Update on the Management of Parkinson's Disease for General Neurologists

Starting with 24-h levodopa carbidopa intestinal gel at initiation in a large cohort of advanced Parkinson's disease patients

Continuous intra-jejunal infusion of levodopa-carbidopa intestinal gel (LCIG) is a long-term proven and effective treatment in advanced Parkinson's Disease (APD). Efficacy and safety of 16-h administration of LCIG has already been established. Additional benefits of 24-h LCIG administration have been reported in several case series and small clinical studies. The aim of this retrospective study was to compare the characteristics of patients who needed 24-h LCIG from the beginning of the DAT (device-aided treatment) with those who remained with the standard 16-h LCIG treatment and to identify particular motives if any. We initiated LCIG in 150 patients out of which in case of 62 patients (41,3%) due to unsatisfactory initial clinical benefits continuous 24-h LCIG was deemed necessary. Despite the subjective complaints and more severe clinical condition, at baseline evaluation we found statistically significant differences between 16-h LCIG cohort and 24-h LCIG cohort only in case of incidence of freezing (47% vs 65%, p = 0.03) and sudden off (32% vs 48%, p = 0.04). Wake hours/daytime LCIG does not always sufficiently improve the patient's quality of life in some patients due to persistent nighttime troublesome symptoms. Instead of labeling the patient as a non-responder, it is worth trying the 24-h LCIG dosage in a carefully selected group of patients, as there is currently no consensus on reliable criteria that serve the decision in these patients.

Levodopa use in Australia: an analysis of Pharmaceutical Benefits Scheme 10% data

Background

Levodopa remains the mainstay of treatment of Parkinson's disease, however, over time motor fluctuations and levodopa-induced dyskinesia develop, requiring add-on therapies to control emerging symptoms. To date, however, there is no clear consensus in Australia, or elsewhere, at which dose of levodopa that add-on therapies should be considered.

Objectives

The purpose of this study was to examine the treatment patterns of patients with Parkinson's disease in Australia, with particular focus on levodopa doses at the time of first add-on.

Methods

This was a retrospective, observational, non-interventional study of patients with Parkinson's disease within the Australian Department of Human Services Pharmaceutical Benefits Scheme (PBS) 10% sample. Data on all reimbursed prescriptions (both general and concession), prescriber type and item code were extracted for patients who were dispensed at least three PBS reimbursed prescriptions for levodopa in the previous 12 months prescription from 1 January 2007 to 31 December 2021.

Results

154 850 unique patients were included, of whom 42 330 (27%) commenced add-on therapy during the period. In the 12 months prior to add-on therapy, levodopa doses ranged from 100 mg/day to 1000 mg/day. The majority of patients were prescribed add-on therapy by a neurologist and approximately 40% of patients were prescribed levodopa doses of 600 mg/day or more prior to the first add-on therapy being initiated.

Conclusions

A large proportion of patients in Australia are managed with levodopa monotherapy doses that are considered high and many of these patients may benefit from the addition of add-on therapy to their regimen.

Should continuous dopaminergic stimulation be a standard of care in advanced Parkinson's disease?

The standard of care is a term that refers to the level of care, skill, and treatment that a healthcare provider should offer to a patient based on the current scientific evidence and the level of medical knowledge available in the field. For Parkinson's disease (PD), the standard care is mostly considered to be oral treatment with dopaminergic drugs, particularly levodopa which remains the 'gold standard'. However, effective management with levodopa during the later stages of the disease becomes increasingly challenging due to the ongoing neurodegenerative process, the consequences of its pulsatile dopaminergic stimulation, and the gastrointestinal barriers to effective drug absorption. As a result, the concept of applying continuous dopaminergic stimulation has emerged with infusion therapies (continuous subcutaneous apomorphine, levodopa-carbidopa intestinal gel, and levodopa-entacapone-carbidopa intestinal gel infusion). These therapies seek to provide continuous stimulation of striatal dopamine receptors that is efficient not only in alleviating clinical symptoms, but also in delaying, reducing, and possibly preventing the onset of levodopa-related motor (fluctuations, dyskinesia) and non-motor complications; and they are also associated with clinically relevant side effects. Clinical studies and real-life experience support the notion that infusion therapies should be accepted as part of the standard of care for patients with advanced PD who have refractory, severe, and disabling motor complications that affect their quality of life. However, they should be considered based on the needs of individualized patients and the access to these advanced therapies needs to be made more accessible to the general PD population.

