Nonmotor symptoms in Parkinson's disease: expanding the view of Parkinson's disease beyond a pure motor, pure dopaminergic problem

State-dependent alteration of respiration in a rat model of Parkinson's disease

Parkinson's disease (PD) is the second most frequent neurodegenerative disorder. Besides major deficits in motor coordination, patients may also display sensory and cognitive impairments, which are often overlooked despite being inherently part of the PD symptomatology. Amongst those symptoms, respiration, a key mechanism involved in the regulation of multiple physiological and neuronal processes, appears to be altered. Importantly, breathing patterns are highly correlated with the animal's behavioral states. This raises the question of the potential impact of behavioral state on respiration deficits in PD. To answer this question, we first characterized the respiratory parameters in a neurotoxin-induced rat model of PD (6-OHDA) across three different vigilance states: sleep, quiet waking and exploration. We noted a significantly higher respiratory frequency in 6-OHDA rats during quiet waking compared to Sham rats. A higher respiratory amplitude was also observed in 6-OHDA rats during both quiet waking and exploration. No effect of the treatment was noted during sleep. Given the relation between respiration and olfaction and the presence of olfactory deficits in PD patients, we then investigated the odor-evoked sniffing response in PD rats, using an odor habituation/cross-habituation paradigm. No substantial differences were observed in olfactory abilities between the two groups, as assessed through sniffing frequency. These results corroborate the hypothesis that respiratory impairments in 6-OHDA rats are vigilance-dependent. Our results also shed light on the importance of considering the behavioral state as an impacting factor when analyzing respiration.

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

BACKGROUND

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

METHODS

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

RESULTS

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

CONCLUSION

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

Antioxidant responses driven by Hesperetin and Hesperidin counteract Parkinson's disease-like phenotypes in Drosophila melanogaster

The study investigated the protective effects of Hesperetin (HSP) and Hesperidin (HSD) on 1 methyl, 4 phenyl, 1,2,3,6 tetrahydropyridine hydrochloride (MPTP)-induced Parkinsonism in Drosophila melanogaster (D. melanogaster). After a lifespan study to select exposure time and concentrations, flies were co-exposed to MPTP (0.4 mg/g diet), Hesperetin (0.2 and 0.4 mg/g diet), and Hesperidin (0.1 and 0.4 mg/g) for 7 days. In addition to in vivo parameters, we assayed some markers of oxidative stress and antioxidant status (lipid peroxidation, protein carbonylation, thiol content, hydrogen peroxide, and nitrate/nitrite levels, mRNA expression of Keap-1 (Kelch-like ECH associated protein 1), /Nrf2 (Nuclear factor erythroid 2 related factor 2), catalase, and glutathione-S-transferase (GST) activities), and cholinergic (acetyl cholinesterase activity (AChE) and dopaminergic signaling content and the mRNA expression of tyrosine hydroxylase (TH), monoamine oxidase (MAO-like) activity). In addition to increasing the lifespan of flies, we found that both flavonoids counteracted the adverse effects of MPTP on survival, offspring emergence, and climbing ability of flies. Both flavonoids also reduced the oxidative damage on lipids and proteins and reestablished the basal levels of pro-oxidant species and activities of antioxidant enzymes in MPTP-exposed flies. These responses were accompanied by the normalization of the mRNA expression of Keap1/Nrf2 disrupted in flies exposed to MPTP. MPTP exposure also elicited changes in mRNA expression and content of TH as well as in MAO and AChE activity, which were reversed by HST and HSD. By efficiently hindering the oxidative stress in MPTP-exposed flies, our findings support the promising role of Hesperetin and Hesperidin as adjuvant therapy to manage Parkinsonism induced by chemicals such as MPTP.

Dietary approach to stop hypertension (DASH), but not Mediterranean and MIND, dietary pattern protects against Parkinson's disease

The neuroprotective effects of dietary patterns have been reported in previous studies. This study aimed to examine the association between the dietary approach to stop hypertension (DASH), the Mediterranean diet (MeDi), and the Mediterranean-DASH intervention for neurodegenerative delay (MIND) with the severity and risk of Parkinson's disease (PD). In this comparative cross-sectional study, 120 patients with PD and 50 healthy participants participated. Adherence to DASH, MeDi, and MIND dietary patterns was determined according to the dietary intake data using a food frequency questionnaire (FFQ). The Severity of PD was determined by the Unified Parkinson's Disease Rating Scale (UPDRS). The mean score of the DASH was significantly lower in the PD group compared to the healthy group (p = .006), but the mean score of MeDi and MIND did not significantly differ between the two groups (p > .05). Also, the mean score of the DASH was significantly lower in men than in women in the healthy group (p = .018). High adherence to the DASH diet decreased the risk of PD by 15% (OR = 0.856, 95% CI: 0.751, 0.976, p = .020). Participants in quartiles 3 and 4 of the DASH dietary pattern had 86% (p = .003) and 87% (p = .007), respectively, lower risk of PD. MeDi and MIND diets were not significantly associated with the risk of PD. There was no significant association between dietary patterns and the severity of PD. The findings indicate that high adherence to the DASH dietary pattern may protect against PD.

Exendin-4: A potential therapeutic strategy for Alzheimer's disease and Parkinson's disease

Neurodegenerative disorders, which affect millions worldwide, are marked by a steady decline of neurons that are selectively susceptible. Due to the complex pathological processes underlying neurodegeneration, at present, there is no viable therapy available for neurodegenerative disorders. Consequently, the establishment of a novel therapeutic approach for such conditions is a clinical void that remains. The potential significance of various peptides as neuroprotective interventions for neurodegenerative disorders is gaining increasing attention. In the past few years, there has been growing scientific interest in glucagon-like peptide-1 receptor agonists due to their claimed neuroprotective effects. Exendin-4 is a glucagon-like peptide-1 receptor agonist that is known to possess anti-diabetic effects and does not degrade for hours, making it a superior candidate for such disorders. Moreover, exendin-4's neuroprotective effects have been reported in several preclinical studies. Exendin-4's diverse therapeutic targets suggest its potential therapeutic uses in neurodegenerative ailments like Alzheimer's disease and Parkinson's disease and have garnered an increasing amount of attention. Given the substantial body of evidence supporting the neuroprotective potential of exendin-4 in various research models, this article is dedicated to exploring the promising role of exendin-4 as a therapeutic agent for the treatment and management of Alzheimer's disease and Parkinson's disease. This review draws insights from the findings of numerous preclinical and clinical studies to highlight the collective neuroprotective advantages of exendin-4 and the potential mechanisms that underlie its neuroprotective effects.

Evaluation of Knowledge and Attitudes of the Population of Tabuk City Regarding Parkinson's Disease: A Cross-Sectional Study

BACKGROUND

The lack of awareness and information about PD may be a barrier to early diagnosis and the delivery of the best care to patients with the condition, given its rising prevalence. In order to determine the variables that are connected to these parameters, this study sought to ascertain the general public's knowledge and awareness of PD in Tabuk City.

METHODS

 In Tabuk City, a cross-sectional demographic survey was carried out. A validated structured questionnaire was used to interview adult respondents by random sampling regarding specific knowledge, attitudes, and awareness related to Parkinson's disease. According to the density of the city, a total of 426 members of the general population were chosen at random and interviewed by skilled interviewers.

RESULTS

 Age and educational attainment were independently linked to PD awareness. Bachelor's degree subjects and those between the ages of 18 and 45 displayed a greater awareness of PD. Those above 60 and those between the ages of 46 and 60 lacked sufficient knowledge. The majority of participants demonstrated adequate understanding and awareness of PD in their respective occupations.

CONCLUSIONS

 Age, gender, occupation, and level of education were all adequately covered by knowledge and understanding of PD. To increase public knowledge, attitudes, and awareness of PD, however, suitable educational tactics and approaches targeting particular subgroups are required.

Association between Low Blood Pressure and Subsequent Risk of Parkinson's Disease in Older Adults Aged ≥75 Years

INTRODUCTION

The association between blood pressure (BP) and incidence of Parkinson's disease (PD) in older adults remains uncertain. Therefore, this study aimed to investigate the association between BP (high or low) and PD incidence in adults aged ≥75 years.

