Elucidating the genetic contributions to Parkinson's disease aetiology across diverse ancestries is a critical priority for the development of targeted therapies in a global context. We conducted the largest sequencing characterization of potentially disease-causing, protein-altering and splicing mutations in 710 cases and 11 827 controls from genetically predicted African or African admixed ancestries. We explored copy number variants (CNVs) and runs of homozygosity in prioritized early onset and familial cases. Our study identified rare GBA1 coding variants to be the most frequent mutations among patients with Parkinson's disease, with a frequency of 4% in our case cohort. Of the 18 GBA1 variants identified, 10 were previously classified as pathogenic or likely pathogenic, four were novel and four were reported as of uncertain clinical significance. The most common known disease-associated GBA1 variants in the Ashkenazi Jewish and European populations, p.Asn409Ser, p.Leu483Pro, p.Thr408Met and p.Glu365Lys, were not identified among the screened Parkinson's disease cases of African and African admixed ancestry. Similarly, the European and Asian LRRK2 disease-causing mutational spectrum, including LRRK2 p.Gly2019Ser and p.Gly2385Arg genetic risk factors, did not appear to play a major role in Parkinson's disease aetiology among West African ancestry populations. However, we found three heterozygous novel missense LRRK2 variants of uncertain significance, with two (p.Glu268Ala and p.Arg1538Cys) displaying higher frequencies in the African ancestry population reference datasets. Structural variant analyses revealed the presence of PRKN CNVs with a frequency of 0.7% in African and African admixed cases, with 66% of CNVs detected being compound heterozygous or homozygous in early-onset cases, providing further insights into the genetic underpinnings in early-onset juvenile Parkinson's disease in these populations. Short tandem repeat analysis also identified ATXN3 CAG repeat expansions within the pathogenic range (CAGn > 45) in three patients with Parkinson's disease of African ancestry. Novel genetic variation among screened genes warrants further replication and functional prioritization to unravel their pathogenic potential. Here, we created the most comprehensive genetic catalogue of both known and novel coding and splicing variants potentially linked to Parkinson's disease aetiology in an underserved population and further conducted global and local ancestry analyses to further explore population-specific effects. Our study has the potential to guide the development of targeted therapies in the emerging era of precision medicine. By expanding genetics research to involve underrepresented populations, we hope that future Parkinson's disease treatments are not only effective but also inclusive, addressing the needs of diverse ancestral groups.
Determining the genetic contributions to Parkinson’s disease (PD) across diverse ancestries is a high priority as this work can guide therapeutic development in a global setting. The genetics of PD spans the etiological risk spectrum, from rare, highly deleterious variants linked to monogenic forms with Mendelian patterns of inheritance, to common variation involved in sporadic disease. A major limitation in PD genomics research is lack of racial and ethnic diversity. Enrollment disparities have detrimental consequences on the generalizability of results and exacerbate existing inequities in care. The Black and African American Connections to Parkinson’s Disease (BLAAC PD) study is part of the Global Parkinson’s Genetics Program, supported by the Aligning Science Across Parkinson’s initiative. The goal of the study is to investigate the genetic architecture underlying PD risk and progression in the Black and/or African American populations. This cross-sectional multicenter study in the United States has a recruitment target of up to 2,000 individuals with PD and up to 2,000 controls, all of Black and/or African American ancestry. The study design incorporates several strategies to reduce barriers to research participation. The multifaceted recruitment strategy aims to involve individuals with and without PD in various settings, emphasizing community outreach and engagement. The BLAAC PD study is an important first step toward informing understanding of the genetics of PD in a more diverse population.