Understanding support systems for Parkinson's disease management in community settings: A cross-national qualitative study

BACKGROUND

Health and social care systems face difficulties in managing multimorbidity, disease burden and complex needs in long-term conditions such as Parkinson's disease.

OBJECTIVE

This study aimed to develop a European understanding of how health and social care professionals can collaborate with stakeholders from different organizations and sectors to enhance the management of Parkinson's disease in a community setting by identifying the existing gaps in this process and how people with Parkinson's disease and their family carers could benefit from these partnerships.

METHODS

A mixed-methods sequential study was conducted in Denmark, Norway, Spain and the United Kingdom. The findings from the qualitative phase are presented. Individual semistructured interviews were analysed using Braun's and Clarke's thematic analysis. A meta-ethnography approach was used to analyse and synthesize cross-national findings.

RESULTS

A total of 41 healthcare professionals and 39 stakeholders from different disciplines and sectors were interviewed in the four countries. The participants acknowledged a lack of awareness of available resources and poor communication between the different support systems in the management of Parkinson's disease. To promote multiagency collaborations, the participants highlighted the need to organize services along the Parkinson's disease journey, patient involvement and strategic involvement of carers in organizing resources and Parkinson's disease care pathways. According to the participants, the benefits from multiagency partnerships could lead to an enhanced continuity of care and specialized knowledge, mobilization of resources in the community, personalized support and improved access to services.

CONCLUSIONS

Policymakers are called upon to create formal structures that facilitate multisectoral collaborations to promote an integrated system of care for the management of Parkinson's disease in the community. To address this challenge, we propose five strategies showing how organizations can work together to optimize the use of resources and enhance the management of Parkinson's disease throughout the illness trajectory.

PATIENT OR PUBLIC CONTRIBUTION

Patient and Public Involvement groups made up of stakeholders, healthcare professionals, patients with Parkinson's disease and family carers participated in the design of the study, the development of the interview guides and the validation of the findings.

Stem Cell-based and Advanced Therapeutic Modalities for Parkinson's Disease: A Risk-effectiveness Patient-centered Analysis

Treatment of Parkinson's disease (PD), the second most prevalent neurodegenerative disorder, is currently considered a challenging issue since it causes substantial disability, poor quality of life, and mortality. Despite remarkable progress in advanced conventional therapeutic interventions, the global burden of the disease has nearly doubled, prompting us to assess the riskeffectiveness of different treatment modalities. Each protocol could be considered as the best alternative treatment depending on the patient's situation. Prescription of levodopa, the most effective available medicine for this disorder, has been associated with many complications, i.e., multiple episodes of "off-time" and treatment resistance. Other medications, which are typically used in combination with levodopa, may have several adverse effects as well. As a result, the therapies that are more in line with human physiology and make the least interference with other pathways are worth investigating. On the other hand, remaining and persistent symptoms after therapy and the lack of effective response to the conventional approaches have raised expectations towards innovative alternative approaches, such as stem cell-based therapy. It is critical to not overlook the unexplored side effects of innovative approaches due to the limited number of research. In this review, we aimed to compare the efficacy and risk of advanced therapies with innovative cell-based and stemcell- based modalities in PD patients. This paper recapitulated the underlying factors/conditions, which could lead us to more practical and established therapeutic outcomes with more advantages and few complications. It could be an initial step to reconsider the therapeutic blueprint for patients with Parkinson's disease.