METHODS

In this nationwide population-based cohort study, we enrolled participants aged ≥75 years without a prior PD diagnosis who had undergone health examination provided by the Korean National Health Insurance Service at least once from January 1, 2009, to December 31, 2012. The participants were followed up until December 31, 2019, or the date of their death. The Cox proportional hazards model was used to assess the risk of PD depending on systolic BP (SBP), diastolic BP (DBP), and pulse pressure.

RESULTS

Overall, 963,525 participants were enrolled in the analysis and followed up until December 31, 2019, or the date of death (40.7% male, mean age 78.5 ± 3.6 years). The mean SBP and DBP were 131.4 ± 16.7 and 77.9 ± 10.3 mm Hg, respectively. During the 10-year follow-up period, 16,414 (1.7%) newly diagnosed cases of PD were reported. A significant inverse dose-response association was found between SBP and PD incidence. In the subgroup analysis, this association was maintained for most variables, including sex, use of antihypertensive medication, comorbidities, alcohol consumption, physical activity, and body mass index, except for smoking status.

CONCLUSION

Lower SBP and DBP were associated with a higher PD incidence in older adults. These results may have substantial implications for determining the optimal BP control target in adults aged ≥75 years.

Parkinson's Neuropathology Puzzle: A Systematic Review Uncovering the Pathological Culprits Behind the Neurological Disease

Being one of the most prevalent progressive neurodegenerative disorders (falling second only to Alzheimer's disease) with a clinical pattern affecting millions of lives all over the world, Parkinson's disease (PD) has never failed to attract a formidable interest from the vast majority of neurologists and researchers worldwide. This review article will analyze the pathophysiology, etiology, genetics, and pathological stages of Parkinson's disease with their corresponding clinical sequels. A review article was conducted using research databases including PubMed, PubMed Central, Springer, and Elsevier. The research articles reviewed using databases were written in English, German, Japanese, and Chinese and published within the preceding 50 years. Based on the article's findings, we concluded that Parkinson's disease is a progressive disorder with a variety of motor and non-motor symptoms that are influenced by a cascade of pathological neuronal abnormalities such as Lewy neurites and Lewy bodies that gradually build up with an eventual consequence of neurodegeneration of dopamine-secreting neurons. Multiple genetic mutations, pathophysiological events, and environmental factors act as the foundation to initiate that cascade.

Deep Brain Stimulation beyond the Clinic: Navigating the Future of Parkinson's and Alzheimer's Disease Therapy

Deep brain stimulation (DBS) is a surgical procedure that uses electrical neuromodulation to target specific regions of the brain, showing potential in the treatment of neurodegenerative disorders such as Parkinson's disease (PD) and Alzheimer's disease (AD). Despite similarities in disease pathology, DBS is currently only approved for use in PD patients, with limited literature on its effectiveness in AD. While DBS has shown promise in ameliorating brain circuits in PD, further research is needed to determine the optimal parameters for DBS and address any potential side effects. This review emphasizes the need for foundational and clinical research on DBS in different brain regions to treat AD and recommends the development of a classification system for adverse effects. Furthermore, this review suggests the use of either a low-frequency system (LFS) or high-frequency system (HFS) depending on the specific symptoms of the patient for both PD and AD.

Role of Deubiquitinases in Parkinson's Disease-Therapeutic Perspectives

Parkinson's disease (PD) is a neurodegenerative disorder that has been associated with mitochondrial dysfunction, oxidative stress, and defects in mitophagy as well as α-synuclein-positive inclusions, termed Lewy bodies (LBs), which are a common pathological hallmark in PD. Mitophagy is a process that maintains cellular health by eliminating dysfunctional mitochondria, and it is triggered by ubiquitination of mitochondrial-associated proteins-e.g., through the PINK1/Parkin pathway-which results in engulfment by the autophagosome and degradation in lysosomes. Deubiquitinating enzymes (DUBs) can regulate this process at several levels by deubiquitinating mitochondrial substrates and other targets in the mitophagic pathway, such as Parkin. Moreover, DUBs can affect α-synuclein aggregation through regulation of degradative pathways, deubiquitination of α-synuclein itself, and/or via co-localization with α-synuclein in inclusions. DUBs with a known association to PD are described in this paper, along with their function. Of interest, DUBs could be useful as novel therapeutic targets against PD through regulation of PD-associated defects.

Cannabinoids in neuroinflammatory disorders: Focusing on multiple sclerosis, Parkinsons, and Alzheimers diseases

The medicinal properties of cannabis and cannabinoid-derivative are entirely investigated and known. In addition, the identification of psychotropic plant cannabinoids has led to more studies regarding the cannabinoid system and its therapeutic features in the treatment and management of clinical symptoms of neuroinflammatory disorders, such as multiple sclerosis (MS), Parkinsons disease (PD), and Alzheimers disease (AD). In fact, cannabinoid agonists are able to control and regulate inflammatory responses. In contrast to the cannabinoid receptor type 1 (CB1) and its unwanted adverse effects, the cannabinoid receptor type 2 (CB2) and its ligands hold promise for new and effective therapeutic approaches. So far, some successes have been achieved in this field. This review will discuss an outline of the endocannabinoid system's involvement in neuroinflammatory disorders. Moreover, the pharmacological efficacy of different natural and synthetic preparations of phytocannabinoids acting on cannabinoid receptors, particularly in MS, PD, and AD, will be updated. Also, the reasons for targeting CB2 for neurodegeneration will be explained.

Rotenone induced olfactory deficit in Parkinson's disease rat model: The protective role of adenosine A2A receptors antagonist

BACKGROUND

Parkinson's disease is both a motor and non-motor disorder. Despite the non-motor being an intrinsic feature of PD, it has been poorly researched and understood in clinical practices; olfactory deficit is one of the first established non motor symptom and nearly all ∼90 % of sporadic PD cases are associated with olfactory dysfunction and there is inconsistency in various pharmacological approaches. Hence this study aimed to evaluate the impact of caffeine at the A2A receptors of the olfactory bulb of a rotenone rat model of Parkinson's disease.

MATERIALS AND METHODS

About 50 male Adult Wistar Rats were used for this study. The rats were randomly divided into five groups of 10 rats each as follows: Group A (vehicle; ethanol), Group B (rotenone 3 mg/kg, i.p), Group C (caffeine 30 mg/kg, i.p + rotenone 3 mg/kg, i.p), Group D (rotenone 3 mg/kg, i.p + caffeine 30 mg/kg, i.p), Group E (caffeine 30 mg/kg, i.p). The animals were subjected to neurobehavioral assay and sacrificed, and brains were excised, weighed, and processed histologically; appropriate sections were taken and processed. The photomicrographs, Morphometric and Statistical analysis was done using Omax led digital Microscope, Image J Software and Graph Pad Prism 7, respectively.

RESULTS

The results showed a significant decrease in body weight (P < 0.05), relative brain weight, mitral/tufted cells count, and high latency in food-seeking test in Rotenone treated groups. Histopathological presentations include degenerated concentric layers of Olfactory bulb, neuronal degeneration, distorted appearance, degenerated neuropile and vacuolation, all of which were abrogated/reversed following caffeine treatment.

CONCLUSION

In conclusion, this study was able to establish the neuroprotective and therapeutic candidature of caffeine acting via the A2A receptor to ameliorate or reverse the various pathological insults caused by rotenone administration.

High-frequency rTMS improves quality of life and depressive symptoms in Parkinson's disease: A case report

Introduction

Parkinson's disease (PD) is a common neurodegenerative disorder, characterised by both motor and nonmotor symptoms. There is currently no cure for PD, although there are several treatment options for relieving PD symptoms. Repetitive transcranial magnetic stimulation (rTMS) is a noninvasive brain stimulation therapy that shows promising results for the treatment of PD.

Methods

Here, we present a patient with PD. We investigated whether an accelerate form of high-frequency (HF) rTMS on the contralateral side to the patient's main difficulties is clinically effective in treating health-related quality of life (QoL) symptomatology and depressive symptoms in PD as well as the long-term effects of rTMS in PD during the maintenance phase.

