: −3.53 to −0.86, P = 0.001). In the systematic review, we qualitatively analyzed the efficacy of melatonin on the objective sleep quality of patients with PD, and the results showed that melatonin exerted a positive effect with good safety and tolerability. However, there was no significant improvement in excessive daytime sleepiness assessed by the Epworth Sleepiness Scale (ESS).

Conclusion

We found that melatonin can significantly improve the subjective and objective sleep quality of patients with PD with good safety and tolerability. Melatonin could be considered an effective treatment for insomnia in patients with PD.

A Transcriptome Analysis of mRNAs and Long Non-Coding RNAs in Patients with Parkinson's Disease

Parkinson's disease (PD) is the second most common neurodegenerative disorder. The number of cases of PD is expected to double by 2030, representing a heavy burden on the healthcare system. Clinical symptoms include the progressive loss of dopaminergic neurons in the substantia nigra of the midbrain, which leads to striatal dopamine deficiency and, subsequently, causes motor dysfunction. Certainly, the study of the transcriptome of the various RNAs plays a crucial role in the study of this neurodegenerative disease. In fact, the aim of this study was to evaluate the transcriptome in a cohort of subjects with PD compared with a control cohort. In particular we focused on mRNAs and long non-coding RNAs (lncRNA), using the Illumina NextSeq 550 DX System. Differential expression analysis revealed 716 transcripts with padj ≤ 0.05; among these, 630 were mRNA (coding protein), lncRNA, and MT_tRNA. Ingenuity pathway analysis (IPA, Qiagen) was used to perform the functional and pathway analysis. The highest statistically significant pathways were: IL-15 signaling, B cell receptor signaling, systemic lupus erythematosus in B cell signaling pathway, communication between innate and adaptive immune cells, and melatonin degradation II. Our findings further reinforce the important roles of mitochondria and lncRNA in PD and, in parallel, further support the concept of inverse comorbidity between PD and some cancers.

A Transcriptome Analysis of mRNAs and Long Non-Coding RNAs in Patients with Parkinson's Disease

Parkinson's disease (PD) is the second most common neurodegenerative disorder. The number of cases of PD is expected to double by 2030, representing a heavy burden on the healthcare system. Clinical symptoms include the progressive loss of dopaminergic neurons in the substantia nigra of the midbrain, which leads to striatal dopamine deficiency and, subsequently, causes motor dysfunction. Certainly, the study of the transcriptome of the various RNAs plays a crucial role in the study of this neurodegenerative disease. In fact, the aim of this study was to evaluate the transcriptome in a cohort of subjects with PD compared with a control cohort. In particular we focused on mRNAs and long non-coding RNAs (lncRNA), using the Illumina NextSeq 550 DX System. Differential expression analysis revealed 716 transcripts with padj ≤ 0.05; among these, 630 were mRNA (coding protein), lncRNA, and MT_tRNA. Ingenuity pathway analysis (IPA, Qiagen) was used to perform the functional and pathway analysis. The highest statistically significant pathways were: IL-15 signaling, B cell receptor signaling, systemic lupus erythematosus in B cell signaling pathway, communication between innate and adaptive immune cells, and melatonin degradation II. Our findings further reinforce the important roles of mitochondria and lncRNA in PD and, in parallel, further support the concept of inverse comorbidity between PD and some cancers.