Repositioning of drugs for Parkinson's disease and pharmaceutical nanotechnology tools for their optimization

Parkinson's disease (PD) significantly affects patients' quality of life and represents a high economic burden for health systems. Given the lack of safe and effective treatments for PD, drug repositioning seeks to offer new medication alternatives, reducing research time and costs compared to the traditional drug development strategy. This review aimed to collect evidence of drugs proposed as candidates to be reused in PD and identify those with the potential to be reformulated into nanocarriers to optimize future repositioning trials. We conducted a detailed search in PubMed, Web of Science, and Scopus from January 2015 at the end of 2021, with the descriptors "Parkinson's disease" and "drug repositioning" or "drug repurposing". We identified 28 drugs as potential candidates, and six of them were found in repositioning clinical trials for PD. However, a limitation of many of these drugs to achieve therapeutic success is their inability to cross the blood-brain barrier (BBB), as is the case with nilotinib, which has shown promising outcomes in clinical trials. We suggest reformulating these drugs in biodegradable nanoparticles (NPs) based on lipids and polymers to perform future trials. As a complementary strategy, we propose functionalizing the NPs surface by adding materials to the surface layer. Among other advantages, functionalization can promote efficient crossing through the BBB and improve the affinity of NPs towards certain brain regions. The main parameters to consider for the design of NPs targeting the central nervous system are highlighted, such as size, PDI, morphology, drug load, and Z potential. Finally, current advances in the use of NPs for Parkinson's disease are cited.

Mechanisms of NLRP3 activation and pathology during neurodegeneration

Inflammasomes are multiprotein complexes that are mainly present in resident and infiltrating immune cells in the central nervous system. Inflammasomes function as intracellular sensors of immunometabolic stress, infection and changes in the local microenvironment. Inflammasome assembly in response to these 'danger signals', triggers recruitment and cluster-dependent activation of caspase-1 and the subsequent proteolytic activation of inflammatory cytokines such as interleukin-1β and interleukin-18. This is typically followed by a form of inflammatory cell death through pyroptosis. Since the discovery of inflammasomes in 2002, they have come to be recognized as central regulators of acute and chronic inflammation, a hallmark of progressive neurological diseases. Indeed, over the last decade, extensive inflammasome activation has been found at the sites of neuropathology in all progressive neurodegenerative diseases. Disease-specific misfolded protein aggregates which accumulate in neurodegenerative diseases, such as alpha synuclein or beta amyloid, have been found to be important triggers of NLRP3 inflammasome activation in the central nervous system. Together, these discoveries have transformed our understanding of how chronic inflammation is triggered and sustained in the central nervous system, and how it can contribute to neuronal death and disease progression in age-related neurodegenerative diseases. Therapeutic strategies around inhibition of NLRP3 activation in the central nervous system are already being evaluated to determine their effectiveness to slow progressive neurodegeneration. This review summarizes current understanding of inflammasomes in the most prevalent neurodegenerative diseases and discusses current knowledge gaps and inflammasome inhibition as a therapeutic strategy.

Capturing Subjective Mild Cognitive Decline in Parkinson’s Disease

This study aimed to capture subjective daily functional cognitive decline among patients with Parkinson’s disease. Participants (40–79 y; 78 with Parkinson’s disease and 41 healthy matched controls) completed the Unified Parkinson’s Disease Rating Scale (MDS-UPDRS), Parkinson’s Disease Cognitive Functional Rating Scale (CFRS), Daily Living Questionnaire (DLQ), and Time Organisation and Participation Scale (TOPS) questionnaires. Patients with Parkinson’s disease were divided into groups with or without suspected mild cognitive decline according to their scores on the Cognitive Functional (CF) feature, which is based on certain items of the MDS-UPDRS. Significant between-group differences were found in the DLQ and TOPS scores. Significant correlations were found among the questionnaire results, with specific DLQ and TOPS items accounting for 35% of the variance in the CF feature, which correlated with daily cognitive functional states. This study’s results are relevant for detecting subtle deficits in Parkinson’s disease patients suspected of mild cognitive decline, which can affect health and quality of life and relates to risk for later dementia.