Estimates of the spectrum and frequency of pathogenic variants in Parkinson's disease (PD) in different populations are currently limited and biased. Furthermore, although therapeutic modification of several genetic targets has reached the clinical trial stage, a major obstacle in conducting these trials is that PD patients are largely unaware of their genetic status and, therefore, cannot be recruited. Expanding the number of investigated PD-related genes and including genes related to disorders with overlapping clinical features in large, well-phenotyped PD patient groups is a prerequisite for capturing the full variant spectrum underlying PD and for stratifying and prioritizing patients for gene-targeted clinical trials. The Rostock Parkinson's disease (ROPAD) study is an observational clinical study aiming to determine the frequency and spectrum of genetic variants contributing to PD in a large international cohort. We investigated variants in 50 genes with either an established relevance for PD or possible phenotypic overlap in a group of 12 580 PD patients from 16 countries [62.3% male; 92.0% White; 27.0% positive family history (FH+), median age at onset (AAO) 59 years] using a next-generation sequencing panel. Altogether, in 1864 (14.8%) ROPAD participants (58.1% male; 91.0% White, 35.5% FH+, median AAO 55 years), a PD-relevant genetic test (PDGT) was positive based on GBA1 risk variants (10.4%) or pathogenic/likely pathogenic variants in LRRK2 (2.9%), PRKN (0.9%), SNCA (0.2%) or PINK1 (0.1%) or a combination of two genetic findings in two genes (similar to 0.2%). Of note, the adjusted positive PDGT fraction, i.e. the fraction of positive PDGTs per country weighted by the fraction of the population of the world that they represent, was 14.5%. Positive PDGTs were identified in 19.9% of patients with an AAO <= 50 years, in 19.5% of patients with FH+ and in 26.9% with an AAO <= 50 years and FH+. In comparison to the idiopathic PD group (6846 patients with benign variants), the positive PDGT group had a significantly lower AAO (4 years, P = 9 x 10(-34)). The probability of a positive PDGT decreased by 3% with every additional AAO year (P = 1 x 10(-35)). Female patients were 22% more likely to have a positive PDGT (P = 3 x 10(-4)), and for individuals with FH+ this likelihood was 55% higher (P = 1 x 10(-14)). About 0.8% of the ROPAD participants had positive genetic testing findings in parkinsonism-, dystonia/dyskinesia- or dementia-related genes. In the emerging era of gene-targeted PD clinical trials, our finding that similar to 15% of patients harbour potentially actionable genetic variants offers an important prospect to affected individuals and their families and underlines the need for genetic testing in PD patients. Thus, the insights from the ROPAD study allow for data-driven, differential genetic counselling across the spectrum of different AAOs and family histories and promote a possible policy change in the application of genetic testing as a routine part of patient evaluation and care in PD.
Data sharing not applicable-no new data generated, or the article describes entirely theoretical research.
Objective: To present the adverse event (AE) profile of IPX203 in the Phase 3 clinical trials in Parkinson disease (PD). Background: IPX203 is an investigational oral extended-release carbidopa-levodopa (CD-LD) designed to produce prolonged therapeutic LD plasma concentrations. IPX203 has shown improvement in "Good On" time compared to immediate-release CD-LD. Design/Methods: Safety data from a multi-center, double-blind, randomized, active-controlled Phase 3 study and an open-label extension Phase 3 study were combined and analyzed. Results: Safety population consisted of 630 patients with PD experiencing motor fluctuations, with a mean age of 66.5yrs (9.0), and mean duration of disease of 8.5yrs (4.9). The average total daily dose (TDD) of IPX203 was 1520.97 mg (±587.78); most subjects (83.0%) received IPX203 at an average TDD between 800 mg and <2400 mg of LD. The average daily dosing frequency of IPX203 was 3.08 times/day, the mean (range) treatment duration was 242.9 (2 to 553) days and person-years of exposure was 388.34. The majority, 385/584 (65.9%), were exposed to IPX203 for 6 months or longer, and 179 (30.7%) were exposed for 12 months or longer. In the Phase 3 studies pool, 397 (67.4%) of IPX203 subjects