Novel Series of Dual NRF2 Inducers and Selective MAO-B Inhibitors for the Treatment of Parkinson’s Disease

Parkinson’s disease (PD) is the second most prevalent neurodegenerative disease. It is characterized by a complex network of physiopathological events where oxidative stress plays a central role among other factors such as neuroinflammation and protein homeostasis. Nuclear factor-erythroid 2 p45-related factor 2 (NRF2) has a multitarget profile itself as it controls a plethora of cellular processes involved in the progression of the disease. In this line, we designed a novel family of 2-(1H-indol-3-yl)ethan-1-amine derivatives as NRF2 inducers with complementary activities. Novel compounds are based on melatonin scaffold and include, among other properties, selective monoamine oxidase B (MAO-B) inhibition activity. Novel multitarget compounds exhibited NRF2 induction activity and MAO-B selective inhibition, combined with anti-inflammatory, antioxidant, and blood–brain barrier permeation properties. Furthermore, they exert neuroprotective properties against oxidative stress toxicity in PD-related in vitro. Hit compound 14 reduced oxidative stress markers and exerted neuroprotection in rat striatal slices exposed to 6-hydroxydopamine or rotenone. In conclusion, we developed a promising family of dual NRF2 inducers and selective MAO-B inhibitors that could serve as a novel therapeutic strategy for PD treatment.

Zonisamide for the Efficacy of Sleep Abnormality in Parkinson's Disease (ZEAL Study): A Protocol for Randomized Controlled Trials

Background: Sleep disorders are one of the most frequent non-motor symptoms of Parkinson's disease (PD), and the efficacy of dopaminergic agents remains controversial. Clinical randomized control trials for the treatment of sleep disorders in PD are limited. Zonisamide (1,2-benzisoxazole-3-methanesulfonamide) improved motor symptoms and wearing-off in patients with PD. Patients with PD were reported to have dream-enacting behavior that was resolved after treatment with zonisamide. This study aimed to verify the safety and efficacy of zonisamide for sleep disorders and rapid eye movement (REM) sleep behavioral disorders using a mobile two-channel electroencephalography (EEG)/electrooculography (EOG) recording system.

Methods and Analysis: The present study is a randomized placebo-controlled trial to determine the efficacy of zonisamide for sleep disorders in patients with PD. This study was designed to be single-blind, but the subject allocation is randomized by an independent allocation manager via computer-generated block randomization. The subjects in the treatment group took zonisamide (25 mg per day) before bedtime for 28 days. The sleep index is analyzed using a portable EEG/EOG recording system collected on two consecutive nights within 7 days prior to the intervention and reobtained on one night within 2 days after the 28-day administration of zonisamide. The amount of change in sleep efficiency before and after the 28-day administration will be compared between the zonisamide treatment group and placebo group concerning the primary endpoint. As for the secondary endpoint, the change in the ratio of other sleep parameters, including REM sleep without atonia, or sleep architecture will be evaluated.

Ethics and Dissemination: The protocol was approved by the Nara Medical University Certified Review Board (CRB5200002). The trial was notified and registered with the Japan Registry of Clinical Trials (jRCTs051200160). Written informed consent will be obtained from every participant using informed consent approved by the CRB. The results of this trial will be disseminated through peer-reviewed scientific journals.

Effect of melatonin supplementation on sleep quality: a systematic review and meta-analysis of randomized controlled trials

BACKGROUND

The Present study was conducted to systematically review the effect of the melatonin on sleep quality. We summarized evidence from randomized clinical trials (RCTs) that investigated the effects of melatonin on sleep quality as assessed by the Pittsburgh Sleep Quality Index (PSQI) in adults with various diseases.

METHODS

The literature searches of English publications in MEDLINE and EMBASE databases were performed up June 2020. Results were summarized as mean differences (MD) with 95% confidence intervals (CI) using random effects model (DerSimonian-Laird method). Heterogeneity among studies was evaluated by the Cochrane Q test and I-squared (I2). To determine the predefined sources of heterogeneity, subgroup analysis was performed.

RESULTS

Of 2642 papers, 23 RCTs met inclusion criteria. Our results indicated that melatonin had significant effect on sleep quality as assessed by the Pittsburgh Sleep Quality Index (PSQI) (WMD: - 1.24; 95% CI - 1.77, - 0.71, p = 0.000). There was significant heterogeneity between studies (I² = 80.7%, p = 0.000). Subgroup analysis based on health status and kind of intervention were potential between-study heterogeneity. Subgroup analysis based on health status revealed melatonin intervention in subjects with Respiratory diseases (WMD: - 2.20; 95% CI - 2.97, - 1.44, p = 0.000), Metabolic disorders (WMD: - 2.74; 95% CI - 3.48, - 2.00, p = 0.000) and sleep disorders (WMD: - 0.67; 95% CI - 0.98, - 0.37, p = 0.000) has significant effect on sleep quality.

