Levodopa Dose Equivalency in Parkinson's Disease: Updated Systematic Review and Proposals.

BACKGROUND: To compare drug regimens across clinical trials in Parkinson's disease (PD) conversion formulae between antiparkinsonian drugs have been developed. These are reported in relation to levodopa as the benchmark drug in PD pharmacotherapy as 'levodopa equivalent dose' (LED). Currently, the LED conversion formulae proposed in 2010 by Tomlinson et al. based on a systematic review are predominantly used. However, new drugs with established and novel mechanisms of action and novel formulations of longstanding drugs have been developed since 2010. Therefore, consensus proposals for updated LED conversion formulae are needed. OBJECTIVES: To update LED conversion formulae based on a systematic review. METHODS: The MEDLINE, CENTRAL, and Embase databases were searched from January 2010 to July 2021. Additionally, in a standardized process according to the GRADE grid method, consensus proposals were issued for drugs with scarce data on levodopa dose equivalency. RESULTS: The systematic database search yielded 3076 articles of which 682 were eligible for inclusion in the systematic review. Based on these data and the standardized consensus process, we present proposals for LED conversion formulae for a wide range of drugs that are currently available for the pharmacotherapy of PD or are expected to be introduced soon. CONCLUSIONS: The LED conversion formulae issued in this Position Paper will serve as a research tool to compare the equivalence of antiparkinsonian medication across PD study cohorts and facilitate research on the clinical efficacy of pharmacological and surgical treatments as well as other non-pharmacological interventions in PD. © 2023 The Authors. Movement Disorders published by Wiley Periodicals LLC on behalf of International Parkinson and Movement Disorder Society.

Levodopa Equivalent Daily Dosage: Geographical Variations and Real-Life Modules in Parkinson's Disease.

BACKGROUND: The Levodopa Equivalent Daily Dosage (LEDD) calculation algorithms help in capturing and harmonization of Parkinson's Disease (PD) therapies. Analyzing these updates is essential for validating their effectiveness. OBJECTIVE: To assess updated LEDD conversion factors in capturing the newer therapies in PD and therapy modules in different geographical cohorts. METHODS: Data were sourced from 10 Centers from 6 countries representing 2 different continents. The study compared the LEDD conversion factors proposed by Tomlinson et al and Jost et al, alongside investigating demographic disparities. RESULTS: The analysis involved 2943 subjects; 87% (n = 2577) met the UK Brain Bank criteria for PD. The LEDD differed significantly across methodologies (Tomlinson vs. Jost, 598 mg vs 610 mg, P < 0.0001). Geographical disparities highlighted variations in PD onset age (P < 0.0001). Jost and Tomlinson's calculations demonstrated consistency within but significant differences across countries (P < 0.0001).Age at onset revealed statistically significant differences in LEDD requirements (P < 0.0001), which were particularly higher in 21-50 years (718 mg vs 566 mg). This subgroup also demonstrated increased usage of non-Levodopa therapies (P < 0.0001). Men exhibited higher total LEDD (P = 0.001). 34% reported dyskinesia, associated with higher LEDD (756 mg, P < 0.0001). Surgically treated patients also had higher LEDD (P < 0.0001) and a significant difference between Jost and Tomlinson dosages (761 mg vs716mg) reflecting the incorporation of newer therapeutic molecules. CONCLUSION: This analysis delineates the importance of updated LEDD algorithms and intricacies in the landscape of PD treatment, underscored by geographical, age-related, and gender-specific variations, in real-life management scenarios.

Exercise Habits in People with Parkinson's: A Multinational Survey.

BACKGROUND: Exercise has been demonstrated to result in improvements in physical function, cognition, and quality of life in People with Parkinson's (PwP) but its adoption is variable. OBJECTIVES: To investigate exercise preferences, levels, influencing factors among a diverse Parkinson's disease (PD) population, to understand exercise adoption patterns and plan informed interventions. METHODS: A cross-sectional survey collected data through online platforms and paper-based methods. The Exercise Index (ExI) calculated exercise level based on frequency and duration. RESULTS: Of 2976 PwP, 40.6% exercised regularly, 38.3% occasionally, and 21.2% did not exercise. The overall mean ExI was 18.99 ± 12.37. Factors associated with high exercise levels included exercising in groups (ExI 24-26), weightlifting (ExI 27 (highest)), using muscle-building equipment (ExI 25-26), and exercising at home following an app (ExI 26). A positive trend between ExI and varied exercise groups, locations, types, and equipment was observed. No expected benefit from exercise achieved the lowest ExI (8). Having at least two exercise-promoting factors, a bachelor's degree or higher, receiving exercise advice at initial visits, and aged ≤40 years at PD onset were strong predictors of exercise (adjust OR = 7.814; 6.981; 4.170; 3.565). Falls and "other" most troublesome PD symptoms were negative predictors (aOR = 0.359; 0.466). Barriers to exercise did not predict the odds of exercise. CONCLUSIONS: The study shows that PwP's exercise behavior is influenced by their exercise belief, age at PD onset, doctor's advice at initial visits, education level, symptoms, and exercise-promoting factors. High exercise levels were associated with certain types of exercises and exercising in groups.

