Nonmotor symptoms in patients with Parkinson disease: A cross-sectional observational study

Does hazelnut consumption affect brain health and function against neurodegenerative diseases?

INTRODUCTION

A healthy daily diet and consuming certain nutrients, such as polyphenols, vitamins, and unsaturated fatty acids, may help neuronal health maintenance. Polyphenolic chemicals, which have antioxidant and anti-inflammatory properties, are involved in the neuroprotective pathway. Because of their nutritional value, nuts have been shown in recent research to be helpful in neuroprotection.

OBJECTIVE

Hazelnut is often consumed worldwide in various items, including processed foods, particularly in bakery, chocolate, and confectionery products. This nut is an excellent source of vitamins, amino acids, tocopherols, phytosterols, polyphenols, minerals, and unsaturated fatty acids. Consuming hazelnut may attenuate the risk of neurodegenerative disorders including Alzheimer's disease, Parkinson's disease, amyotrophic lateral sclerosis, multiple sclerosis, and Huntington's disease due to its anti-inflammatory and anti-oxidant qualities.

RESULTS

Many documents introduce hazelnut as an excellent choice to provide neuroprotection against neurodegenerative disorders and there is some direct proof of its neuroprotective effects.

DISCUSSION

So hazelnut consumption in daily diet may reduce neurodegenerative disease risk and be advantageous in reducing the imposed costs of dealing with neurodegenerative diseases.

Role of the Gut Microbiome and Bacterial Amyloids in the Development of Synucleinopathies

Less than ten years ago, evidence began to accumulate about association between the changes in the composition of gut microbiota and development of human synucleinopathies, in particular sporadic form of Parkinson's disease. We collected data from more than one hundred and thirty experimental studies that reported similar results and summarized the frequencies of detection of different groups of bacteria in these studies. It is important to note that it is extremely rare that a unidirectional change in the population of one or another group of microorganisms (only an elevation or only a reduction) was detected in the patients with Parkinson's disease. However, we were able to identify several groups of bacteria that were overrepresented in the patients with Parkinson's disease in the analyzed studies. There are various hypotheses about the molecular mechanisms that explain such relationships. Usually, α-synuclein aggregation is associated with the development of inflammatory processes that occur in response to the changes in the microbiome. However, experimental evidence is accumulating on the influence of bacterial proteins, including amyloids (curli), as well as various metabolites, on the α-synuclein aggregation. In the review, we provided up-to-date information about such examples.

The Influence of Kynurenine Metabolites on Neurodegenerative Pathologies

As the kynurenine pathway's links to inflammation, the immune system, and neurological disorders became more apparent, it attracted more and more attention. It is the main pathway through which the liver breaks down Tryptophan and the initial step in the creation of nicotinamide adenine dinucleotide (NAD+) in mammals. Immune system activation and the buildup of potentially neurotoxic substances can result from the dysregulation or overactivation of this pathway. Therefore, it is not shocking that kynurenines have been linked to neurological conditions (Depression, Parkinson's, Alzheimer's, Huntington's Disease, Schizophrenia, and cognitive deficits) in relation to inflammation. Nevertheless, preclinical research has demonstrated that kynurenines are essential components of the behavioral analogs of depression and schizophrenia-like cognitive deficits in addition to mediators associated with neurological pathologies due to their neuromodulatory qualities. Neurodegenerative diseases have been extensively associated with neuroactive metabolites of the kynurenine pathway (KP) of tryptophan breakdown. In addition to being a necessary amino acid for protein synthesis, Tryptophan is also transformed into the important neurotransmitters tryptamine and serotonin in higher eukaryotes. In this article, a summary of the KP, its function in neurodegeneration, and the approaches being used currently to target the route therapeutically are discussed.

Cognitive Effects of Three β-Adrenoceptor Acting Drugs in Healthy Volunteers and Patients with Parkinson's Disease

Background

Noradrenergic signaling declines in Parkinson's disease (PD) following locus coeruleus neurodegeneration. Epidemiologic studies demonstrate that β-acting drugs slow PD progression.

Objective

The primary objective was to compare the safety and effects of 3 β-adrenoceptor (β-AR) acting drugs on central nervous system (CNS) function after a single dose in healthy volunteers (HVs) and evaluate the effects of multiple doses of β-AR acting drugs in HVs and PD-patients.

Methods

In Part A, HVs received single doses of 32 mg salbutamol, 160μg clenbuterol, 60 mg pindolol and placebo administered in a randomized, 4-way cross-over study. In Part B (randomized cross-over) and Part C (parallel, 2:1 randomized), placebo and/or clenbuterol (20μg on Day 1, 40μg on Day 2, 80μg on Days 3-7) were administered. CNS functions were assessed using the NeuroCart test battery, including pupillometry, adaptive tracking and recall tests.

Results

Twenty-seven HVs and 12 PD-patients completed the study. Clenbuterol improved and pindolol reduced the adaptive tracking and immediate verbal recall performance. Clenbuterol and salbutamol increased and pindolol decreased pupil-to-iris ratios. Clenbuterol was selected for Parts B and C. In Part B, clenbuterol significantly increased performance in adaptive tracking with a tendency toward improved performance in immediate and delayed verbal recall. In Part C trends toward improved performance in immediate and delayed verbal recall were observed in PD-patients. Typical cardiovascular peripheral β2-AR effects were observed with clenbuterol.

Conclusions

This study demonstrates the pro-cognitive effects of clenbuterol in HVs with similar trends in PD-patients. The mechanism of action is likely activation of β2-ARs in the CNS.

Olfactory dysfunction in patients with Parkinson's disease: A systematic review and meta-analysis

Background: Parkinson's disease (PD) is a progressive neuro-degenerative disease and olfactory dysfunction is considered as an important issue in these patients. The prevalence of olfactory dysfunction in patients with PD was reported variously in previous studies. Therefore, we designed this systematic review and meta-analysis to estimate the pooled prevalence of olfactory dysfunction in patients with PD. Methods: Two expert researchers systematically searched PubMed, Scopus, EMBASE, Web of Science, Google Scholar, references of the papers, and conference abstracts. The titles and abstracts of the potential studies were evaluated after deleting the duplicates. We extracted data regarding the total number of participants, first author, publication year, the country of origin, mean age, mean disease duration, female/male, number with olfactory dysfunction, and name of the test. We evaluated the risk of potential bias by the Newcastle-Ottawa Quality Assessment Scale (adapted for cross-sectional studies). All statistical analyses were done using Stata software. To determine heterogeneity between the findings of included studies, inconsistency (I2) was calculated. We applied random effect model when I2 was more than 50%. P-value less than 0.05 was considered significant. Results: The literature search revealed 1546 studies; after deleting duplicates, 894 remained. Finally, twelve studies remained for meta-analysis. Studies were published between years of 2009 to 2021, the sample size of studies ranged between 30 and 2097, and the mean age ranged between 61 and 70 years. The pooled prevalence of olfactory dysfunction in patients with PD was estimated as 64% [95% confidence interval (CI): 44-84, I2 = 99.7%, P < 0.001]. The pooled prevalence of olfactory dysfunction using Sniffin's test was 67% (95% CI: 51-83) and using other tests was 60% (95% CI: 28-92). Conclusion: The results of this systematic review and meta-analysis showed that the pooled prevalence of olfactory dysfunction in patients with PD was 64% which should be considered by physicians.

