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Background: Electronic medical record (EMR)-based studies hold great potential for epidemiologic investigations of Parkinson's disease (PD) causal factors and phenomenology, but diagnostic misclassification may obscure or bias inferences., Objectives: The aims were to determine the validity of PD diagnostic codes in the Veterans Administration (VA) national electronic medical databases and develop recommendations for maximizing ascertainment accuracy., Methods: We investigated a cohort of 146,776 veterans who utilized VA healthcare between 1999 and 2021. We reviewed the medical records of individuals with a PD International Classification of Diseases (ICD) code in outpatient, inpatient, or community care encounters to assign a gold-standard diagnosis. We determined diagnostic accuracy based on provider type, coding frequency, medications, and potentially exclusionary ICD codes overall and by race., Results: A total of 377 of 810 (46.5%) with a PD ICD code had PD. Veterans whose PD was coded by a PD-specialist neurologist were most likely to have PD (83.6%), but sensitivity was low (15.0%). Diagnostic accuracy decreased for PD coded by any neurologist (66.9%), but sensitivity improved (69.4%). Requiring two or more PD codes in combination with two or more levodopa prescriptions improved accuracy, particularly among nonneurologists. Neuroleptic-induced parkinsonism was the most frequent diagnosis in those without PD (15.6%). Accuracy was lower in Black (29.0%) than White (50.5%) veterans regardless of provider type (miscoding odds ratio 2.5, 95% confidence interval 1.7-3.6)., Conclusions: These results highlight the limitations of EMR-based PD ascertainment. Researchers can maximize accuracy by considering provider specialty, coding frequency, pharmacy data, and exclusionary diagnoses, but some degree of record review is required to ensure high accuracy. Higher miscoding among Black veterans warrants further study. © 2024 The Author(s). Movement Disorders published by Wiley Periodicals LLC on behalf of International Parkinson and Movement Disorder Society. This article has been contributed to by U.S. Government employees and their work is in the public domain in the USA., (© 2024 The Author(s). Movement Disorders published by Wiley Periodicals LLC on behalf of International Parkinson and Movement Disorder Society. This article has been contributed to by U.S. Government employees and their work is in the public domain in the USA.)

Background: We recently reported an increased risk of Parkinson's disease (PD) in service members who resided at Marine Base Camp Lejeune, North Carolina, when water supplies were contaminated with trichloroethylene and other volatile organic compounds (VOCs). Prior studies suggest that environmental exposures may affect PD phenotype or progression, but this has not been reported for VOCs., Objective: The objective of this study was to test whether PD progression is faster in individuals exposed to VOCs in water at Camp Lejeune., Methods: A cohort of 172,128 marines residing at Camp Lejeune between 1975 and 1985 was previously assembled. We identified individuals with PD in Veterans Health Administration and Medicare databases between 2000 and 2021. Using estimates derived by the US Agency for Toxic Substances and Disease Registry, we classified individuals as exposed or unexposed to VOCs in residential water. We used Kaplan-Meier and Cox regression models to test differences between exposed and unexposed groups in the time from PD diagnosis until psychosis, fracture, fall, or death., Results: Among 270 persons with PD, 177 (65.6%) were exposed to VOCs in residential water. Median cumulative exposure was 4970 μg/L-months, >50-fold the permissible level. Time until psychosis, fracture, and fall were all shorter in the exposed group, with adjusted hazard ratios (HRs) exceeding 2: psychosis HR, 2.19 (95% confidence interval [CI]: 0.99-4.83); fracture HR, 2.44 (95% CI: 0.91-6.55); and fall HR, 2.64 (95% CI: 0.97-7.21). A significant dose response was observed for time to fall (P trend, 0.032). No differences were observed for time until death., Conclusions: PD progression may be faster in persons exposed to trichloroethylene and other VOCs in water decades earlier. © 2024 The Author(s). Movement Disorders published by Wiley Periodicals LLC on behalf of International Parkinson and Movement Disorder Society. This article has been contributed to by U.S. Government employees and their work is in the public domain in the USA., (© 2024 The Author(s). Movement Disorders published by Wiley Periodicals LLC on behalf of International Parkinson and Movement Disorder Society. This article has been contributed to by U.S. Government employees and their work is in the public domain in the USA.)

Purpose of Review: In recent decades, epidemiological understanding of Parkinson disease (PD) has evolved significantly. Major discoveries in genetics and large epidemiological investigations have provided a better understanding of the genetic, behavioral, and environmental factors that play a role in the pathogenesis and progression of PD. In this review, we provide an epidemiological update of PD with a particular focus on advances in the last five years of published literature., Recent Findings: We include an overview of PD pathophysiology, followed by a detailed discussion of the known distribution of disease and varied determinants of disease. We describe investigations of risk factors for PD, and provide a critical summary of current knowledge, knowledge gaps, and both clinical and research implications. We emphasize the need to characterize the epidemiology of the disease in diverse populations. Despite increasing understanding of PD epidemiology, recent paradigm shifts in the conceptualization of PD as a biological entity will also impact epidemiological research moving forward and guide further work in this field., (© 2024. The Author(s), under exclusive licence to Springer Science+Business Media, LLC, part of Springer Nature.)

Introduction: Dystonia is a painful OFF-related complication in Parkinson's disease (PD) with limited treatment options., Methods: Post-hoc analysis using pooled data from two extended-release amantadine pivotal trials and follow-on open-label extension. Dystonia was assessed using the Unified Dyskinesia Rating Scale (UDysRS) Part 2 and the Movement Disorder Society-Unified PD Rating Scale (MDS-UPDRS) item 4.6., Results: Of 196 participants, 119 (60.7%) reported OFF-related dystonia at baseline per UDysRS. Twelve-week treatment with extended-release amantadine improved OFF dystonia (treatment differences vs placebo: UDysRS Part 2, -1.0 [-1.9,-0.1]; p = 0.03 and MDS-UPDRS Item 4.6, -0.3 [-0.6,-0.05]; p = 0.02). There was no correlation between changes in OFF time and changes in OFF dystonia. Double-blind improvements in OFF dystonia were sustained throughout the 2-year follow-up., Conclusions: Extended-release amantadine yielded a sustained reduction in OFF-related dystonia in PD patients that was independent from a reduction in OFF time. A randomized controlled trial is warranted to confirm these findings., Competing Interests: Declaration of competing interest The authors declare the following financial interests/personal relationships which may be considered as potential competing interests:Alberto J. Espay has received grant support from the NIH and the Michael J Fox Foundation; personal compensation as a consultant/scientific advisory board member for Neuroderm, Neurocrine, Amneal, Acadia, Acorda, Bexion, Kyowa Kirin, Sunovion, Supernus (formerly, USWorldMeds), Avion Pharmaceuticals, and Herantis Pharma; personal compensation as honoraria for speakership for Avion; and publishing royalties from Lippincott Williams & Wilkins, Cambridge University Press, and Springer. He cofounded REGAIN Therapeutics (a biotech start-up developing nonaggregating peptide analogues as replacement therapies for neurodegenerative diseases) and is co-owner of a patent that covers synthetic soluble nonaggregating peptide analogues as replacement treatments in proteinopathies. Jill Ostrem reports grant support from the NIH, Parkinson Foundation, Biogen, Medtronic, Boston Scientific, Neuroderm, Rune; personal compensation as a consultant for Abbott, Acorda, Supernus, and Jazz Pharmaceuticals. Andrea E. Formella is employed by Supernus Pharmaceuticals Inc. Caroline Tanner reports grant support from the NIH, the Michael J Fox Foundation, the Department of Defense, the Parkinson Foundation, the Marcus Program in Precision Medicine, Gateway LLC, Roche-Genentech, Biogen, Bioelectron Technology Corporation; personal compensation as a consultant/scientific advisory board/data & safety monitoring board member for CNS Ratings, Cadent, Adamas, Biogen, Acorda, Amneal, Neurocrine, Kyowa Kirin, Jazz/Cavion and the Australian Parkinson's Mission., (Copyright © 2024 The Authors. Published by Elsevier Ltd.. All rights reserved.)

Background: Environmental exposure to trichloroethylene (TCE), a carcinogenic dry-cleaning chemical, may be linked to Parkinson's disease (PD)., Objective: The objective of this study was to determine whether PD and cancer were elevated among attorneys who worked near a contaminated site., Methods: We surveyed and evaluated attorneys with possible exposure and assessed a comparison group., Results: Seventy-nine of 82 attorneys (96.3%; mean [SD] age: 69.5 [11.4] years; 89.9% men) completed at least one phase of the study. For comparison, 75 lawyers (64.9 [10.2] years; 65.3% men) underwent clinical evaluations. Four (5.1%) of them who worked near the polluted site reported PD, more than expected based on age and sex (1.7%; P = 0.01) but not significantly higher than the comparison group (n = 1 [1.3%]; P = 0.37). Fifteen (19.0%), compared to four in the comparison group (5.3%; P = 0.049), had a TCE-related cancer., Conclusions: In a retrospective study, diagnoses of PD and TCE-related cancers appeared to be elevated among attorneys who worked next to a contaminated dry-cleaning site. © 2024 The Authors. Movement Disorders published by Wiley Periodicals LLC on behalf of International Parkinson and Movement Disorder Society., (© 2024 The Authors. Movement Disorders published by Wiley Periodicals LLC on behalf of International Parkinson and Movement Disorder Society.)

