New clinical trials for nonmotor manifestations of Parkinson's disease

Escalating Bi-Directional Feedback Loops between Proinflammatory Microglia and Mitochondria in Ageing and Post-Diagnosis of Parkinson's Disease

Parkinson's disease (PD) is a chronic and progressive age-related neurodegenerative disease affecting up to 3% of the global population over 65 years of age. Currently, the underlying physiological aetiology of PD is unknown. However, the diagnosed disorder shares many common non-motor symptoms associated with ageing-related neurodegenerative disease progression, such as neuroinflammation, microglial activation, neuronal mitochondrial impairment, and chronic autonomic nervous system dysfunction. Clinical PD has been linked to many interrelated biological and molecular processes, such as escalating proinflammatory immune responses, mitochondrial impairment, lower adenosine triphosphate (ATP) availability, increasing release of neurotoxic reactive oxygen species (ROS), impaired blood brain barrier integrity, chronic activation of microglia, and damage to dopaminergic neurons consistently associated with motor and cognitive decline. Prodromal PD has also been associated with orthostatic hypotension and many other age-related impairments, such as sleep disruption, impaired gut microbiome, and constipation. Thus, this review aimed to present evidence linking mitochondrial dysfunction, including elevated oxidative stress, ROS, and impaired cellular energy production, with the overactivation and escalation of a microglial-mediated proinflammatory immune response as naturally occurring and damaging interlinked bidirectional and self-perpetuating cycles that share common pathological processes in ageing and PD. We propose that both chronic inflammation, microglial activation, and neuronal mitochondrial impairment should be considered as concurrently influencing each other along a continuum rather than as separate and isolated linear metabolic events that affect specific aspects of neural processing and brain function.

Development of Small Molecules Targeting α-Synuclein Aggregation: A Promising Strategy to Treat Parkinson’s Disease

Parkinson’s disease, the second most common neurodegenerative disorder worldwide, is characterized by the accumulation of protein deposits in the dopaminergic neurons. These deposits are primarily composed of aggregated forms of α-Synuclein (α-Syn). Despite the extensive research on this disease, only symptomatic treatments are currently available. However, in recent years, several compounds, mainly of an aromatic character, targeting α-Syn self-assembly and amyloid formation have been identified. These compounds, discovered by different approaches, are chemically diverse and exhibit a plethora of mechanisms of action. This work aims to provide a historical overview of the physiopathology and molecular aspects associated with Parkinson’s disease and the current trends in small compound development to target α-Syn aggregation. Although these molecules are still under development, they constitute an important step toward discovering effective anti-aggregational therapies for Parkinson’s disease.

Alpha-synuclein in Parkinson's disease and other synucleinopathies: from overt neurodegeneration back to early synaptic dysfunction

Although the discovery of the critical role of α-synuclein (α-syn) in the pathogenesis of Parkinson's disease (PD) is now twenty-five years old, it still represents a milestone in PD research. Abnormal forms of α-syn trigger selective and progressive neuronal death through mitochondrial impairment, lysosomal dysfunction, and alteration of calcium homeostasis not only in PD but also in other α-syn-related neurodegenerative disorders such as dementia with Lewy bodies, multiple system atrophy, pure autonomic failure, and REM sleep behavior disorder. Furthermore, α-syn-dependent early synaptic and plastic alterations and the underlying mechanisms preceding overt neurodegeneration have attracted great interest. In particular, the presence of early inflammation in experimental models and PD patients, occurring before deposition and spreading of α-syn, suggests a mechanistic link between inflammation and synaptic dysfunction. The knowledge of these early mechanisms is of seminal importance to support the research on reliable biomarkers to precociously identify the disease and possible disease-modifying therapies targeting α-syn. In this review, we will discuss these critical issues, providing a state of the art of the role of this protein in early PD and other synucleinopathies.

The Role of α-Synuclein in the Regulation of Serotonin System: Physiological and Pathological Features

In patients affected by Parkinson's disease (PD), up to 50% of them experience cognitive changes, and psychiatric disturbances, such as anxiety and depression, often precede the onset of motor symptoms and have a negative impact on their quality of life. Pathologically, PD is characterized by the loss of dopamine (DA) neurons in the substantia nigra pars compacta (SNc) and the presence of intracellular inclusions, called Lewy bodies and Lewy neurites, composed mostly of α-synuclein (α-Syn). Much of PD research has focused on the role of α-Syn aggregates in the degeneration of SNc DA neurons due to the impact of striatal DA deficits on classical motor phenotypes. However, abundant Lewy pathology is also found in other brain regions including the midbrain raphe nuclei, which may contribute to non-motor symptoms. Indeed, dysfunction of the serotonergic (5-HT) system, which regulates mood and emotional pathways, occurs during the premotor phase of PD. However, little is known about the functional consequences of α-Syn inclusions in this neuronal population other than DA neurons. Here, we provide an overview of the current knowledge of α-Syn and its role in regulating the 5-HT function in health and disease. Understanding the relative contributions to α-Syn-linked alterations in the 5-HT system may provide a basis for identifying PD patients at risk for developing depression and could lead to a more targeted therapeutic approach.

The relationship between meaning in life and apathy in people with Parkinson's disease: a cross-sectional analysis

BACKGROUND

Apathy remains a common and problematic neuropsychiatric feature associated with Parkinson's disease resulting in reductions in health-related quality of life, and effective treatments remain elusive. Meaning in life (MIL) has been implicated in a variety of positive health outcomes, and this study assesses the relationship between apathy and MIL while hoping to identify a potential new interventional target.

METHODS

A cross-sectional sample of 237 PwPD completed surveys to evaluate MIL and a variety of non-motor symptoms (NMS), and a hierarchical regression analysis was conducted to evaluate relationships of interest.

RESULTS

Correlational analysis indicated the presence of meaning in life was statistically negatively and moderately to strongly correlated with apathy (r = - 0.60, p < .001). Hierarchical regression analysis results showed that presence of meaning in life explained a total of 48% of variance in apathy. More specifically, the presence of meaning in life (β = - 0.43, p < .001) was associated with apathy after controlling for sociodemographic and other potentially confounding variables.

CONCLUSIONS

This study demonstrates the significant negative relationship between MIL and apathy. Considering the lack of effective treatments for apathy, which is one of the most disabling symptoms affecting PwPD, identifying a potential target for intervention is exciting. MIL has the potential to offer clinicians a novel intervention to provide a much-needed treatment option to improve both apathy and HRQoL.

Advances in the Therapeutic Use of Non-Ergot Dopamine Agonists in the Treatment of Motor and Non-Motor Symptoms of Parkinson's Disease

Dopamine (DA) agonists, as an excellent dopamine replacement therapy for patients with early and advanced Parkinson's disease (PD), play a vital role in controlling motor and several nonmotor symptoms. Besides, the application of DA agonists may delay levodopa therapy and the associated risk of motor complications. Indeed, each DA agonist has unique pharmacokinetic and pharmacodynamic characteristics and therefore has different therapeutic efficacy and safety profile. The comorbidities, significant non-motor manifestations, concomitant medications, and clinical features of PD individuals should guide the selection of a specific DA agonist to provide a more patient-tailored treatment option. Thorough knowledge of DA agonists helps clinicians better balance clinical efficacy and side effects. Therefore, this review refers to recent English-written articles on DA agonist therapy for PD patients and summarizes the latest findings on non-ergot DA agonists as well as the advantages and disadvantages of each compound to help clinicians in the selection of a specific DA agonist. In addition, novel D1/D5 partial agonists and new formulations of DA agonists are also discussed.