Continuous Subcutaneous Infusion Delivery of Apomorphine in Parkinson's Disease: A Systematic Review.

Background: Continuous subcutaneous apomorphine infusion (CSAI) is one of the advanced therapies for Parkinson's disease (PD). Methods: A systematic review of all published articles in English on CSAI for PD till January 30, 2022 was conducted. Results: A total of 82 articles met the search criteria. Publications included retrospective or prospective open-label observational studies, with a limited number of randomized control trials (RCT). Publications were highly heterogeneous and focused on different aspects of CSAI and included clinical audits, effects on cognition/behavior, axial symptoms, nocturnal issues, adverse events/reasons for discontinuation and comparison with other continuous dopaminergic therapies. CSAI was used in patients who presented severe motor fluctuations not resolved by oral therapy, poor candidates for deep brain stimulation (DBS) due to cognitive/behavioral issues or in those with DBS weaning effect. Recent studies have also shown that CSAI was useful for nocturnal usage in advanced PD, in addition to daytime utilization. Adverse effects were common and include skin lesions, sedation and nausea. Pump management difficulties and patient decisions were common reasons for therapy dropout, predominantly during the initial stages of the CSAI. Conclusion: There is consistent agreement on the benefits of CSAI in reducing OFF periods and improving ON periods without troublesome dyskinesia and specific motor and non-motor symptoms. Although there is a paucity of RCTs, current data from almost 30 years of use suggests CSAI to be beneficial in advanced cases of PD.

Task-specific oromandibular dystonia secondary to chewing Khat (Catha edulis)- A series of 35 cases.

BACKGROUND: The leaves of "Khat" (Catha edulis), an indigenous shrub of Yemen and Arabian Peninsula are habitually chewed by the inhabitants for psychostimulant properties. OBJECTIVE: To describe a unique task specific Oro-mandibular dystonia (OMD) in Yemenese men, with a temporal association with chewing "Khat". METHODS: Multicentric, retrospective analysis (2009-2020) of patients with OMD associated with "Khat" chewing, evaluating clinical features and response to Onabotulinum toxin A. RESULTS: 35 Yemenese men with a negative family history, normal neuroimaging mean age of 44.31(±3.21) years and prolonged (20.31 ± 3.27 years) history of chewing Khat, around 5.16(±0.80) hours/day presented with OMD-20 jaw opening, 13 jaw closing and 2 mixed affecting chewing (n = 6), speech (n = 3), or both (n = 26). Additional lingual dystonia was seen in five. CONCLUSIONS: Chewing of khat is a repetitive task involving the jaw musculature and may be one of the causative factors of this task specific OMD. Recognition can prevent disability in these regions.

Genetic Movement Disorders Commonly Seen in Asians.

The increasing availability of molecular genetic testing has changed the landscape of both genetic research and clinical practice. Not only is the pace of discovery of novel disease-causing genes accelerating but also the phenotypic spectra associated with previously known genes are expanding. These advancements lead to the awareness that some genetic movement disorders may cluster in certain ethnic populations and genetic pleiotropy may result in unique clinical presentations in specific ethnic groups. Thus, the characteristics, genetics and risk factors of movement disorders may differ between populations. Recognition of a particular clinical phenotype, combined with information about the ethnic origin of patients could lead to early and correct diagnosis and assist the development of future personalized medicine for patients with these disorders. Here, the Movement Disorders in Asia Task Force sought to review genetic movement disorders that are commonly seen in Asia, including Wilson's disease, spinocerebellar ataxias (SCA) types 12, 31, and 36, Gerstmann-Sträussler-Scheinker disease, PLA2G6-related parkinsonism, adult-onset neuronal intranuclear inclusion disease (NIID), and paroxysmal kinesigenic dyskinesia. We also review common disorders seen worldwide with specific mutations or presentations that occur frequently in Asians.