Parkinson's disease and dementia with Lewy bodies are currently defined by their clinical features, with α-synuclein pathology as the gold standard to establish the definitive diagnosis. We propose that, given biomarker advances enabling accurate detection of pathological α-synuclein (ie, misfolded and aggregated) in CSF using the seed amplification assay, it is time to redefine Parkinson's disease and dementia with Lewy bodies as neuronal α-synuclein disease rather than as clinical syndromes. This major shift from a clinical to a biological definition of Parkinson's disease and dementia with Lewy bodies takes advantage of the availability of tools to assess the gold standard for diagnosis of neuronal α-synuclein (n-αsyn) in human beings during life. Neuronal α-synuclein disease is defined by the presence of pathological n-αsyn species detected in vivo (S; the first biological anchor) regardless of the presence of any specific clinical syndrome. On the basis of this definition, we propose that individuals with pathological n-αsyn aggregates are at risk for dopaminergic neuronal dysfunction (D; the second biological anchor). Our biological definition establishes a staging system, the neuronal α-synuclein disease integrated staging system (NSD-ISS), rooted in the biological anchors (S and D) and the degree of functional impairment caused by clinical signs or symptoms. Stages 0-1 occur without signs or symptoms and are defined by the presence of pathogenic variants in the SNCA gene (stage 0), S alone (stage 1A), or S and D (stage 1B). The presence of clinical manifestations marks the transition to stage 2 and beyond. Stage 2 is characterised by subtle signs or symptoms but without functional impairment. Stages 2B-6 require both S and D and stage-specific increases in functional impairment. A biological definition of neuronal α-synuclein disease and an NSD-ISS research framework are essential to enable interventional trials at early disease stages. The NSD-ISS will evolve to include the incorporation of data-driven definitions of stage-specific functional anchors and additional biomarkers as they emerge and are validated. Presently, the NSD-ISS is intended for research use only; its application in the clinical setting is premature and inappropriate., Competing Interests: Declaration of interests TSi declares consultancies for 4D Pharma, Acadia, AcureX, AskBio, Amneal, Blue Rock Therapeutics, Caraway, Critical Path for Parkinson's Consortium, Denali, The Michael J Fox Foundation, Neuroderm, Roche, Sanofi, Sinopia, Sunovion, Takeda, UCB, Vanqua Bio, and Voyager. LMC declares research support and consulting fees from The Michael J Fox Foundation. KP declares consultancies for Curasen; was on a scientific advisory board for Curasen and Amprion; honoraria from invited scientific presentations to universities and professional societies not exceeding $5000 per year from California Congress of Clinical Neurology, California Neurological Society, and Johns Hopkins University; and patents or patent applications numbers 17/314,979 and 63/377,293. KP also declares grants to her institution (Stanford University School of Medicine) from NIH/NINDS NS115114, NS062684, NS075097, NIH/NIA U19 AG065156, P30 AG066515, The Michael J Fox Foundation, Lewy Body Dementia Association, Alzheimer's Drug Discovery Foundation, Sue Berghoff LBD Research Fellowship, and the Knight Initiative for Brain Resilience. MB declares travel grants from The Michael J Fox Foundation. SC declares employment for and travel grants from The Michael J Fox Foundation. The Michael J Fox Foundation received funding support from named non-profit institutions (Cure Parkinson's, Lewy Body Dementia Association, Parkinson Canada, Parkinson's UK, and Shake It Up Australia Foundation) to convene an in-person roundtable of experts in April 2023 in which The Michael J Fox Foundation (employer) cost-shared; The Michael J Fox Foundation (employer) provided funding for an in-person meeting in January, 2023. CC declares grants from The Michael J Fox Foundation and NIH/NINDS. LC-M declares employment for, and employee stock options in, Amprion; grants from The Michael J Fox Foundation; and patents or patent applications (numbers US 20210277076A1, US 20210311077A1, US 20190353669A1, and US 20210223268A1). TD declares former employment of and might hold stock or stock options in Biogen. TF declares travel grants and grant payments to her institution (Indiana University) from The Michael J Fox Foundation. MF declares employment for The Michael J Fox Foundation and an unpaid advisory role at Vaxxinity. CG declares research funding to her institution from The Michael J Fox Foundation. DJ declares employment for and employee stock options from Denali Therapeutics. KK declares support to his institution (University of Rochester Medical Center) from The Michael J Fox Foundation. CK declares employment for and travel grants from The Michael J Fox Foundation. KMe declares consultancies for The Michael J Fox Foundation, AcuRx, Caraway, Cerebral Therapeutics, NRG Therapeutics (scientific advisory board), Nitrase Therapeutics (scientific advisory board), Nurabio, Retromer Therapeutics (director on the board, part-time chief scientific officer), Schrodinger, Sinopia Biosciences (scientific advisory board), and Vanqua Biosciences (scientific advisory board); stock ownership for Cognition Therapeutics, Eli Lilly (retiree stock holder), Envisagenics, Nitrase Therapeutics, Sinopia Biosciences, and Retromer Therapeutics; honoraria for the University of Utah; patents or patent applications for Retromer Therapeutics (planned patent); a research grant from The Michael J Fox Foundation; and travel grants from the University of Utah. BM declares consultancies from Roche, Biogen, and The Michael J Fox Foundation; grants from The Michael J Fox Foundation, ASAP, and DFG; honoraria for AbbVie; and travel grants for AbbVie. TM declares support to his institution (Stanford University School of Medicine) from The Michael J Fox Foundation. KN declares support from The Michael J Fox Foundation. GP declares employment for F Hoffmann-La Roche and stock ownership for F Hoffmann-La Roche, Atea, Novartis, and Eli Lilly. JS declares consultancies from Invicro, Biogen, and AbbVie; and stock ownership from RealmIDX, MNI Holdings, and LikeMinds, as well as grants from The Michael J Fox Foundation. TSh declares employment for The Michael J Fox Foundation. ASin declares employment for NIH who received grants from The Michael J Fox Foundation and ASAP. ASin declares Diagnostic for Stroke royalties (unrelated to current work); honoraria from Movement Disorders Society and Nature Publishing Group; travel grants from Chan Zuckerberg Initiative, The Michael J Fox Foundation, and Weill Cornell. Asin's spouse is an employee of GeneDx. DS has no declarations. MS declared consultancies for Mediflix, and Health and Wellness Partners; honoraria from Atria Foundation, International Parkinson and Movement Disorder Society, Neurocrine, Luye Pharma, and Acorda. MS serves on advisory board at Neuroderm, Alexza, Alexion, and Biogen. CS declares employment for Amprion; stock ownership for Amprion; honoraria (will receive royalties for the sale of seed amplification assay) from Amprion; and patents or patent applications, awarded and amplified in conjunction with Amprion for the seed amplification assay. CT declares consultancies for CNS Ratings, Australian Parkinson's Mission, Biogen, Evidera, Cadent (data safety monitoring board), Adamas (steering committee), Biogen (via the Parkinson Study Group steering committee), Kyowa Kirin (advisory board), Lundbeck (advisory board), Jazz–Cavion (steering committee), Acorda (advisory board), Bial (DMC), and Genentech. CT also declares grant support to UCSF from The Michael J Fox Foundation, National Institute of Health, Gateway, Department of Defense, Roche Genentech, Biogen, Parkinson Foundation, and Marcus Program in Precision Medicine. DW declares salary support from The Michael J Fox Foundation for serving on an executive steering committee for the Parkinson Progression Markers Initiative. YX declares employment for and travel grants from The Michael J Fox Foundation. ASid declares consultancies for SPARC Therapeutics, Capsida Therapeutics, and Parkinson Study Group; honoraria from Bial; grants from The Michael J Fox Foundation (member of Parkinson Progression Markers Initiative steering committee), and NIH; and participation on board at Wave Life Sciences, Inhibikase, Prevail and Huntington Study Group, and Massachusetts General Hospital. BD has received consulting fees and travel support for his role as an advisor for Arch Venture Partners, Cerveau Technologies, Epilepsy Foundation, F-PRIME Capital, Loulou Foundation, and The Michael J Fox Foundation. BD has a leadership or fiduciary role in the Virginia Neurological Society (past president) and Prothena (Director). BD holds stock options with Prothena. KM declares support to his institution (Institute for Neurodegenerative Disorders) from The Michael J Fox Foundation. KMa also declares consultancies for Invicro, The Michael J Fox Foundation, Roche, Calico, Coave, Neuron23, Orbimed, Biohaven, Anofi, Koneksa, Merck, Lilly, Inhibikase, Neuramedy, IRLabs, and Prothena. KMa participates on DSMB at Biohaven. TB, MC, PD, and ET and declare no competing interests., (Copyright © 2024 Elsevier Ltd. All rights reserved.)

Background and Objectives: In Parkinson disease (PD), Alzheimer disease (AD) copathology is common and clinically relevant. However, the longitudinal progression of AD CSF biomarkers-β-amyloid 1-42 (Aβ 42 ), phosphorylated tau 181 (p-tau 181 ), and total tau (t-tau)-in PD is poorly understood and may be distinct from clinical AD. Moreover, it is unclear whether CSF p-tau 181 and serum neurofilament light (NfL) have added prognostic utility in PD, when combined with CSF Aβ 42 . First, we describe longitudinal trajectories of biofluid markers in PD. Second, we modified the AD β-amyloid/tau/neurodegeneration (ATN) framework for application in PD (ATN PD ) using CSF Aβ 42 (A), p-tau 181 (T), and serum NfL (N) and tested ATN PD prediction of longitudinal cognitive decline in PD., Methods: Participants were selected from the Parkinson's Progression Markers Initiative cohort, clinically diagnosed with sporadic PD or as controls, and followed up annually for 5 years. Linear mixed-effects models (LMEMs) tested the interaction of diagnosis with longitudinal trajectories of analytes (log transformed, false discovery rate [FDR] corrected). In patients with PD, LMEMs tested how baseline ATN PD status (AD [A+T+N±] vs not) predicted clinical outcomes, including Montreal Cognitive Assessment (MoCA; rank transformed, FDR corrected)., Results: Participants were 364 patients with PD and 168 controls, with comparable baseline mean (±SD) age (patients with PD = 62 ± 10 years; controls = 61 ± 11 years]; Mann-Whitney Wilcoxon: p = 0.4) and sex distribution (patients with PD = 231 male individuals [63%]; controls = 107 male individuals [64%]; χ 2 : p = 1). Patients with PD had overall lower CSF p-tau 181 (β = -0.16, 95% CI -0.23 to -0.092, p = 2.2e-05) and t-tau than controls (β = -0.13, 95% CI -0.19 to -0.065, p = 4e-04), but not Aβ 42 ( p = 0.061) or NfL ( p = 0.32). Over time, patients with PD had greater increases in serum NfL than controls (β = 0.035, 95% CI 0.022 to 0.048, p = 9.8e-07); slopes of patients with PD did not differ from those of controls for CSF Aβ 42 ( p = 0.18), p-tau 181 ( p = 1), or t-tau ( p = 0.96). Using ATN PD , PD classified as A+T+N± (n = 32; 9%) had worse cognitive decline on global MoCA (β = -73, 95% CI -110 to -37, p = 0.00077) than all other ATN PD statuses including A+ alone (A+T-N-; n = 75; 21%)., Discussion: In patients with early PD, CSF p-tau 181 and t-tau were low compared with those in controls and did not increase over 5 years of follow-up. Our study shows that classification using modified ATN PD (incorporating CSF Aβ 42 , CSF p-tau 181 , and serum NfL) can identify biologically relevant subgroups of PD to improve prediction of cognitive decline in early PD.

In 2011, the UK medical research charity Cure Parkinson's set up the international Linked Clinical Trials (iLCT) committee to help expedite the clinical testing of potentially disease modifying therapies for Parkinson's disease (PD). The first committee meeting was held at the Van Andel Institute in Grand Rapids, Michigan in 2012. This group of PD experts has subsequently met annually to assess and prioritize agents that may slow the progression of this neurodegenerative condition, using a systematic approach based on preclinical, epidemiological and, where possible, clinical data. Over the last 12 years, 171 unique agents have been evaluated by the iLCT committee, and there have been 21 completed clinical studies and 20 ongoing trials associated with the initiative. In this review, we briefly outline the iLCT process as well as the clinical development and outcomes of some of the top prioritized agents. We also discuss a few of the lessons that have been learnt, and we conclude with a perspective on what the next decade may bring, including the introduction of multi-arm, multi-stage clinical trial platforms and the possibility of combination therapies for PD.

Post-traumatic stress disorder (PTSD) may be a risk factor for Parkinson's disease (PD). We examined the relation between PTSD and PD in a cohort of 158,122 Veterans who had any Veterans Health Administration (VHA) or Medicare health care utilization between 10/1/1999- 2/17/2021. Using a nested case-control design we matched 10 controls to each Veteran with PD by sex, race, and rank. In conditional logistic regression models adjusted for camp and smoking, a PTSD diagnosis was significantly associated with PD (OR = 1.35; p = 0.0002); odds were higher if PTSD was coded before PD (OR = 1.53, p < 0.0001). PTSD may be a risk factor for PD.