The Crucial Role of the Interstitial Cells of Cajal in Neurointestinal Diseases

Neurointestinal diseases result from dysregulated interactions between the nervous system and the gastrointestinal (GI) tract, leading to conditions such as Hirschsprung's disease and irritable bowel syndrome. These disorders affect many people, significantly diminishing their quality of life and overall health. Central to GI motility are the interstitial cells of Cajal (ICC), which play a key role in muscle contractions and neuromuscular transmission. This review highlights the role of ICC in neurointestinal diseases, revealing their association with various GI ailments. Understanding the functions of the ICC could lead to innovative perspectives on the modulation of GI motility and introduce new therapeutic paradigms. These insights have the potential to enhance efforts to combat neurointestinal diseases and may lead to interventions that could alleviate or even reverse these conditions.

Sexual Dysfunction and Related Factors in Patients With Parkinson's Disease

The current cross-sectional study investigated sexual dysfunction and related factors in patients with Parkinson's disease (PD). The sample comprised 76 patients with PD in the neurology clinic of a training and research hospital. Data were collected using the Hospital Anxiety and Depression Scale and Arizona Sexual Experiences Scale. Approximately nine (88.2%) in 10 participants had sexual dysfunction. Sexual dysfunction depended on sex, educational background, employment status, side effects, body image, difficulty falling asleep, self-care, and walking dependence. Sexual dysfunction was positively correlated with age and symptoms of depression and anxiety. Sexual dysfunction was more prevalent in females than males. Advanced age and high risk of depression resulted in increased prevalence of sexual dysfunction. Health care professionals should evaluate the causes of sexual dysfunction and plan and implement appropriate interventions for patients with PD. [Journal of Psychosocial Nursing and Mental Health Services, 61(3), 45-55.].

The Clinical Development of Levodopa Inhalation Powder

ABSTRACT

Oral levodopa is the most effective treatment for Parkinson disease, but OFF periods emerge over time. Gastrointestinal dysfunction and food effects impact levodopa absorption, contributing to unpredictable control of OFF periods. Inhaled levodopa powder (Inbrija) is approved for on-demand treatment of OFF periods in patients receiving oral levodopa-dopa decarboxylase inhibitors. The 84-mg dose is administered via a breath-actuated inhaler. It provides pulmonary delivery of levodopa to the systemic circulation and is taken when a patient has an OFF period in between doses of regular oral levodopa medication. The pivotal SPAN-PD trial in patients experiencing OFF periods on oral dopaminergic therapy showed that levodopa inhalation powder 84 mg produced significant improvement in Unified Parkinson Disease Rating Scale Part III score, as measured 30 minutes postdose at week 12, and improvement was seen as early as 10 minutes. More patients in the levodopa inhalation powder group turned ON within 60 minutes of treatment and remained ON at 60 minutes than in the placebo group. Levodopa inhalation powder can also be used to treat early-morning OFF periods and, when used for up to 12 months, produced no clinically significant differences in pulmonary function compared with an untreated cohort. Levodopa inhalation powder 84 mg increased plasma levodopa concentration rapidly and with less variability than oral levodopa/carbidopa (25/100 mg). Most common adverse event associated with levodopa inhalation powder is cough, found in ~15% of patients in the SPAN-PD trial; otherwise, reported adverse events were consistent with those known to be associated with oral levodopa.

Cordycepin improved the cognitive function through regulating adenosine A2A receptors in MPTP induced Parkinson's disease mice model

BACKGROUND

Parkinson's disease (PD), the most common neurodegenerative disorder, primarily affects dopaminergic neurons in the substantia nigra (SN). In addition to severe motor dysfunction, PD patients appear apparent cognitive impairments in the late stage. Cognitive dysfunction is accompanied by synaptic transmission damage in the hippocampus. Cordycepin has been reported to alleviate cognitive impairments in neurodegenerative diseases.

PURPOSE

The study aimed to estimate the protection roles of cordycepin on cognitive dysfunction in PD model and explore the potential mechanisms.

METHODS

1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine (MPTP) was used to establish the PD model in vivo and in vitro experiments. In the in vivo experiments, the C57BL / 6 mice were intraperitoneally injected with MPTP and intragastric administration with cordycepin. Open field test (OFT) was used to estimate the exercise ability. Spontaneous alternation behavioral (SAB) and morris water maze (MWM) tests were used to evaluate the learning and memory abilities. The hippocampal slices from C57BL / 6 and Kunming mice in the in vitro experiments were used to record field excitatory postsynaptic potential (fEPSP) by electrophysiological methods. Western blotting was used to examine the level of tyrosine hydroxylase (TH) in the in vivo experiments and the levels of adenosine A₁ and A_2A receptors (A₁R and A_2AR) in the in vitro experiments, respectively. The drugs of MPTP, cordycepin, DPCPX and SCH58261 were perfused through dissolving in artificial cerebrospinal fluid.

RESULTS

Cordycepin could significantly reduce the impairments on motor, exploration, spatial learning and memory induce by MPTP. MPTP reduced the amplitude of LTP in hippocampal CA1 area but cordycepin could improve LTP amplitudes. Cordycepin at dosage of 20 mg/kg also increased the TH level in SN. In the in vitro experiments, MPTP inhibited synaptic transmission in hippocampal Schaffer-CA1 pathway with a dose-dependent relationship, while cordycepin could reverse the inhibition of synaptic transmission. Furthermore, the roles of cordycepin on synaptic transmission could been attenuated in the presence of the antagonists of A₁R and A_2AR, DPCPX and SCH58261, respectively. Interestingly, the level of A_2AR rather than A₁R in hippocampus was significantly decreased in the cordycepin group as compared to the control.

CONCLUSION

The present study has showed that cordycepin could improve cognitive function in the PD model induced by MPTP through regulating the adenosine A_2A receptors. These findings were helpful to provide a new strategy for the dementia caused by Parkinson's disease.

Parkinson disease primer, part 2: management of motor and nonmotor symptoms

OBJECTIVE

To provide family physicians with an approach to the management of motor and nonmotor symptoms of Parkinson disease (PD).

SOURCES OF INFORMATION

Published guidelines on the management of PD were reviewed. Database searches were conducted to retrieve relevant research articles published between 2011 and 2021. Evidence levels ranged from I to III.

MAIN MESSAGE

Family physicians can play an important role in identifying and treating motor and nonmotor symptoms of PD. Family physicians should initiate levodopa treatment for motor symptoms if they affect function and if specialist wait times are long, and they should be aware of basic titration approaches and possible side effects of dopaminergic therapies. Abrupt withdrawal of dopaminergic agents should be avoided. Nonmotor symptoms are common and underrecognized and are a major factor in disability, quality of life, and risk of hospitalization and poor outcomes for patients. Family physicians can manage common autonomic symptoms such as orthostatic hypotension and constipation. Family physicians can treat common neuropsychiatric symptoms such as depression and sleep disorders, and they can help recognize and treat psychosis and PD dementia. Referrals to physiotherapy, occupational therapy, speech language therapy, and exercise groups are recommended to help preserve function.