Putting music to trial: Consensus on key methodological challenges investigating music-based rehabilitation

Major advances in music neuroscience have fueled a growing interest in music-based neurological rehabilitation among researchers and clinicians. Musical activities are excellently suited to be adapted for clinical practice because of their multisensory nature, their demands on cognitive, language, and motor functions, and music's ability to induce emotions and regulate mood. However, the overall quality of music-based rehabilitation research remains low to moderate for most populations and outcomes. In this consensus article, expert panelists who participated in the Neuroscience and Music VII conference in June 2021 address methodological challenges relevant to music-based rehabilitation research. The article aims to provide guidance on challenges related to treatment, outcomes, research designs, and implementation in music-based rehabilitation research. The article addresses how to define music-based rehabilitation, select appropriate control interventions and outcomes, incorporate technology, and consider individual differences, among other challenges. The article highlights the value of the framework for the development and evaluation of complex interventions for music-based rehabilitation research and the need for stronger methodological rigor to allow the widespread implementation of music-based rehabilitation into regular clinical practice.

Computational reinforcement learning, reward (and punishment), and dopamine in psychiatric disorders

In the DSM-5, psychiatric diagnoses are made based on self-reported symptoms and clinician-identified signs. Though helpful in choosing potential interventions based on the available regimens, this conceptualization of psychiatric diseases can limit basic science investigation into their underlying causes. The reward prediction error (RPE) hypothesis of dopamine neuron function posits that phasic dopamine signals encode the difference between the rewards a person expects and experiences. The computational framework from which this hypothesis was derived, temporal difference reinforcement learning (TDRL), is largely focused on reward processing rather than punishment learning. Many psychiatric disorders are characterized by aberrant behaviors, expectations, reward processing, and hypothesized dopaminergic signaling, but also characterized by suffering and the inability to change one's behavior despite negative consequences. In this review, we provide an overview of the RPE theory of phasic dopamine neuron activity and review the gains that have been made through the use of computational reinforcement learning theory as a framework for understanding changes in reward processing. The relative dearth of explicit accounts of punishment learning in computational reinforcement learning theory and its application in neuroscience is highlighted as a significant gap in current computational psychiatric research. Four disorders comprise the main focus of this review: two disorders of traditionally hypothesized hyperdopaminergic function, addiction and schizophrenia, followed by two disorders of traditionally hypothesized hypodopaminergic function, depression and post-traumatic stress disorder (PTSD). Insights gained from a reward processing based reinforcement learning framework about underlying dopaminergic mechanisms and the role of punishment learning (when available) are explored in each disorder. Concluding remarks focus on the future directions required to characterize neuropsychiatric disorders with a hypothesized cause of underlying dopaminergic transmission.

Imaging of cerebral tryptophan metabolism using 7-[18F]FTrp-PET in a unilateral Parkinsonian rat model

Degradation products of the essential amino acid tryptophan (Trp) are important signaling molecules in the mammalian brain. Trp is metabolized either through the kynurenine pathway or enters serotonin and melatonin syntheses. The aim of the present work was to examine the potential of the novel PET tracer 7-[¹⁸F]fluorotryptophan ([¹⁸F]FTrp) to visualize all three pathways in a unilateral 6-OHDA rat model. [¹⁸F]FDOPA-PET scans were performed in nine 6-OHDA-injected and six sham-operated rats to assess unilateral dopamine depletion severity four weeks after lesion placement. Afterwards, 7-[¹⁸F]FTrp-PET scans were conducted at different timepoints up to seven months after 6-OHDA injection. In addition, two 6-OHDA-injected rats were examined for neuroinflammation using [¹⁸F]DAA1106-PET. 7-[¹⁸F]FTrp-PET showed significantly increased tracer uptake at the 6-OHDA injection site which was negatively correlated to time after lesion placement. Accumulation of [¹⁸F]DAA1106 at the injection site was increased as well, suggesting that 7-[¹⁸F]FTrp uptake in this region may reflect kynurenine pathway activity associated with inflammation. Bilaterally in the dorsal hippocampus, 7-[¹⁸F]FTrp uptake was significantly decreased and was inversely correlated to dopamine depletion severity, indicating that it reflects reduced serotonin synthesis. Finally, 7-[¹⁸F]FTrp uptake in the pineal gland was significantly increased in relation with dopamine depletion severity, providing evidence that melatonin synthesis is increased in the 6-OHDA rat model. We conclude that 7-[¹⁸F]FTrp is able to detect alterations in both serotonin/melatonin and kynurenine metabolic pathways, and can be applied to visualize pathologic changes related to neurodegenerative processes.

Biomaterial Strategies for Restorative Therapies in Parkinson's Disease

Parkinson's disease (PD) is a progressive neurological disorder, in which dopaminergic midbrain neurons degenerate, leading to dopamine depletion that is associated with neuronal death. In this Review, we initially describe the pathogenesis of PD and established therapies that unfortunately only delay progression of the disease. With a rapidly escalating incidence in PD, there is an urgent need to develop new therapies that not only halt progression but even reverse degeneration. Biomaterials are playing critical roles in these new therapies which include controlled and site-specific delivery of neurotrophins, increased engraftment of implanted neural stem cells, and redirection of endogenous stem cell populations away from their niche to encourage reparative mechanisms. This Review will therefore cover important design features of biomaterials used in regenerative medicine and tissue engineering strategies targeted at PD.

Nanoparticle-Guided Brain Drug Delivery: Expanding the Therapeutic Approach to Neurodegenerative Diseases

Neurodegenerative diseases (NDs) represent a heterogeneous group of aging-related disorders featured by progressive impairment of motor and/or cognitive functions, often accompanied by psychiatric disorders. NDs are denoted as 'protein misfolding' diseases or proteinopathies, and are classified according to their known genetic mechanisms and/or the main protein involved in disease onset and progression. Alzheimer's disease (AD), Parkinson's disease (PD) and Huntington's disease (HD) are included under this nosographic umbrella, sharing histopathologically salient features, including deposition of insoluble proteins, activation of glial cells, loss of neuronal cells and synaptic connectivity. To date, there are no effective cures or disease-modifying therapies for these NDs. Several compounds have not shown efficacy in clinical trials, since they generally fail to cross the blood-brain barrier (BBB), a tightly packed layer of endothelial cells that greatly limits the brain internalization of endogenous substances. By engineering materials of a size usually within 1-100 nm, nanotechnology offers an alternative approach for promising and innovative therapeutic solutions in NDs. Nanoparticles can cross the BBB and release active molecules at target sites in the brain, minimizing side effects. This review focuses on the state-of-the-art of nanoengineered delivery systems for brain targeting in the treatment of AD, PD and HD.