Background: The penetrance of common genetic risk variants for Parkinson's disease (PD) is low. Pesticide exposure increases PD risk, but how exposure affects penetrance is not well understood., Objective: To determine the relationship between occupational pesticide exposure and PD in people with LRRK2 and GBA risk variants., Methods: Participants of the Parkinson's Progression Markers Initiative (PPMI) with a LRRK2-G2019 S or GBA risk variant provided information about occupational pesticide exposure. We compared exposure in carriers with and without PD. Among carriers with PD, we used Cox proportional hazard models to compare time-to impairment in balance, cognition, and activities of daily living (ADLs) between participants with and without prior occupational pesticide exposure., Results: 378 participants with a risk variant provided exposure information; 176 with LRRK2-G2019 S (54 with and 122 without PD) and 202 with GBA variants (47 with and 155 without PD). Twenty-six participants reported pesticide exposure. People with a GBA variant and occupational pesticide exposure had much higher odds of PD (aOR: 5.4, 95% CI 1.7-18.5, p < 0.01). People with a LRRK2 variant and a history of occupational pesticide exposure had non-significantly elevated odds of PD (aOR 1.3, 95% CI 0.4-4.6, p = 0.7). Among those with PD, pesticide exposure was associated with a higher risk of balance problems and cognitive impairment in LRRK2-PD and functional impairment in GBA-PD, although associations were not statistically significant., Conclusions: Occupational pesticide exposure may increase penetrance of GBA-PD and may be associated with faster symptom progression. Further studies in larger cohorts are necessary.

Importance: Parkinsonism and Parkinson disease (PD) are known to result from repetitive head impacts from boxing. Repetitive head impacts from American football may also be associated with increased risk of neurodegenerative pathologies that cause parkinsonism, yet in vivo research on the association between football play and PD is scarce and limited by small samples and equivocal findings., Objective: To evaluate the association between football participation and self-reported parkinsonism or PD diagnosis., Design, Setting, and Participants: This cross-sectional study leveraged data from the online Fox Insight study. Participants completed online questionnaires and self-reported whether they currently had a diagnosis of Parkinson disease or parkinsonism by a physician or other health care professional. In November 2020, the Boston University Head Impact Exposure Assessment was launched for data collection on repetitive head impacts. Data used for this manuscript were obtained from the Fox Insight database on June 9, 2022. A total of 1875 men who endorsed playing any organized sport were included. Former athletes were divided into those who participated in football (n = 729 [38.9%]) and those who participated in other sports (reference group)., Exposures: Self-reported participation in football, duration and level of football play, age at first exposure., Main Outcomes and Measures: Logistic regression tested associations between PD status and history of football play, duration of football play, highest level played, and age at first exposure, controlling for age, education, history of diabetes or heart disease, body mass index, history of traumatic brain injury with loss of consciousness, and family history of PD., Results: In this sample of 1875 men (mean [SD] age, 67.69 [9.84] years) enriched for parkinsonism or PD (n = 1602 [85.4%]), 729 (38.9%) played football (mean [SD] duration, 4.35 [2.91] years). History of playing football was associated with higher odds of having a parkinsonism or PD diagnosis (odds ratio [OR], 1.61; 95% CI, 1.19-2.17). Among the entire sample, longer duration of play was associated with higher odds of having a parkinsonism or PD diagnosis (OR, 1.12; 95% CI, 1.06-1.19). Among football players, longer duration of football play (OR, 1.12; 95% CI, 1.02-1.23) and higher level of play (OR, 2.93; 95% CI, 1.28-6.73) were associated with higher odds of having parkinsonism or PD., Conclusions and Relevance: In this cross-sectional study of participants enriched for PD, participation in football was associated with higher odds of having a reported parkinsonism or PD diagnosis.

Little is known about electrocardiogram (ECG) markers of Parkinson's disease (PD) during the prodromal stage. The aim of the study was to build a generalizable ECG-based fully automatic artificial intelligence (AI) model to predict PD risk during the prodromal stage, up to 5 years before disease diagnosis. This case-control study included samples from Loyola University Chicago (LUC) and University of Tennessee-Methodist Le Bonheur Healthcare (MLH). Cases and controls were matched according to specific characteristics (date, age, sex and race). Clinical data were available from May, 2014 onward at LUC and from January, 2015 onward at MLH, while the ECG data were available as early as 1990 in both institutes. PD was denoted by at least two primary diagnostic codes (ICD9 332.0; ICD10 G20) at least 30 days apart. PD incidence date was defined as the earliest of first PD diagnostic code or PD-related medication prescription. ECGs obtained at least 6 months before PD incidence date were modeled to predict a subsequent diagnosis of PD within three time windows: 6 months-1 year, 6 months-3 years, and 6 months-5 years. We applied a novel deep neural network using standard 10-s 12-lead ECGs to predict PD risk at the prodromal phase. This model was compared to multiple feature engineering-based models. Subgroup analyses for sex, race and age were also performed. Our primary prediction model was a one-dimensional convolutional neural network (1D-CNN) that was built using 131 cases and 1058 controls from MLH, and externally validated on 29 cases and 165 controls from LUC. The model was trained on 90% of the MLH data, internally validated on the remaining 10% and externally validated on LUC data. The best performing model resulted in an external validation AUC of 0.67 when predicting future PD at any time between 6 months and 5 years after the ECG. Accuracy increased when restricted to ECGs obtained within 6 months to 3 years before PD diagnosis (AUC 0.69) and was highest when predicting future PD within 6 months to 1 year (AUC 0.74). The 1D-CNN model based on raw ECG data outperformed multiple models built using more standard ECG feature engineering approaches. These results demonstrate that a predictive model developed in one cohort using only raw 10-s ECGs can effectively classify individuals with prodromal PD in an independent cohort, particularly closer to disease diagnosis. Standard ECGs may help identify individuals with prodromal PD for cost-effective population-level early detection and inclusion in disease-modifying therapeutic trials., (© 2023. The Author(s).)

Importance: An increased risk of Parkinson disease (PD) has been associated with exposure to the solvent trichloroethylene (TCE), but data are limited. Millions of people in the US and worldwide are exposed to TCE in air, food, and water., Objective: To test whether the risk of PD is higher in veterans who served at Marine Corps Base Camp Lejeune, whose water supply was contaminated with TCE and other volatile organic compounds (VOCs), compared with veterans who did not serve on that base., Design, Setting, and Participants: This population-based cohort study examined the risk for PD among all Marines and Navy personnel who resided at Camp Lejeune, North Carolina (contaminated water) (n = 172 128), or Camp Pendleton, California (uncontaminated water) (n = 168 361), for at least 3 months between 1975 and 1985, with follow-up from January 1, 1997, until February 17, 2021. Veterans Health Administration and Medicare databases were searched for International Classification of Diseases diagnostic codes for PD or other forms of parkinsonism and related medications and for diagnostic codes indicative of prodromal disease. Parkinson disease diagnoses were confirmed by medical record review., Exposures: Water supplies at Camp Lejeune were contaminated with several VOCs. Levels were highest for TCE, with monthly median values greater than 70-fold the permissible amount., Main Outcome and Measures: Risk of PD in former residents of Camp Lejeune relative to residents of Camp Pendleton. In those without PD or another form of parkinsonism, the risk of being diagnosed with features of prodromal PD were assessed individually and cumulatively using likelihood ratio tests., Results: Health data were available for 158 122 veterans (46.4%). Demographic characteristics were similar between Camp Lejeune (5.3% women, 94.7% men; mean [SD] attained age of 59.64 [4.43] years; 29.7% Black, 6.0% Hispanic, 67.6% White; and 2.7% other race and ethnicity) and Camp Pendleton (3.8% women, 96.2% men; mean [SD] age, 59.80 [4.62] years; 23.4% Black, 9.4% Hispanic, 71.1% White, and 5.5% other race and ethnicity). A total of 430 veterans had PD, with 279 from Camp Lejeune (prevalence, 0.33%) and 151 from Camp Pendleton (prevalence, 0.21%). In multivariable models, Camp Lejeune veterans had a 70% higher risk of PD (odds ratio, 1.70; 95% CI, 1.39-2.07; P < .001). No excess risk was found for other forms of neurodegenerative parkinsonism. Camp Lejeune veterans also had a significantly increased risk of prodromal PD diagnoses, including tremor, anxiety, and erectile dysfunction, and higher cumulative prodromal risk scores., Conclusions and Relevance: The study's findings suggest that the risk of PD is higher in persons exposed to TCE and other VOCs in water 4 decades ago. Millions worldwide have been and continue to be exposed to this ubiquitous environmental contaminant.