CONCLUSION

Patients with PD present with complex combinations of motor and nonmotor symptoms. Family physicians should have basic knowledge of dopaminergic treatments and their side effects. Family physicians can play important roles in management of motor symptoms and particularly nonmotor symptoms and can have a positive impact on patients' quality of life. An interdisciplinary approach involving specialty clinics and allied health experts is an important part of management.

Abécédaire de la maladie de Parkinson, partie 2 : prise en charge des symptômes moteurs et non moteurs

Objectif

Présenter aux médecins de famille une approche pour la prise en charge des symptômes moteurs et non moteurs de la maladie de Parkinson (MP).

Sources de l’information

Les lignes directrices sur la prise en charge de la MP ont été passées en revue. Des recensions dans les bases de données ont été effectuées pour en extraire les articles de recherche publiés entre 2011 et 2021. Le niveau des données probantes varie entre I et III.

Message principal

Les médecins de famille peuvent jouer un rôle important dans la détection et le traitement des symptômes moteurs et non moteurs de la MP. Les médecins de famille devraient amorcer un traitement à la lévodopa pour les symptômes moteurs s’ils nuisent au fonctionnement et si les temps d’attente pour voir un spécialiste sont longs. Ils devraient être au courant des approches de base du titrage, de même que les effets secondaires possibles des thérapies dopaminergiques. Il faudrait éviter une cessation abrupte des agents dopaminergiques. Les symptômes non moteurs sont fréquents et peu reconnus, et ils influent grandement sur l’incapacité, la qualité de vie, le risque d’hospitalisation et les mauvais résultats chez les patients. Les médecins de famille peuvent prendre en charge les symptômes courants du fonctionnement autonome, comme l’hypotension orthostatique et la constipation. Ils peuvent traiter les symptômes neuropsychiatriques communs, comme la dépression et les troubles du sommeil, et aider à reconnaître et à traiter la psychose et la démence de la MP. Il est recommandé de demander des consultations en physiothérapie, en ergothérapie et en orthophonie, et de conseiller les groupes d’activité physique pour aider à préserver le fonctionnement.

Conclusion

Les patients atteints de la MP présentent des combinaisons complexes de symptômes moteurs et non moteurs. Les médecins de famille devraient avoir des connaissances de base sur les traitements dopaminergiques et leurs effets secondaires. Les médecins de famille peuvent jouer des rôles importants dans la prise en charge des symptômes moteurs, et surtout des symptômes non moteurs, et ils peuvent exercer une influence positive sur la qualité de vie des patients. Une approche interdisciplinaire impliquant des cliniques et d’autres professionnels de la santé spécialisés est une importante composante de la prise en charge.

The Potential Roles of Extracellular Vesicles as Biomarkers for Parkinson’s Disease: A Systematic Review

Parkinson’s disease (PD) is a slowly progressive neurodegenerative disorder, characterized by the misfolding and aggregation of α-synuclein (α-syn) into Lewy bodies and the degeneration of dopaminergic neurons in the substantia nigra pars compacta. The urge for an early diagnosis biomarker comes from the fact that clinical manifestations of PD are estimated to appear once the substantia nigra has deteriorated and there has been a reduction of the dopamine levels from the striatum. Nowadays, extracellular vesicles (EVs) play an important role in the pathogenesis of neuro-degenerative diseases as PD. A systematic review dated August 2022 was carried out with the Preferred Reporting Items for Systematic Reviews and Meta-Analyses with the aim to analyze the potential role of EVs as biomarkers for PD. From a total of 610 articles retrieved, 29 were eligible. This review discusses the role of EVs biochemistry and their cargo proteins, such as α-syn and DJ-1 among others, detected by a proteomic analysis as well as miRNAs and lncRNAs, as potential biomarkers that can be used to create standardized protocols for early PD diagnosis as well as to evaluate disease severity and progression.

Comparative Analysis of the Effects of Escitalopram, Pramipexole, and Transcranial Magnetic Stimulation on Depression in Patients With Parkinson Disease: An Open-Label Randomized Controlled Trial

OBJECTIVE

This study aimed to compare the effects of different antidepressant therapies on depression in patients with Parkinson disease (PD) and to provide a reference for clinical treatment.

METHODS

A total of 328 patients with idiopathic PD were selected consecutively. Subjects met Diagnostic and Statistical Manual of Mental Disease, Fourth Edition, criteria for a depressive disorder, or operationally defined subsyndromal depression, and scored greater than 17 on the 17-item Hamilton Depression Scale (HAMD-17). One hundred thirty-one patients with PD accompanied with depression were enrolled into the experimental group. The subjects were randomly divided into 4 groups, and 118 were eventually completed: routine treatment group (n = 29), routine treatment + escitalopram group (n = 29), routine treatment + pramipexole group (n = 31), and routine treatment + transcranial magnetic stimulation (TMS) group (n = 29). After 4 weeks of treatments, the efficacy of each treatment was evaluated using HAMD score and reduction rate.

RESULTS

After 4 weeks of treatment, the HAMD score was used for pair-to-pair comparison between the 4 groups. The therapeutic efficiency of escitalopram, pramipexole, and repetitive TMS was superior to routine anti-PD treatment, and the differences were statistically significant (P < 0.05). There was no statistical difference between escitalopram and pramipexole, but all of them were superior to rTMS. Further logistic regression analysis suggested that 50% reduction in HAMD score from baseline was associated with the treatment method. Among them, escitalopram had statistical significance (P < 0.05).

CONCLUSIONS

Escitalopram, pramipexole, and high-frequency TMS had better efficacy in patients with PD complicated with depression. At 4 weeks, escitalopram showed better antidepressant effects and improved patients' quality of life and did not worsen motor function.

Pathophysiology and Symptomatology of Drooling in Parkinson’s Disease

Drooling can present in patients with Parkinson’s disease (PD), and it is manifested as an excessive pooling of saliva inside the oral cavity. Currently, the exact pathophysiological mechanism of drooling in PD is not yet fully explicated. Thus, it becomes crucial to understand if some clinical characteristics may emphasize drooling or if they are just concomitant. In PD, excessive drooling has been associated with a higher burden of non-motor symptoms, such as cognitive impairment, sleep problems, autonomic dysfunction, constipation and orthostatic hypotension, and of worse severity of motor fluctuations and bradykinesia. PD patients with excessive drooling also showed a reduction of striatal DAT availability at DaTSCAN imaging. Excessive drooling in patients with Parkinson’s cannot be attributed to a single factor but to a mixture of factors, including but not limited to impaired nigrostriatal pathways.

Self-Reported Visual Complaints in People with Parkinson's Disease: A Systematic Review

BACKGROUND

Scientific research increasingly focuses on visual symptoms of people with Parkinson's disease (PD). However, this mostly involves functional measures, whereas self-reported data are equally important for guiding clinical care.

OBJECTIVE

This review provides an overview of the nature and prevalence of self-reported visual complaints by people with PD, compared to healthy controls.

METHODS

A systematic literature search was performed. Studies from three databases (PubMed, PsycInfo, and Web of Science) were screened for eligibility. Only studies that reported results of visual self-reports in people with idiopathic PD were included.