Levodopa-Carbidopa Intestinal Gel in Advanced Parkinson’s Disease: Observations and Dilemmas after 10 Years of Real-Life Experience

Advanced Parkinson’s disease (APD) cannot be treated efficiently using the classical medications however, in recent decades invasive therapeutical methods were implemented and confirmed as effective. One of these methods makes it possible to continue the levodopa (LD) supplementation as a gel administered directly into the upper intestine. However, there are a number of unanswered questions regarding this method. Therefore, we retrospectively analyzed a 10-year period of selected patients that were treated with levodopa/carbidopa intestinal gel (LCIG). We included all APD patients with motor fluctuations and dyskinesia at presentation. LCIG treatment was started in 150 patients: on average these patients received LD for 10.6 ± 4.4 years with a frequency of 5.2 ± 1.0/day until the introduction of LCIG. The estimated and the real LCIG dose differed significantly (mean: 1309 ± 321 mg vs. 1877 ± 769 mg). The mean duration of LCIG administration was 19.8 ± 3.6 h, but in a number of 62 patients we had to administer it for 24 h, to maximize the therapeutic benefit. A carefully and individually adjusted LCIG treatment improves the quality of life of APD patients, but questions remain unresolved even after treating a large number of patients. It is important to share the ideas and observations based on the real-life experience related to the optimal timing, the appropriate dose and duration of administration of the LCIG.

How I treat Parkinson's disease

BACKGROUND

Parkinson's disease (PD) is a complex neurodegenerative condition. Treatment strategies through all stages of disease progression could affect quality of life and influence the development of future complications, making it crucial for the clinician to be on top of the literature.

OBJECTIVE

This paper reviews the current treatment of PD, from early to advanced stages.

METHODS

A literature review was conducted focusing on the treatment of PD, in the different stages of progression.

RESULTS

Every individual with a new diagnosis of PD should be encouraged to start exercising regularly. In the early stage, treatment should focus on using the lowest dose of levodopa or combination therapy that provides maximum functional capacity, and does not increase the risk of complications, such as peak dose dyskinesias and impulse control disorders. At the moderate and advanced stages, motor fluctuations and complications of treatment dominate the picture, making quality of life one important issue. Rehabilitation programs can improve motor symptoms and should be offered to all patients at any stage of disease progression.

CONCLUSION

Many factors need to be considered when deciding on the best treatment strategy for PD, such as disease progression, presence of risk factors for motor and behavioral complications, potential side effects from dopaminergic therapy and phenotypical variabilities. Treatment should focus on functional capacity and quality of life throughout the whole disease course.

Perspectives on the urological care in Parkinson's disease patients

Parkinson's disease (PD) is recognized as the most common neurodegenerative disorder after Alzheimer's disease. Lower urinary tract symptoms are common in patients with PD, either storage symptoms (overactive bladder symptoms or OAB) or voiding symptoms. The most important diagnostic clues for urinary disturbances are provided by the patient's medical history. Urodynamic evaluation allows the determination of the underlying bladder disorder and may help in the treatment selection. Pharmacologic interventions especially anticholinergic medications are the first-line option for treating OAB in patients with PD. However, it is important to balance the therapeutic benefits of these drugs with their potential adverse effects. Intra-detrusor Botulinum toxin injections, electrical stimulation were also used to treat OAB in those patients with variable efficacy. Mirabegron is a β3-agonist that can also be used for OAB with superior tolerability to anticholinergics. Desmopressin is effective for the management of nocturnal polyuria which has been reported to be common in PD. Deep brain stimulation (DBS) surgery is effective in improving urinary functions in PD patients. Sexual dysfunction is also common in PD. Phosphodiesterase type 5 inhibitors are first-line therapies for PD-associated erectile dysfunction (ED). Treatment with apomorphine sublingually is another therapeutic option for PD patients with ED. Pathologic hypersexuality has occasionally been reported in patients with PD, linked to dopaminergic agonists. The first step of treatment of hypersexuality consists of reducing the dose of dopaminergic medication. This review summarizes the epidemiology, pathogenesis, risk factors, genetic, clinical manifestations, diagnostic test, and management of PD. Lastly, the urologic outcomes and therapies are reviewed.

Multidisciplinary Rehabilitation for People with Parkinson’s Disease: A Systematic Review and Meta-Analysis

Introduction

Guidelines endorse to implement an integrated and multidisciplinary team approach in the management of people with Parkinson's disease (PD). However, there is no net and clear finding that shows the supremacy of multidisciplinary team interventions over conventional interventions for people with PD. Therefore, we perform a systematic review and meta-analysis to determine the supremacy of multidisciplinary interventions for people with PD.