Background: Emerging evidence shows that α-synuclein seed amplification assays (SAAs) have the potential to differentiate people with Parkinson's disease from healthy controls. We used the well characterised, multicentre Parkinson's Progression Markers Initiative (PPMI) cohort to further assess the diagnostic performance of the α-synuclein SAA and to examine whether the assay identifies heterogeneity among patients and enables the early identification of at-risk groups., Methods: This cross-sectional analysis is based on assessments done at enrolment for PPMI participants (including people with sporadic Parkinson's disease from LRRK2 and GBA variants, healthy controls, prodromal individuals with either rapid eye movement sleep behaviour disorder (RBD) or hyposmia, and non-manifesting carriers of LRRK2 and GBA variants) from 33 participating academic neurology outpatient practices worldwide (in Austria, Canada, France, Germany, Greece, Israel, Italy, the Netherlands, Norway, Spain, the UK, and the USA). α-synuclein SAA analysis of CSF was performed using previously described methods. We assessed the sensitivity and specificity of the α-synuclein SAA in participants with Parkinson's disease and healthy controls, including subgroups based on genetic and clinical features. We established the frequency of positive α-synuclein SAA results in prodromal participants (RBD and hyposmia) and non-manifesting carriers of genetic variants associated with Parkinson's disease, and compared α-synuclein SAA to clinical measures and other biomarkers. We used odds ratio estimates with 95% CIs to measure the association between α-synuclein SAA status and categorical measures, and two-sample 95% CIs from the resampling method to assess differences in medians between α-synuclein SAA positive and negative participants for continuous measures. A linear regression model was used to control for potential confounders such as age and sex., Findings: This analysis included 1123 participants who were enrolled between July 7, 2010, and July 4, 2019. Of these, 545 had Parkinson's disease, 163 were healthy controls, 54 were participants with scans without evidence of dopaminergic deficit, 51 were prodromal participants, and 310 were non-manifesting carriers. Sensitivity for Parkinson's disease was 87·7% (95% CI 84·9-90·5), and specificity for healthy controls was 96·3% (93·4-99·2). The sensitivity of the α-synuclein SAA in sporadic Parkinson's disease with the typical olfactory deficit was 98·6% (96·4-99·4). The proportion of positive α-synuclein SAA was lower than this figure in subgroups including LRRK2 Parkinson's disease (67·5% [59·2-75·8]) and participants with sporadic Parkinson's disease without olfactory deficit (78·3% [69·8-86·7]). Participants with LRRK2 variant and normal olfaction had an even lower α-synuclein SAA positivity rate (34·7% [21·4-48·0]). Among prodromal and at-risk groups, 44 (86%) of 51 of participants with RBD or hyposmia had positive α-synuclein SAA (16 of 18 with hyposmia, and 28 of 33 with RBD). 25 (8%) of 310 non-manifesting carriers (14 of 159 [9%] LRRK2 and 11 of 151 [7%] GBA) were positive., Interpretation: This study represents the largest analysis so far of the α-synuclein SAA for the biochemical diagnosis of Parkinson's disease. Our results show that the assay classifies people with Parkinson's disease with high sensitivity and specificity, provides information about molecular heterogeneity, and detects prodromal individuals before diagnosis. These findings suggest a crucial role for the α-synuclein SAA in therapeutic development, both to identify pathologically defined subgroups of people with Parkinson's disease and to establish biomarker-defined at-risk cohorts., Funding: PPMI is funded by the Michael J Fox Foundation for Parkinson's Research and funding partners, including: Abbvie, AcureX, Aligning Science Across Parkinson's, Amathus Therapeutics, Avid Radiopharmaceuticals, Bial Biotech, Biohaven, Biogen, BioLegend, Bristol-Myers Squibb, Calico Labs, Celgene, Cerevel, Coave, DaCapo Brainscience, 4D Pharma, Denali, Edmond J Safra Foundation, Eli Lilly, GE Healthcare, Genentech, GlaxoSmithKline, Golub Capital, Insitro, Janssen Neuroscience, Lundbeck, Merck, Meso Scale Discovery, Neurocrine Biosciences, Prevail Therapeutics, Roche, Sanofi Genzyme, Servier, Takeda, Teva, UCB, VanquaBio, Verily, Voyager Therapeutics, and Yumanity., Competing Interests: Declaration of interests AS declares consultancy for Merck, Parkinson Study Group; and honoraria from Bial. LC-M declares employment for Amprion; stock ownership (employee stock options) for Amprion; and patent or patent applications numbers US 20210277076A1, US 20210311077A1, US 20190353669A1, and US 20210223268A1. CMF declares employment for Amprion; stock ownership (employee stock options) for Amprion; and patent or patent applications numbers US 20210277076A1 and US 20210311077A1. YM declares employment for Amprion; stock ownership (employee stock options) for Amprion; and patent or patent applications number US 20210277076A1. PAU declares employment for Amprion; and stock ownership (employee stock options) for Amprion. HN declares employment for Amprion; and stock ownership (employee stock options) for Amprion. RNA declares consultancies for Janssen, Sanofi, Ono Therapuetics, Avrobio, Takeda, Gain Therapuetics, Merck, GlaxoSmithKline, and Caraway. LMC declares honoraria (royalties) from Elsevier and Wolters Kluwel. TF declares travel grants from the Michael J Fox Foundation. KMe declares consultancies for the Michael J Fox Foundation, AcuRx, Caraway, Cerebral Therapeutics, NRG Therapeutics (scientific advisory board), Nurabio, Retromer Therapeutics (director on the board, part-time chief scientific officer), Schrodinger, Sinopia Biosciences (scientific advisory board), and Vanqua Biosciences (scientific advisory board); stock ownership for Cognition Therapeutics, Eli Lilly (retiree stock holder), Envisagenics, and Retromer Therapeutics; honoraria for the University of Utah; patents or patent applications for Retromer Therapeutics (planned patent); and travel grants from the University of Utah. BM declares consultancies from Roche, Biogen, and the Michael J Fox Foundation; honoraria for Abbvie; and travel grants for Abbvie. KLP declares consultancies for Curasen; was on a scientific advisory board for Curasen and Amprion; honoraria from invited scientific presentations to universities and professional societies not exceeding $5000 per year from California Congress of Clinical Neurology, California Neurological Society, and Johns Hopkins University; and patents or patent applications numbers 17/314,979 and 63/377,293. JS declares consultancies from Invicro, Biogen, and Abbvie; and stock ownership from RealmIDX, MNI Holdings, and LikeMinds. TSi declares consultancies for 4D Pharma, Acadia, AcureX, AskBio, Amneal, Blue Rock Therapeutics, Caraway, Critical Path for Parkinson's Consortium, Denali, Michael J Fox Foundation, Neuroderm, Roche, Sanofi, Sinopia, Sunovion, Takeda, UCB, Vanqua Bio, and Voyager. CMT declares consultancies for CNS Ratings, Australian Parkinson's Mission, Biogen, Evidera, Cadent (data safety monitoring board), Adamas (steering committee), Biogen (via the Parkinson Study Group steering committee), Kyowa Kirin (advisory board), Lundbeck (advisory board), Jazz/Cavion (steering committee), and Acorda (advisory board). DW declares receiving salary support from Michael J Fox Foundation for serving on an Executive Steering Committee for the PPMI. AV declares consultancies for CoA Therapeutics, XW Pharma, and Biogen. MF declares employment for the Michael J Fox Foundation. LMAO declares employment for the Michael J Fox Foundation. SJH declares employment for the Michael J Fox Foundation. TSh declares employment for the Michael J Fox Foundation. KMa declares consultancies for Invicro, MJFF, Roche, Calico, Coave, Neuron23, Orbimed, Neuroderm, Sanofi, Takeda, Merck, Lilly, Inhibikase, and Neuramedy. CS declares employment for Amprion; stock ownership for Amprion; honoraria (will receive royalties for the sale of seed amplification assay [SAA]) from Amprion; and patents or patent applications, awarded and amplified in conjunction with Amprion for the SAA assay., (Copyright © 2023 Elsevier Ltd. All rights reserved.)

Background: Identifying a meaningful progression metric for Parkinson's disease (PD) that reflects heterogeneity remains a challenge., Objective: To assess the frequency and baseline predictors of progression to clinically relevant motor and non-motor PD milestones., Methods: Using data from the Parkinson's Progression Markers Initiative (PPMI) de novo PD cohort, we monitored 25 milestones across six domains ("walking and balance"; "motor complications"; "cognition"; "autonomic dysfunction"; "functional dependence"; "activities of daily living"). Milestones were intended to be severe enough to reflect meaningful disability. We assessed the proportion of participants reaching any milestone; evaluated which occurred most frequently; and conducted a time-to-first-event analysis exploring whether baseline characteristics were associated with progression., Results: Half of participants reached at least one milestone within five years. Milestones within the cognitive, functional dependence, and autonomic dysfunction domains were reached most often. Among participants who reached a milestone at an annual follow-up visit and remained active in the study, 82% continued to meet criteria for any milestone at one or more subsequent annual visits and 55% did so at the next annual visit. In multivariable analysis, baseline features predicting faster time to reaching a milestone included age (p < 0.0001), greater MDS-UPDRS total scores (p < 0.0001), higher GDS-15 depression scores (p = 0.0341), lower dopamine transporter binding (p = 0.0043), and lower CSF total α-synuclein levels (p = 0.0030). Symptomatic treatment was not significantly associated with reaching a milestone (p = 0.1639)., Conclusion: Clinically relevant milestones occur frequently, even in early PD. Milestones were significantly associated with baseline clinical and biological markers, but not with symptomatic treatment. Further studies are necessary to validate these results, further assess the stability of milestones, and explore translating them into an outcome measure suitable for observational and therapeutic studies.

The etiologies of Parkinson's disease (PD) remain unclear. Some, such as certain genetic mutations and head trauma, are widely known or easily identified. However, these causes or risk factors do not account for the majority of cases. Other, less visible factors must be at play. Among these is a widely used industrial solvent and common environmental contaminant little recognized for its likely role in PD: trichloroethylene (TCE). TCE is a simple, six-atom molecule that can decaffeinate coffee, degrease metal parts, and dry clean clothes. The colorless chemical was first linked to parkinsonism in 1969. Since then, four case studies involving eight individuals have linked occupational exposure to TCE to PD. In addition, a small epidemiological study found that occupational or hobby exposure to the solvent was associated with a 500% increased risk of developing PD. In multiple animal studies, the chemical reproduces the pathological features of PD.Exposure is not confined to those who work with the chemical. TCE pollutes outdoor air, taints groundwater, and contaminates indoor air. The molecule, like radon, evaporates from underlying soil and groundwater and enters homes, workplaces, or schools, often undetected. Despite widespread contamination and increasing industrial, commercial, and military use, clinical investigations of TCE and PD have been limited. Here, through a literature review and seven illustrative cases, we postulate that this ubiquitous chemical is contributing to the global rise of PD and that TCE is one of its invisible and highly preventable causes. Further research is now necessary to examine this hypothesis.

Background: Free-text, verbatim replies in the words of people with Parkinson's disease (PD) have the potential to provide unvarnished information about their feelings and experiences. Challenges of processing such data on a large scale are a barrier to analyzing verbatim data collection in large cohorts., Objective: To develop a method for curating responses from the Parkinson's Disease Patient Report of Problems (PD-PROP), open-ended questions that asks people with PD to report their most bothersome problems and associated functional consequences., Methods: Human curation, natural language processing, and machine learning were used to develop an algorithm to convert verbatim responses to classified symptoms. Nine curators including clinicians, people with PD, and a non-clinician PD expert classified a sample of responses as reporting each symptom or not. Responses to the PD-PROP were collected within the Fox Insight cohort study., Results: Approximately 3,500 PD-PROP responses were curated by a human team. Subsequently, approximately 1,500 responses were used in the validation phase; median age of respondents was 67 years, 55% were men and median years since PD diagnosis was 3 years. 168,260 verbatim responses were classified by machine. Accuracy of machine classification was 95% on a held-out test set. 65 symptoms were grouped into 14 domains. The most frequently reported symptoms at first report were tremor (by 46% of respondents), gait and balance problems (>39%), and pain/discomfort (33%)., Conclusion: A human-in-the-loop method of curation provides both accuracy and efficiency, permitting a clinically useful analysis of large datasets of verbatim reports about the problems that bother PD patients.

Background: To date, no medication has slowed the progression of Parkinson's disease (PD). Preclinical, epidemiological, and experimental data on humans all support many benefits of endurance exercise among persons with PD. The key question is whether there is a definitive additional benefit of exercising at high intensity, in terms of slowing disease progression, beyond the well-documented benefit of endurance training on a treadmill for fitness, gait, and functional mobility. This study will determine the efficacy of high-intensity endurance exercise as first-line therapy for persons diagnosed with PD within 3 years, and untreated with symptomatic therapy at baseline., Methods: This is a multicenter, randomized, evaluator-blinded study of endurance exercise training. The exercise intervention will be delivered by treadmill at 2 doses over 18 months: moderate intensity (4 days/week for 30 min per session at 60-65% maximum heart rate) and high intensity (4 days/week for 30 min per session at 80-85% maximum heart rate). We will randomize 370 participants and follow them at multiple time points for 24 months. The primary outcome is the Movement Disorders Society-Unified Parkinson's Disease Rating Scale (MDS-UPDRS) motor score (Part III) with the primary analysis assessing the change in MDS-UPDRS motor score (Part III) over 12 months, or until initiation of symptomatic antiparkinsonian treatment if before 12 months. Secondary outcomes are striatal dopamine transporter binding, 6-min walk distance, number of daily steps, cognitive function, physical fitness, quality of life, time to initiate dopaminergic medication, circulating levels of C-reactive protein (CRP), and brain-derived neurotrophic factor (BDNF). Tertiary outcomes are walking stride length and turning velocity., Discussion: SPARX3 is a Phase 3 clinical trial designed to determine the efficacy of high-intensity, endurance treadmill exercise to slow the progression of PD as measured by the MDS-UPDRS motor score. Establishing whether high-intensity endurance treadmill exercise can slow the progression of PD would mark a significant breakthrough in treating PD. It would have a meaningful impact on the quality of life of people with PD, their caregivers and public health., Trial Registration: ClinicalTrials.gov NCT04284436 . Registered on February 25, 2020., (© 2022. The Author(s).)