RESULTS

One hundred and thirty-nine eligible articles were analyzed. Visual complaints ranged from function-related complaints (e.g., blurred vision, double vision, increased sensitivity to light or changes in contrast sensitivity) to activity-related complaints (e.g., difficulty reading, reaching, or driving). Visual complaints were more prevalent in people with PD compared to healthy controls. The presence of visual complaints leads to a reduced quality of life (QoL). Increased prevalence and severity of visual complaints in people with PD are related to longer disease duration, higher disease severity, and off-state.

CONCLUSION

A large proportion of people with PD have visual complaints, which negatively affect QoL. Complaints are diverse in nature, and specific and active questioning by clinicians is advised to foster timely recognition, acknowledgement, and management of these complaints.

Relationship between sleep disorders and neuropsychiatric symptoms in Parkinson's disease: A narrative review

Aim: The objective of this narrative review was to describe the versatile links between mental status and sleep in patients with Parkinson's disease. Methods: We searched randomized controlled studies, observational studies, meta-analyses, systematic reviews, and case reports written in English in PubMed during 2015 - 2021. Additionally, to ensure the completeness of the review, a second, more in-depth literature search was performed using the same electronic database with the search inquiries of increased specificity. Results: The information on pathophysiology, epidemiology, clinical features and risk factors was extracted and formed the basis for this review. Despite how widespread sleep disorders in Parkinson's disease are, there is no systematic information about their association with neuropsychiatric symptoms, such as depression, anxiety, impulse control disorders, apathy, cognitive impairment and psychosis. In this review, we described relationships between these non-motor symptoms of Parkinson's disease, their timeline occurrence, gap in knowledge and perspectives for further research. We suppose that early treatment of sleep disorders in patients with Parkinson's disease can reduce the incidence and extent of neuropsychiatric symptoms. Conclusion: We have demonstrated multiple, multidirectional relationships between sleep disorders and neuropsychiatric symptoms. However, some of them remain unexplored. The described knowledge can be applied to further study the possibility of influencing neuropsychiatric symptoms through the correction of sleep disorders in patients with different stages of Parkinson's disease.

Assessment of Non-Motor Symptoms of Parkinson's Disease and Their Impact on the Quality of Life: An Observatiobnal Study

Background

During the past decade the view of Parkinson's disease (PD) as a motor disorder has changed significantly and currently it is recognized as a multisystem disorder with diverse non-motor symptoms (NMS).

Aims

The present study aimed to evaluate and characterize the NMS and study their impact on quality of life (QoL) in a PD patient cohort.

Material and Methods

This was a cross-sectional study where 92 PD patients fulfilling the UK Parkinson's disease society brain bank criteria were enrolled from a movement disorder clinic. All patients were evaluated using unified Parkinson's disease rating scale, non-motor symptoms scale (NMSS) for the non-motor symptoms, and Parkinson's disease questionnaire-39 (PDQ-39) for the QoL. The impact of NMS on QoL was assessed statistically.

Results

A total of 92 patients were enrolled with a mean age of 55.40 ± 7.37 years, mean age of onset of disease 51.62 ± 6.38 years, and mean disease duration of 3.78 ± 1.54 years. Type of disease was akinetic rigid variant in 29.3% (n = 27), tremor predominant type in 36.9%(n = 34), and mixed type in 33.6% (n = 31). Mean Hoehn and Yahr stage was 2.12 ± 0.54. In the NMSS, most common symptom was sleep and fatigue (83%), followed by urinary tract symptoms (63%), mood and cognition (51%), cardiovascular symptoms and falls (43%), gastrointestinal tract symptoms (38%), and sexual function (33%). Univariate analyses showed that all NMS domains had a significant correlation with PDQ-39 with P < 001.

Conclusion

Our study shows that NMS in PDare fairly common and significantly impact the QoL.

Polyphenols and Stem Cells for Neuroregeneration in Parkinson's Disease and Amyotrophic Lateral Sclerosis

Parkinson's disease (PD) and Amyotrophic lateral sclerosis (ALS) are neurological disorders, pathologically characterized by chronic degeneration of dopaminergic neurons and motor neurons respectively. There is still no cure or effective treatment against the disease progression and most of the treatments are symptomatic. The present review offers an overview of the different factors involved in the pathogenesis of these diseases. Subsequently, we focused on the recent advanced studies of dietary polyphenols and stem cell therapies, which have made it possible to slow down the progression of neurodegeneration. To date, stem cells and different polyphenols have been used for the directional induction of neural stem cells into dopaminergic neurons and motor neurons. We have also discussed their involvement in the modulation of different signal transduction pathways and growth factor levels in various in vivo and in vitro studies. Likewise stem cells, polyphenols also exhibit the potential of neuroprotection by their anti-apoptotic, anti-inflammatory, anti-oxidant properties regulating the growth factors levels and molecular signaling events. Overall this review provides a detailed insight into recent strategies that promise the use of polyphenol with stem cell therapy for the possible treatment of PD and ALS.

The Biology and Pathobiology of Glutamatergic, Cholinergic, and Dopaminergic Signaling in the Aging Brain

The elderly population is growing worldwide, with important health and socioeconomic implications. Clinical and experimental studies on aging have uncovered numerous changes in the brain, such as decreased neurogenesis, increased synaptic defects, greater metabolic stress, and enhanced inflammation. These changes are associated with cognitive decline and neurobehavioral deficits. Although aging is not a disease, it is a significant risk factor for functional worsening, affective impairment, disease exaggeration, dementia, and general disease susceptibility. Conversely, life events related to mental stress and trauma can also lead to accelerated age-associated disorders and dementia. Here, we review human studies and studies on mice and rats, such as those modeling human neurodegenerative diseases, that have helped elucidate (1) the dynamics and mechanisms underlying the biological and pathological aging of the main projecting systems in the brain (glutamatergic, cholinergic, and dopaminergic) and (2) the effect of defective glutamatergic, cholinergic, and dopaminergic projection on disabilities associated with aging and neurodegenerative disorders, such as Alzheimer's and Parkinson's diseases. Detailed knowledge of the mechanisms of age-related diseases can be an important element in the development of effective ways of treatment. In this context, we briefly analyze which adverse changes associated with neurodegenerative diseases in the cholinergic, glutaminergic and dopaminergic systems could be targeted by therapeutic strategies developed as a result of our better understanding of these damaging mechanisms.

Characterization of nonmotor behavioral impairments and their neurochemical mechanisms in the MitoPark mouse model of progressive neurodegeneration in Parkinson's disease

Mitochondrial dysfunction has been implicated as a key player in the pathogenesis of Parkinson's disease (PD). The MitoPark mouse, a transgenic mitochondrial impairment model developed by specific inactivation of TFAM in dopaminergic neurons, spontaneously exhibits progressive motor deficits and neurodegeneration, recapitulating several features of PD. Since nonmotor symptoms are now recognized as important features of the prodromal stage of PD, we comprehensively assessed the clinically relevant motor and nonmotor deficiencies from ages 8-24 wk in both male and female MitoPark mice and their littermate controls. As expected, motor deficits in MitoPark mice began around 12-14 wk and became severe by 16-24 wk. Interestingly, MitoPark mice exhibited olfactory deficits in the novel and social scent tests as early as 10-12 wk as compared to age-matched littermate controls. Additionally, male MitoPark mice showed spatial memory deficits before female mice, beginning at 8 wk and becoming most severe at 16 wk, as determined by the Morris water maze. MitoPark mice between 16 and 24 wk spent more time immobile in forced swim and tail suspension tests, and made fewer entries into open arms of the elevated plus maze, indicating a depressive and anxiety-like phenotype, respectively. Importantly, depressive behavior as determined by immobility in forced swim test was reversible by antidepressant treatment with desipramine. Neurochemical and mechanistic studies revealed significant changes in CREB phosphorylation, BDNF, and catecholamine levels as well as neurogenesis in key brain regions. Collectively, our results indicate that MitoPark mice progressively exhibit deficits in olfactory discrimination, cognitive learning and memory, and anxiety- and depression-like behaviors as well as key neurochemical signaling associated with nonmotor deficits in PD. Thus, MitoPark mice can serve as an invaluable model for studying nonmotor deficits in addition to studying the motor deficits related to pathology in PD.