What substance P might tell us about the prognosis and mechanism of Parkinson's disease?

The neuropeptide substance P (SP) plays an important role in neurodegenerative disorders, among which Parkinson's disease (PD). In the present work we have reviewed the involvement of SP and its preferred receptor (NK1-R) in motor and non-motor PD symptoms, in both PD animal models and patients. Despite PD is primarily a motor disorder, non-motor abnormalities, including olfactory deficits and gastrointestinal dysfunctions, can represent diagnostic PD predictors, according to the hypothesis that the olfactory and the enteric nervous system represent starting points of neurodegeneration, ascending to the brain via the sympathetic fibers and the vagus nerve. In PD patients, the α-synuclein aggregates in the olfactory bulb and the gastrointestinal tract, as well as in the dorsal motor nucleus of the vagus nerve often co-localize with SP, indicating SP-positive neurons as highly vulnerable sites of degeneration. Considering the involvement of the SP/NK1-R in both the periphery and specific brain areas, this system might represent a neuronal substrate for the symptom and disease progression, as well as a therapeutic target for PD.

Serotonergic imaging in Parkinson's disease

Parkinson's disease (PD) is a neurodegenerative disorder characterized by the progressive degeneration of monoaminergic central pathways such as the serotonergic. The degeneration of serotonergic signaling in striatal and extrastriatal brain regions is an early feature of PD and is associated with several motor and non-motor complications of the disease. Molecular imaging techniques with Positron Emission Tomography (PET) have greatly contributed to the investigation of biological changes in vivo and to the understanding of the extent of serotonergic pathology in patients or individuals at risk for PD. Such discoveries provide with opportunities for the identification of new targets that can be used for the development of novel disease-modifying drugs or symptomatic treatments. Future studies of imaging serotonergic molecular targets will better clarify the importance of serotonergic pathology in PD, including progression of pathology, target-identification for pharmacotherapy, and relevance to endogenous synaptic serotonin levels. In this article, we review the current status and understanding of serotonergic imaging in PD.

Therapeutic Strategies to Treat or Prevent Off Episodes in Adults with Parkinson's Disease

Parkinson's disease is a chronic, neurodegenerative disease, which manifests with a mixture of motor, cognitive and behavioural symptoms. Levodopa is the most effective antiparkinsonian treatment to date, although chronic use engenders a mixture of complications in a substantial proportion of patients. Amongst these is the occurrence of episodes of worsening symptoms-'off' phenomena. These episodes can manifest with either motor or non-motor symptoms or a combination of these features and have been found to have profound impacts on patients' quality of life. Although preventative measures are poorly evidenced, avoiding excessive total daily levodopa intake in selected populations that are deemed to be of a higher risk for developing these episodes warrants further exploration. Methods to improve levodopa bioavailability and delivery to the brain are currently available and are of value in addressing these episodes once they have become established. These include modifications to levodopa formulations as well as the use of complimentary agents that improve levodopa bioavailability. The deployment of device-assisted approaches is a further dimension that can be considered in addressing these debilitating episodes. This review summarises the clinical manifestations of 'off' phenomena and the current approaches to treat them. Although we briefly discuss clinical advances on the horizon, the predominant focus is on existing, established treatments.

[Mild cognitive impairment: modern aspects of diagnostics and therapy]

The article provides a review of current literature on the diagnosis and treatment of mild cognitive impairment (MCI). MCI is not a common outcome of brain aging; it is an intermediate state between normal cognitive status and mild dementia. The MCI concept has been actively developing over the past few decades, a lot of knowledge and clinical experience has been accumulated, and numerous clinical trials are being conducted to develop effective methods of diagnosis and therapy. Treatment of pre-dementia cognitive disorders differs in many ways from therapy for dementia and has a better prognosis, therefore, it is recommended to diagnose and begin treating cognitive disorders as early as possible. The main possibilities of drug and non-drug therapy are described, with an emphasis on the use of the dopamine receptor agonist piribedil in the treatment of MCI and sensory deficit in elderly patients. The mechanisms of action of the drug are analyzed, data from the main clinical studies of the efficacy and safety of piribedil are presented: the positive effect of the drug on cognitive functions has been shown in more than 10 international clinical trials including about 7000 patients and in a number of post-marketing works performed on the Russian population of patients. Piribedil is successfully used for various types of cognitive disorders, both neurodegenerative and vascular, of mild to moderate severity.

Locus Coeruleus Modulates Neuroinflammation in Parkinsonism and Dementia

Locus Coeruleus (LC) is the main noradrenergic nucleus of the central nervous system, and its neurons widely innervate the whole brain. LC is severely degenerated both in Alzheimer’s disease (AD) and in Parkinson’s disease (PD), years before the onset of clinical symptoms, through mechanisms that differ among the two disorders. Several experimental studies have shown that noradrenaline modulates neuroinflammation, mainly by acting on microglia/astrocytes function. In the present review, after a brief introduction on the anatomy and physiology of LC, we provide an overview of experimental data supporting a pathogenetic role of LC degeneration in AD and PD. Then, we describe in detail experimental data, obtained in vitro and in vivo in animal models, which support a potential role of neuroinflammation in such a link, and the specific molecules (i.e., released cytokines, glial receptors, including pattern recognition receptors and others) whose expression is altered by LC degeneration and might play a key role in AD/PD pathogenesis. New imaging and biochemical tools have recently been developed in humans to estimate in vivo the integrity of LC, the degree of neuroinflammation, and pathology AD/PD biomarkers; it is auspicable that these will allow in the near future to test the existence of a link between LC-neuroinflammation and neurodegeneration directly in patients.

Real-World Nonmotor Changes in Patients with Parkinson's Disease and Motor Fluctuations: J-FIRST

Background

Nonmotor symptoms (NMSs) of Parkinson's disease (PD) impair health‐related quality of life.

Objectives

To identify changes in NMSs during 52 weeks in Japanese PD patients exhibiting motor fluctuations.

Methods

In PD patients with ≥1 NMS and wearing‐off, changes in total/subscore of the Movement Disorder Society Unified PD Rating Scale (MDS‐UPDRS) Part I and 8‐item PD Questionnaire were assessed. Group‐based trajectory models were used to characterize longitudinal patterns of MDS‐UPDRS Part I.

Results

Data from 996 patients were analyzed. MDS‐UPDRS Part I subscores for cognitive function decreased linearly over time. Total and subscores for apathy and lightheadedness on standing significantly deteriorated with fluctuations, whereas other subscores fluctuated without significant deterioration. Changes in the MDS‐UPDRS Part I total score correlated with changes in the 8‐item PD Questionnaire total score. Based on group‐based trajectory models, longitudinal pattern analysis of MDS‐UPDRS Part I scores yielded the following 3 separate groups: unchanged (63.8%), deteriorated (20.1%), and improved (16.2%). The improved group had significantly more NMSs at baseline, significantly higher MDS‐UPDRS Part I/8‐item PD Questionnaire total scores, and modified Hoehn and Yahr scores, and had received treatment for NMSs. The multivariate analysis revealed significant associations between severe motor disability and receiving any treatment for NMSs at baseline and improvement of MDS‐UPDRS Part I total scores.