Background: Aggregated α-synuclein plays an important role in Parkinson's disease pathogenesis. Cinpanemab, a human-derived monoclonal antibody that binds to α-synuclein, is being evaluated as a disease-modifying treatment for Parkinson's disease., Methods: In a 52-week, multicenter, double-blind, phase 2 trial, we randomly assigned, in a 2:1:2:2 ratio, participants with early Parkinson's disease to receive intravenous infusions of placebo (control) or cinpanemab at a dose of 250 mg, 1250 mg, or 3500 mg every 4 weeks, followed by an active-treatment dose-blinded extension period for up to 112 weeks. The primary end points were the changes from baseline in the Movement Disorder Society-sponsored revision of the Unified Parkinson's Disease Rating Scale (MDS-UPDRS) total score (range, 0 to 236, with higher scores indicating worse performance) at weeks 52 and 72. Secondary end points included MDS-UPDRS subscale scores and striatal binding as assessed on dopamine transporter single-photon-emission computed tomography (DaT-SPECT)., Results: Of the 357 enrolled participants, 100 were assigned to the control group, 55 to the 250-mg cinpanemab group, 102 to the 1250-mg group, and 100 to the 3500-mg group. The trial was stopped after the week 72 interim analysis owing to lack of efficacy. The change to week 52 in the MDS-UPDRS score was 10.8 points in the control group, 10.5 points in the 250-mg group, 11.3 points in the 1250-mg group, and 10.9 points in the 3500-mg group (adjusted mean difference vs. control, -0.3 points [95% confidence interval {CI}, -4.9 to 4.3], P = 0.90; 0.5 points [95% CI, -3.3 to 4.3], P = 0.80; and 0.1 point [95% CI, -3.8 to 4.0], P = 0.97, respectively). The adjusted mean difference at 72 weeks between participants who received cinpanemab through 72 weeks and the pooled group of those who started cinpanemab at 52 weeks was -0.9 points (95% CI, -5.6 to 3.8) for the 250-mg dose, 0.6 points (95% CI, -3.3 to 4.4) for the 1250-mg dose, and -0.8 points (95% CI, -4.6 to 3.0) for the 3500-mg dose. Results for secondary end points were similar to those for the primary end points. DaT-SPECT imaging at week 52 showed no differences between the control group and any cinpanemab group. The most common adverse events with cinpanemab were headache, nasopharyngitis, and falls., Conclusions: In participants with early Parkinson's disease, the effects of cinpanemab on clinical measures of disease progression and changes in DaT-SPECT imaging did not differ from those of placebo over a 52-week period. (Funded by Biogen; SPARK ClinicalTrials.gov number, NCT03318523.)., (Copyright © 2022 Massachusetts Medical Society.)

Remote health assessments that gather real-world data (RWD) outside clinic settings require a clear understanding of appropriate methods for data collection, quality assessment, analysis and interpretation. Here we examine the performance and limitations of smartphones in collecting RWD in the remote mPower observational study of Parkinson's disease (PD). Within the first 6 months of study commencement, 960 participants had enrolled and performed at least five self-administered active PD symptom assessments (speeded tapping, gait/balance, phonation or memory). Task performance, especially speeded tapping, was predictive of self-reported PD status (area under the receiver operating characteristic curve (AUC) = 0.8) and correlated with in-clinic evaluation of disease severity (r = 0.71; P < 1.8 × 10 -6 ) when compared with motor Movement Disorder Society-Unified Parkinson's Disease Rating Scale (MDS-UPDRS). Although remote assessment requires careful consideration for accurate interpretation of RWD, our results support the use of smartphones and wearables in objective and personalized disease assessments., (© 2021. The Author(s), under exclusive licence to Springer Nature America, Inc.)

Background: Parkinson's disease (PD) is a debilitating neurodegenerative disease with both motor and non-motor manifestations. Available treatment reduces symptoms and is critical for improving quality of life. Treatment options include drugs, device-aided therapies, and non-pharmacological therapies. Complementary and alternative therapies (CATs) are also used in some countries., Objective: To examine the availability of PD treatment by country, and differences by national income as defined by the World Bank (high income countries (HICs), upper middle income countries (UMICs), lower middle income countries (LMICs) and low income countries (LICs))., Methods: This study was conducted by surveying International Parkinson and Movement Disorders Society members about availability of PD treatment. LMICs and LICs (LMICs/LICs) were analysed together., Results: There were 352 valid responses from 76 countries (41.5% from HICs, 30.4% from UMICs, and 28.1% from LMICs/LICs). Levodopa was widely available across all income groups (99%). Availability of other PD drugs decreased with national income. Availability of device-aided therapies decreased with national income (100% availability in HICs, 92.5% among UMICs, and 57.6% among LMICs/LICs). A similar trend was observed for CATs (37.0% availability in HICs, 31.8% in UMICs, and 19.2% in LMIC/LICs). Physiotherapy was the most available non-pharmacological therapy (> 90% respondents). Occupational therapy and SALT were less available in LMIC/LICs (49.5% and 55.6% respectively) compared to HICs (80.1% and 84.9% respectively)., Conclusion: Our survey highlights significant discrepancies in availability of PD treatments between countries and income groups. This is concerning given the symptomatic benefit patients gain from treatment. Improving equitable access to PD treatment should be prioritised.

Epidemiology is the study of the distribution of disease in human populations, which is important in evaluating burden of illness, identifying modifiable risk factors, and planning for current and projected needs of the health care system. Parkinson's disease (PD) is the second most common serious neurodegenerative illness and is expected to further increase in prevalence. Cognitive changes are increasingly viewed as an integral non-motor feature in PD, emerging even in the prodromal phase of the disease. The prevalence of PD-MCI ranges from 20% to 40% depending on the population studied. The incidence of PD-dementia increases with duration of disease, with estimates growing from 3% to 30% of individuals followed for 5 years or less to over 80% after 20 years. There are several challenges in estimating the frequency of cognitive change, including only recently standardized diagnostic criteria, variation depending on exact neuropsychological evaluations performed, and differences in population sampling. Clinical features associated with cognitive decline include older age, increased disease duration and severity, early gait dysfunction, dysautonomia, hallucinations and other neuropsychiatric features, the presence of REM behavior disorder, and posterior predominant dysfunction on neuropsychological testing. There is increasing evidence that genetic risk factors, in particular GBA and MAPT mutations, contribute to cognitive change. Possible protective factors include higher cognitive reserve and regular exercise. Important sequelae of cognitive decline in PD include higher caregiver burden, decreased functional status, and increased risk of institutionalization and mortality. Many remaining uncertainties regarding the epidemiology of cognitive change in PD require future research, with improved biomarkers and more sensitive and convenient outcome measures., (Copyright © 2022 Elsevier B.V. All rights reserved.)

Background: Parkinson's disease (PD) is a chronic, disabling neurodegenerative disorder., Objective: To predict a future diagnosis of PD using questionnaires and simple non-invasive clinical tests., Methods: Participants in the prospective Kuakini Honolulu-Asia Aging Study (HAAS) were evaluated biannually between 1995-2017 by PD experts using standard diagnostic criteria. Autopsies were sought on all deaths. We input simple clinical and risk factor variables into an ensemble-tree based machine learning algorithm and derived models to predict the probability of developing PD. We also investigated relationships of predictive models and neuropathologic features such as nigral neuron density., Results: The study sample included 292 subjects, 25 of whom developed PD within 3 years and 41 by 5 years. 116 (46%) of 251 subjects not diagnosed with PD underwent autopsy. Light Gradient Boosting Machine modeling of 12 predictors correctly classified a high proportion of individuals who developed PD within 3 years (area under the curve (AUC) 0.82, 95%CI 0.76-0.89) or 5 years (AUC 0.77, 95%CI 0.71-0.84). A large proportion of controls who were misclassified as PD had Lewy pathology at autopsy, including 79%of those who died within 3 years. PD probability estimates correlated inversely with nigral neuron density and were strongest in autopsies conducted within 3 years of index date (r = -0.57, p < 0.01)., Conclusion: Machine learning can identify persons likely to develop PD during the prodromal period using questionnaires and simple non-invasive tests. Correlation with neuropathology suggests that true model accuracy may be considerably higher than estimates based solely on clinical diagnosis.

Background: Investigation of sex-related motor and non-motor differences and biological markers in Parkinson's disease (PD) may improve precision medicine approach., Objective: To examine sex-related longitudinal changes in motor and non-motor features and biologic biomarkers in early PD., Methods: We compared 5-year longitudinal changes in de novo, untreated PD men and women (at baseline N = 423; 65.5%male) of the Parkinson's Progression Markers Initiative (PPMI), assessing motor and non-motor manifestations of disease; and biologic measures in cerebrospinal fluid (CSF) and dopamine transporter deficit on DaTscanTM uptake., Results: Men experienced greater longitudinal decline in self-reported motor (p < 0.001) and non-motor (p = 0.009) aspects of experiences of daily living, such that men had a yearly increase in MDS-UPDRS part II by a multiplicative factor of 1.27 compared to women at 0.7, while men had a yearly increase in MDS-UPDRS part I by a multiplicative factor of 0.98, compared to women at 0.67. Compared to women, men had more longitudinal progression in clinician-assessed motor features in the ON medication state (p = 0.010) and required higher dopaminergic medication dosages over time (p = 0.014). Time to reach specific disease milestones and longitudinal changes in CSF biomarkers and DaTscanTM uptake were not different by sex., Conclusion: Men showed higher self-assessed motor and non-motor burden of disease, with possible contributions from suboptimal dopaminergic therapeutic response in men. However, motor features of disease evaluated with clinician-based scales in the OFF medication state, as well as biological biomarkers do not show specific sex-related progression patterns.