The role of glutamatergic neurotransmission in the motor and non-motor symptoms in Parkinson's disease: Clinical cases and a review of the literature

Glutamate is the major excitatory neurotransmitter in the central nervous system and, as such, many brain regions, including the basal ganglia, are rich in glutamatergic neurons. The importance of the basal ganglia in the control of voluntary movement has long been recognised, with the effect of dysfunction of the region exemplified by the motor symptoms seen in Parkinson's disease (PD). However, the basal ganglia and the associated glutamatergic system also play a role in the modulation of emotion, nociception and cognition, dysregulation of which result in some of the non-motor symptoms of PD (depression/anxiety, pain and cognitive deficits). Thus, while the treatment of PD has traditionally been approached from the perspective of dopaminergic replacement, using agents such as levodopa and dopamine receptor agonists, the glutamatergic system offers a novel treatment target for the disease. Safinamide has been approved in over 20 countries globally for fluctuating PD as add-on therapy to levodopa regimens for the management of 'off' episodes. The drug has both dopaminergic and non-dopaminergic pharmacological effects, the latter including inhibition of abnormal glutamate release. The effect of safinamide on the glutamatergic system might present some advantages over dopamine-based therapies for PD by providing efficacy for motor (levodopa-induced dyskinesia) as well as non-motor (anxiety, mood disorders, pain) symptoms. In this article, we discuss the potential role of glutamatergic inhibition on these symptoms, using illustrative real-world examples of patients we have treated with safinamide.

Topological changes in white matter connectivity network in patients with Parkinson's disease and depression

Depression is the most common non-motor symptom accompanying Parkinson's disease (PD) with high prevalence but unclear pathophysiological mechanism. Relatively little is known about the topological patterns of white matter structural networks in depressed patients with PD. In this study, we used diffusion-tensor imaging (DTI) and graph theory approaches to explore the brain structural connectome in non-depressed patients with PD (n = 47), depressed patients with PD (n = 20) and healthy controls (n = 46). All three groups exhibited small-world topology. Compared with healthy controls, non-depressed patients with PD and depressed patients with PD showed a significant reduction of network efficiency in the cortico-subcortical circuits. Moreover, depressed patients with PD exhibited higher network efficiency in fronto-limbic system, compared to non-depressed patients with PD. To sum up, our data indicated a disrupted integrity in the large-scale brain systems in depressed patients with PD patients. The structural connectome provided a basis for functional alterations in depressed patients with PD that may advance our current understanding of pathophysiological mechanism underlying Parkinson's disease.

The Impact of Depression Symptoms in Patients with Parkinson's Disease: A Novel Case-Control Investigation

Parkinson's disease is a common neurodegenerative disease and it is known to cause motor disturbances associated with musculoskeletal problems of the locomotor apparatus, and non-motor symptoms, that are believed to have a harmful effect on health, social functioning and mobility. The aim of this study was to evaluate depression in patients with Parkinson's Disease (PD) compared to subjects who do not have it. The sample consisted of 124 participants (mean age 69.18 ± 9.12). Patients with PD were recruited from a center of excellence for Parkinson's disease (cases n = 62) and healthy subjects without PD from their relatives and caregivers (control n = 62). The Spanish version of Beck's Depression Inventory (BDI) scores and categories were collected. A clear statistically significant difference (p < 0.05) was evident in the BDI scores between both groups. Parkinson's patients presented worse results on the BDI = 15.48 ± 7.24 points compared to healthy subjects with BDI = 7.03 ± 6.99 points. Regarding BDI categories, there were statistically significant differences (p < 0.001) for the greater BDI categories in the Parkinson's group compared with healthy subjects. The depression represents an important potential risk for increased symptoms and negative impact among patients with PD compared with healthy subjects.

Clinical features and relative factors of constipation in a cohort of Chinese patients with Parkinson's disease

BACKGROUND

Constipation as a most common non-motor symptom of Parkinson's disease (PD), has a higher prevalence compared to the general population. The etiologies of constipation in PD are diverse. In addition to physical weakness and other factors of disease, the lifestyles and eating habits are also important factors. Therefore, the prevalence and influencing factors of constipation may vary among different populations.

AIM

To determine the prevalence of constipation and analyze relative factors in a cohort of Chinese patients with PD.

METHODS

All the patients diagnosed with PD according to the movement disorders society criteria were consecutively collected by a self-developed questionnaire. Rome III diagnostic criteria were used to assess functional constipation and Wexner score was used to estimate the severity of constipation. Non-motor symptoms (NMS) were assessed with the non-motor symptoms assessment scale (NMSS). Unified Parkinson's disease Rating Scale III (UPDRS III) was used to evaluate the severity of motor symptoms. The modified Hoehn-Yahr stage was used to evaluate the severity of PD. Cognitive function was assessed using Montreal cognitive assessment (MoCA). Depression and anxiety were rated with the Hamilton depression scale (HAMD) and the Hamilton anxiety scale (HAMA). Quality of life was assessed using the Parkinson’s disease Questionnaire-39 items (PDQ-39).

RESULTS

Of 166 patients enrolled, 87 (52.41%) were accompanied with constipation, and 30 (34.48%) experienced constipation for 6.30 ± 5.06 years before motor symptoms occurred. Age, Hoehn-Yahr stage, disease duration, levodopa medication times, incidence of motor complications, the scores of UPDRS total, UPDRS III, NMSS, HAMD, HAMA, and PDQ-39 in the constipation group were higher than those in the non-constipation group (P < 0.05), but there was no difference in the scores of MoCA, clinical types, or medications between the two groups (P > 0.05). There was a higher incidence of depression in patients with constipation (P < 0.05), but there were no difference in the incidence of anxiety and cognitive impairment between the two groups (P > 0.05). As Hoehn-Yahr stages increased, the severity of constipation increased (P < 0.05), but not the incidence of constipation (P > 0.05). Pearson correlation analysis showed that constipation was moderately positively correlated with age, Hoehn-Yahr stage, and scores of NMSS, UPDRS III, UPDRS total, PDQ-39, HAMD, and HAMA (r = 0.255, 0.172, 0.361, 0.194, 0.221, 0.237, 0.238, and 0.207, P < 0.05). Logistic regression analysis showed that only NMSS score was an independent risk factor for constipation (P < 0.001).

CONCLUSION

Our findings confirm that constipation has a relatively high frequency in patients with PD. PD patients with constipation have a higher incidence of depression, which leads to worse quality of life.