experienced 1355 treatment-emergent AEs (TEAEs) (837 mild, 419 moderate, 99 severe). Of these, 205 (34.8%) experienced 471 TEAEs that were treatment-related. The most reported TEAEs were dyskinesia (10.7%), nausea (7.5%), fall (5.9%), and urinary tract infection (5.3%). The analysis of TEAEs by duration of exposure to study treatment showed that most IPX203 subjects (55.0%) experienced TEAEs (first onset) within the first 3 months. The occurrence of TEAEs remained stable over time. Conclusions: Considering the disease duration and presence of motor fluctuations in the PD cohort enrolled in our Phase 3 trials, IPX203 was generally safe and well tolerated; the safety profile was stable over time and consistent with the known effects of other LD formulations. Disclosure: Dr. Fernandez has received personal compensation in the range of $500-$4,999 for serving as a Consultant for Abbvie. Dr. Fernandez has received personal compensation in the range of $500-$4,999 for serving as a Consultant for Cerevel. Dr. Fernandez has received personal compensation in the range of $500-$4,999 for serving as a Consultant for Amneal. Dr. Fernandez has received personal compensation in the range of $10,000-$49,999 for serving as an Editor, Associate Editor, or Editorial Advisory Board Member for Elsevier. The institution of Dr. Fernandez has received research support from Biogen. The institution of Dr. Fernandez has received research support from Michael J Fox Founda. The institution of Dr. Fernandez has received research support from Roche. The institution of Dr. Fernandez has received research support from Parkinson Foundation. The institution of Dr. Fernandez has received research support from UCB. Dr. Fernandez has received publishing royalties from a publication relating to health care. Dr. Fernandez has received personal compensation in the range of $10,000-$49,999 for serving as a Steering Committee/Advisory Committee Member with Parkinson Study Group. Dr. Hauser has received personal compensation in the range of $500-$4,999 for serving as a Consultant for Acadia Pharmaceuticals. Dr. Hauser has received personal compensation in the range of $10,000-$49,999 for serving as a Consultant for Acorda Therapeutics. Dr. Hauser has received personal compensation in the range of $10,000-$49,999 for serving as a Consultant for Adamas Pharmaceuticals. Dr. Hauser has received personal compensation in the range of $500-$4,999 for serving as a Consultant for Aptinyx. Dr. Hauser has received personal compensation in the range of $500-$4,999 for serving as a Consultant for Britannia. Dr. Hauser has received personal compensation in the range of $10,000-$49,999 for serving as a Consultant for CAVR. Dr. Hauser has received personal compensation in the range of $500-$4,999 for serving as a Consultant for ClearView Healthcare Partners. Dr. Hauser has received personal compensation in the range of $500-$4,999 for serving as a Consultant for Decision Resource Group (DRG). Dr. Hauser has received personal compensation in the range of $500-$4,999 for serving as a Consultant for Enterin. Dr. Hauser has received personal compensation in the range of $500-$4,999 for serving as a Consultant for FirstWord. Dr. Hauser has received personal compensation in the range of $500-$4,999 for serving as a Consultant for Global Kinetics Consulting (GKC). Dr. Hauser has received personal compensation in the range of $500-$4,999 for serving as a Consultant for GuidePoint Global. Dr. Hauser has received personal compensation in the range of $500-$4,999 for serving as a Consultant for Huron. Dr. Hauser has received personal compensation in the range of $0-$499 for serving as a Consultant for InSearch Consulting. Dr. Hauser has received personal compensation in the range of $0-$499 for serving as a Consultant for Insignia Strategies. Dr. Hauser has received personal compensation in the range of $5,000-$9,999 for serving as a Consultant for Jazz Pharmaceuticals. Dr. Hauser has received personal compensation in the range of $500-$4,999 for serving as a Consultant for KeiferRX LLC. Dr. Hauser has received personal compensation in the range of $500-$4,999 for serving as a Consultant for KeyQuest. Dr. Hauser has received personal compensation in the range of $500-$4,999 for serving as a Consultant for KX Advisors. Dr. Hauser has received personal compensation in the range of $50,000-$99,999 for