Background: Traditional in-person Parkinson's disease (PD) research studies are often slow to recruit and place unnecessary burden on participants. The ongoing COVID-19 pandemic has added new impetus to the development of new research models., Objective: To compare recruitment processes and outcomes of three remote decentralized observational PD studies with video visits., Methods: We examined the number of participants recruited, speed of recruitment, geographic distribution of participants, and strategies used to enhance recruitment in FIVE, a cross-sectional study of Fox Insight participants with and without PD (n = 203); VALOR-PD, a longitudinal study of 23andMe, Inc. research participants carrying the LRRK2 G2019S variant with and without PD (n = 277); and AT-HOME PD, a longitudinal study of former phase III clinical trial participants with PD (n = 226)., Results: Across the three studies, 706 participants from 45 U.S. states and Canada enrolled at a mean per study rate of 4.9 participants per week over an average of 51 weeks. The cohorts were demographically homogenous with regard to race (over 95%white) and level of education (over 90%with more than a high school education). The number of participants living in primary care Health Professional Shortage Areas in each study ranged from 30.3-42.9%. Participants reported interest in future observational (98.5-99.6%) and interventional (76.1-87.6%) research studies with remote video visits., Conclusion: Recruitment of large, geographically dispersed remote cohorts from a single location is feasible. Interest in participation in future remote decentralized PD studies is high. More work is needed to identify best practices for recruitment, particularly of diverse participants.

Background: Cerebrospinal fluid (CSF) levels of monoamine metabolites may represent biomarkers of Parkinson's disease (PD)., Objective: The aim of this study was quantification of multiple metabolites in CSF from PD versus healthy control subjects (HCs), including longitudinal analysis., Methods: Absolute levels of multiple monoamine metabolites in CSF were quantified by liquid chromatography coupled with tandem mass spectrometry from 161 individuals with early PD and 115 HCs from the Parkinson's Progression Marker Initiative and de novo PD (DeNoPA) studies., Results: Baseline levels of homovanillic acid (HVA) and 3,4-dihydroxyphenylacetic acid (DOPAC) were lower in individuals with PD compared with HCs. HVA levels correlated with Movement Disorder Society Unified Parkinson's Disease Rating Scale total scores (P < 0.01). Both HVA/dopamine and DOPAC/dopamine levels correlated with caudate nucleus and raw DOPAC with putamen dopamine transporter single-photon emission computed tomography uptake ratios (P < 0.01). No metabolite changed over 2 years in drug-naive individuals, but some changed on starting levodopa treatment., Conclusions: HVA and DOPAC CSF levels mirrored nigrostriatal pathway damage, confirming the central role of dopaminergic degeneration in early PD. © 2021 The Authors. Movement Disorders published by Wiley Periodicals LLC on behalf of International Parkinson and Movement Disorder Society., (© 2021 The Authors. Movement Disorders published by Wiley Periodicals LLC on behalf of International Parkinson and Movement Disorder Society.)

Background: Many countries have implemented drastic measures to fight the COVID-19 pandemic. Restrictions and diversion of resources may have negatively affected patients with Parkinson's disease (PD). Our aim was to examine whether COVID-19 had an impact on access to PD medication by region and income., Methods: This study was conducted as part of a survey sent to members of the Movement Disorders Society focusing on access to PD medication globally., Results: Of 346 responses, 157 (45.4%) agreed that COVID-19 had affected access to PD medication, while 189 (54.6%) disagreed. 22.8% of high-income and 88.9% of low-income countries' respondents agreed that access to PD medication was affected by COVID-19. 59% of all 'yes' respondents reported increased disability of patients as an impact., Conclusions: Access to PD medication is likely to have been affected by COVID-19 and result in deterioration of patients' symptomatic control. Resource-poor countries appear to be disproportionately affected compared to more affluent countries. © 2020 The Authors. Movement Disorders published by Wiley Periodicals LLC on behalf of International Parkinson and Movement Disorder Society., (© 2020 The Authors. Movement Disorders published by Wiley Periodicals LLC on behalf of International Parkinson and Movement Disorder Society.)

Background: The objective of this study was to assess neurofilament light chain as a Parkinson's disease biomarker., Methods: We quantified neurofilament light chain in 2 independent cohorts: (1) longitudinal cerebrospinal fluid samples from the longitudinal de novo Parkinson's disease cohort and (2) a large longitudinal cohort with serum samples from Parkinson's disease, other cognate/neurodegenerative disorders, healthy controls, prodromal conditions, and mutation carriers., Results: In the Parkinson's Progression Marker Initiative cohort, mean baseline serum neurofilament light chain was higher in Parkinson's disease patients (13 ± 7.2 pg/mL) than in controls (12 ± 6.7 pg/mL), P = 0.0336. Serum neurofilament light chain increased longitudinally in Parkinson's disease patients versus controls (P < 0.01). Motor scores were positively associated with neurofilament light chain, whereas some cognitive scores showed a negative association., Conclusions: Neurofilament light chain in serum samples is increased in Parkinson's disease patients versus healthy controls, increases over time and with age, and correlates with clinical measures of Parkinson's disease severity. Although the specificity of neurofilament light chain for Parkinson's disease is low, it is the first blood-based biomarker candidate that could support disease stratification of Parkinson's disease versus other cognate/neurodegenerative disorders, track clinical progression, and possibly assess responsiveness to neuroprotective treatments. However, use of neurofilament light chain as a biomarker of response to neuroprotective interventions remains to be assessed. © 2020 The Authors. Movement Disorders published by Wiley Periodicals LLC on behalf of International Parkinson and Movement Disorder Society., (© 2020 The Authors. Movement Disorders published by Wiley Periodicals LLC on behalf of International Parkinson and Movement Disorder Society.)

Parkinson disease affects nearly 1 million people in the United States, and the prevalence is expected to increase to at least 1.2 million people by 2030. Parkinson disease is a chronic, incurable disease. Most treatments focus on controlling motor symptoms; however, as the disease progresses, periods of reduced therapeutic benefit, or OFF periods, become more frequent and increasingly troublesome. OFF periods contribute to the already substantial economic burden of Parkinson disease. People with Parkinson disease who experience OFF periods and their caregivers have reported more work days with low productivity and more missed work days compared with those who do not experience OFF periods. More caregivers of people with Parkinson disease who experience OFF episodes reported that due to the disease, they had reduced or changed working hours, lost opportunities, or had reduced work productivity, and these caregivers reported an average of more than twice the amount of employment income lost compared with caregivers of people with Parkinson disease who do not experience OFF periods.

Background: The penetrance of leucine rich repeat kinase 2 (LRRK2) mutations is incomplete and may be influenced by environmental and/or other genetic factors. Nonsteroidal anti-inflammatory drugs (NSAIDs) are known to reduce inflammation and may lower Parkinson's disease (PD) risk, but their role in LRRK2-associated PD is unknown., Objectives: The objective of this study is to evaluate the association of regular NSAID use and LRRK2-associated PD., Methods: Symptomatic ("LRRK2-PD") and asymptomatic ("LRRK2-non-PD") participants with LRRK2 G2019S, R1441X, or I2020T variants (definitely pathogenic variant carriers) or G2385R or R1628P variants (risk variant carriers) from 2 international cohorts provided information on regular ibuprofen and/or aspirin use (≥2 pills/week for ≥6 months) prior to the index date (diagnosis date for PD, interview date for non-PD). Multivariate logistic regression was used to evaluate the relationship between regular NSAID use and PD for any NSAID, separately for ibuprofen and aspirin in all carriers and separately in pathogenic and risk variant groups., Results: A total of 259 LRRK2-PD and 318 LRRK2-non-PD participants were enrolled. Regular NSAID use was associated with reduced odds of PD in the overall cohort (odds ratio [OR], 0.34; 95% confidence interval [CI], 0.21-0.57) and in both pathogenic and risk variant carriers (OR Pathogenic , 0.38; 95% CI, 0.21-0.67 and OR RiskVariant , 0.19; 95% CI, 0.04-0.99). Similar associations were observed for ibuprofen and aspirin separately (OR Ibuprofen , 0.19; 95% CI, 0.07-0.50 and OR Aspirin , 0.51; 95% CI, 0.28-0.91)., Conclusions: Regular NSAID use may be associated with reduced penetrance in LRRK2-associated PD. The LRRK2 protein is involved in inflammatory pathways and appears to be modulated by regular anti-inflammatory use. Longitudinal observational and interventional studies of NSAID exposure and LRRK2-PD are needed to confirm this association. © 2020 International Parkinson and Movement Disorder Society., (© 2020 International Parkinson and Movement Disorder Society.)

Parkinson disease, the second-most-common neurodegenerative disorder, affects approximately 1 million individuals in the United States, and this number is projected to increase to 1.2 million by 2030. Characterized pathologically by degeneration of dopaminergic neurons, with widespread pathology in nondopaminergic systems, Parkinson disease leads to an array of motor and nonmotor symptoms that can significantly impact an affected individual's quality of life. Treatments for Parkinson disease typically focus on controlling the motor symptoms of the disease, including treating OFF periods when motor symptoms return. OFF periods can occur for many individuals with Parkinson disease, especially as the disease progresses, and can pose a substantial burden to those with the disease and their caregivers. Available treatments for OFF periods may help alleviate this burden.

Autonomic nervous system involvement precedes the motor features of Parkinson's disease (PD). Our goal was to develop a proof-of-concept model for identifying subjects at high risk of developing PD by analysis of cardiac electrical activity. We used standard 10-s electrocardiogram (ECG) recordings of 60 subjects from the Honolulu Asia Aging Study including 10 with prevalent PD, 25 with prodromal PD, and 25 controls who never developed PD. Various methods were implemented to extract features from ECGs including simple heart rate variability (HRV) metrics, commonly used signal processing methods, and a Probabilistic Symbolic Pattern Recognition (PSPR) method. Extracted features were analyzed via stepwise logistic regression to distinguish between prodromal cases and controls. Stepwise logistic regression selected four features from PSPR as predictors of PD. The final regression model built on the entire dataset provided an area under receiver operating characteristics curve (AUC) with 95% confidence interval of 0.90 [0.80, 0.99]. The five-fold cross-validation process produced an average AUC of 0.835 [0.831, 0.839]. We conclude that cardiac electrical activity provides important information about the likelihood of future PD not captured by classical HRV metrics. Machine learning applied to ECGs may help identify subjects at high risk of having prodromal PD.

Background: There are limited data on the phenotypic and dopamine transporter (DAT) imaging characterization of the Parkinson's disease (PD) patients with leucine rich kinase 2 (LRRK2) and glucosylceramidase beta (GBA) mutations., Objective: The objective of this study was to examine baseline clinical and DAT imaging characteristics in GBA and LRRK2 mutation carriers with early PD compared with sporadic PD., Methods: The Parkinson's Progression Markers Initiative is an ongoing observational longitudinal study that enrolled participants with sporadic PD, LRRK2 and GBA PD carriers from 33 sites worldwide. All participants are assessed annually with a battery of motor and nonmotor scales, 123-I Ioflupane DAT imaging, and biologic variables., Results: We assessed 158 LRRK2 (89% G2019S), 80 GBA (89 %N370S), and 361 sporadic PD participants with the mean (standard deviation) disease duration of 2.9 (1.9), 3.1 (2.0), and 2.6 (0.6) years, respectively. When compared with sporadic PD, the GBA PD patients had no difference in any motor, cognitive, or autonomic features. The LRRK2 PD patients had less motor disability and lower rapid eye movement behavior disorder questionnaire scores, but no meaningful difference in cognitive or autonomic features. Both genetic cohorts had a higher score on the impulse control disorders scale when compared with sporadic PD, but no difference in other psychiatric features. Both genetic PD cohorts had less loss of dopamine transporter on DAT imaging when compared with sporadic PD., Conclusions: We confirm previous reports of milder phenotype associated with LRRK2-PD. A previously reported more aggressive phenotype in GBA-PD is not evident early in the disease in N370s carriers. This observation identifies a window for potential disease-modifying interventions. Longitudinal data will be essential to define the slope of progression for both genetic cohorts., Trial Registration: ClinicalTrials.gov (NCT01141023). © 2020 The Authors. Movement Disorders published by Wiley Periodicals, Inc. on behalf of International Parkinson and Movement Disorder Society., (© 2020 The Authors. Movement Disorders published by Wiley Periodicals, Inc. on behalf of International Parkinson and Movement Disorder Society.)