Results

Results showed that HF-rTMS administered over the right primary motor cortex (M1) is a safe and well-tolerated treatment that improved the patient's health related QoL and depressive symptoms. These positive effects lasted at least five months post treatment.

Conclusion

Therefore, HF-rTMS over the right M1 can be a possible treatment option for patients with PD, although further investigations are necessary to validate the findings of the present case report.

Naringenin: A prospective therapeutic agent for Alzheimer's and Parkinson's disease

Neurodegenerative disorders (NDs) are a cluster of progressive, severe, and disabling disorders that affect millions of people worldwide and are on the surge. These disorders are characterized by the gradual loss of a selectively vulnerable group of neurons. Due to the complex pathophysiological mechanisms behind neurodegeneration and despite enormous efforts and understanding of the occurrence and progression of NDs, there is still a lack of an effective treatment for such diseases. Therefore, the development of a new therapeutic strategy for NDs is an unmet clinical need. Various natural compounds extracted from medicinal plants or fruits have shown promising activities in treating different types of NDs by targeting multiple signaling pathways. Among natural entities, flavonoids have incited a rise in public and scientific interest in recent years because of their purported health-promoting effects. Dietary supplementation of flavonoids has been shown to mitigate the severity of NDs such as Parkinson's disease (PD), Alzheimer's disease (AD), and dementia by their antioxidant effects. Naringenin is a citrus flavonoid that is known to possess numerous biological activities like antioxidant, anti-proliferative, and anti-inflammatory activities. Therefore, naringenin has emerged as a potential therapeutic agent that exerts preventive and curative effects on several neurological disorders. Increasing evidence has attained special attention on the variety of therapeutic targets along with complex signaling pathways of naringenin, which suggest its possible therapeutic applications in several NDs. Derived from the results of several pre-clinical research and considering the therapeutic effects of this compound, this review focuses on the potential role of naringenin as a pharmacological agent for the treatment and management of Alzheimer's and Parkinson's disease. The overall neuroprotective effects and different possible underlying mechanisms related to naringenin are discussed. In the light of substantial evidence for naringenin's neuroprotective efficacy in several experimental paradigms, this review suggests that this molecule should be investigated further as a viable candidate for the management of Alzheimer's and Parkinson's disease, with an emphasis on mechanistic and clinical trials to determine its efficacy. PRACTICAL APPLICATIONS: Naringenin is a flavanone, aglycone of Naringin, predominantly found in citrus fruits with a variety of pharmacological actions. Naringenin has been shown to exhibit remarkable therapeutic efficacy and has emerged as a potential therapeutic agent for the management of a variety of diseases such as various heart, liver, and metabolic disorders. Similarly, it has shown efficacy in neurodegenerative illnesses. Therefore, this review enables us to better understand the neuroprotective effects and different possible underlying mechanisms of naringenin. Also, this review provides a new indication to manage the symptoms of NDs like AD and PD. Furthermore, naringenin will be useful in the field of medicine as a new active ingredient for the treatment of neurodegenerative disorders like AD and PD.

Effects of Levodopa-Carbidopa Intestinal Gel Compared with Optimized Medical Treatment on Nonmotor Symptoms in Advanced Parkinson’s Disease: INSIGHTS Study

Background. Nonmotor symptoms (NMS) are common in advanced Parkinson’s disease (APD) and reduce health-related quality of life. Objective. The aim of the study was to evaluate levodopa-carbidopa intestinal gel (LCIG) versus optimized medical treatment (OMT) on NMS in APD. Methods. INSIGHTS was a phase 3b, open-label, randomized, multicenter study in patients with APD (LCIG or OMT, 26 weeks) (NCT02549092). Primary outcomes assessed were total NMS (NMS scale (NMSS) and PD sleep scale (PDSS-2)). Key secondary outcomes included the Unified PD Rating Scale (UPDRS) Part II, Clinical Global Impression of Change (CGI-C), and PD Questionnaire-8 (PDQ-8). Additional secondary measures of Patient Global Impression of Change (PGIC), King’s PD Pain Scale (KPPS), and Parkinson Anxiety Scale (PAS) also were evaluated. Finally, safety was assessed. Results. Out of 89 patients randomized, 87 were included in the analysis (LCIG, n = 43; OMT, n = 44). There were no significant differences in NMSS or PDSS-2 total score changes (baseline to Week 26) between LCIG and OMT; within-group changes were significant for NMSS (LCIG, $p<0.001$ ; OMT, $p=0.005$ ) and PDSS-2 (LCIG, $p<0.001$ ; OMT, $p<0.001$ ). Between-group treatment differences were nominally significant for UPDRS Part II ( $p=0.006$ ) and CGI-C ( $p<0.001$ ) at Week 26 in favor of LCIG; however, statistical significance could not be claimed in light of primary efficacy outcomes. PGIC (Week 26) and KPPS (Week 12) scores were nominally significantly reduced with LCIG versus OMT ( $p<0.001$ ; $p<0.05$ ). There were no significant differences in PDQ-8 or PAS. Adverse events (AEs) were mostly mild to moderate; common serious AEs were pneumoperitoneum (n = 2) and stoma-site infection (n = 2) (LCIG). Conclusions. There were no significant differences between LCIG versus OMT in NMSS or PDSS-2; both LCIG and OMT groups significantly improved from baseline. AEs were consistent with the known safety profile.

Nitric Oxide Involvement in Cardiovascular Dysfunctions of Parkinson Disease

Parkinson’s disease (PD) is characterized by the loss of dopaminergic neurons in the substantia nigra, causing motor changes. In addition to motor symptoms, non-motor dysfunctions such as psychological, sensory and autonomic disorders are recorded. Manifestations related to the autonomic nervous system include the cardiovascular system, as postural hypotension, postprandial hypotension, and low blood pressure. One of the mediators involved is the nitric oxide (NO). In addition to the known roles such as vasodilator, neuromodulator, NO acts as an important mediator of the immune response, increasing the inflammatory response provoked by PD in central nervous system. The use of non-specific NOS inhibitors attenuated the neurodegenerative response in animal models of PD. However, the mechanisms by which NO contributes to neurodegeneration are still not well understood. The literature suggest that the contribution of NO occurs through its interaction with superoxides, products of oxidative stress, and blocking of the mitochondrial respiratory chain, resulting in neuronal death. Most studies involving Parkinsonism models have evaluated brain NO concentrations, with little data available on its peripheral action. Considering that studies that evaluated the involvement of NO in the neurodegeneration in PD, through NOS inhibitors administration, showed neuroprotection in rats, it has prompted new studies to assess the participation of NOS isoforms in cardiovascular changes induced by parkinsonism, and thus to envision new targets for the treatment of cardiovascular disorders in PD. The aim of this study was to conduct a literature review to assess available information on the involvement of nitric oxide (NO) in cardiovascular aspects of PD.

Association between Mediterranean diet and Parkinson’s disease in adults: A systematic review and meta-analysis of cohort studies

BACKGROUND: Parkinson’s disease (PD) is a chronic neurodegenerative disorder, and previous studies have shown that the Mediterranean diet (MeDi) can be effective in reducing the incidence and progression of the disease. OBJECTIVE: The purpose of this study was to determine an association between adherence to MeDi and the risk of PD in adults by meta-analysis of cohort studies. METHODS: Online databases including Scopus, PubMed, Web of Science, and Google Scholar were searched up to March 2021. Cohort studies that examined the association of PD risk with adherence to MeDi were included. A pooled relative risk with a 95% confidence interval was calculated by a random effects meta-analysis. As well, bias assessment, assessment of heterogeneity, sensitivity, and subgroup analyses were carried out. The primary outcome was Parkinson’s incidence. RESULTS: Overall four papers on PD risk were included in the present systematic review and meta-analysis. The effect size of the summary for the risk of overall PD, comparing the highest with the lowest adherence to MeDi, was 0.76 (95% CI: 0.59, 0.98), indicating a significant inverse association. CONCLUSIONS: Adherence to MeDi has a protective role against PD. Also, adhering to this dietary pattern at a younger age may be more beneficial in reducing the risk of PD. However, we suggest more prospective cohort studies in this regard.