Energy Metabolism Decline in the Aging Brain-Pathogenesis of Neurodegenerative Disorders

There is a growing body of evidencethat indicates that the aging of the brain results from the decline of energy metabolism. In particular, the neuronal metabolism of glucose declines steadily, resulting in a growing deficit of adenosine triphosphate (ATP) production-which, in turn, limits glucose access. This vicious circle of energy metabolism at the cellular level is evoked by a rising deficiency of nicotinamide adenine dinucleotide (NAD) in the mitochondrial salvage pathway and subsequent impairment of the Krebs cycle. A decreasing NAD level also impoverishes the activity of NAD-dependent enzymes that augments genetic errors and initiate processes of neuronal degeneration and death.This sequence of events is characteristic of several brain structures in which neurons have the highest energy metabolism. Neurons of the cerebral cortex and basal ganglia with long unmyelinated axons and these with numerous synaptic junctions are particularly prone to senescence and neurodegeneration. Unfortunately, functional deficits of neurodegeneration are initially well-compensated, therefore, clinical symptoms are recognized too late when the damages to the brain structures are already irreversible. Therefore, future treatment strategies in neurodegenerative disorders should focus on energy metabolism and compensation age-related NAD deficit in neurons. This review summarizes the complex interrelationships between metabolic processes on the systemic and cellular levels and provides directions on how to reduce the risk of neurodegeneration and protect the elderly against neurodegenerative diseases.

Celecoxib promotes survival and upregulates the expression of neuroprotective marker genes in two different in vitro models of Parkinson's disease

Parkinson's disease (PD) is the second most common age-related neurodegenerative disorder after Alzheimer's disease. Increasing evidence highlights the role of age-related chronic inflammation, oxidative stress and mitochondrial dysfunction in the pathogenesis of PD. A combination of these factors impairs the crosstalk between mitochondria and lysosomes, resulting in compromised cell homeostasis. Apolipoprotein D (APOD), an ancient and highly conserved anti-inflammatory and antioxidant lipocalin, and the transcription factor EB (TFEB), a master regulator of mitophagy, autophagy and lysosomal biogenesis, play key roles in these processes. Both APOD and TFEB have attracted attention as therapeutic targets for PD. The aim of this study was to investigate if the selective cyclooxygenase-2 inhibitor celecoxib (CXB) exerts a direct neuroprotective effect in 6-hydroxydopamine (6-OHDA) and paraquat (PQ) PD models. We found that CXB rescued SH-SY5Y cells challenged by 6-OHDA- and PQ-induced toxicity. Furthermore, treatment with CXB led to a marked and sustained upregulation of APOD and the two microphthalmia transcription factors TFEB and MITF. In sum, this study highlights the clinically approved drug CXB as a promising neuroprotective therapeutic tool in PD research that has the potential to increase the survival rate of dopaminergic neurons that are still alive at the time of diagnosis.

Actively targeted gold nanoparticle composites improve behavior and cognitive impairment in Parkinson's disease mice

Parkinson's disease (PD) is characterized by motor and non-motor symptoms, primarily affecting dopaminergic neurons (DAergic neurons) in substantia nigra (SN). However, it is still very challenging to identify new drugs that not only inhibit motor dysfunction but also improve non-motor dysfunction. It has been identified as a potential PD treatment that the inhibition of α-syn aggregation could decrease the death of DAergic neurons in SN. In this study, we synthesized gold nanoparticle composites (NPs) that were loaded with plasmid DNA (pDNA) to inhibit α-syn expression. In vivo, our results showed that NPs improved tyrosine hydroxylase (TH) levels and decreased aggregation of α-syn in the SN. Additionally, NPs attenuated motor dysfunction and exploration ability declined. Moreover, NPs reversed the inhibition of long-term potentiation (LTP) and improved non-motor dysfunction in PD mice. These results indicated that NPs had significantly neuroprotective effects not only in motor, but also in non-motor dysfunction to PD mice, providing a new strategy for gene therapy in PD.

Leveraging sequence-based faecal microbial community survey data to identify alterations in gut microbiota among patients with Parkinson's disease

Parkinson's disease is a common degenerative disease of the elderly. Although the majority of studies have focused on the central nervous system (CNS) features of Parkinson's disease, recent findings suggest there is a functional link between the gut microbiome and the hallmarks of the disease. PubMed, Web of Science, EMBASE and other Chinese and English databases were searched for relevant literature. Studies on changes to intestinal microbiota in Parkinson's patients were retrieved and systematically reviewed. Quality filtering, clustering and species annotation were performed on 16s sequencing raw data from retrieved studies to achieve comparability across studies. Alpha-diversity indices and a random effect model were used to analyse significantly altered microbiota. A total of nine studies were included in this retrospective analysis, four of which contained raw data. Alpha diversity was significantly different between control and Parkinson's disease patients in two of the four studies. Using the raw data from four individual studies, we observed differences in the phlya Bacteroidetes and Actinobacteria. Additionally, differences were observed between control and Parkinson's disease patients at the level of family (Prevotellacaea and Lactobacillaceae) and genus (Bifidobacterium and Clostridium). This study confirmed that changes in the microbiome are a consistent feature of Parkinson's disease patients and, therefore, may contribute to the onset of disease.

Abnormal white matter microstructures in Parkinson's disease and comorbid depression: A whole-brain diffusion tensor imaging study

OBJECTIVE

Depressive symptoms are the most common non-motor symptom accompanying Parkinson's disease (PD); however, the neural basis of depression in PD remains unclear. The aim of this study was to characterize possible depression-related white matter microstructural differences in patients with PD and comorbid depression compared with PD patients and healthy controls (HC) without depression.

METHODS

We used diffusion tensor imaging (DTI) to analyze white matter integrity in depressed PD patients (n = 30), non-depressed PD patients (n = 43), and HC (n = 91). Five MRI-derived indices were estimated: fractional anisotropy (FA), mean diffusivity (MD), axial diffusivity (AD), radial diffusivity (RD), and white matter volume (WMV).

RESULTS

Compared with HC and non-depressed PD, depressed PD patients showed significantly increased AD values in the body of corpus callosum, right anterior corona radiate, and left hippocampal part of the cingulum, as well as increased MD values in the left hippocampal part of the cingulum.

CONCLUSIONS

Our results show that frontal and limbic white matter integrity is impaired in depressed PD patients. These findings can be used to better understand potential mechanisms of depression in PD.

Prevalence of Non-motor Symptoms in Parkinson's Disease and Its Impact on Quality of Life in Tertiary Care Center in India

Context:

Parkinson's disease (PD) is a neurodegenerative disease characterized by traditional motor features. Non-motor symptoms (NMS) are also seen in PD, which inevitably emerge through the disease progression and are often under-recognized and untargeted.

Aims:

We studied the prevalence of NMS in PD and their impact on health-related quality of life (HRQoL).

Materials and Methods:

A cross-sectional observational study from January 2017 to July 2017 of PD patients (n = 100) was done. NMS and HRQoL are measured using NMS scoring scale; PD questionnaire-39 and Hoehn and Yahr scale, respectively. Motor symptoms were assessed using scales for outcome in Parkinson's disease (SCoPA) - motor scoring scale.