Methods

A systematic review and meta-analysis of randomized controlled trials were conducted. PubMed, Physiotherapy Evidence Database, Cochrane Library, and Google Scholar were searched from inception until May 2021. Randomized controlled trials comparing multidisciplinary intervention with conventional physiotherapy were included. The outcome measures were gait balance, disability status, quality of life, and depression level. The PEDro scale was used to systematically appraise methodological quality. Two reviewers screened, extracted, and performed a quality assessment of included studies independently. Review Manager V.5.4 (Cochrane Collaboration) software was used for statistical analysis. Heterogeneity was analyzed using I² statistics, and a standardized mean difference with 95% CI and Pvalue was used to calculate the treatment effect for outcome variables.

Results

A total of 6 studies with 1260 participants were included. The average PEDro methodological quality score was 6.67. No statistically significant difference between multidisciplinary and conventional rehabilitation on functional capacity (SMD: 0.69; 95% CI: −0.13, 1.51; P=0.10), disability status (SMD: 0.65; 95% CI: −0.16, 1.46; P=0.11), and quality of life (SMD: 0.28; 95% CI: −0.31, 0.59; P=0.08) was found. However, there is a statistically significant improvement in caregivers' anxiety levels in the multidisciplinary group (SMD: 0.39; 95% CI 0.06, 1.73; P=0.02).

Conclusion

This systematic review and meta-analysis show no significant difference between multidisciplinary and conventional rehabilitation on functionality, disability, and quality of life. Caregivers' anxiety levels show improvement following multidisciplinary interventions. However, large-scale studies with long-term follow-up were required for concrete and clinical recommendations.

Parkinson's Disease: Is there a Role for Dietary and Herbal Supplements?

Parkinson's Disease (PD) is characterised by degeneration of the neurons of the nigrostriatal dopaminergic pathway of the brain. The pharmacological cornerstone of PD management is mainly the use of dopamine precursors, dopamine receptor agonists, and agents that inhibit the biochemical degradation of dopamine. While these drugs initially provide relief to the symptoms and improve the quality of life of the patients, progression of the underlying pathological processes, such as oxidative stress and neuroinflammation (which have been strongly associated with PD and other neurodegenerative disorders), eventually reduce their benefits, making further benefits achievable, only at high doses due to which the magnitude and frequency of side-effects are amplified. Also, while it is becoming obvious that mainstream pharmacological agents may not always provide the much-needed answer, the question remains what succour can nature provide through dietary supplements, nutraceuticals and herbal remedies? This narrative review examines current literature for evidence of the possible roles (if any) of nutraceuticals, dietary supplements and herbal remedies in the prevention or management of PD by examining how these compounds could modulate key factors and pathways that are crucial to the pathogenesis and/or progression of PD. The likely limitations of this approach and its possible future roles in PD prevention and management are also considered.

The effect of water-soluble pristine C60 fullerene on 6-OHDA-induced Parkinson’s disease in rats

Oxidative stress is thought to be one of the mechanisms that leads to the dysfunction and degeneration of dopaminergic neurons in Parkinson’s disease pathogenesis and presumed to be underway during the prodromal phase. Therefore, therapy, which is effective against pre-motor symptoms, might be effective in preventing or delaying the development and progression of Parkinson’s disease. The aim of our study was to investigate the therapeutic efficiency of pristine C60 fullerene aqueous solution (C60FAS) during Parkinson’s disease in rats. The unilateral dopamine deficiency was induced in male Wistar rats (220–250 g) by stereotaxic microinjection of neurotoxin 6-hydroxydopamine (6-OHDA, 12 μg). C60FAS was injected to rats intraperitoneally daily for 10 days (0.65 mg/kg per day). The percentage of destroyed dopaminergic neurons was determined by the apomorphine test and by IHC staining of tyrosine hydroxylase-positive neurons in substantia nigra. We evaluated the rat body weight, the water and food intake, Open Field behavioural test, the level of biochemical antioxidant system, the activity of peritoneal macrophages. Levels of spontaneous and carbachol-stimulated colon motility were estimated by ballonographic method in vivo. C60FAS showed a positive tendency to increase the number of tyrosine hydroxylase-positive cells in the midbrain, which was associated with more profound improvement in apomorphine-rotation behaviour and slight relief of the anxiety level in Open Field test. Furthermore, C60FAS treatment increased the index of stimulated distal colon motor activity while it did not have a significant effect on water content in feces and total gastrointestinal transit time. C60FAS treatment did not affect water intake behaviour or body weight changes while it induced an increase of glutathione level and decrease activity of glutathione peroxidase in the brain as well as an increase in activity of peritoneal macrophages in 6-OHDA-Parkinson’s disease rats. These findings confirmed the potential therapeutic effectiveness of water-soluble pristine C60 fullerene in Parkinson’s disease pathogenesis, though there is ground for caution because of its systemic mild toxic effect.