serving as a Consultant for Kyowa Kirin Pharmaceuticals. Dr. Hauser has received personal compensation in the range of $500-$4,999 for serving as a Consultant for L.E.K. Consulting. Dr. Hauser has received personal compensation in the range of $500-$4,999 for serving as a Consultant for Lundbeck A/S. Dr. Hauser has received personal compensation in the range of $50,000-$99,999 for serving as a Consultant for Neurocrine Biosciences. Dr. Hauser has received personal compensation in the range of $5,000-$9,999 for serving as a Consultant for NeuroDerm. Dr. Hauser has received personal compensation in the range of $500-$4,999 for serving as a Consultant for NOVUS. Dr. Hauser has received personal compensation in the range of $0-$499 for serving as a Consultant for Perception OpCo (Cerevel Therapeutics LLC). Dr. Hauser has received personal compensation in the range of $500-$4,999 for serving as a Consultant for ROCHE . Dr. Hauser has received personal compensation in the range of $500-$4,999 for serving as a Consultant for Scion Neurostim LLC. Dr. Hauser has received personal compensation in the range of $10,000-$49,999 for serving as a Consultant for Sunovion Pharmaceuticals. Dr. Hauser has received personal compensation in the range of $500-$4,999 for serving as a Consultant for Tolmar Inc.. Dr. Hauser has received personal compensation in the range of $500-$4,999 for serving as a Consultant for US World Meds. Dr. Hauser has received personal compensation in the range of $500-$4,999 for serving as a Consultant for Pharmather. Dr. Hauser has received personal compensation in the range of $0-$499 for serving as a Consultant for Global Life Sciences. Dr. Hauser has received personal compensation in the range of $500-$4,999 for serving as a Consultant for Revance Therapeutics. Dr. Hauser has received personal compensation in the range of $10,000-$49,999 for serving as a Consultant for Supernus Pharma. Dr. Hauser has received personal compensation in the range of $500-$4,999 for serving as a Consultant for Inhibikase. Dr. Hauser has received personal compensation in the range of $500-$4,999 for serving as a Consultant for LifeSciences Consultants. Dr. Hauser has received personal compensation in the range of $500-$4,999 for serving as a Consultant for Research Catalyst . Dr. Hauser has received personal compensation in the range of $500-$4,999 for serving as a Consultant for Curium Pharma. Dr. Hauser has received personal compensation in the range of $500-$4,999 for serving as a Consultant for Syneos. Dr. Hauser has received personal compensation in the range of $500-$4,999 for serving as a Consultant for Merz. Dr. Hauser has received personal compensation in the range of $500-$4,999 for serving as a Consultant for Cerevance. Dr. Hauser has received personal compensation in the range of $5,000-$9,999 for serving as a Consultant for Pharma 2 B. Dr. Hauser has received personal compensation in the range of $10,000-$49,999 for serving as a Consultant for Vivifi Biotech. Dr. Hauser has received personal compensation in the range of $500-$4,999 for serving as a Consultant for Sio Gene Therapies. Dr. Hauser has received personal compensation in the range of $500-$4,999 for serving as a Consultant for Abbvie. Dr. Hauser has received personal compensation in the range of $500-$4,999 for serving as a Consultant for Sage Therapeutics. Dr. Hauser has received personal compensation in the range of $5,000-$9,999 for serving as a Consultant for Merck. Dr. Hauser has received personal compensation in the range of $500-$4,999 for serving as a Consultant for Alterity. Dr. Hauser has received personal compensation in the range of $5,000-$9,999 for serving as a Consultant for Ameal. Dr. Hauser has received personal compensation in the range of $500-$4,999 for serving as a Consultant for Projects in Knowledge. Dr. Hauser has received personal compensation in the range of $500-$4,999 for serving as a Consultant for DDB Health. Dr. Hauser has received personal compensation in the range of $10,000-$49,999 for serving as a Consultant for BRACKET/Signant. Dr. Hauser has received personal compensation in the range of $5,000-$9,999 for serving as a Consultant for Efficient CME. Dr. Hauser has received personal compensation in the range of $5,000-$9,999 for serving as a Consultant for Kansas City Southwest Clinical Society. Dr. Hauser has received personal compensation