Historical and More Common Nongenetic Movement Disorders From Asia.

Nongenetic movement disorders are common throughout the world. The movement disorders encountered may vary depending on the prevalence of certain disorders across various geographical regions. In this paper, we review historical and more common nongenetic movement disorders in Asia. The underlying causes of these movement disorders are diverse and include, among others, nutritional deficiencies, toxic and metabolic causes, and cultural Latah syndrome, contributed by geographical, economic, and cultural differences across Asia. The industrial revolution in Japan and Korea has led to diseases related to environmental toxin poisoning, such as Minamata disease and ß-fluoroethyl acetate-associated cerebellar degeneration, respectively, while religious dietary restriction in the Indian subcontinent has led to infantile tremor syndrome related to vitamin B12 deficiency. In this review, we identify the salient features and key contributing factors in the development of these disorders.

Nine Hereditary Movement Disorders First Described in Asia: Their History and Evolution.

Clinical case studies and reporting are important to the discovery of new disorders and the advancement of medical sciences. Both clinicians and basic scientists play equally important roles leading to treatment discoveries for both cures and symptoms. In the field of movement disorders, exceptional observation of patients from clinicians is imperative, not just for phenomenology but also for the variable occurrences of these disorders, along with other signs and symptoms, throughout the day and the disease course. The Movement Disorders in Asia Task Force (TF) was formed to help enhance and promote collaboration and research on movement disorders within the region. As a start, the TF has reviewed the original studies of the movement disorders that were preliminarily described in the region. These include nine disorders that were first described in Asia: Segawa disease, PARK-Parkin, X-linked dystonia-parkinsonism, dentatorubral-pallidoluysian atrophy, Woodhouse-Sakati syndrome, benign adult familial myoclonic epilepsy, Kufor-Rakeb disease, tremulous dystonia associated with mutation of the calmodulin-binding transcription activator 2 gene, and paroxysmal kinesigenic dyskinesia. We hope that the information provided will honor the original researchers and help us learn and understand how earlier neurologists and basic scientists together discovered new disorders and made advances in the field, which impact us all to this day.

COVID-19: The cynosure of rise of Parkinson's disease.

Parkinson's disease (PD) is one of the most common age-related disorders globally. The pathophysiological mechanisms and precipitating factors underlying PD manifestations, including genetic and environmental parameters, inflammation/stress and ageing, remain elusive. Speculations about whether the Coronavirus Disease 2019 (Covid-19) pandemic could be a pivotal factor in affecting the prevalence and severity of PD or triggering a wave of new-onset parkinsonism in both the near and distant future have recently become very popular, with researchers wondering if there is a changing trend in current parkinsonism cases. Could the current understanding of the Covid-19 pathophysiology provide clues for an impending rise of parkinsonism cases in the future? Are there any lessons to learn from previous pandemics? Our aim was to look into these questions and available current literature in order to investigate if Covid-19 could constitute a cardinal event affecting the parkinsonism landscape.

Genome-Wide Polygenic Score Predicts Large Number of High Risk Individuals in Monogenic Undiagnosed Young Onset Parkinson's Disease Patients from India.

Parkinson's disease (PD) is a genetically heterogeneous neurodegenerative disease with poorly defined environmental influences. Genomic studies of PD patients have identified disease-relevant monogenic genes, rare variants of significance, and polygenic risk-associated variants. In this study, whole genome sequencing data from 90 young onset Parkinson's disease (YOPD) individuals are analyzed for both monogenic and polygenic risk. The genetic variant analysis identifies pathogenic/likely pathogenic variants in eight of the 90 individuals (8.8%). It includes large homozygous coding exon deletions in PRKN and SNV/InDels in VPS13C, PLA2G6, PINK1, SYNJ1, and GCH1. Eleven rare heterozygous GBA coding variants are also identified in 13 (14.4%) individuals. In 34 (56.6%) individuals, one or more variants of uncertain significance (VUS) in PD/PD-relevant genes are observed. Though YOPD patients with a prioritized pathogenic variant show a low polygenic risk score (PRS), patients with prioritized VUS or no significant rare variants show an increased PRS odds ratio for PD. This study suggests that both significant rare variants and polygenic risk from common variants together may contribute to the genesis of PD. Further validation using a larger cohort of patients will confirm the interplay between monogenic and polygenic variants and their use in routine genetic PD diagnosis and risk assessment.