CONCLUSION

We found that the treatment with exogenous melatonin has positive effects on sleep quality as assessed by the Pittsburgh Sleep Quality Index (PSQI) in adult. In adults with respiratory diseases, metabolic disorders, primary sleep disorders, not with mental disorders, neurodegenerative diseases and other diseases.

Current Update on Clinically Relevant Sleep Issues in Parkinson's Disease: A Narrative Review

Sleep disturbances are among the common nonmotor symptoms in patients with Parkinson’s disease (PD). Sleep can be disrupted by nocturnal motor and nonmotor symptoms and other comorbid sleep disorders. Rapid eye movement sleep behavior disorder (RBD) causes sleep-related injury, has important clinical implications as a harbinger of PD and predicts a progressive clinical phenotype. Restless legs syndrome (RLS) and its related symptoms can impair sleep initiation. Excessive daytime sleepiness (EDS) is a refractory problem affecting patients’ daytime activities. In particular, during the COVID-19 era, special attention should be paid to monitoring sleep problems, as infection-prevention procedures for COVID-19 can affect patients’ motor symptoms, psychiatric symptoms and sleep. Therefore, screening for and managing sleep problems is important in clinical practice, and the maintenance of good sleep conditions may improve the quality of life of PD patients. This narrative review focused on the literature published in the past 10 years, providing a current update of various sleep disturbances in PD patients and their management, including RBD, RLS, EDS, sleep apnea and circadian abnormalities.

Melatonin as a Chronobiotic and Cytoprotective Agent in Parkinson's Disease

This article discusses the role that melatonin may have in the prevention and treatment of Parkinson’s disease (PD). In parkinsonian patients circulating melatonin levels are consistently disrupted and the potential therapeutic value of melatonin on sleep disorders in PD was examined in a limited number of clinical studies using 2–5 mg/day melatonin at bedtime. The low levels of melatonin MT1 and MT2 receptor density in substantia nigra and amygdala found in PD patients supported the hypothesis that the altered sleep/wake cycle seen in PD could be due to a disrupted melatonergic system. Motor symptomatology is seen in PD patients when about 75% of the dopaminergic cells in the substantia nigra pars compacta region degenerate. Nevertheless, symptoms like rapid eye movement (REM) sleep behavior disorder (RBD), hyposmia or depression may precede the onset of motor symptoms in PD for years and are index of worse prognosis. Indeed, RBD patients may evolve to an α-synucleinopathy within 10 years of RBD onset. Daily bedtime administration of 3–12 mg of melatonin has been demonstrated effective in RDB treatment and may halt neurodegeneration to PD. In studies on animal models of PD melatonin was effective to curtail symptomatology in doses that allometrically projected to humans were in the 40–100 mg/day range, rarely employed clinically. Therefore, double-blind, placebo-controlled clinical studies are urgently needed in this respect.

Oxidative Stress in Parkinson's Disease: Potential Benefits of Antioxidant Supplementation

Parkinson's disease (PD) occurs in approximately 1% of the population over 65 years of age and has become increasingly more common with advances in age. The number of individuals older than 60 years has been increasing in modern societies, as well as life expectancy in developing countries; therefore, PD may pose an impact on the economic, social, and health structures of these countries. Oxidative stress is highlighted as an important factor in the genesis of PD, involving several enzymes and signaling molecules in the underlying mechanisms of the disease. This review presents updated data on the involvement of oxidative stress in the disease, as well as the use of antioxidant supplements in its therapy.