The impact of clinical scales in Parkinson’s disease: a systematic review

Background

Parkinson’s disease is one of the non-curable diseases and occurs by the prominent loss of neurotransmitter (dopamine) in substantia nigra pars compacta (SNpc). The main cause behind this is not yet identified and even its diagnosis is very intricate phase due to non-identified onset symptoms. Despite the fact that PD has been extensively researched over the decades, and various algorithms and strategies for early recognition and avoiding misdiagnosis have been published. The objective of this article is to focus on the current scenario and to explore the involvement of various clinical diagnostic scales in the detection of PD.

Method

An exhaustive literature review is conducted to synthesize the earlier work in this area, and the articles were searched using different keywords like Parkinson disease, motor/non-motor, treatment, diagnosis, scales, PPMI, etc., in all repositories such as Google scholar, Scopus, Elsevier, PubMed and many more. From the year 2017 to 2021, a total of 451 publications were scanned, but only 24 studies were chosen for a review process.

Findings

Mostly as clinical tools, UPDRS and HY scales are commonly used and even there are many other scales which can be helpful in detection of symptoms such as depression, anxiety, sleepiness, apathy, smell, anhedonia, fatigue, pain, etc., that affect the QoL of pateint. The recognition of non-motor manifests is typically very difficult than motor signs.

Conclusion

This study can give the beneficial research paths at an early stage diagnosis by focusing on frequent inspection of daily activities, interactions, and routine, which may also give a plethora of information on status changes, directing self-reformation, and clinical therapy.

Longitudinal risk factors for developing depressive symptoms in Parkinson's disease

BACKGROUND

Despite the established importance of identifying depression in Parkinson's disease, our understanding of the factors which place the Parkinson's disease patient at future risk of depression is limited.

METHODS

Our sample consisted of 874 patients from two longitudinal cohorts, PPMI and PDBP, with median follow-up durations of 7 and 3 years respectively. Risk factors for depressive symptoms at baseline were determined using logistic regression. A Cox regression model was then used to identify baseline factors that predisposed the non-depressed patient to develop depressive symptoms that were sustained for at least one year, while adjusting for antidepressant use and cognitive impairment. Common predictors between the two cohorts were identified with a random-effects meta-analysis.

RESULTS

We found in our analyses that the majority of baseline non-depressed patients would develop sustained depressive symptoms at least once during the course of the study. Probable REM sleep behavior disorder (pRBD), age, duration of diagnosis, impairment in daily activities, mild constipation, and antidepressant use were among the baseline risk factors for depression in either cohort. Our Cox regression model indicated that pRBD, impairment in daily activities, hyposmia, and mild constipation could serve as longitudinal predictors of sustained depressive symptoms.

CONCLUSIONS

We identified several potential risk factors to aid physicians in the early detection of depression in Parkinson's disease patients. Our findings also underline the importance of adjusting for multiple covariates when analyzing risk factors for depression.

Deep Brain Stimulation for Parkinson's Disease: Currents Status and Emerging Concepts

The clinical application of DBS has become manifold and there has been a tremendous growth in DBS technology in the last few decades making it safer and user friendly. The earlier concept of its delayed application in motor fluctuations of Parkinson's disease has been replaced by Class-I evidence of EARLY-STIM trial in 2013, leading to its FDA approval to be used in early-stage despite criticism. Various studies have provided evidence of beneficial effects of bilateral STN-DBS on both motor as well as nonmotor symptoms and different new targets such as the pedunculopontine nucleus, posterior subthalamic area or caudal zona incerta, centromedian-parafascicular complex, and substantia nigra pars reticulata have now become a new area of interest in addition to the subthalamic nucleus and globus pallidus internus for the alleviation of both motor and nonmotor symptoms of Parkinson's disease. New data has confirmed that the DBS is clinically as effective and safe in elderly patients as it is in younger ones. Technological advances like current steering, directional leads, and closed-loop DBS are directed towards reducing the stimulation-induced adverse effects and preservation of the battery life for a longer period. Results of the long-term efficacy of DBS on Parkinson's disease are now available. These have shown that as the motor benefit continues, the clinical progression of Parkinson's disease also continues. We plan to discuss all these in this paper.

Effects of Lee Silverman Voice Treatment BIG and conventional physiotherapy on non-motor and motor symptoms in Parkinson's disease: a randomized controlled study comparing three exercise models

Background:

Parkinson’s disease (PD) patients experience disabling motor dysfunctions as well as non-motor symptoms (NMSs) that can highly impact their perceived quality of life. Besides pharmacological treatment options, active intervention programs have set some attention in managing these symptoms. However, previous studies mainly assessed the effectiveness of active intervention programs on functional mobility and motor symptoms.

Objective:

This study aimed to investigate the effect of Lee Silverman Voice Treatment (LSVT) BIG, an intensified and personalized physiotherapy (INTENSIVE), and a conventional physiotherapy (NORMAL) on NMSs in PD.

Method:

Forty-four patients with mild to moderate PD were randomly assigned to one of the three treatment groups. LSVT BIG and INTENSIVE were delivered one-on-one in 16 1-hour sessions within 4 weeks (4×/week). Patients assigned to NORMAL received 16 individual 1-hour sessions within 8 weeks (2×/week). The primary outcome measure was the difference in change from baseline in the non-motor symptom assessment scale for Parkinson’s disease (NMSS) between treatment groups to follow up at week 8. Patients were blinded for the NMSS being the primary outcome, but not the different treatment groups.

Results:

ANCOVA (Analysis of Covariance) showed reduced NMSS scores for all groups, with INTENSIVE being superior to NORMAL (p = 0.033). For secondary outcome measures (stride length, gait velocity and chair rising test) LSVT BIG and INTENSIVE were both superior to NORMAL.

Conclusions:

The study provides evidence that all three exercise programs are effective techniques to improve NMSs as well as motor function in PD.

DRKS registration number:

DRKS00008732

24-Hour Levodopa-Carbidopa Intestinal Gel: Clinical Experience and Practical Recommendations

Infusion of levodopa-carbidopa intestinal gel (LCIG; also designated carbidopa-levodopa enteral suspension) for 16 hours is a standard treatment for patients with advanced Parkinson's disease, and clinical observations suggest that 24-hour LCIG infusion may further reduce symptoms. This review provides practical advice on the management of patients transitioning to 24-hour LCIG infusion. We review available clinical data for 24-hour infusion and discuss adjustments to dosing, recommendations for monitoring, and management of patient concerns, based on our clinical experience. Data from multiple studies suggest that LCIG may improve non-motor symptoms. Although few studies have examined 24-hour LCIG infusion, available data indicate that certain patients may benefit from around-the-clock treatment. Studies of 24-hour LCIG infusion are limited by small sample sizes and open-label study designs, which may hamper translation to clinical practice. In our experience, we have found that patients may benefit from 24-hour infusion when reductions in nocturnal symptoms and improvements to quality of sleep are needed. Levodopa-unresponsive freezing of gait or poorly controlled troublesome dyskinesias may also indicate a patient may benefit from 24-hour infusion. Dose adjustments, especially of the nocturnal rate, are typically necessary and, as with 16-hour infusion, patients should be monitored for autonomic dysfunction; overnight wearing off symptoms; weight changes; fluctuations in plasma levels of vitamins B₆/B₁₂, folate, and homocysteine; changes in sleep patterns; or worsening of hallucinations, delusions, and/or nightmares. Available data and our clinical experience suggest that 24-hour LCIG may be warranted among selected patients who have poorly controlled nocturnal fluctuations or early morning "off" symptoms.

Parkinson Disease Epidemiology, Pathology, Genetics, and Pathophysiology

Parkinson disease is a complex, age-related, neurodegenerative disease associated with dopamine deficiency and both motor and nonmotor deficits. Many environmental and genetic factors influence Parkinson disease risk, with different factors predominating in different patients. These factors converge on specific pathways, including mitochondrial dysfunction, oxidative stress, protein aggregation, impaired autophagy, and neuroinflammation. Ultimately, treatment of Parkinson disease may focus on targeted therapies for pathophysiologically defined subtypes of Parkinson disease patients.