Statistical Analysis:

Descriptive statistics calculated for NMS' prevalence. Continuous variables were assessed by two-tailed t-test and discrete and categorical variables by chi-square test. Multiple linear regression analysis was done among scoring scales to identify the influence on 39-item Parkinson's disease questionnaire (PDQ-39) scoring scale. All statistical data collected are analyzed with SSPS software version- 20 for windows.

Results:

In 100 study population, 66 were males and 34 females. The mean age was 68.35 years and median onset of duration of PD was 3.49 with 64.6% on treatment. Fatigue, pain, and lightheadedness were more prevalent NMS with 78%, 75%, and 69%, respectively. With regression analysis, strongest predictor was NMSS score (P = 0.000), with each unit increase, it is associated with nearly 0.65 increase in PDQ-39 score.

Conclusion:

Though motor symptoms define the disease, NMS have a larger impact on HRQoL in PD and on caregiver's life. Understanding the pattern and effect of NMS is needed for targeted treatment strategies.

Molecular evidence of impaired iron metabolism and its association with Parkinson's disease progression

The aim of the study is to investigate the role of ATP-binding cassette subfamily B member 7 (ABCB7) in correlation with the progression of Parkinson's disease. Initially, the neurotoxin 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine (MPTP) was used to develop a mouse model of mild and severe forms of Parkinson's disease. Histology, immunohistology, and Western blotting were used to investigate the role of ABCB7 in disease progression. Mice injected with MPTP, at doses of 18 and 30 mg/kg for 10 and 15 consecutive days, respectively, developed mild and severe forms of Parkinson's disease, respectively. Motor dysfunction is accessed through pole test in which, mild and severe forms of Parkinson's disease developed mice takes 1.7 and 3.3 times more time to reach the floor than the control mice. Similarly, in rotarod test, the progression of Parkinson's disease is evident with the progressive loss of motor stability. Histologically, the progression of Parkinson's disease is evident with formation of cell aggregates in mild form; with the formation of more Lewy body structure and tissue hardening in a severe form of Parkinson's disease. Immunohistochemistry showed gradual upregulation of ABCB7 in the cellular cytoplasm in mild stage Parkinson's disease, while significant overexpression of ABCB7 was observed in the severe forms. Western blotting results confirmed 1.6- and 2.9-fold overexpression of ABCB7 in mild and severe forms of Parkinson's disease, respectively. Collectively, the results showed that ABCB7 was present during Parkinson's disease progression. However, upregulation of ABCB7 increased the cytoplasm level of the iron-sulfur complex, which negatively regulated the iron-dependent protein and can be used to determine the progression of Parkinson's disease.

The Challenge and Opportunity to Diagnose Parkinson's Disease in Midlife

Parkinson's disease (PD) is the most common neurodegenerative movement disorder that affects extensive regions of the nervous system. Its current clinical diagnosis is based on motor symptoms that appear late during disease progression when substantial proportions of the nigrostriatal dopaminergic neuron population are lost already. Although disturbances in sleep and other biofunctions often surface years prior to motor impairments and point to a long prodromal phase, these phenotypic signs in a person's midlife lack predictive power. They do, however, signal the unfolding of the disease and suggest molecular correlates that begin deviating early on. Revealing such trajectories, hence, promises not only a better understanding of prodromal PD but may also enable a much-needed earlier diagnosis. A nexus that may harbor such molecular trajectories is the epigenome as key etiological factors of PD-genetics, age, and environment-influence this substrate. An earlier diagnosis would also allow earlier interventions and lifestyle adjustments to improve brain function and reduce symptoms. In this review, we describe the challenges of diagnosing PD early on and highlight the opportunities that may arise from steering research efforts towards comprehensive interrogations of molecular layers during the long-time neglected midlife phase. In particular, we emphasize how existing cohorts of at-risk individuals, available animal models, and suitable markers may come together and aid in revealing molecular trajectories that offer diagnostic utility for PD in its prodromal stage.

Improvement of Subthalamic Nucleus Deep Brain Stimulation in Sleeping Symptoms in Parkinson's Disease: A Meta-Analysis

Introduction

The aim of this meta-analysis was to evaluate the effects of STN DBS on sleep quality and restless leg symptoms in individuals with PD.

Methods

We searched the PubMed, Web of Science, EMBASE, CNKI, and WANFANG databases published between 1990 and 2019. The articles included were those that contained both pre- and postsurgery data acquired using International RLS Study Group criteria and the Pittsburgh sleep quality index (PSQI) questionnaire with patients' follow-up of at least three months. All studies that met the quality requirements were included in a meta-analysis performed using STATA 12.0 software.

Results

Of 73 articles identified, 7 studies comprising 82 patients were qualified for the current meta-analysis. After adjusting for heterogeneity in study effect sizes, the random effects meta-analysis indicated that STN DBS improved sleep quality and restless leg symptoms significantly (SMD = −1.111, 95% CI: −1.918∼−0.304, P=0.007). Subgroup analysis showed that different sleep scoring criteria had different effects on the condition of sleeping after surgery.

Conclusions

STN DBS is a powerful method in the management of sleep quality and restless leg symptoms in PD patients, but its long-term effects with larger populations must be thoroughly assessed.

Parkinson's disease in China: a forty-year growing track of bedside work

The number and health burden of Parkinson's disease increase rapidly in China. It is estimated that China will have nearly half of the Parkinson's disease population in the world in 2030. In this review, we present an overview of epidemiology and health economics status of Parkinson's disease across China and discuss the risk factors of Parkinson's disease and related complications. From the view of clinical research, we also discuss the current status of clinical trials, diagnostic biomarkers, treatment of Parkinson's disease, tertiary network and post-occupation education in Chinese Parkinson's disease clinics.

Non-Motor Symptoms of Parkinson's Disease and Their Impact on Quality of Life in a Cohort of Moroccan Patients

Background

Non-motor symptoms (NMSs) are a real burden in Parkinson’s disease (PD). They may appear in early pre-symptomatic stage as well as throughout the disease course. However, their relationship with the deterioration of the patient’s quality of life (QoL) is still under debate. This study aimed to investigate the prevalence of NMSs and their impact on the QoL in a cohort of Moroccan patients.

Methods

We carried out a cross-transactional study, where a total of 117 patients were submitted to a structured clinical interview and examination investigating motor and NMSs based on common and conventional scales. Motor symptoms were assessed by the UPDRS I–VI during ON condition. The NMSs were evaluated with common scales and their relationship with the QoL was investigated.

Results

The mean patient’s age was 60.77 ± 11.36 years old, and the median disease duration was 6 years [2.5–9.5]. Motor’s phenotype subtypes were the mixed form in 40.2% of patients, akinetic-rigid in 20.5% and a tremor-dominant form in 39.3%. The median Hoehn and Yahr staging was 2 [1–2.5]. Regarding NMSs, the most common were urinary dysfunctions (82.6%), sleep (80.6%), and gastrointestinal (80%) disorders. Other autonomic dysfunctions were also frequent: thermoregulatory dysfunctions 58.6%, cardiovascular troubles 50.9%, and sexual dysfunctions 47.9%. Depression was present in 47.9% and fatigue symptoms in 23.1%. The median score of SCOPA-AUT was 14 [7.75–21.80]. The median PD questionnaire 39-score index (PDQ39-SI) was 23.22% and the most affected dimension was “mobility.” Univariate and multivariate analyses showed that the SCOPA-AUT score impacted the QoL (p = 0.001), especially the gastrointestinal (p = 0.007), and cardiovascular (p = 0.049) dimensions.