in the range of $500-$4,999 for serving as a Consultant for Triangle Insights. Dr. Hauser has received personal compensation in the range of $500-$4,999 for serving as a Consultant for Clarity Science, LLC. Dr. Hauser has received personal compensation in the range of $500-$4,999 for serving as a Consultant for BioMedical Insights. Dr. Hauser has received personal compensation in the range of $0-$499 for serving as a Consultant for Coleman Research. Dr. Hauser has received personal compensation in the range of $0-$499 for serving as a Consultant for Deallus. Dr. Hauser has received personal compensation in the range of $500-$4,999 for serving as a Consultant for EPI-Q. Dr. Hauser has received personal compensation in the range of $500-$4,999 for serving as a Consultant for Orion. Dr. Hauser has received personal compensation in the range of $500-$4,999 for serving as a Consultant for Health Advances. Dr. Hauser has received personal compensation in the range of $5,000-$9,999 for serving as a Consultant for Ovid Therapeutics. Dr. Hauser has received personal compensation in the range of $50,000-$99,999 for serving as a Consultant for Amneal. Dr. Hauser has received personal compensation in the range of $500-$4,999 for serving on a Scientific Advisory or Data Safety Monitoring board for Inhibikase. Dr. Hauser has received personal compensation in the range of $5,000-$9,999 for serving on a Scientific Advisory or Data Safety Monitoring board for Vivifi Biotech. Dr. Hauser has received personal compensation in the range of $10,000-$49,999 for serving on a Speakers Bureau for Acorda Therapeutics. Dr. Hauser has received personal compensation in the range of $10,000-$49,999 for serving on a Speakers Bureau for ADAMAS . Dr. Hauser has received personal compensation in the range of $500-$4,999 for serving on a Speakers Bureau for Ameal . Dr. Hauser has received personal compensation in the range of $10,000-$49,999 for serving on a Speakers Bureau for Amneal. Dr. Hauser has received personal compensation in the range of $10,000-$49,999 for serving on a Speakers Bureau for Kyowa Kirin. Dr. Hauser has received personal compensation in the range of $500-$4,999 for serving on a Speakers Bureau for Neurochallenge. Dr. Hauser has received personal compensation in the range of $10,000-$49,999 for serving on a Speakers Bureau for Neurocrine. Dr. Hauser has received personal compensation in the range of $5,000-$9,999 for serving on a Speakers Bureau for Sunovion. Dr. Hauser has received personal compensation in the range of $500-$4,999 for serving on a Speakers Bureau for Kansas City Southwest Clinical Society. Dr. Hauser has stock in Inhibikase. Dr. Hauser has stock in Axial Therapeutics. The institution of Dr. Hauser has received research support from Biogen, Inc.. The institution of Dr. Hauser has received research support from Cavion, Inc. The institution of Dr. Hauser has received research support from Centogene. The institution of Dr. Hauser has received research support from Cerevel. The institution of Dr. Hauser has received research support from Cynapsus Therapeutics. The institution of Dr. Hauser has received research support from Enterin. The institution of Dr. Hauser has received research support from Global Kinetics Corporation. The institution of Dr. Hauser has received research support from Impax Laboratory. The institution of Dr. Hauser has received research support from Intec Pharma. The institution of Dr. Hauser has received research support from Jazz Pharmaceuticals, Inc.. The institution of Dr. Hauser has received research support from Neuro Derm. The institution of Dr. Hauser has received research support from Northwestern University. The institution of Dr. Hauser has received research support from Pfizer. The institution of Dr. Hauser has received research support from Pharma 2 B. The institution of Dr. Hauser has received research support from Revance Therapeutics. The institution of Dr. Hauser has received research support from Roche. The institution of Dr. Hauser has received research support from Sun Pharma Advanced Research. The institution of Dr. Hauser has received research support from Sunovion. The institution of Dr. Hauser has received research support from AbbVie. The institution of Dr. Hauser has received research support from Axovant Sciences Ltd.. The institution of Dr. Hauser has received research support