Conclusions

Changes in MDS‐UPDRS Part I scores were variable and related to changes in health‐related quality of life in PD patients with motor fluctuations.

Effect of Antidepressants on Psychotic Symptoms in Parkinson Disease: A Review of Case Reports and Case Series

OBJECTIVES

The treatment of Parkinson disease (PD) psychosis remains a challenge. Only a few treatments eliciting significant relief of psychotic symptoms have passed the test of randomized controlled trials.

METHODS

Here, we conducted a review of the literature on the effect of antidepressants on PD psychosis. Because there is no randomized controlled trial that assessed the antipsychotic effects of antidepressants in PD, only case reports, case series, and open-label trials were available to review. Because of the scarce literature, statistical analysis could not be performed.

RESULTS

The following antidepressants alleviated hallucinations in PD: amoxapine, citalopram, clomipramine, escitalopram, mianserin, mirtazapine, and venlafaxine. The antidepressants were generally well tolerated, with the exception of amoxapine, which exacerbated parkinsonism.

CONCLUSIONS

Whereas the conclusions that can be drawn on the efficacy of antidepressants at reducing PD psychosis are limited because of the poor quality of the reported studies, it is encouraging to notice that there are positive anecdotal reports. Further studies are needed to confirm the potential of these drugs and also to determine if a subtype of patients or of psychotic features may be more likely to be improved by antidepressants.

Parkinsonism and subthalamic deep brain stimulation dysregulate behavioral motivation in a rodent model

BACKGROUND

Apathy and impulsivity constitute opposite poles of a behavioral motivation spectrum often disrupted by both the symptoms and therapies for Parkinson's Disease (PD). Upwards of 70% of PD patients experience symptoms of apathy, frequently unresolved or worsened by deep brain stimulation (DBS) of the subthalamic nucleus (STN). Worse, more than half of patients receiving DBS for PD experience new-onset impulse control disorders of varying severity following therapy initiation. While these symptoms and side-effects have been widely reported in clinical studies, they are largely unexplored in animal models.

METHODS

We applied high-frequency DBS in a 6-OHDA hemiparkinsonian rat model. We trained rats on a series of go/stop and go/no-go behavioral paradigms and examined how parkinsonism and DBS modulated task responses.

RESULTS

STN DBS in healthy rodents drove impulsive behavior in the form of stop and no-go task failure, impulsive reward seeking, and noninstructed task attempts. While trained rats without DBS only tended to fail stop and no-go cues very shortly after the cue, DBS led to failures at significantly later time points. Hemiparkinsonism slowed response times and reduced response rates, not alleviated by effective DBS.

INTERPRETATIONS

PD interrupts neural signaling responsible for healthy action selection, not restored by DBS. PD may be associated with a dearth of action commands, manifesting as apathy. Conversely, effective DBS may bias the system toward the impulsive end of the behavioral motivation spectrum without restoring behaviorally reasonable actions, mis-weighting reward-based action selection and manifesting as impulsivity, aided by DBS interfering with stop signaling.

The movement disorder society nonmotor rating scale: Initial validation study

BACKGROUND

The Movement Disorder Society-sponsored Nonmotor Rating Scale is an update of the existing Parkinson's disease Nonmotor Symptoms Scale modified to address some limitations in Nonmotor Symptoms Scale scoring, structure, and symptom coverage.

METHODS

PD patients were recruited from movement disorder centers in an international, multicenter study. The Movement Disorder Society Nonmotor Rating Scale, consisting of 13 domains plus a subscale for nonmotor fluctuations, was rater administered, along with the Nonmotor Symptoms Scale and other clinical assessments. Standard reliability and validity testing were conducted.

RESULTS

Four hundred and two PD patients were recruited (mean age ± standard deviation, 67.42 ± 9.96 years; mean age at PD onset ± standard deviation, 59.27 ± 10.67 years; median Hoehn and Yahr stage 2 (interquartile range 2-3). Data quality was satisfactory for all Movement Disorder Society Nonmotor Rating Scale domains except sexual (6.7% missing data). There were no floor or ceiling effects for the Movement Disorder Society Nonmotor Rating Scale and nonmotor fluctuations total score; domains had no ceiling effects, but some floor effects (13.5%-83.5%). The Movement Disorder Society Nonmotor Rating Scale and nonmotor fluctuations total score internal consistency were acceptable (average Cronbach's alpha, 0.66 and 0.84, respectively); interrater reliability was excellent (intraclass correlation coefficient, >0.95); for test-retest reliability, the intraclass correlation coefficient was 0.84 for the Movement Disorder Society Nonmotor Rating Scale and 0.70 for Movement Disorder Society nonmotor fluctuations total score, and precision was excellent for the Movement Disorder Society Nonmotor Rating Scale (standard error of measurement, 25.30) and fair for nonmotor fluctuations (standard error of measurement, 7.06). Correlations between Movement Disorder Society Nonmotor Rating Scale score and the corresponding Nonmotor Symptoms Scale and Movement Disorder Society UPDRS scores were high. There were no significant sex or age effects. The Movement Disorder Society Nonmotor Rating Scale score increased with increasing PD duration, disease severity, and PD medication dose (all P < 0.001).

CONCLUSIONS

The Movement Disorder Society Nonmotor Rating Scale is a valid measure for measuring the burden of a wide range of Nonmotor Rating Scale scores, including nonmotor fluctuations, in PD patients. © 2019 International Parkinson and Movement Disorder Society.

Non-motor Parkinson disease: new concepts and personalised management

Most patients with Parkinson disease (PD) have non-motor symptoms (NMS), and on average these can range from four to 19 different symptoms. NMS dominate the prodromal phase of PD and some may serve as clinical biomarkers of PD. NMS can be dopaminergic, non-dopaminergic, of genetic origin or drug induced. Clinical assessment of NMS should include the NMS Questionnaire (completed by patients) for screening, as recommended by the International Parkinson and Movement Disorders Society and other international societies. The total number of NMS in a patient with PD constitutes the NMS burden, which can be graded using validated cut-off scores on the NMS Questionnaire and Scale and can be used as an outcome measure in clinical trials. Despite NMS burden having a major effect on the quality of life of patients and carers, a large European study showed that NMS are often ignored in the clinic. The syndromic nature of PD is underpinned by non-motor subtypes which are likely to be related to specific dysfunction of cholinergic, noradrenergic, serotonergic pathways in the brain, not just the dopaminergic pathways. NMS can be treated by dopaminergic and non-dopaminergic strategies, but further robust studies supported by evidence from animal models are required. The future of modern treatment of PD needs to be supported by the delivery of personalised medicine.