Background: β-adrenoceptors are widely expressed in different human organs, mediate important body functions and are targeted by medications for various diseases (such as coronary heart disease and heart attack) and many β-adrenoceptor acting drugs are listed on the WHO Model List of Essential Medicines. β-adrenoceptor antagonists are used by billions of patients with neurological disorders, primarily for the treatment of migraine and action tremor (mainly essential tremor), worldwide., Recent Developments: An observational study reported a link between the chronic use of the β-adrenoceptor antagonist propranolol and an increased risk of Parkinson's disease, while the chronic use of the β-adrenoceptor agonists was associated with a decreased risk. Further support of this association was provided by a dose-dependent decrease in the risk of Parkinson's disease with chronic β-adrenoceptor agonist (eg, salbutamol) use, and by functional data indicating a possible underlying molecular mechanism. Five additional epidemiological studies have examined the modulation of the risk of Parkinson's disease as a result of the use of β-adrenoceptor-acting drugs in different populations. Overall, similar estimates but different interpretations of the associations were provided. Several findings suggest that the increase in risk of Parkinson's disease associated with β-adrenoceptor antagonists use can be explained by reverse causation because prodromal Parkinson's disease is often associated with non-specific action tremor, which is usually treated with propranolol. The lower risk of Parkinson's disease seen in patients receiving β-adrenoceptor agonists is likely to be indirectly mediated by smoking because smoking has a strong inverse association with Parkinson's disease (people that smoke have a reduced risk of developing Parkinson's disease). Smoking also causes chronic obstructive pulmonary disease, which is treated with β-adrenoceptor-agonist medications. Even if causal, the effect of β-adrenoceptor antagonists on the risk of Parkinson's disease would be small compared with other Parkinson's disease risk factors and would be similar to the risk evoked by pesticide exposure. The estimated risk of Parkinson's disease because of β-adrenoceptor antagonists use corresponds to one case in 10 000 patients after 5 years of propranolol use, and would be considered a very rare adverse effect. Thus, not using β-adrenoceptor antagonists would severely harm patients with recommended indications, such as heart disease or migraine. Similarly, 50 000 people would have to be treated for 5 years with salbutamol to prevent Parkinson's disease in one patient, suggesting that primary preventive therapy studies on disease modification are not warranted. WHERE NEXT?: Epidemiological evidence for a causal relationship between use of β2-adrenoceptor antagonists and the increased risk of Parkinson's disease is weak, with other explanations for the association being more probable. Future observational studies are warranted to clarify this association. However, given the very low risk associated with propranolol, most clinicians are unlikely to change their treatment approach., (Copyright © 2020 Elsevier Ltd. All rights reserved.)

Parkinson disease is a complex, age-related, neurodegenerative disease associated with dopamine deficiency and both motor and nonmotor deficits. Many environmental and genetic factors influence Parkinson disease risk, with different factors predominating in different patients. These factors converge on specific pathways, including mitochondrial dysfunction, oxidative stress, protein aggregation, impaired autophagy, and neuroinflammation. Ultimately, treatment of Parkinson disease may focus on targeted therapies for pathophysiologically defined subtypes of Parkinson disease patients., (Copyright © 2019 Elsevier Inc. All rights reserved.)

Background: Online tools for data collection could be of value in patient-oriented research. The Fox Insight (FI) study collects data online from individuals with self-reported Parkinson's disease (PD). Comparing the FI cohort to other cohorts assessed through more traditional (in-person) observational research studies would inform the representativeness and utility of FI data., Objective: To compare self-reported demographic characteristics, symptoms, medical history, and PD medication use of the FI PD cohort to other recent observational research study cohorts assessed with in-person visits., Methods: The FI PD cohort (n = 12,654) was compared to 3 other cohorts, selected based on data accessibility and breadth of assessments: Parkinson's Progression Markers Initiative (PPMI; PD n = 422), Parkinson's Disease Biomarker Program (PDBP; n = 700), and PD participants in the LRRK2 consortium without LRRK2 mutations (n = 508). Demographics, motor and non-motor assessments, and medications were compared across cohorts. Where available, identical items on surveys and assessments were compared; otherwise, expert opinion was used to determine comparable definitions for a given variable., Results: The proportion of females was significantly higher in FI (45.56%) compared to PPMI (34.36%) and PDBP (35.71%). The FI cohort had greater educational attainment as compared to all other cohorts. Overall, prevalence of difficulties with motor experiences of daily living and non-motor symptoms in the FI cohort was similar to other cohorts, with only a few significant differences that were generally small in magnitude. Missing data were rare for the FI cohort, except on a few variables., Discussion: Patterns of responses to patient-reported assessments obtained online on the PD cohort of the FI study were similar to PD cohorts assessed in-person.

Background: The effect of the COVID-19 pandemic on people with Parkinson's disease (PD) is poorly understood., Objective: To rapidly identify areas of need and improve care in people with PD during the COVID-19 pandemic, we deployed a survey to assess COVID-19 symptoms and the pandemic's effect among those with and without COVID-19., Methods: People with and without PD participating in the online study Fox Insight (FI) were invited to complete a survey between April 23 and May 23, 2020. Among people reporting COVID-19 diagnoses, we compared symptoms and outcomes in people with and without PD. Among people not reporting COVID-19, we assessed access to healthcare and services and PD symptoms., Results: 7,209/9,762 active FI users responded (approximately 74% response rate), 5,429 people with PD and 1,452 without PD. COVID-19 diagnoses were reported by 51 people with and 26 without PD. Complications were more frequent in people with longer PD duration. People with PD and COVID-19 experienced new or worsening motor (63%) and nonmotor (75%) symptoms. People with PD not diagnosed with COVID-19 reported disrupted medical care (64%), exercise (21%), and social activities (57%), and worsened motor (43%) and non-motor (52%) symptoms. Disruptions were more common for those living alone, with lower income and non-White race., Conclusions: The COVID-19 pandemic is associated with wide-ranging effects on people with PD, and certain groups may be at particular risk. FI provides a rapid, patient-centered means to assess these effects and identify needs that can be used to improve the health of people with PD.

Background: Gocovri® (amantadine) extended release capsules are approved for the treatment of dyskinesia in patients with Parkinson's disease (PD) receiving levodopa-based therapy., Objective: To evaluate the long-term safety, tolerability, and efficacy of Gocovri in patients with PD experiencing levodopa-induced dyskinesia., Methods: In this 2-year open-label trial, patients completing double-blind Gocovri clinical trials or excluded from prior trials because of deep-brain stimulation (DBS) received Gocovri 274 mg once daily at bedtime. The primary objective was to evaluate long-term safety and tolerability. In addition, dyskinesia and OFF time were assessed using Part IV (Motor Complications) scores on the Movement Disorder Society-Unified Parkinson's Disease Rating Scale (MDS-UPDRS)., Results: Among 223 enrolled patients (mean PD duration, 11.7 years; mean levodopa use, 9.3 years), 75.8% completed 1 year of treatment and 57.8% completed the trial, with a median treatment duration of 1.9 years. Common adverse events were fall (32.7%), hallucination (24.2%), peripheral edema (16.1%), constipation (13.5%), and urinary tract infection (10.3%); 31 patients (13.9%) discontinued because of adverse events considered related to study drug. At baseline, MDS-UPDRS Part IV scores were lower for patients continuing Gocovri (mean, 6.5 points) than for previous placebo (9.4) or DBS groups (10.5) but were similar for all groups by week 8 (6.3, 6.2, 6.4, respectively), and remained low for the duration of the trial (at week 100: 6.9, 7.3, 7.0, respectively)., Conclusions: In patients with PD, Gocovri showed long-term safety and tolerability consistent with double-blind trial findings, and durable reduction in motor complications (dyskinesia and OFF time).

Background: Availability of validated Parkinson's disease (PD) questionnaires in languages spoken in Africa will enable the conduct of epidemiological studies., Objective: The aims of the current study were to develop cross-cultural translated and validated Arabic and French versions of a PD screening questionnaire, and determine its diagnostic accuracy for recognition of parkinsonism in early and moderate-advanced PD in three countries (Cameroon (French), Egypt (Arabic), and Nigeria (English))., Methods: This cross-sectional study screened 159 participants (81 PD and 78 controls) using the PD screening questionnaire. The questionnaire was translated into Arabic and French versions using standard protocols. Cognitive function was assessed using the Montreal Cognitive Assessment and the Identification and Intervention for Dementia in Elderly Africans cognitive screen. Co-morbidity burden was documented using the Charlson Comorbidity Index. PD severity and stage were evaluated using the MDS Unified Parkinson Disease Rating Scale and the Hoehn and Yahr scale respectively., Results: Both PD patients and controls were matched regarding age, gender, education, and co-morbidity burden. The PD screening questionnaire scores were significantly higher in PD (median 8.0, IQR 6.0-10.0) in contrast to controls (0.0, IQR 0.0-0.0) (p < 0.0001), with a similar pattern and level of significance across all country sites. In ROC analysis, the questionnaire demonstrated high diagnostic accuracy for PD overall, with an AUC of 0.992 (95% CI 0.981-1.002)., Conclusion: The Arabic, French, and English versions of this PD screening questionnaire are valid and accurate screening instruments for recognition of Parkinsonism. This paves the way for conducting epidemiological studies in many African countries.