from Cerevance. The institution of Dr. Hauser has received research support from MJFF. The institution of Dr. Hauser has received research support from Neuraly. The institution of Dr. Hauser has received research support from Sanofi US Services, Inc.. The institution of Dr. Hauser has received research support from Bukwang Pharmaceuticals. The institution of Dr. Hauser has received research support from Integrative Research Laboratories Sweden AB. The institution of Dr. Hauser has received research support from Genentech, Inc.. The institution of Dr. Hauser has received research support from UCB Biopharma SPRL. Dr. Hauser has received intellectual property interests from a discovery or technology relating to health care. The institution of Dr. Hinson has received research support from Biogen. The institution of Dr. Hinson has received research support from Scion Neurostim. The institution of Dr. Hinson has received research support from PPD Development/Takeda Development. The institution of Dr. Hinson has received research support from Parexel Biopharma. The institution of Dr. Hinson has received research support from Impax Laboratories. Dr. Pavasia has received personal compensation in the range of $50,000-$99,999 for serving on a Speakers Bureau for Neurocrine. Dr. Pavasia has received personal compensation in the range of $50,000-$99,999 for serving on a Speakers Bureau for Kyowa Kirin. Dr. Pavasia has received personal compensation in the range of $10,000-$49,999 for serving on a Speakers Bureau for Amneal. Dr. Pavasia has received personal compensation in the range of $50,000-$99,999 for serving on a Speakers Bureau for Supernus. Dr. Pavasia has received personal compensation in the range of $10,000-$49,999 for serving on a Speakers Bureau for Abbvie. Dr. Molho has received personal compensation in the range of $500-$4,999 for serving as a Consultant for Lundbeck. Dr. Molho has received personal compensation in the range of $5,000-$9,999 for serving as a Consultant for CNS Ratings. Dr. Molho has received personal compensation in the range of $5,000-$9,999 for serving on a Speakers Bureau for Neurocrine Biosciences. The institution of Dr. Zeitlin has received personal compensation in the range of $10,000-$49,999 for serving as a Consultant for Veranex Solutions. Hester Visser has received personal compensation for serving as an employee of Amneal Pharmaceuticals LLC. Hester Visser has received stock or an ownership interest from Amneal Pharmaceuticals LLC. Richard D'Souza has nothing to disclose.
BackgroundIn pre-clinical animal models of Parkinson's disease (PD), vagus nerve stimulation (VNS) can rescue motor deficits and protect susceptible neuronal populations. Transcutaneous auricular vagus nerve stimulation (taVNS) has emerged as a non-invasive alternative to traditional invasive cervical VNS. This is the first report summarizing the safety, feasibility, and preliminary efficacy of repeated sessions of taVNS in participants with PD.ObjectivesTo evaluate the feasibility, safety, and possible efficacy of taVNS for motor and non-motor symptoms in mild to moderate PD.MethodsThis is a double-blind, sham controlled RCT (NCT04157621) of taVNS in 30 subjects with mild to moderate PD without cognitive impairment. Participants received 10, 1-h taVNS sessions (25 Hz, 200% of sensory threshold, 500 μs pulse width, 60 s on and 30 s off) over a 2-week period. Primary outcome measures were feasibility and safety of the intervention; secondary outcomes included the MDS-UPDRS, cognitive function and self-reported symptom improvement.ResultstaVNS treatment was feasible, however, daily in-office visits were reported as being burdensome for participants. While five participants in the taVNS group and three in the sham group self-reported one or more minor adverse events, no major adverse events occurred. There were no group differences on blood pressure and heart rate throughout the intervention. There were no group differences in MDS-UPDRS scores or self-reported measures. Although global cognitive scores remained stable across groups, there was a reduction in verbal fluency within the taVNS group.ConclusionstaVNS was safe, and well-tolerated in PD participants. Future studies of taVNS for PD should explore at-home stimulation devices and optimize stimulation parameters to reduce variability and maximize engagement of neural targets.