Nabilone for non-motor symptoms of Parkinson's disease: a randomized placebo-controlled, double-blind, parallel-group, enriched enrolment randomized withdrawal study (The NMS-Nab Study)

Although open-label observations report a positive effect of cannabinoids on non-motor symptoms (NMS) in Parkinson's disease (PD) patients, these effects remain to be investigated in a controlled trial for a broader use in NMS in PD patients. Therefore, we decided to design a proof-of-concept study to assess the synthetic cannabinoid nabilone for the treatment of NMS. We hypothesize that nabilone will improve NMS in patients with PD and have a favorable safety profile. The NMS-Nab Study is as a mono-centric phase II, randomized, placebo-controlled, double-blind, parallel-group, enriched enrollment withdrawal study. The primary efficacy criterion will be the change in Movement Disorders Society-Unified Parkinson's Disease-Rating Scale Part I score between baseline (i.e. randomization) and week 4. A total of 38 patients will have 80% power to detect a probability of 0.231 that an observation in the treatment group is less than an observation in the placebo group using a Wilcoxon rank-sum test with a 0.050 two-sided significance level assuming a true difference of 2.5 points between nabilone and placebo in the primary outcome measure and a standard deviation of the change of 2.4 points. The reduction of harm through an ineffective treatment, the possibility of individualized dosing, the reduction of sample size, and the possible evaluation of the influence of the placebo effect on efficacy outcomes justify this design for a single-centered placebo-controlled investigator-initiated trial of nabilone. This study should be the basis for further evaluations of long-term efficacy and safety of the use of cannabinoids in PD patients.

Cognitive-Behavioral Therapy for Anxiety in Parkinson's Disease

Parkinson's disease (PD) is characterized by motor symptoms, but nonmotor symptoms also significantly impair daily functioning and reduce quality of life. Anxiety is prevalent and debilitating in PD, but remains understudied and undertreated. Much affective research in PD focuses on depression rather than anxiety, and as such, there are no evidence-based treatments for anxiety in this population. Cognitive-behavioral therapy (CBT) has shown promise for treating depression in PD and may be efficacious for anxiety. This exploratory study implemented a multiple-baseline single-case experimental design to evaluate the utility and feasibility of CBT for individuals with PD who also met criteria for a DSM-5 anxiety disorder (n = 9). Participants were randomized to a 2-, 4-, or 6-week baseline phase, followed by 12 CBT sessions, and two post treatment assessments (immediately post treatment and 6-week follow-up). Multiple outcome measures of anxiety and depression were administered weekly during baseline and intervention. Weekly CBT sessions were conducted in-person (n = 5) or via secure videoconferencing (n = 4). At post treatment, seven of the nine participants showed significant reductions in anxiety and/or depression, with changes functionally related to treatment and most improvements maintained at 6-week follow-up. Effects of CBT on secondary outcomes varied across participants, with preliminary evidence for reduction in fear of falling. Adherence and retention were high, as were treatment satisfaction and acceptability. The findings of this pilot study provide preliminary evidence for the utility of CBT as a feasible treatment for anxiety and comorbid depressive symptoms in PD and highlight the potential of telehealth interventions for mood in this population.

Parkinson's disease: Diagnosis and appreciation of comorbidities

Parkinson's disease (PD) is a complex neuropsychiatric disorder that manifests with a variety of motor and nonmotor symptoms. Its incidence increases with age. It is important for clinicians to be able to distinguish symptoms of aging and other comorbidities from those of PD. The diagnosis of PD has traditionally been rendered using strict criteria that mainly rely on the cardinal motor symptoms of rest tremor, rigidity, and bradykinesia. However, newer diagnostic criteria proposed by the Movement Disorders Society for diagnosis of PD collectively reflect a greater appreciation for the nonmotor symptoms. The treatment of PD remains symptomatic and the most noticeable improvements have been documented in the motor symptoms. Levodopa remains the gold standard for therapy, however there are now many other potential medical and surgical treatment strategies. Nonmotor symptoms have been shown to affect quality of life more than the motor symptoms. There is ongoing research into symptomatic and disease modifying treatments. Given the multisystem involvement in PD, an interdisciplinary patient-centered approach is recommended by most experts. This chapter addresses first the diagnostic approach and the many geriatric considerations. This is followed by a review of the nonmotor symptoms. Finally, a summary of current treatment strategies in PD is presented along with potential treatment complications.

Exercise as a therapeutic intervention for motor and non-motor symptoms in Parkinson's disease: Evidence from rodent models

Parkinson's disease (PD) is characterised by degeneration of dopaminergic neurons of the nigrostriatal pathway, which leads to the cardinal motor symptoms of the disease - tremor, rigidity and postural instability. A number of non-motor symptoms are also associated with PD, including cognitive impairment, mood disturbances and dysfunction of gastrointestinal and autonomic systems. Current therapies provide symptomatic relief but do not halt the disease process, so there is an urgent need for preventative strategies. Lifestyle interventions such as aerobic exercise have shown potential to lower the risk of developing PD and to alleviate both motor and non-motor symptoms. However, there is a lack of large-scale randomised clinical trials that have employed exercise in PD patients. This review will focus on the evidence from studies on rodent models of PD, for employing exercise as an intervention for both motor and non-motor symptoms.

Update on the clinical application of deep brain stimulation in sleep dysfunction of Parkinson's disease

Sleep dysfunctions, including rapid eye movement sleep behavior disorder, sleep fragmentation, excessive daytime sleepiness and various other dysfunctions, can seriously affect quality of life in patients with Parkinson's disease (PD). Emerging evidence suggests that deep brain stimulation (DBS) exerts a substantial effect when used to treat sleep dysfunctions, which are common nonmotor symptoms experienced by patients with PD. However, far less is known about the specific mechanisms underlying the effects of DBS on sleep processes and the factors that potentially influence these effects. These issues therefore need to be further clarified. Intriguingly, a number of recent studies have evaluated the effects of applying DBS to various brain targets on sleep in patients with PD. Deeper research into the efficacy of applying DBS to each brain target may help determine which region should be targeted during surgery in PD patients. Furthermore, compared with pharmacological therapy, DBS had more beneficial effects on sleep symptoms, and appropriate management involving the joint application of dopamine replacement therapy and DBS might accelerate the effects of treatment. Here, we review the potential roles DBS may play and provide clinical guidance for the use of DBS in treating sleep dysfunctions in PD patients.

Health-related quality of life outcomes from botulinumtoxin treatment in blepharospasm

OBJECTIVE

Blepharospasm associates with impairment in generic health-related quality of life (HR-QoL). Albeit botulinum toxin is widely used to alleviate the motor symptoms of blepharospasm, its effect on generic health-related quality of life (HR-QoL) is heterogeneous.

PATIENTS AND METHODS

In this open-label clinical observational study, we characterized outcomes on HR-QoL in terms of the EuroQol (EQ-5D-5 L) from botulinum toxin (BoNT) injection in a prospective cohort of patients with blepharospasm (n = 55). Additionally, we characterized motor and non-motor signs of blepharospasm including motor symptom improvement, life satisfaction, depressive symptoms, pain and sleep quality. Patients were assessed at the end of a regular three-month period from last injection (Timepoint1) and four weeks after the re-injection of BoNT (Timepoint2).