Zebrafish and Medaka: Important Animal Models for Human Neurodegenerative Diseases

Animal models of human neurodegenerative disease have been investigated for several decades. In recent years, zebrafish (Danio rerio) and medaka (Oryzias latipes) have become popular in pathogenic and therapeutic studies about human neurodegenerative diseases due to their small size, the optical clarity of embryos, their fast development, and their suitability to large-scale therapeutic screening. Following the emergence of a new generation of molecular biological technologies such as reverse and forward genetics, morpholino, transgenesis, and gene knockout, many human neurodegenerative disease models, such as Parkinson's, Huntington's, and Alzheimer's, were constructed in zebrafish and medaka. These studies proved that zebrafish and medaka genes are functionally conserved in relation to their human homologues, so they exhibit similar neurodegenerative phenotypes to human beings. Therefore, fish are a suitable model for the investigation of pathologic mechanisms of neurodegenerative diseases and for the large-scale screening of drugs for potential therapy. In this review, we summarize the studies in modelling human neurodegenerative diseases in zebrafish and medaka in recent years.

ADP/ATP translocase 1 protects against an α-synuclein-associated neuronal cell damage in Parkinson's disease model

BACKGROUND

ADP/ATP translocase 1 (ANT1) is involved in the exchange of cytosolic ADP and mitochondrial ATP, and its defection plays an important role in mitochondrial pathogenesis. To reveal an etiological implication of ANT1 for Parkinson's disease (PD), a neurodegenerative disorder, a mouse model treated with 1-Methyl-4-phenyl-1,2,3,6-tetrahydropyridine and neuroblastoma cell model induced by 1-methyl-4-pehny1-pyridine were utilized in this study.

RESULTS

The tissue-specific abundance in ANT1 in mouse brains was accessed using the analysis of Western blot and immunohistochemistry. Down-regulated soluble ANT1 was found to be correlated with PD, and ANT1 was associated with PD pathogenesis via forming protein aggregates with α-synuclein. This finding was confirmed at cellular level using neuroblastoma cell models. ANT1 supplement in neuronal cells revealed the protective roles of ANT1 against cytotoxicity caused by MPP⁺. Protein interaction assay, coupled with the analysis of LC-MS/MS, silver-stained SDS-PAGE and Western blot against anti-ANT1 antibody respectively, illustrated the interaction of ANT1 with α-synuclein using the expressed α-synuclein as a bite. Additionally, a significant increasing ROSs was detected in the MPP⁺-treated cells.

CONCLUSIONS

This study indicated that ANT1 was a potentially causative factor of PD, and led to neuropathogenic injury via promoting the formation of protein aggregates with α-synuclein. This investigation potentially promotes an innovative understanding of ANT1 on the etiology of PD and provides valuable information on developing potential drug targets in PD treatment or reliable biomarkers in PD prognostication.

Management Challenges of Severe, Complex Dyskinesia. Data from a Large Cohort of Patients Treated with Levodopa-Carbidopa Intestinal Gel for Advanced Parkinson's Disease

BACKGROUND

In the advanced stages of Parkinson's disease (APD), complex forms of dyskinesia may severely impair the patient's quality of life.

OBJECTIVE

In the present study, we aimed to analyze the evolution under LCIG therapy of the most important motor fluctuations and complex disabling dyskinesias, including diphasic dyskinesia.