Purpose of Review To perform a systematic review and determine the prevalence of rhinorrhea in Parkinson disease (PD). Recent Findings Of 451 patients with PD and 233 controls, the pooled prevalence of rhinorrhea in patients with PD was 45.0% (95% confidence interval 33.94-56.40), which was significantly greater than that in controls (p < 0.001). The prevalence of self-reported olfactory dysfunction was greater in patients with PD; however, a pooled analysis of studies using objective scores showed no difference. The mean age of patients with PD was greater than that of controls (p = 0.002). The mean age of patients with PD with rhinorrhea was also greater than that of patients with PD without rhinorrhea (p < 0.001), but disease characteristics did not differ. Summary There is a high prevalence of rhinorrhea in patients with PD; therefore, providers should query for rhinorrhea during visits and understand the treatment options available. Future studies should explore the pathophysiology of rhinorrhea in PD and the relationship between rhinorrhea and disease severity and duration, as well as determine whether treatment-specific outcomes differ in patients with PD.
To perform a systematic review and determine the prevalence of rhinorrhea in Parkinson disease (PD).
s Brain Stimulation 14 (2021) 1708e1752 expression, which are key regulators of autophagy and lysosomal biogenesis. These changes were observed using Nanostring assay on hippocampal tissue combined with immunofluorescence staining. Overall, these data highlight a novel role for vagus nerve stimulation in regulating neuroimmune interactions and resolving inflammation in delirium superimposed on dementia.
Patient 1: The parents of a 16-year-old boy ask that their son be urgently evaluated for an exacerbation of his tics. He was diagnosed with Gilles de la Tourette's syndrome (GTS) at age 5 years and never required pharmacotherapy for his tics. Since the start of the school year and the transition to junior high school, he has developed frequent grunting, coughing, and shouting. These vocal tics are extremely disruptive and socially embarrassing. Classmates have commented, some heckling him, and one concerned student asked him if he was taking illicit drugs. The boy refuses to go to school and his grades are dropping. He recently had a bad cold, and started taking pseudonephrine, and feels his tics are even worse. On examination, there are mild multifocal motor tics, and severe repetitive vocal tics. The remainder of the examination is normal.
OBJECTIVES/GOALS: This study uses diffusion kurtosis imaging (DKI) to investigate the structural profiles of basal ganglia (BG) motor circuitry in Vascular Parkinsonism (VP), Parkinson’s disease (PD), and healthy aging controls (HC). VP is a clinical diagnosis of lower body predominant parkinsonism without significant benefit from levodopa. VP is distinct from PD, yet the concept of VP remains debated due to the inability of prior studies to identify specific causative changes. One reason for this may be limitations in measuring intricate BG connectivity in vivo. Given the predominant lower body parkinsonism symptoms in VP, we hypothesized that VP would be associated with decreased connectivity specifically within the BG motor loop. METHODS/STUDY POPULATION: We obtained DKI brain imaging in subjects with VP (N = 7), PD (N = 21), and HCs (N = 58), the latter of which had cardiovascular risk factors but no neurological symptoms. The VP and PD groups were evaluated by a parkinsonism-focused motor exam and brief cognitive testing. We compared BG motor loop connectivity between groups and investigated for correlation between connectivity and clinical scores. To account for differences in fiber counts due to the different imaging scanners and protocols between cohorts, we used a BG motor loop proportion, which was the ratio of the BG motor loop fiber count over a control loop, the visual processing pathway. We used Kruskal-Wallis rank sum test with post-hoc Dunn tests to assess imaging findings between subject groups, and Pearson’s correlation to look for correlation between clinical scores and fiber counts. RESULTS/ANTICIPATED RESULTS: The whole brain connectome showed the fewest number of fibers in VP, followed by PD, and then HC (p<0.0001). The BG motor loop proportion fiber count of the BG motor loop was lower in the VP group, compared to the PD and HC cohorts (p = 0.031). In the VP group, the whole brain connectome fiber count correlated with a gait and balance subscore of the Movement Disorders Society - Unified Parkinson Disease Rating Scale (R = −0.87, p = 0.01). DISCUSSION/SIGNIFICANCE OF IMPACT: This study indicates that VP is associated with decreased structural connectivity, with a disproportionate degree of loss in the BG motor circuitry. While the etiology for this susceptibility to injury and preferential damage to BG remains to be defined, these findings can provide an important starting point for a biological understanding of VP, and a potential future marker for diagnosis and tracking disease progression.