RESULTS

There was no improvement of generic HR-QoL on group-level. Individual findings were heterogeneous, dividing patients in three groups of responders (RESP), unchanged outcomes (UNCHN), and worsening (WORSE). We identified, that these subgroups differed at Timepoint 1 with respect to EQ-5D-5 L, EQ-VAS, life satisfaction (health and movement disorders domains), Beck's Depression inventory, and sleep quality (One-way ANOVAs, P <  0.05, adjusted for multiple comparisons). In post-hoc Tuckey tests, RESP or WORSE showed distinct differences from UNCHN that might help to separate the subgroups in future. As such, RESP showed higher impairment in EQ-5D-5L, EQ-VAS, and Beck's Depression Inventory compared to UNCHN (unlike WORSE), whereas WORSE showed higher impairment in life satisfaction 'movement disorders' domain (unlike RESP).

CONCLUSION

Our study suggests, that several dependent non-motor, life satisfaction and generic HR-QoL measures associate to individual patient outcomes. The variables identified in this study may be validated in future studies to predict HR-QoL outcomes in patients with blepharospasm.

Alteration of nociceptive integration in the spinal cord of a rat model of Parkinson's disease

BACKGROUND

Pain is a major non motor symptom that contributes to impaired quality of life in PD. However, its mechanism is unknown.

OBJECTIVES AND METHODS

We sought to identify the pain phenotypes and parallel changes in spinal integration of peripheral stimuli in a rat model of PD induced by lesions of SN dopamine neurons, using behavioral plantar and von Frey tests as well as electrophysiology of the dorsal horn.

RESULTS

We show that dopamine depletion by 6-OHDA induced hypersensitivity to mechanical and thermal stimuli. These abnormal behaviors were paralleled by increased neuronal responses and hyperexcitability of wide dynamic range neurons of lamina V of the dorsal horn of the spinal cord in response to electrical stimulation of the sciatic nerve in the 6-OHDA model as compared to sham rats.

CONCLUSIONS

These results provide evidence for alteration of nociceptive integration in the spinal dorsal horn neurons in 6-OHDA rats that can reflect changes in pain behavior. © 2018 International Parkinson and Movement Disorder Society.

Cognitive correlates of "pure apathy" in Parkinson's disease

INTRODUCTION

Previous studies exploring the association between apathy and cognitive deficits in Parkinson's disease (PD) employed scales and questionnaires for apathy, which did not control for the possible confounding effect of motor symptoms. Here we investigated the cognitive correlates of "pure apathy" by the Dimensional Apathy Scale, which allows us to assess apathy minimizing the influence of motor symptoms.

METHODS

Consecutive PD outpatients referred to our centre were screened. All participants underwent a neuropsychological battery to assess verbal memory, executive functions and visuospatial abilities, apathy and depressive symptoms.

RESULTS

We enrolled 56 non-depressed and non-demented PD patients, of whom 28 were apathetic and 28 were not. The two groups did not differ on demographic and clinical aspects; apathetic PD patients performed worse than non-apathetic PD patients on the part A, B and B-A of Trail Making Test and the interference task of Stroop test. No significant differences were found on memory and perceptual visuospatial tasks.

CONCLUSIONS

Our results demonstrated that "pure apathy" is associated with more severe executive dysfunctions such as alteration of set-shifting and inhibitory control, which are mediated by prefrontal cortex and subcortical regions (i.e. basal ganglia). Our findings also supported the hypothesis that co-occurrence of apathy and executive deficits may be the epiphenomenon of damage in prefrontal-striatal cortical circuitries connecting dorsolateral prefrontal cortex, anterior cingulate cortex and basal ganglia.

Early manifestation of depressive-like behavior in transgenic mice that express dementia with Lewy body-linked mutant β-synuclein

Aim

We previously generated transgenic (Tg) mice that expressed P123H β‐synuclein (βS), a dementia with Lewy body‐linked mutant βS. Notably, these mice recapitulated neurodegenerative features of Lewy body disease, reflected by motor dysfunction, greater protein aggregation, and memory impairment. Since recent studies suggested that non‐motor symptoms, such as depression, might be manifested in the prodromal stage of Lewy body disease, the main objective of the present study was to investigate the early expression of behavior in P123H βS Tg mice.

Methods

Nest building, locomotor activity, and depressive‐like behavior were assessed using 6‐ to 10‐month‐old male and female P123H βS Tg and wildtype mice.

Key Results

P123H βS Tg mice exhibited hyperlocomotor activity in a novel environment, a decrease in mobility time in the tail suspension test, and impairments in nest building.

Conclusions

Importantly, these non‐motor behaviors were manifested before the onset of motor dysfunction, suggesting that P123H βS Tg mice could be a valid model for investigating the early phase of Lewy body disease.

Transgenicmice that expressed P123H beta‐synuclein recapitulated neurodegenerative features of Lewy body disease. In the present study, we found that P123H beta‐synuclein transfenic mice exhibited non‐motor behaviors including depressive‐like behavior that were manifested before the onset of motor dysfunction. Thus, P123H beta‐synuclein transgenic mice may be a valid model for investigatig early hase of Lewy body disease.

Safinamide: a new hope for Parkinson's disease?

The loss of dopaminergic neurons (DAn) and reduced dopamine (DA) production underlies the reasoning behind the gold standard treatment for Parkinson's disease (PD) using levodopa (L-DOPA). Recently licensed by the European Medicine Agency (EMA) and US Food and Drug Administration (FDA), safinamide [a monoamine oxidase B (MOA-B) inhibitor] is an alternative to L-DOPA; as we discuss here, it enhances dopaminergic transmission with decreased secondary effects compared with L-DOPA. In addition, nondopaminergic actions (neuroprotective effects) have been reported, with safinamide inhibiting glutamate release and sodium/calcium channels, reducing the excitotoxic input to dopaminergic neuronal death. Effects of safinamide have been correlated with the amelioration of non-motor symptoms (NMS), although these remain under discussion. Overall, safinamide can be considered to have potential antidyskinetic and neuroprotective effects and future trials and/or studies should be performed to provide further evidence for its potential as an anti-PD drug.

Cognitive behavioral group therapy versus psychoeducational intervention in Parkinson's disease

OBJECTIVE

The aim of the current study was to evaluate whether cognitive behavioral group therapy has a positive impact on psychiatric, and motor and non-motor symptoms in Parkinson's disease (PD).

METHODS

We assigned 20 PD patients with a diagnosis of psychiatric disorder to either a 12-week cognitive behavioral therapy (CBT) group or a psychoeducational protocol. For the neurological examination, we administered the Unified Parkinson's Disease Rating Scale and the non-motor symptoms scale. The severity of psychiatric symptoms was assessed by means of the Hamilton Depression Rating Scale, the Hamilton Anxiety Rating Scale, the Brief Psychiatric Rating Scale, and the Clinical Global Impressions.

RESULTS

Cognitive behavioral group therapy was effective in treating depression and anxiety symptoms as well as reducing the severity of non-motor symptoms in PD patients; whereas, no changes were observed in PD patients treated with the psychoeducational protocol.

CONCLUSION

CBT offered in a group format should be considered in addition to standard drug therapy in PD patients.