METHODS

In this retrospective study, we analyzed the characteristics of patients with APD who had at least 30 min of diphasic dyskinesia (DID) in 3 consecutive days, were considered responders and were treated with LCIG in our clinic. Patients were evaluated before and after PEG and at 6, 12 and 18 months, when the changes in the therapy were recorded, and they completed a 7-point Global Patient Impression of Improvement (PGI-I) scale.

RESULTS

Forty patients fulfilled the inclusion criteria-out of which, 34 performed all visits. There was a substantial difference between the calculated and real LCIG (1232 ± 337 mg vs. 1823 ± 728 mg). The motor fluctuations and most dyskinesias improved significantly after starting LCIG, but an increasing number of patients needed longer daily administrations of LCIG (24 instead of 16 h).

CONCLUSIONS

Patients with APD with complex dyskinesias must be tested in dedicated hospitals, and they need a special therapeutic approach. The properly adapted LCIG treatment regarding the dose and time of administration completed with well-selected add-on medication should offer improvement for patients who want to or can only choose this DAT vs. others.

The Promise of the Zebrafish Model for Parkinson's Disease: Today's Science and Tomorrow's Treatment

The second most prevalent neurodegenerative disorder in the elderly is Parkinson's disease (PD). Its etiology is unclear and there are no available disease-modifying medicines. Therefore, more evidence is required concerning its pathogenesis. The use of the neurotoxin 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine (MPTP) is the basis of most animal models of PD. MPTP is metabolized by monoamine oxidase B (MAO B) to MPP + and induces the loss of dopaminergic neurons in the substantia nigra in mammals. Zebrafish have been commonly used in developmental biology as a model organism, but owing to its perfect mix of properties, it is now emerging as a model for human diseases. Zebrafish (Danio rerio) are cheap and easy to sustain, evolve rapidly, breed transparent embryos in large amounts, and are readily manipulated by different methods, particularly genetic ones. Furthermore, zebrafish are vertebrate species and mammalian findings obtained from zebrafish may be more applicable than those derived from genetic models of invertebrates such as Drosophila melanogaster and Caenorhabditis elegans. The resemblance cannot be taken for granted, however. The goal of the present review article is to highlight the promise of zebrafish as a PD animal model. As its aminergic structures, MPTP mode of action, and PINK1 roles mimic those of mammalians, zebrafish seems to be a viable model for studying PD. The roles of zebrafish MAO, however, vary from those of the two types of MAO present in mammals. The benefits unique to zebrafish, such as the ability to perform large-scale genetic or drug screens, should be exploited in future experiments utilizing zebrafish PD models.

Retinal applications of swept source optical coherence tomography (OCT) and optical coherence tomography angiography (OCTA)

The advent of optical coherence tomography (OCT) revolutionized both clinical assessment and research of vitreoretinal conditions. Since then, extraordinary advances have been made in this imaging technology, including the relatively recent development of swept-source OCT (SS-OCT). SS-OCT enables a fast scan rate and utilizes a tunable swept laser, thus enabling the incorporation of longer wavelengths than conventional spectral-domain devices. These features enable imaging of larger areas with reduced motion artifact, and a better visualization of the choroidal vasculature, respectively. Building on the principles of OCT, swept-source OCT has also been applied to OCT angiography (SS-OCTA), thus enabling a non-invasive in depth-resolved imaging of the retinal and choroidal microvasculature. Despite their advantages, the widespread use of SS-OCT and SS-OCTA remains relatively limited. In this review, we summarize the technical details, advantages and limitations of SS-OCT and SS-OCTA, with a particular emphasis on their relevance for the study of retinal conditions. Additionally, we comprehensively review relevant studies performed to date to the study of retinal health and disease, and highlight current gaps in knowledge and opportunities to take advantage of swept source technology to improve our current understanding of many medical and surgical chorioretinal conditions. We anticipate that SS-OCT and SS-OCTA will continue to evolve rapidly, contributing to a paradigm shift to more widespread adoption of new imaging technology to clinical practice.