Background: The Parkinson's Progression Markers Initiative (PPMI) is an ongoing observational, longitudinal cohort study of participants with Parkinson's disease, healthy controls, and carriers of the most common Parkinson's disease-related genetic mutations, which aims to define biomarkers of Parkinson's disease diagnosis and progression. All participants are assessed annually with a battery of motor and non-motor scales, 123-I Ioflupane dopamine transporter (DAT) imaging, and biological variables. We aimed to examine whether non-manifesting carriers of LRRK2 and GBA mutations have prodromal features of Parkinson's disease that correlate with reduced DAT binding., Methods: This cross-sectional analysis is based on assessments done at enrolment in the subset of non-manifesting carriers of LRRK2 and GBA mutations enrolled into the PPMI study from 33 participating sites worldwide. The primary objective was to examine baseline clinical and DAT imaging characteristics in non-manifesting carriers with GBA and LRRK2 mutations compared with healthy controls. DAT deficit was defined as less than 65% of putamen striatal binding ratio expected for the individual's age. We used t tests, χ 2 tests, and Fisher's exact tests to compare baseline demographics across groups. An inverse probability weighting method was applied to control for potential confounders such as age and sex. To account for multiple comparisons, we applied a family-wise error rate to each set of analyses. This study is registered with ClinicalTrials.gov, number NCT01141023., Findings: Between Jan 1, 2014, and Jan 1, 2019, the study enrolled 208 LRRK2 (93% G2019S) and 184 GBA (96% N370S) non-manifesting carriers. Both groups were similar with respect to mean age, and about 60% were female. Of the 286 (73%) non-manifesting carriers that had DAT imaging results, 18 (11%) LRRK2 and four (3%) GBA non-manifesting carriers had a DAT deficit. Compared with healthy controls, both LRRK2 and GBA non-manifesting carriers had significantly increased mean scores on the Movement Disorders Society Unified Parkinson's Disease Rating Scale (total score 4·6 [SD 4·4] healthy controls vs 8·4 [7·3] LRRK2 vs 9·5 [9·2] GBA, p<0·0001 for both comparisons) and the Scale for Outcomes for PD - autonomic function (5·8 [3·7] vs 8·1 [5·9] and 8·4 [6·0], p<0·0001 for both comparisons). There was no difference in daytime sleepiness, anxiety, depression, impulsive-compulsive disorders, blood pressure, urate, and rapid eye movement (REM) behaviour disorder scores. Hyposmia was significantly more common only in LRRK2 non-manifesting carriers (69 [36%] of 194 healthy controls vs 114 [55%] of 208 LRRK2 non-manifesting carriers; p=0·0003). Finally, GBA but not LRRK2 non-manifesting carriers showed increased DAT striatal binding ratios compared with healthy controls in the caudate (healthy controls 2·98 [SD 0·63] vs GBA 3·26 [0·63]; p<0·0001), putamen (2·15 [0·56] vs 2·48 [0·52]; p<0·0001), and striatum (2·56 [0·57] vs 2·87 [0·55]; p<0·0001)., Interpretation: Our data show evidence of subtle motor and non-motor signs of Parkinson's disease in non-manifesting carriers compared with healthy controls that can precede DAT deficit. Longitudinal data will be essential to confirm these findings and define the trajectory and predictors for development of Parkinson's disease., Funding: Michael J Fox Foundation for Parkinson's Research., (Copyright © 2020 Elsevier Ltd. All rights reserved.)

Background: Clinical research in Parkinson's disease (PD) faces practical and ethical challenges due to two interrelated problems: participant under-recruitment and lack of diversity. Fox Insight (FI) is a web-based longitudinal study collecting patient-reported outcomes and genetic data worldwide to inform therapeutic studies. FI's online platform provides an opportunity to evaluate online strategies for recruiting large, diverse research cohorts., Objective: This project aimed to determine 1) whether FI's digital marketing was associated with increased enrollment overall and from under-represented patient groups, compared to traditional recruitment methods; 2) the clinical and demographic characteristics of samples recruited online, and 3) the cost of this online recruitment., Method: FI recruitment during a 6-week baseline period without digital promotion was compared to recruitment during several periods of digital outreach. Separate online recruiting intervals included general online study promotion and unique Facebook and Google ad campaigns targeting under-represented subgroups: early PD, late/advanced PD, and residents of underrepresented/rural geographic areas., Results: Early PD, late PD, and geotargeting campaigns enrolled more individuals in their respective cohorts compared to baseline. All online campaigns also yielded greater total FI enrollment, attracting more participants who were non-White, Hispanic, older, female, and had lower educational attainment and income, and more medical comorbidities. Cost per new participant ranged from $21 (Facebook) to $108 (Google)., Conclusion: Digital marketing may allow researchers to increase, accelerate, and diversify recruitment for PD clinical studies, by tailoring digital ads to target PD cohort characteristics.

Objective: While excessive daytime sleepiness (EDS) can predate the clinical diagnosis of Parkinson disease (PD), associations with underlying PD pathogenesis are unknown. Our objective is to determine if EDS is related to brain Lewy pathology (LP), a marker of PD pathogenesis, using clinical assessments of EDS with postmortem follow-up., Methods: Identification of LP was based on staining for α-synuclein in multiple brain regions in a sample of 211 men. Data on EDS were collected at clinical examinations from 1991 to 1999 when participants were aged 72-97 years., Results: Although EDS was more common in the presence vs absence of LP ( p = 0.034), the association became stronger in neocortical regions. When LP was limited to the olfactory bulb, brainstem, and basal forebrain (Braak stages 1-4), frequency of EDS was 10% (4/40) vs 17.5% (20/114) in decedents without LP ( p = 0.258). In contrast, compared to the absence of LP, EDS frequency doubled (36.7% [11/30], p = 0.023) when LP reached the anterior cingulate gyrus, insula mesocortex, and midfrontal, midtemporal, and inferior parietal neocortex (Braak stage 5). With further infiltration into the primary motor and sensory neocortices (Braak stage 6), EDS frequency increased threefold (51.9% [14/27], p < 0.001). Findings were similar across sleep-related features and persisted after adjustment for age and other covariates, including the removal of PD and dementia with Lewy bodies., Conclusions: The association between EDS and PD includes relationships with extensive topographic LP expansion. The neocortex could be especially vulnerable to adverse relationships between sleep disorders and aggregation of misfolded α-synuclein and LP formation., (© 2019 American Academy of Neurology.)

Background: Aggregation of α-synuclein is central to the pathophysiology of PD. Biomarkers related to α-synuclein may be informative for PD diagnosis/progression., Objectives: To analyze α-synuclein in CSF in drug-naïve PD, healthy controls, and prodromal PD in the Parkinson's Progression Markers Initiative., Methods: Over up to 36-month follow-up, CSF total α-synuclein and its association with MDS-UPDRS motor scores, cognitive assessments, and dopamine transporter imaging were assessed., Results: The inception cohort included PD (n = 376; age [mean {standard deviation} years]: 61.7 [9.62]), healthy controls (n = 173; age, 60.9 [11.3]), hyposmics (n = 16; age, 68.3 [6.15]), and idiopathic rapid eye movement sleep behavior disorder (n = 32; age, 69.3 [4.83]). Baseline CSF α-synuclein was lower in manifest and prodromal PD versus healthy controls. Longitudinal α-synuclein decreased significantly in PD at 24 and 36 months, did not change in prodromal PD over 12 months, and trended toward an increase in healthy controls. The decrease in PD was not shown when CSF samples with high hemoglobin concentration were removed from the analysis. CSF α-synuclein changes did not correlate with longitudinal MDS-UPDRS motor scores or dopamine transporter scan., Conclusions: CSF α-synuclein decreases early in the disease, preceding motor PD. CSF α-synuclein does not correlate with progression and therefore does not reflect ongoing dopaminergic neurodegeneration. Decreased CSF α-synuclein may be an indirect index of changes in the balance between α-synuclein secretion, solubility, or aggregation in the brain, reflecting its overall turnover. Additional biomarkers more directly related to α-synuclein pathophysiology and disease progression and other markers to be identified by, for example, proteomics and metabolomics are needed. © 2019 International Parkinson and Movement Disorder Society., (© 2019 International Parkinson and Movement Disorder Society.)

Objective: To determine the feasibility, safety and tolerability of lumbar punctures (LPs) in research participants with early Parkinson disease (PD), subjects without evidence of dopaminergic deficiency (SWEDDs) and healthy volunteers (HC)., Background: Cerebrospinal fluid (CSF) analysis is becoming an essential part of the biomarkers discovery effort in PD with still limited data on safety and feasibility of serial LPs in PD participants., Design/methods: Parkinson's Progression Marker Initiative (PPMI) is a longitudinal observation study designed to identify PD progression biomarkers. All PPMI participants undergo LP at baseline, 6, 12 months and yearly thereafter. CSF collection is performed by a trained investigator using predominantly atraumatic needles. Adverse events (AEs) are monitored by phone one week after LP completion. We analyzed safety data from baseline LPs., Results: PPMI enrolled 683 participants (423 PD/196 HC/64 SWEDDs) from 23 study sites. CSF was collected at baseline in 97.5% of participants, of whom 5.4% underwent collection under fluoroscopy. 23% participants reported any related AEs, 68% of all AE were mild while 5.6% were severe. The most common AEs were headaches (13%) and low back pain (6.5%) and both occurred more commonly in HC and SWEDDs compared to PD participants. Factors associated with higher incidence of AEs across the cohorts included female gender, younger age and use of traumatic needles with larger diameter. AEs largely did not impact compliance with the future LPs., Conclusions: LPs are safe and feasible in PD research participants. Specific LP techniques (needle type and gauge) may reduce the overall incidence of AEs., (Copyright © 2019 Elsevier Ltd. All rights reserved.)

Parkinson's disease (PD) is a neurodegenerative disease in which genetic risk has been mapped to HLA , but precise allelic associations have been difficult to infer due to limitations in genotyping methodology. Mapping PD risk at highest possible resolution, we performed sequencing of 11 HLA genes in 1,597 PD cases and 1,606 controls. We found that susceptibility to PD can be explained by a specific combination of amino acids at positions 70-74 on the HLA-DRB1 molecule. Previously identified as the primary risk factor in rheumatoid arthritis and referred to as the "shared epitope" (SE), the residues Q/R-K/R-R-A-A at positions 70-74 in combination with valine at position 11 (11-V) is highly protective in PD, while risk is attributable to the identical epitope in the absence of 11-V. Notably, these effects are modified by history of cigarette smoking, with a strong protective effect mediated by a positive history of smoking in combination with the SE and 11-V ( P = 10 -4 ; odds ratio, 0.51; 95% confidence interval, 0.36-0.72) and risk attributable to never smoking in combination with the SE without 11-V ( P = 0.01; odds ratio, 1.51; 95% confidence interval, 1.08-2.12). The association of specific combinations of amino acids that participate in critical peptide-binding pockets of the HLA class II molecule implicates antigen presentation in PD pathogenesis and provides further support for genetic control of neuroinflammation in disease. The interaction of HLA-DRB1 with smoking history in disease predisposition, along with predicted patterns of peptide binding to HLA, provide a molecular model that explains the unique epidemiology of smoking in PD., Competing Interests: Conflict of interest statement: S.L.H. currently serves on the Science Advisory Boards of Symbiotix, Annexon, Bionure, and Molecular Stethoscope and on the Board of Trustees of Neurona, and has received travel reimbursement and writing assistance from F. Hoffman-La Roche for CD20-related meetings and presentations., (Copyright © 2019 the Author(s). Published by PNAS.)

During the 1990s, we estimated the genetic contribution to Parkinson's disease risk in a large, population-based twin registry. Because many unaffected twins were still alive, previous concordance estimates were based on incomplete information. Ninety-five percent of twins are now deceased. Here, we update concordance and heritability through 2015 using National Death Index data. In total, we identified 30 concordant and 193 discordant pairs. Proband-wise concordance was 0.20 in monozygotic and 0.13 in dizygotic pairs. Heritability was 0.27 overall, 0.83 in pairs diagnosed ≤50, and 0.19 in pairs diagnosed >50. High concordance in dizygotic twins suggests shared effects of early childhood environment. Ann Neurol 2019;85:600-605., (© 2019 American Neurological Association.)