A randomized controlled efficacy study of the Medido medication dispenser in Parkinson's disease

Background

Complex medication schedules in Parkinson’s disease (PD) result in lower therapy adherence, which contributes to suboptimal therapy and clinical deterioration. Medication reminder systems might improve therapy adherence and subsequently improve symptoms of PD. This randomized controlled study assessed the effect of the electronic medication dispenser Medido on physical disability in PD, as a proxy for changes in therapy adherence.x

Methods

Eighty-seven patients were randomized into the Medido group or control group. The primary outcome of physical disability was measured by the AMC Linear Disability Scale (ALDS). Secondary outcomes were quality of life (QoL) (PDQ-39), health status (EQ5D-5L, VAS), non-motor symptoms (NMS-Quest), and QoL of the caregiver (PDQ-carer). Measurements were performed at baseline, and after 3 and 6 months follow-up.

Results

When using the Medido, a non-significant improvement of 3.0 points (95% CI -5.6;11.6) was seen in ALDS. The exploratory subgroup Hoehn & Yahr classification (H&Y) > 2.5 improved significantly on ALDS with 14.7 points (95% CI -28.5;-0.9, p = 0.029 for group x time interaction). QoL deteriorated with 1.0 point in PDQ-39 (p = 0.01 for group x time interaction) in favor of the control group. Non-significant differences were observed for VAS (0.4 points, p = 0.057) and NMS-Quest (1.3 points, p = 0.095) in favor of the Medido group. No changes over time were observed in EQ5D-5L and PDQ-carer.

Conclusions

Based on these data, no firm conclusion can be drawn, but use of the Medido medication dispenser may result in a clinical improvement of physical disability and seems particularly appropriate for more severe patients.

Trial registration

NTR3917. Registered 19 March 2013.

Decreased Striatal Vesicular Monoamine Transporter Type 2 Correlates With the Nonmotor Symptoms in Parkinson Disease

OBJECTIVE

Nonmotor symptoms (NMS) are critical players in the patients' quality of life in Parkinson disease (PD). Vesicular monoamine transporter type 2 (VMAT2) has been reported owing to a role in affecting dopamine neurons in the striatum. Therefore, this study set out to characterize the relationship between VMAT2 distribution in the striatum in relation to the NMS in PD.

METHODS

Totally, 21 age-matched normal controls and 37 patients with PD in the moderate stages were included, followed by examination using F-DTBZ (F-AV133) PET/CT. The specific uptake ratio (SUR) of each striatal subregion was then determined with the occipital cortex as the reference background region. The overall NMSs of each individual patient were evaluated. Finally, the role of the striatal SURs in the clinical symptom scores were evaluated through the application of a Spearman correlation analysis as well as a multivariable stepwise regression analysis.

RESULTS

Patients with PD, particularly those at a more advanced stage, exhibited a more pronounced reduction in SURs in the bilateral putamen and caudate nucleus (P < 0.05, vs healthy controls). Meanwhile, patients at more advanced PD stages were found to have significantly worse scores in NMS except cognitive function. The Spearman correlation analysis demonstrated that NMS scores, with the exception of cognition scores, were correlated with striatal SURs (P < 0.05).

CONCLUSION

The key findings of the study identified a correlation between decreased striatal VMAT2 with a broad spectrum of NMS in patients with PD, highlighting the association between diminished dopamine supply and the development of NMS in PD.

Rotigotine Transdermal Patch: A Review in Parkinson's Disease

Rotigotine (Neupro^®), a non-ergolinic dopamine agonist (DA), is administered once daily via a transdermal patch (TP) that delivers the drug over a 24-h period. In the EU, the rotigotine TP is approved as monotherapy for the treatment of early Parkinson's disease (PD) and as combination therapy with levodopa throughout the course of the disease. It is also approved for the treatment of PD in numerous other countries, including Australia, the USA, China and Japan. Rotigotine TP effectively improved motor and overall functioning in clinical trials in Caucasian and Asian patients with early PD (as monotherapy) or advanced PD (in combination with levodopa); treatment benefits appeared to be maintained in open-label extensions that followed patients for up to 6 years. Rotigotine TP was not consistently non-inferior to ropinirole and pramipexole in studies that included these oral non-ergolinic DAs as active comparators. Rotigotine TP variously improved some non-motor symptoms of PD, in particular sleep disturbances and health-related quality of life (HRQOL), based on findings from individual studies and/or a meta-analysis. Rotigotine TP was generally well tolerated, with an adverse event profile characterized by adverse events typical of dopaminergic stimulation and transdermal patch application. Available for more than a decade, rotigotine TP is a well-established, once-daily DA formulation for use in the short- and longer-term treatment of PD. It offers a convenient alternative when non-oral administration of medication is preferred and may be particularly useful in patients with gastrointestinal disturbances that reduce the suitability of oral medication.

Psychiatric morbidity, cognitive dysfunction and quality of life in drug-naive patients with Parkinson's disease: A comparative study

BACKGROUND

To better understand the psychiatric disorders and cognition in Parkinson's disease (PD) and its impact on quality of life (QoL), patients need to be studied soon after diagnosis, before initiation of dopamine replacement therapy.

AIM

This study aims to compare the nature and frequency of psychiatric morbidity, cognitive dysfunction, and quality of life in drug-naive patients with PD and healthy controls.

MATERIALS AND METHODS

The cross-sectional, comparative study was conducted in tertiary care center. Fifty drug-naive PD patients and fifty healthy controls were included and assessed on Modified Hoehn and Yahr scale, PD Questionnaire 8, Kolkata cognitive screening battery, General Health Questionnaire-12, and Hamilton Anxiety and Depression Rating Scale (HAM-A and HAM-D).

RESULTS

The mean scores of HAM-A and HAM-D of patients with PD were significantly higher than that of the comparison group. The patients with PD had statistically significant impairment in verbal fluency, Mini-Mental State Examination, calculation, memory immediate recall, visuoconstructional ability, and memory (delayed recall and recognition) in comparison to patients without PD. No statistically significant difference was observed with respect to object naming between the two groups.

CONCLUSION

QoL of a PD patient is adversely affected by both the motor and nonmotor symptoms of the disease such as depression, anxiety, apathy, sleep disturbances, and cognitive impairment. The link between nonmotor symptoms and reduced QoL has important implications for the management of PD because the nonmotor symptoms often appear before patients are given anti-parkinsonian therapy. Screening of nonmotor symptoms in early stage of disease will decrease the morbidity and mortality and improve the QoL.

High-Order Visual Processing, Visual Symptoms, and Visual Hallucinations: A Possible Symptomatic Progression of Parkinson's Disease

Objective: To determine whether Parkinson disease (PD) patients with (VH) have different clinical characteristics and gray-matter volume than those with visual misperceptions (VM) or other visual symptoms (OvS). Background: The spectrum of visual complaints in PD is broad and complex. Methods: We conducted a retrospective chart review of 525 PD patients to identify the frequency of visual symptoms and the association with clinical and radiological features. Brain volumetric MRI data was analyzed using multivariate logistic regression to differentiate cases with and without visual symptoms. Results: Among 525 PD cases, visual complaints were documented in 177 (33.7%). Among these, 83 (46.9%) had VH, 31 (17.5%) had VM, and 63 (35.6%) had OvS (diplopia, blurry vision, photophobia, dry eyes, and eye pain or soreness). When compared to OvS, patients with VH had significantly higher age, duration of disease, rate of REM sleep behavior disorder, and cognitive impairment. Visual hallucinations patients had decreased age-adjusted volumetric averages in 28/30 gray-matter regions when compared to PD without visual symptoms and 30/30 gray-matter regions when compared to VM patients. Conclusions: Visual symptoms in PD may represent a spectrum from OvS to VM to VH, with progression of the latter associated with older age, duration of disease, presence of REM sleep behavior disorder, cognitive impairment, and decreased gray-matter volume.

Diagnosing Parkinson Disease

PURPOSE OF REVIEW

While establishing the diagnosis of Parkinson disease (PD) can be straightforward, it can be challenging in some patients, even for the experienced neurologist. The misdiagnosis rate ranges from 10% to 20% or greater depending on clinician experience.