Conclusion

Our data show that all patients have presented at least one NMS. Autonomic and sleep disorders were the most frequent, and in contrast to other studies, digestive and cardiovascular disorders were rather the factors influencing negatively the QoL of patients. Understanding the pathophysiology of these NMSs should be placed at the forefront in order to develop new therapeutic approaches by improving the QoL of PD patients.

Locomotor differences in mice expressing wild-type human α-synuclein

Parkinson's disease manifests as a progressive movement disorder with underlying degeneration of dopaminergic neurons in the substantia nigra, consequent depletion of dopamine levels, and the accumulation of Lewy bodies in the brain. Because α-synuclein (α-Syn) protein is the major component of Lewy bodies, mouse models expressing wild-type or mutant SNCA/α-Syn genes provide a useful tool to investigate canonical characteristics of the disease. We evaluated a mouse model (denoted M20) that expresses human wild-type SNCA gene. The M20 mice showed abnormal locomotor behavior and reduced species-specific home cage activity. However, the direction of behavioral changes was task specific. In comparison with their control littermates, the M20 mice exhibited shorter grip endurance, and longer times to traverse elevated beams, but they descended the vertical pole faster and stayed longer on the accelerated rod than the control mice. The M20 mice were also impaired in burrowing and nest building activities. These results indicate a possible role of α-Syn in motor coordination and the motivation to perform species-specific behaviors in the presymptomatic model of synucleinopathy.

Slower saccadic reading in Parkinson's disease

Idiopathic Parkinson's Disease (PD) is characterized by degeneration of dopaminergic and other neurons, leading to motor and non-motor deficits. Abnormal eye movements in PD, including fixations, saccades, and convergence, are well described. However, saccadic reading, which requires serial and alternating saccades and fixations, is not well studied, despite its obvious impact on the quality of life. In this study, we assessed saccadic reading using variations of the King-Devick (KD) test, a rapid single digit number naming test, as a way to assess the ability to make serial left-to-right ocular motor movements necessary for reading. We recruited 42 treated PD patients and 80 age-matched controls and compared their reading times with a variety of measures, including age, duration of disease, Unified Parkinson's Disease Rating Scale (UPDRS), the National Eye Institute 25-Item Visual Functioning Questionnaire 25 (VFQ-25), and Montreal Cognitive assessment (MoCA) test. The subjects performed 4 trials of reading 120 single digit numbers aloud as fast as possible without making errors. In each trial, they read 3 pages (KD1, KD2, and KD3), and each page contained 40 numbers per page in 8 lines with 5 numbers/line. We found that PD patients read about 20% slower than controls on all tests (KD1, 2, and 3 tests) (p < 0.02), and both groups read irregularly spaced numbers slower than regularly spaced numbers. Having lines between numbers to guide reading (KD1 tests) did not impact reading time in both PD and controls, but increased visual crowding as a result of decreased spacing between numbers (KD3 tests) was associated with significantly slower reading times in both PD and control groups. Our study revealed that saccadic reading is slower in PD, but controls and PD patients are both impacted by visuospatial planning challenges posed by increased visual crowding and irregularity of number spacing. Reading time did not correlate with UPDRS or MoCA scores in PD patients but significantly correlated with age, duration of disease, and VFQ-25 scores. The presence of convergence insufficiency did not significantly correlate with reading time in PD patients, although on average there was slower reading time in those with convergence insufficiency by 8 s (p = 0.2613). We propose that a simple reading task using 120 single-digit numbers can be used as a screening tool in the clinical setting to assess functional ocular motor difficulties in Parkinson's disease that can have a profound impact on quality of life.

Novel biomolecular information in rotenone-induced cellular model of Parkinson's disease

In order to uncover the remarkable pathogenic genes or molecular pathological process in Parkinson's disease (PD), we employed a microarray analysis upon the cellular PD model induced by rotenone. Compared to the control group, 2174 genes were screened out to be expressed differently in the rotenone-induced group by certain criterion. GO analysis and the pathways analysis showed the significant enrichment of genes that were associated with the biological process of cell cycle, apoptotic process, organelle fusion, mitochondrial lesion, endoplasmic reticulum stress and so on. Among these significant DE genes, some were sorted out to be involved in cell cycle and protein processing in endoplasmic reticulum. As the PPI network analysis showed, the interaction relationship of the DEGs involved in the process of protein generation in endoplasmic reticulum(ER) was clearly showed up. As a prediction, we emphasized the genes EDEM1, ATF4, TRAF2 might play central roles in the protein misfolding process during the progression of Parkinson's disease and these new-found genes might be the future research focus and therapeutic targets in PD.

An unexpected improvement in spatial learning and memory ability in alpha-synuclein A53T transgenic mice

Growing evidence suggests, as Parkinson's disease (PD) progresses, that its non-motor symptoms appear prior to or in parallel with its motor deficits. Alpha-synuclein A53T transgenic mouse (A53T) is an essential tool to investigate the onsets and the extents of PD non-motor symptoms. Our aim is to investigate spatial learning and memory ability in A53T mice. In our rotarod tests, no motor coordination impairments were detected in mice of 3, 6, 9, and 12 months old. We then investigated their spatial learning and memory ability through Morris water maze in 3- and 9-month-old mice. No significant difference in escape latency was detected among the A53T mice and the control mice. However, an unexpected improvement in spatial learning and memory ability was observed in the probe session among the A53T mice. Reversal learning by Morris water maze also indicated that 3- and 9-month-old A53T mice exhibited a better cognitive flexibility compared to their littermate controls. Further studies by western blots showed that alpha-synuclein expressions in hippocampus of the A53T mice were noticeably up-regulated. The immunofluorescence staining of 5-bromo-2-deoxyuridine (Brdu) and doublecortin (DCX) demonstrated that neither the Brdu-positive neurons nor the Brdu/DCX positive neurons in hippocampus were significantly altered between the two groups. These results suggest that our A53T mice exhibit improved spatial learning and memory ability prior to their motor coordination deficits. These results are not induced by neurogenesis in the hippocampus.

Neuropathology of Nonmotor Symptoms of Parkinson's Disease

Parkinson's disease (PD), a multiorgan neurodegenerative disorder associated with α-synuclein deposits throughout the nervous system and many organs, is clinically characterized by motor and nonmotor features, many of the latter antedating motor dysfunctions by 20 or more years. The causes of the nonmotor manifestations such as olfactory, autonomic, sensory, neuropsychiatric, visuospatial, sleep, and other disorders are unlikely to be related to single lesions. They are mediated by the involvement of both dopaminergic and nondopaminergic systems, and diverse structures outside the nigrostriatal system that is mainly responsible for the motor features of PD. The nonmotor alterations appear in early/prodromal stages of the disease and its further progression, suggesting a topographical and chronological spread of the lesions. This lends further support for the notion that PD is a multiorgan proteinopathy, although the exact relationship between presymptomatic and later developing nonmotor features of PD and neuropathology awaits further elucidation.