Body awareness training in the treatment of wearing-off related anxiety in patients with Parkinson's disease: Results from a pilot randomized controlled trial

BACKGROUND

In Parkinson's disease (PD) patients, fluctuations in symptoms commonly occur after many years of dopamine replacement therapy. The so-called wearing-off phenomenon exists of both motor and non-motor symptoms, such as rigidity and anxiety. Current treatment options are limited and an integrated approach is needed to address the complex interactions between motor and non-motor symptoms. Since wearing-off is eventually inevitable, treatment needs to focus on coping, acceptance and self-efficacy. We developed the body awareness training, named BEWARE, combining physical therapy with acceptance and commitment therapy to help PD patients deal better with wearing-off related anxiety (WRA).

METHODS

This was an investigator-blinded randomized controlled trial. Forty PD patients with WRA were randomly assigned to the BEWARE or to the treatment as usual (TAU) condition. Assessments were performed prior to and immediately after the treatment period, and at 3-months follow up. The primary outcome was self-efficacy, secondary outcomes focused on mobility, daily functioning, anxiety, depression and quality of life.

RESULTS

There was no significant improvement in self-efficacy in the BEWARE treatment condition when compared to TAU. However, standing balance and emotional wellbeing showed a significant improvement, and feelings of stigmatization showed a trend-significant decrease in the BEWARE condition.

CONCLUSIONS

We consider the BEWARE training to be a promising therapeutic approach to address WRA. Improvement points from the participants included 1) less frequent but longer therapy sessions; 2) active involvement of caregivers; and 3) the development of a supportive workbook. The optimized treatment protocol needs further evaluation in a phase III RCT.

TRIAL REGISTRATION

ClinicalTrials.gov identifier: NCT02054845.

Botulinum Toxin Type A for Pain in Advanced Parkinson’s Disease

Background and Objective Pain is a frequent symptom in Parkinson’s disease (PD), and the therapeutic alternatives are scarce. The goal of this trial was to measure the effects of botulinum toxin type A (BTXA) in the treatment of limb pain in advanced PD. Methods A randomized double-blind crossover versus placebo study of BTXA for limb pain in advanced Parkinson’s disease was conducted. Subjects received individualized BTXA/placebo dosing per pain distribution in limbs. The primary outcome was a measure of change in global pain on a numeric rating scale (NRS) at 4 and 12 weeks postinjection and on a visual analogue scale 12 weeks after treatment. Secondary outcomes included the percentage of responders, physician-rated clinical global impressions, MDS–UPDRS and PDQ–39 scores, and adverse events. Results A total of 12 subjects completed the trial. Treatment with BTXA (average dose=241.66 U) produced a significant reduction in NRS score 4 weeks after the injections (–1.75 points, range from –3 to 7, p=0.033). However, there was no significant difference compared to placebo (p=0.70). Participants with dystonic pain showed a greater reduction in NRS score after 4 weeks when treated with BTXA (2.66 points vs. 0.75 for placebo). There were no significant differences for any of the secondary outcomes or significant adverse events. Conclusions Targeted BTXA injections were safe in patients with limb pain and advanced PD; however, the present study failed to show a significant effect when compared to placebo. Further studies may be focused on evaluating the effect of BTXA particularly in dystonic pain.

Algorithms for the treatment of motor problems in Parkinson's disease

Several different strategies are effective for medical treatment of motor problems in Parkinson's disease (PD). Many guidelines and evidence-based reviews are available, but there is no documentation or consensus in favor of just one treatment strategy. This review presents two algorithms that may be helpful when deciding how to treat a PD patient at various stages of the disease. The first algorithm suggests one way to treat PD from the first onset of motor symptoms. It is largely based on treatment recommendations from the Scandinavian countries and Germany. The other algorithm is meant as assistance for choosing among the different device-aided treatments for advanced PD. There is not sufficient comparative data to recommend one particular line of treatment, neither in early PD nor in advanced disease with motor complications. Individualized treatment is needed for each patient. The current algorithms only represent an alternative for aiding treatment decisions.

Botulinumtoxin Improves both Generic and Disease-Specific Quality of Life in Cervical Dystonia

Botulinumtoxin injection (BoNT) into affected muscles is effective to improve motor symptoms of cervical dystonia (CD) by reducing muscle contraction and involuntary dystonic movement and posturing. However, the understanding of the effect on health-related quality of life (HR-QoL) and patient referral under HR-QoL aspects is incomplete. In this open-label clinical prospective observational study, we characterized the outcomes in CD (n = 159) from botulinumtoxin on both generic HR-QoL (EuroQol; EQ-5D-5L) and disease-specific HR-QoL [craniocervical dystonia questionnaire (CDQ-24)]. Additionally, we characterized motor and non-motor signs of dystonia including motor symptom improvement, depressive symptoms, pain, and sleep quality. We assessed patients at the end of a regular 3-month period from last injection (Timepoint1) and 4 weeks after the re-injection of BoNT (Timepoint2). We aimed to define outcomes on both generic and disease-specific HR-QoL and to evaluate predictors of therapeutic outcome in terms of stepwise multiple regression models. Patients with CD showed a robust improvement of both generic and disease-specific HR-QoL. Furthermore, motor and non-motor signs improved. Multiple regression analyses revealed that EQ-5D-5L and “satisfaction with health” (Fragen zur Lebenszufriedenheit-G) at Timepoint1 predicted treatment response on generic HR-QoL outcome (R² = 0.284; P = 0.019). Similarly, CDQ-24 and Beck’s Depression inventory at Timepoint1 predicted the treatment response on disease-specific HR-QoL (R² = 0.253; P = 0.026). Our study underscores both generic and disease-specific HR-QoL improvements in CD, and provides useful predictors on HR-QoL outcomes.

Quality of Life and Nonmotor Symptoms in Parkinson's Disease

Health-related quality of life (HRQoL) is defined as "the perception and evaluation by patients themselves of the impact caused on their lives by the disease and its consequences." HRQoL is conceptualized as a combination of physical, psychological, and social well-being in the context of a particular disease. Following earlier studies revolving on the impact of the classic motor symptoms of Parkinson's disease on HRQoL, mounting evidence have been produced that nonmotor symptoms (NMS) significantly and independently contribute to worse HRQoL. This holds particularly true for such NMS such as neuropsychiatric disturbances, cognitive impairment, and fatigue, the burden of which might well exceed the effects of the motor symptoms. Nonetheless, there is very sparse evidence on how to manage these NMS and whether targeting NMS would in fact lead to an improvement of HRQoL, which calls for the need of future trials with NMS as primary outcomes.

Nonmotor Subtyping in Parkinson's Disease

Nonmotor symptoms are integral to Parkinson's disease. Several subtypes dominated by specific nonmotor symptoms have emerged. In this chapter, the rationale behind nonmotor subtyping and currently proposed nonmotor subgroups within Parkinson's disease based on data-driven cluster analysis and clinical observations will be summarized. Furthermore, the concept of seven clinical nonmotor subtypes will be discussed in detail including the clinical presentation, potential biomarkers, and the clinical relevance. In future, nonmotor subtypes will possibly play a major role within the aim to achieve personalized medicine.