RECENT FINDINGS

Despite promise in the search for a biomarker that can establish the presence of PD and act as a marker of its progression, the diagnosis of PD continues to be based on clinical examination. Core criteria, exclusion criteria, and supportive criteria have been developed to aid the clinician in establishing the diagnosis. Nonmotor symptoms of PD are usually present at the time of diagnosis, may precede motor symptoms, and should be specifically sought during evaluation. Ancillary testing can be appropriate, but its indications and utility must be clearly understood.

SUMMARY

The diagnosis of PD requires the recognition of the core features of PD and the differentiation of its clinical presentation from other entities with similar and potentially overlapping symptoms. A careful history and examination guided by clinical diagnostic criteria will usually establish the diagnosis of PD or uncover red flags for the possibilities of other diagnoses. Appropriate selection and interpretation of ancillary testing is critical to avoid misdiagnosis and unnecessary tests.

The BSSG rat model of Parkinson's disease: progressing towards a valid, predictive model of disease

ABSTRACT

Parkinson's disease (PD) is a neurodegenerative disorder, classically considered a movement disorder. A great deal is known about the anatomical connections and neuropathology and pharmacological changes of PD, as they relate to the loss of dopaminergic function and the appearance of cardinal motor symptoms. Our understanding of the role of dopamine in PD has led to the development of effective pharmacological treatments of the motor symptoms in the form of dopamine replacement therapy using levodopa and dopaminergic agonists. Much of the information concerning these drug treatments has been obtained using classical neurotoxic models that mimic dopamine depletion (e.g., 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine or MPTP, 6-hydroxydopamine, reserpine). However, PD is more than a disorder of the nigrostriatal dopamine pathway. Our understanding of the neuropathology of PD has undergone massive changes, with the discovery that mutations in α-synuclein cause a familial form of PD and that PD pathology may spread, affecting multiple neurotransmitter systems and brain regions. These new developments in our understanding of PD demand that we reconsider our animal models. While classic neurotoxin models have been useful for the development of effective symptomatic treatments for motor manifestations, the paucity of a valid animal model exhibiting the progressive development of multiple key features of PD pathophysiology and phenotype has impeded the search for neuroprotective therapies, capable of slowing or halting disease progression.

RELEVANCE OF THE ARTICLE FOR PREDICTIVE PREVENTIVE AND PERSONALISED MEDICINE

What characteristics would a good animal model of human PD have? In so much as is possible, a good model would exhibit as many behavioral, anatomical, biochemical, immunological, and pathological changes as are observed in the human condition, developing progressively, with clear, identifiable biomarkers along the way. Here, we review the BSSG rat model of PD, a novel environmental model of PD, with strong construct, face, and predictive validity. This model offers an effective tool for the screening of preventive therapies that may prove to be more predictive of their effects in human patients.

Effects of Kamikihito and Unkei-to on Sleep Behavior of Wild Type and Parkinson Model in Drosophila

Parkinson's disease (PD) is the second most common neurodegenerative disease, and it is associated with sleep behavior disorders. In Drosophila melanogaster disease model, human α-synuclein A30P overexpressing flies (A30P PD model) have been shown for levy body aggregation and movement disorders. We measured sleep rhythms in the A30P PD model flies using the Drosophila Activity Monitoring system and found that they develop sleep defects at 20 days after eclosion. Furthermore, the total amount of sleep is significantly reduced in middle-aged PD model flies and the reduction has been attributed to nighttime sleep. The number and length of sleep bouts also decreased in middle-aged A30P PD model flies. Feeding of the oriental traditional herbal medicines (Kampo), Kamikihito and Unkei-to significantly ameliorate the level of sleep defects in A30P PD model flies. The Kamikihito and Unkei-to recovered 60-min sleep bouts number in the A30P PD model flies to the level of young (5 days after eclosion) flies. Kamikihito recovered sleep both in wild-type and PD model flies. Unkei-to ameliorates not only sleep but also motor function in PD model flies. The data suggest that Kamikihito and Unkei-to might be useful for the sleep defects in human PD patients as well as healthy human.

Remotely Assessing Symptoms of Parkinson's Disease Using Videoconferencing: A Feasibility Study

Purpose. To evaluate the feasibility of assessing a person's symptoms of Parkinson's disease (PD) in their home using the videoconferencing technology they already possess, without a home visit. Method. Eleven participants with PD completed the Movement Disorder Society Unified Parkinson's Disease Rating Scale (MDS-UPDRS) face-to-face and then via videoconferencing within a two-week period. Participants used free software and the computers and webcams available at their home to complete the videoconference assessment with a clinical rater scoring remotely. Clinical raters and participants provided feedback on the experience. Results. Excluding rigidity and postural stability, between zero and seven items could not be completed in the assessment of each participant (median 2.0, IQR 1.0-4.0). Between face-to-face and videoconference assessments, the median difference in scores was 3.0 (IQR 1.5-9.0). Content analysis of feedback identified the clinical raters' reasons why some scoring could not be completed and the participants' hope for future clinical application. Conclusions. In using free everyday technology available in participants' homes, MDS-UPDRS ratings could be obtained without an initial home visit; however some items were unable to be scored for some participants. Use of a protocol or technological advances are likely to reduce missing items.

The Perceive, Recall, Plan and Perform (PRPP) system for persons with Parkinson's disease: a psychometric study

BACKGROUND

The Perceive, Recall, Plan & Perform (PRPP) system of task analysis might be feasible to evaluate occupational performance and information processing strategies for persons with Parkinson's disease (PD).

AIM

To evaluate: (1) the random error between raters (inter-rater study), (2) the random error within raters (intra-rater study), and (3) the internal consistency of the PRPP.

MATERIALS AND METHODS

(1) video-recorded performance of meaningful activities of 13 Dutch persons with PD, scored independently by 38 Dutch PRPP trained occupational therapists were included in the analysis. The random error between raters was analyzed with two-way random Intraclass Correlation Coefficients (ICC). (2) Four videos were scored twice by 30 raters (6 week time interval). The random error within raters was analyzed using one-way random ICC's. (3) Internal consistency study: data of 190 persons with PD were analyzed using Cronbach's alpha (α).

RESULTS

Inter-rater reliability ranged from slight to moderate (ICC= 0.06-0.43). The mean intra-rater reliability ranged from moderate to almost perfect (ICC= 0.60-0.83). Internal consistency is good (α = 0.60-0.86).

CONCLUSION

The limited inter-rater reliability but adequate intra-rater reliability and internal consistency show the feasibility of the PRPP when used for persons with PD. Implications for reliable clinical use are discussed.

Isothiocyanates Are Promising Compounds against Oxidative Stress, Neuroinflammation and Cell Death that May Benefit Neurodegeneration in Parkinson's Disease

Parkinson’s disease (PD) is recognized as the second most common neurodegenerative disorder and is characterized by a slow and progressive degeneration of dopaminergic neurons in the substantia nigra. Despite intensive research, the mechanisms involved in neuronal loss are not completely understood yet; however, misfolded proteins, oxidative stress, excitotoxicity and inflammation play a pivotal role in the progression of the pathology. Neuroinflammation may have a greater function in PD pathogenesis than initially believed, taking part in the cascade of events that leads to neuronal death. To date, no efficient therapy, able to arrest or slow down PD, is available. In this context, the need to find novel strategies to counteract neurodegenerative progression by influencing diseases’ pathogenesis is becoming increasingly clear. Isothiocyanates (ITCs) have already shown interesting properties in detoxification, inflammation, apoptosis and cell cycle regulation through the induction of phase I and phase II enzyme systems. Moreover, ITCs may be able to modulate several key points in oxidative and inflammatory evolution. In view of these considerations, the aim of the present review is to describe ITCs as pleiotropic compounds capable of preventing and modulating the evolution of PD.