Background: Vagus nerve stimulation (VNS) modifies brain rhythms in the locus coeruleus (LC) via the solitary nucleus. Degeneration of the LC in Parkinson’s disease (PD) is an early catalyst of the spreading neurodegenerative process, suggesting that stimulating LC output with VNS has the potential to modify disease progression. We previously showed in a lesion PD model that VNS delivered twice daily reduced neuroinflammation and motor deficits, and attenuated tyrosine hydroxylase (TH)-positive cell loss. Objective: The goal of this study was to characterize the differential effects of three clinically-relevant VNS paradigms in a PD lesion model. Methods: Eleven days after DSP-4 (N-(2-chloroethyl)-N-ethyl-2-bromobenzylamine, noradrenergic lesion, administered systemically)/6-OHDA (6-hydroxydopamine, dopaminergic lesion, administered intrastriatally) rats were implanted with VNS devices, and received either low-frequency VNS, standard-frequency VNS, or high-frequency microburst VNS. After 10 days of treatment and behavioral assessment, rats were euthanized, right prefrontal cortex (PFC) was dissected for norepinephrine assessment, and the left striatum, bilateral substantia nigra (SN), and LC were sectioned for immunohistochemical detection of catecholamine neurons, α-synuclein, astrocytes, and microglia. Results: At higher VNS frequencies, specifically microburst VNS, greater improvements occurred in motor function, attenuation of TH-positive cell loss in SN and LC, and norepinephrine concentration in the PFC. Additionally, higher VNS frequencies resulted in lower intrasomal α-synuclein accumulation and glial density in the SN. Conclusions: These data indicate that higher stimulation frequencies provided the greatest attenuation of behavioral and pathological markers in this PD model, indicating therapeutic potential for these VNS paradigms.
Sunday, April 26April 14, 2020Free AccessHigh-Frequency VNS Attenuates Symptom Severity and Neurodegeneration in a Rat Model of Parkinson’s Disease (4463)Ryan Verner, Ariana Farrand, Ryan McGuire, Vanessa Hinson, and Heather BogerAuthors Info & AffiliationsApril 14, 2020 issue94 (15_supplement)https://doi.org/10.1212/WNL.94.15_supplement.4463 Letters to the Editor
Vagus nerve stimulation (VNS) is being explored as a potential therapeutic for Parkinson's disease (PD). VNS is less invasive than other surgical treatments and has beneficial effects on behavior and brain pathology. It has been suggested that VNS exerts these effects by increasing brain-derived neurotrophic factor (BDNF) to enhance pro-survival mechanisms of its receptor, tropomyosin receptor kinase-B (TrkB). We have previously shown that striatal BDNF is increased after VNS in a lesion model of PD. By chronically administering ANA-12, a TrkB-specific antagonist, we aimed to determine TrkB's role in beneficial VNS effects for a PD model. In this study, we administered a noradrenergic neurotoxin, DSP-4, intraperitoneally and one week later administered a bilateral intrastriatal dopaminergic neurotoxin, 6-OHDA. At this time, the left vagus nerve was cuffed for stimulation. Eleven days later, rats received VNS twice per day for ten days, with daily locomotor assessment. Daily ANA-12 injections were given one hour prior to the afternoon stimulation and concurrent locomotor session. Following the final VNS session, rats were euthanized, and left striatum, bilateral substantia nigra and locus coeruleus were sectioned for immunohistochemical detection of neurons, alpha-synuclein, astrocytes, and microglia. While ANA-12 did not avert behavioral improvements of VNS, and only partially prevented VNS-induced attenuation of neuronal loss in the locus coeruleus, it did stop neuronal and anti-inflammatory effects of VNS in the nigrostriatal system, indicating a role for TrkB in mediating VNS efficacy. However, our data also suggest that BDNF-TrkB is not the sole mechanism of action for VNS in PD.