Characterizing Advanced Parkinson's Disease: Romanian Subanalysis from the OBSERVE-PD Study

OBSERVE-PD was a cross-sectional, multicountry, observational study conducted in 128 Movement Disorders Centers (MDCs) in 18 countries. Overall, the study enrolled 2615 patients. The aim was to determine the proportion of patients with advanced Parkinson's disease (APD) versus non-APD from MDCs and to uncover the clinical burden of APD, as well as a correlation between overall assessment of APD and several indicators of APD. The advanced stage of the disease and severity were assessed by investigators using their clinical judgement. Data were collected during a single visit between February 2015 and January 2016. Agreement on physician judgement of APD diagnosis and fulfillment of at least one previously established APD indicator was calculated. Motor and nonmotor symptoms (NMSs), activities of daily living, treatment complications, quality of life (QoL), conventional treatments, and device-aided therapy (DAT) eligibility were assessed. Here, country-specific results of 161 Romanian patients with PD are presented. In total, 59.0% of patients were diagnosed with APD and 78.8% met at least one APD indicator. There was only moderate agreement between clinical judgement of APD and overall fulfillment of APD indicators. All scores related to motor symptoms, NMSs, and treatment complications, as well as to QoL, showed a higher disease burden for patients with APD versus non-APD. Physicians considered 73.7% of patients with APD eligible for DAT. The majority of patients eligible for DAT (54.3%) did not receive such treatment. Our results highlight the importance of earlier recognition of APD, by combining clinical judgement with more standardized clinical tools, such as generally recognized APD criteria. However, timely diagnosis of APD alone is not enough to improve patient outcomes. Other critical factors include patient acceptance and access to appropriate treatment.

Nanoparticle-Based Technology Approaches to the Management of Neurological Disorders

Neurological disorders are the most devastating and challenging diseases associated with the central nervous system (CNS). The blood-brain barrier (BBB) maintains homeostasis of the brain and contributes towards the maintenance of a very delicate microenvironment, impairing the transport of many therapeutics into the CNS and making the management of common neurological disorders such as Alzheimer's disease (AD), Parkinson's disease (PD), cerebrovascular diseases (CVDs) and traumatic brain injury (TBI), exceptionally complicated. Nanoparticle (NP) technology offers a platform for the design of tissue-specific drug carrying systems owing to its versatile and modifiable nature. The prospect of being able to design NPs capable of successfully crossing the BBB, and maintaining a high drug bioavailability in neural parenchyma, has spurred much interest in the field of nanomedicine. NPs, which also come in an array of forms including polymeric NPs, solid lipid nanoparticles (SLNs), quantum dots and liposomes, have the flexibility of being conjugated with various macromolecules, such as surfactants to confer the physical or chemical property desired. These nanodelivery strategies represent potential novel and minimally invasive approaches to the treatment and diagnosis of these neurological disorders. Most of the strategies revolve around the ability of the NPs to cross the BBB via various influx mechanisms, such as adsorptive-mediated transcytosis (AMT) and receptor-mediated transcytosis (RMT), targeting specific biomarkers or lesions unique to that pathological condition, thereby ensuring high tissue-specific targeting and minimizing off-target side effects. In this article, insights into common neurological disorders and challenges of delivering CNS drugs due to the presence of BBB is provided, before an in-depth review of nanoparticle-based theranostic strategies.

Map kinase signaling as therapeutic target for neurodegeneration

Aging is known to be one of the major risk factors in many neurodegenerative diseases (ND) whose prevalence is estimated to rise in the coming years due to the increase in life expectancy. Examples of neurodegenerative diseases include Huntington's, Parkinson's, and Alzheimer's diseases, along with Amyotrophic Lateral Sclerosis, Spinocerebellar ataxias and Frontotemporal Dementia. Given that so far these ND do not have effective pharmacological therapies, a better understanding of the molecular and cellular mechanisms can contribute to development of effective treatments. During the previous decade, the data indicated that dysregulation of MAP kinases [which included c-Jun N-terminal kinase (JNK), extracellular signal-regulated kinase 1 and 2 (ERK1/2), and p38] are associated with several stages of the inflammatory process which in turn contributes to age-related neurodegenerative diseases. This evidence suggests that control of inflammation through regulation of MAP kinase could be a worthwhile approach against neurodegenerative diseases. In this review we summarize the pathways of MAP kinase signal transduction and different pharmacological inhibitors that can be used in its modulation against ND.