Epidemiology of Parkinson Disease

Parkinson disease (PD) is a common progressive neurodegenerative condition, causing both motor and non motor symptoms. Motor symptoms include stiffness, slowness, rest tremor and poor postural reflexes, whereas nonmotor symptoms include abnormalities of mood, cognition, sleep and autonomic function. Affected patients show cell loss in the substantia nigra pars compacta, and accumulation of aggregated alpha-synuclein into intracellular structures called Lewy bodies, within specific brain regions. The main known non modifiable risk factor is age. The neuroepidemiology of PD is complex with susceptibility genes and a number of modifiable risk factors that can increase and others that can mitigate risk and outcome.

C-Terminal Tyrosine Residue Modifications Modulate the Protective Phosphorylation of Serine 129 of α-Synuclein in a Yeast Model of Parkinson's Disease

Parkinson´s disease (PD) is characterized by the presence of proteinaceous inclusions called Lewy bodies that are mainly composed of α-synuclein (αSyn). Elevated levels of oxidative or nitrative stresses have been implicated in αSyn related toxicity. Phosphorylation of αSyn on serine 129 (S129) modulates autophagic clearance of inclusions and is prominently found in Lewy bodies. The neighboring tyrosine residues Y125, Y133 and Y136 are phosphorylation and nitration sites. Using a yeast model of PD, we found that Y133 is required for protective S129 phosphorylation and for S129-independent proteasome clearance. αSyn can be nitrated and form stable covalent dimers originating from covalent crosslinking of two tyrosine residues. Nitrated tyrosine residues, but not di-tyrosine-crosslinked dimers, contributed to αSyn cytotoxicity and aggregation. Analysis of tyrosine residues involved in nitration and crosslinking revealed that the C-terminus, rather than the N-terminus of αSyn, is modified by nitration and di-tyrosine formation. The nitration level of wild-type αSyn was higher compared to that of A30P mutant that is non-toxic in yeast. A30P formed more dimers than wild-type αSyn, suggesting that dimer formation represents a cellular detoxification pathway in yeast. Deletion of the yeast flavohemoglobin gene YHB1 resulted in an increase of cellular nitrative stress and cytotoxicity leading to enhanced aggregation of A30P αSyn. Yhb1 protected yeast from A30P-induced mitochondrial fragmentation and peroxynitrite-induced nitrative stress. Strikingly, overexpression of neuroglobin, the human homolog of YHB1, protected against αSyn inclusion formation in mammalian cells. In total, our data suggest that C-terminal Y133 plays a major role in αSyn aggregate clearance by supporting the protective S129 phosphorylation for autophagy and by promoting proteasome clearance. C-terminal tyrosine nitration increases pathogenicity and can only be partially detoxified by αSyn di-tyrosine dimers. Our findings uncover a complex interplay between S129 phosphorylation and C-terminal tyrosine modifications of αSyn that likely participates in PD pathology.

Parkinson’s disease is characterized by loss of dopaminergic neurons in midbrain and the presence of αSyn protein inclusions. Human αSyn mimics the disease pathology in yeast resulting in cytotoxicity and aggregate formation. αSyn is abundantly phosphorylated at serine S129 and possesses four tyrosines (Y39, Y125, Y133, and Y136) that can be posttranslationally modified by nitration or phosphorylation. The consequence of each of these possible modifications is still unclear. Nitration as consequence of oxidative stress is a hallmark for neurodegenerative diseases. Here, we addressed the molecular mechanism, how tyrosine posttranslational modifications affect αSyn cytotoxicity. Tyrosine nitration can contribute to αSyn toxicity or can be part of a cellular salvage pathway when di-tyrosine-crosslinked dimers are formed. The Y133 residue, which can be either phosphorylated or nitrated, determines whether S129 is protectively phosphorylated and αSyn inclusions are cleared. This interplay with S129 phosphorylation demonstrates a dual role for C-terminal tyrosine residues. Yeast flavohemoglobin Yhb1 and its human counterpart neuroglobin NGB protect cells against cytotoxicity and aggregate formation. These novel insights into the molecular pathways responsible for αSyn cytotoxicity indicate NGB as a potential target for therapeutic intervention in PD.

The Impact of Pallidal and Subthalamic Deep Brain Stimulation on Urologic Function in Parkinson's Disease

OBJECTIVE

Deep Brain Stimulation (DBS) is an established adjunctive surgical intervention for treating Parkinson's disease (PD) motor symptoms. Both surgical targets, the globus pallidus interna (GPi) and subthalamic nucleus (STN), appear equally beneficial when treating motor symptoms but effects on nonmotor symptoms are not clear. Lower urinary tract symptoms (LUTS) are a common PD complaint. Given prior data in STN-DBS, we aimed to further explore potential benefits in LUTS in both targets.

METHODS

We performed a prospective, nonblinded clinical trial evaluating LUTS in PD patients in both targets pre and post DBS using validated urologic surveys. Participants were already slated for DBS and target selection predetermined before study entry. LUTS was evaluated using: the American Urological Association (AUA-SI), Quality of Life score (QOL), Overactive Bladder 8 Questionnaire (OAB-q), and Sexual Health Inventory for Men (SHIM).

RESULTS

Of 33 participants, 20 underwent STN DBS and 13 had GPi DBS. Patients demonstrated moderate baseline LUTS. The urologic QOL score significantly improved post DBS (3.24 ± 1.77vs. 2.52 ± 1.30; p = 0.03). Analyzed by target, only the STN showed significant change in QOL (3.20 ± 1.61 vs 2.25 ± 1.33; p = 0.04). There were no other significant differences in urologic scores post DBS noted in either target.

CONCLUSION

In PD patients with moderate LUTS, there were notable improvements in QOL for LUTS post DBS in the total sample and STN target. There may be differences in DBS effects on LUTS between targets but this will require further larger, blinded studies.

24-Hour Ambulatory Blood Pressure Monitoring in SWEDDs Patients With Parkinsonism

BACKGROUND

Patients diagnosed with Parkinson's disease (PD) on clinics who subsequently turn out to have normal dopamine transporter images have been referred to as scans without evidence of dopaminergic deficits (SWEDDs) patients. Cardiovascular autonomic dysfunction has frequently been reported in PD. In this study, we determined the similarities and differences in cardiac autonomic dysfunction between SWEDDs and PD patients. This study investigated whether 24-hour ambulatory blood pressure monitoring (24-hour ABPM) can help identify possible cases with SWEDDs.

METHODS

We enrolled 28 SWEDDs patients, 46 patients with PD, and 30 healthy controls. To evaluate cardiac autonomic function, 24-hour ABPM was performed on all subjects. Cardiac metaiodobenzylguanidine (MIBG) scintigraphy was performed on the SWEDDs and PD subjects.

RESULTS

The percentage nocturnal decline in blood pressure differed significantly among SWEDDs patients, PD patients, and controls (p<0.05). In addition to the abnormal nocturnal BP, regulation (nondipping and reverse dipping) was significantly higher in SWEDDs and PD subjects than in the control subjects (p<0.05). There was no significant correlation between the % nocturnal blood pressure reduction and parameters of cardiac MIBG uptake ratio. However, orthostatic hypotension was significant correlated with the nocturnal blood pressure dip (%), nocturnal blood pressure patterns, and the cardiac MIBG uptake ratio (early and late) in combined SWEDDs and PD subjects.

CONCLUSIONS

Pathologic nocturnal blood pressure regulation and nocturnal hypertension, known characteristics of PD, are also present in SWEDDs. Moreover, cardiac sympathetic denervation should not be attributed to cardiac autonomic dysfunction in SWEDDs patients. As with PD patients, the SWEDDs patients studied here tended to have cardiac autonomic dysfunction.