Nonmotor Parkinson's and Future Directions

Nonmotor symptoms (NMS) of Parkinson's disease (PD) are integral to the condition largely regarded as a motor syndrome. A range of NMS underpin the prodromal stage of Parkinson's and are present with variable frequency, range, and nature across the whole journey of a patient with Parkinson's from the onset of the motor disease to palliative stage. These symptoms also are key determinants of quality of life of the patient as well as the carer. Despite this, recognition management and focused treatment of NMS of PD remain poor. Future would, therefore, need to focus on better definition and management of NMS of PD. This would include development of robust animal models of specific NMS such as cognitive, sleep, and autonomic dysfunctions as well as pain to understand the mechanistic pathways of these symptoms. In turn this will lead to better drug development using a bench to bedside model. Nonmotor clinical subtypes of PD have also been described and, in future, proper biomarkers will consolidate these findings in addition to defining the natural history of the subtypes. Revised versions of established scales and questionnaires will enable the adoption of good clinical practice with recognition of these subtypes in clinic. This will enhance the delivery of true subtype-specific therapies. Drug development should also include nondopaminergic and cell replacement restorative therapies with a nonmotor focus. An additional key area of future research would be the formalizing of true personalized medicine for PD. Personalized medicine pathways should concentrate on the role of exercise, complementary medicine as well as age, body weight, ethnicity on various NMS of PD. Genetics and pharmacogenetic developments in PD will add to the precision of the individualized approach.

Non-motor features of Parkinson disease

Many of the motor symptoms of Parkinson disease (PD) can be preceded, sometimes for several years, by non-motor symptoms that include hyposmia, sleep disorders, depression and constipation. These non-motor features appear across the spectrum of patients with PD, including individuals with genetic causes of PD. The neuroanatomical and neuropharmacological bases of non-motor abnormalities in PD remain largely undefined. Here, we discuss recent advances that have helped to establish the presence, severity and effect on the quality of life of non-motor symptoms in PD, and the neuroanatomical and neuropharmacological mechanisms involved. We also discuss the potential for the non-motor features to define a prodrome that may enable the early diagnosis of PD.

Treatment of Nonmotor Symptoms in Parkinson's Disease

Nonmotor symptoms (NMS) are integral to Parkinson's disease (PD) and the management can often be challenging. In spite of the growing evidence that NMS have a key impact on the quality of life of patients and caregivers, most clinical trials still focus on motor symptoms as primary outcomes. As a consequence strong evidence-based treatment recommendations for NMS occurring in PD are spare. In this chapter, the current data addressing the treatment of major NMS such as sleep, cognitive and autonomic dysfunction, and depression and anxiety are described.

The Nonmotor Features of Parkinson's Disease

Nonmotor symptoms (NMS) of Parkinson's disease (PD) were recognized by the great James Parkinson himself who mentioned symptoms such as sleep dysfunction, delirium, dementia, and dysautonomia, in his seminal 1817 essay, "An Essay on the Shaking Palsy" (Parkinson, 1817). In spite of the key impact of PD NMS on quality of life, there was little holistic research and awareness till the validation and use of comprehensive tools such as the NMS questionnaire, scale, and the revised version of the unified PD rating scale. Research studies using these tools highlighted the key impact of the burden of NMS on quality of life of PD patients and the need for NMS to be routinely assessed in clinic. We now define PD as a motor and nonmotor disorder, and the natural history includes a long prodromal phase of PD dominated by a range of NMS. The prodromal phase is the subject of much research particularly in relation to neuroprotection and identifying subjects at risk. Use of NMS tools has also validated burden grading of NMS with cutoff values, which can be used as outcome measure in clinical trials. Finally, the complex multineurotransmitter dysfunction that is seen in PD has been shown to manifest clinically as nonmotor subtypes. Recognition of such subtypes is likely to lead to the emergence of personalized and precision medicine in PD.

Synucleinopathies: common features and hippocampal manifestations

Parkinson's disease (PD), dementia with Lewy Bodies (DLB), and multiple system atrophy (MSA) are three major synucleinopathies characterized by α-synuclein-containing inclusions in the brains of patients. Because the cell types and brain structures that are affected vary markedly between the disorders, the patients have different clinical manifestations in addition to some overlapping symptoms, which are the basis for differential diagnosis. Cognitive impairment and depression associated with hippocampal dysfunction are frequently observed in these disorders. While various α-synuclein-containing inclusions are found in the hippocampal formation, increasing evidence supports that small α-synuclein aggregates or oligomers may be the real culprit, causing deficits in neurotransmission and neurogenesis in the hippocampus and related brain regions, which constitute the major mechanism for the hippocampal dysfunctions and associated neuropsychiatric manifestations in synucleinopathies.

Systematic review on strength training in Parkinson's disease: an unsolved question

The purpose of this study was to investigate the effectiveness of strength training, performed against a different resistance from body weight, in improving motor and nonmotor symptoms in patients with Parkinson’s disease (PD). The following electronic databases were searched: PubMed, Physiotherapy Evidence Database, Cochrane Central Register of Controlled Trials, Scopus, and Web of Science. The review was conducted and reported in accordance with the PRISMA statement. Thirteen high-quality randomized controlled trials were included. Strength training performed against external resistance is well tolerated and appears to be a suitable physical activity to improve both physical parameters and quality of life parameters of PD subjects. However, although the study intervention included strength training, only a few selected studies assessed the improvement of muscle strength. Despite the encouraging results, it is difficult to establish a correlation between strength training and the improvements made. Our review highlights the lack of common intent in terms of study design and the presence of different primary and secondary outcomes. Accordingly, further studies are needed to support the beneficial effects of different types of strength training in PD subjects and to underline the superiority of strength training in PD patients with respect to other training.

Parkinson disease

Parkinson disease is the second-most common neurodegenerative disorder that affects 2-3% of the population ≥65 years of age. Neuronal loss in the substantia nigra, which causes striatal dopamine deficiency, and intracellular inclusions containing aggregates of α-synuclein are the neuropathological hallmarks of Parkinson disease. Multiple other cell types throughout the central and peripheral autonomic nervous system are also involved, probably from early disease onwards. Although clinical diagnosis relies on the presence of bradykinesia and other cardinal motor features, Parkinson disease is associated with many non-motor symptoms that add to overall disability. The underlying molecular pathogenesis involves multiple pathways and mechanisms: α-synuclein proteostasis, mitochondrial function, oxidative stress, calcium homeostasis, axonal transport and neuroinflammation. Recent research into diagnostic biomarkers has taken advantage of neuroimaging in which several modalities, including PET, single-photon emission CT (SPECT) and novel MRI techniques, have been shown to aid early and differential diagnosis. Treatment of Parkinson disease is anchored on pharmacological substitution of striatal dopamine, in addition to non-dopaminergic approaches to address both motor and non-motor symptoms and deep brain stimulation for those developing intractable L-DOPA-related motor complications. Experimental therapies have tried to restore striatal dopamine by gene-based and cell-based approaches, and most recently, aggregation and cellular transport of α-synuclein have become therapeutic targets. One of the greatest current challenges is to identify markers for prodromal disease stages, which would allow novel disease-modifying therapies to be started earlier.