Association between Community Ambulation Walking Patterns and Cognitive Function in Patients with Parkinson's Disease: Further Insights into Motor-Cognitive Links

Background. Cognitive function is generally evaluated based on testing in the clinic, but this may not always reflect real-life function. We tested whether parameters derived from long-term, continuous monitoring of gait are associated with cognitive function in patients with Parkinson's disease (PD). Methods. 107 patients with PD (age: 64.9 ± 9.3 yrs; UPDRS motor sum “off”: 40.4 ± 13.2; 25.23% women) wore a 3D accelerometer on their lower back for 3 days. Computerized measures of global cognitive function, executive function, attention, and nonverbal memory were assessed. Three-day acceleration derived measures included cadence, variability, bilateral coordination, and dynamic postural control. Associations between the acceleration derived measures and cognitive function were determined. Results. Linear regression showed associations between vertical gait variability and cadence and between global cognitive score, attention, and executive function (p ≤ 0.048). Dynamic postural control was associated with global cognitive score and attention (p ≤ 0.027). Nonverbal memory was not associated with the acceleration-derived measures. Conclusions. These findings suggest that metrics derived from a 3-day worn body-fixed sensor reflect cognitive function, further supporting the idea that the gait pattern may be altered as cognition declines and that gait provides a window into cognitive function in patients with PD.

[Critical issues of the biopsychosocial treatment of Parkinson's disease]

This paper is a summary report on the basic questions of the biopsychosocial approach to Parkinson's disease. It deals with cognitive, affective and psychological health issues which significantly influence the outcome of the physical rehabilitation. In spite of the unchanged cognitive status, the psychological burden of the changes in the quality of life, the obstruction, the change in the affective tone, and the shrinking ability to fulfil social roles decrease the patient's quality of life. An interdisciplinary approach is best suited for mitigating these effects. Not only the patient but also his/her family and environment is seriously affected by the disease and its consequences. Treatment and rehabilitation options for increasing or maintaining the quality of life of the affected patients are diverse, and significantly depend on the features of the health care system. The authors believe that the following review emphasizing health psychological principles may contribute to the work of professionals working in clinical and rehabilitational fields and through them may increase the quality of life of patients and their family.

Association of TLR4 gene polymorphisms with sporadic Parkinson's disease in a Han Chinese population

Parkinson's disease (PD) is considered as a multifactorial disorder involving complex interactions between genetic and environmental factors, while previous studies point to a pivotal role of neuroinflammation in the pathophysiology of PD. As a member of pattern recognition receptors, TLR4 plays an important role in the immune response and inflammatory responses. Growing evidences suggest that mutation of TLR4 gene may be connected with the development of PD. The objective of this study was to evaluate whether genetic polymorphisms of the TLR4 gene are associated with PD susceptibility. We genotyped three single-nucleotide polymorphisms of the TLR4 gene (rs1927911, rs1927914 and rs10116253) by polymerase chain reaction and restriction fragment length polymorphism (PCR-RFLP) in unrelated 380 PD patients and 380 healthy-matched controls. Our study revealed that rs1927914 C allele carriers and C allele were probably related to a decreased risk of PD (p = 0.032 and p = 0.028, respectively) as well as male PD (p = 0.034) and early-onset PD (EOPD) (p = 0.023). In addition, there were significant differences in genotype and allele distribution in male PD patients and its healthy-matched control subgroup (p = 0.035 and p = 0.012, respectively). For rs1927911 and rs10116253 polymorphisms, genotype or allele frequencies did not differ between groups. Our data suggest that the TLR4 gene might contribute to the risk of developing PD in Han Chinese and rs1927914 polymorphism may be a protective factor for sporadic PD, male PD and EOPD.

Nonmotor symptoms in sporadic versus familial forms of Parkinson's disease

SUMMARY 

Besides the classical motor symptoms, Parkinson's disease (PD) patients experience a wide range of nonmotor symptoms (NMS) throughout the disease course. However, due to the lack of recognition and understanding of the pathogenesis, NMS symptoms may be overlooked. Familial PD is a well-defined group that can provide a good model to investigate the mechanisms for both motor and NMS in PD. Some studies suggest that the frequency of NMS is not different between genetic and sporadic form of PD while others suggest that specific domains (such as neuropsychiatric symptoms) are more common in the genetic form. Early recognition of NMS may facilitate early diagnosis and monitoring of both sporadic and genetic PD.

Sigma-1 receptor chaperones in neurodegenerative and psychiatric disorders

INTRODUCTION

Sigma-1 receptors (Sig-1Rs) are molecular chaperones that reside mainly in the endoplasmic reticulum (ER) but exist also in the proximity of the plasma membrane. Sig-1Rs are highly expressed in the CNS and are involved in many cellular processes including cell differentiation, neuritogenesis, microglia activation, protein quality control, calcium-mediated ER stress and ion channel modulation. Disturbance in any of the above cellular processes can accelerate the progression of many neurological disorders; therefore, the Sig-1R has been implicated in several neurological diseases.

AREAS COVERED

This review broadly covers the functions of Sig-1Rs including several neurodegenerative disorders in humans and drug addiction-associated neurological disturbance in the case of HIV infection. We discuss how several Sig-1R ligands could be utilized in therapeutic approaches to treat those disorders.

EXPERT OPINION

Emerging understanding of the cellular functions of this unique transmembrane chaperone may lead to the use of new agents or broaden the use of certain available ligands as therapeutic targets in those neurological disorders.

Proteome-wide analysis of neural stem cell differentiation to facilitate transition to cell replacement therapies

Neurodegenerative diseases are devastating disorders and the demands on their treatment are set to rise in connection with higher disease incidence. Knowledge of the spatiotemporal profile of cellular protein expression during neural differentiation and definition of a set of markers highly specific for targeted neural populations is a key challenge. Intracellular proteins may be utilized as a readout for follow-up transplantation and cell surface proteins may facilitate isolation of the cell subpopulations, while secreted proteins could help unravel intercellular communication and immunomodulation. This review summarizes the potential of proteomics in revealing molecular mechanisms underlying neural differentiation of stem cells and presents novel candidate proteins of neural subpopulations, where understanding of their functionality may accelerate transition to cell replacement therapies.

Essential tremor: a neurodegenerative disease?

Background

Essential tremor (ET) is one of the most common neurological disorders among adults, and is the most common of the many tremor disorders. It has classically been viewed as a benign monosymptomatic condition, yet over the past decade, a growing body of evidence indicates that ET is a progressive condition that is clinically heterogeneous, as it may be associated with a spectrum of clinical features, with both motor and non-motor elements. In this review, I will describe the most significant emerging milestones in research which, when taken together, suggest that ET is a neurodegenerative condition.

Methods

A PubMed search conducted in June 2014 crossing the terms “essential tremor” (ET) and “neurodegenerative” yielded 122 entries, 20 of which included the term “neurodegenerative” in the article title. This was supplemented by articles in the author's files that pertained to this topic.

Results/Discussion

There is an open and active dialogue in the medical community as to whether ET is a neurodegenerative disease, with considerable evidence in favor of this. Specifically, ET is a progressive disorder of aging associated with neuronal loss (reduction in Purkinje cells) as well as other post-mortem changes that occur in traditional neurodegenerative disorders. Along with this, advanced neuroimaging techniques are now demonstrating distinct structural changes, several of which are consistent with neuronal loss, in patients with ET. However, further longitudinal clinical and neuroimaging longitudinal studies to assess progression are required.

Copper and copper proteins in Parkinson's disease

Copper is a transition metal that has been linked to pathological and beneficial effects in neurodegenerative diseases. In Parkinson's disease, free copper is related to increased oxidative stress, alpha-synuclein oligomerization, and Lewy body formation. Decreased copper along with increased iron has been found in substantia nigra and caudate nucleus of Parkinson's disease patients. Copper influences iron content in the brain through ferroxidase ceruloplasmin activity; therefore decreased protein-bound copper in brain may enhance iron accumulation and the associated oxidative stress. The function of other copper-binding proteins such as Cu/Zn-SOD and metallothioneins is also beneficial to prevent neurodegeneration. Copper may regulate neurotransmission since it is released after neuronal stimulus and the metal is able to modulate the function of NMDA and GABA A receptors. Some of the proteins involved in copper transport are the transporters CTR1, ATP7A, and ATP7B and the chaperone ATOX1. There is limited information about the role of those biomolecules in the pathophysiology of Parkinson's disease; for instance, it is known that CTR1 is decreased in substantia nigra pars compacta in Parkinson's disease and that a mutation in ATP7B could be associated with Parkinson's disease. Regarding copper-related therapies, copper supplementation can represent a plausible alternative, while copper chelation may even aggravate the pathology.