The impact of coronavirus disease 2019 (COVID-19) on clinical features of Parkinson's disease (PD) has been poorly characterized so far. Of 141 PD patients resident in Lombardy, we found 12 COVID-19 cases (8.5%), whose mean age and disease duration (65.5 and 6.3 years, respectively) were similar to controls. Changes in clinical features in the period January 2020 to April 2020 were compared with those of 36 PD controls matched for sex, age, and disease duration using the clinical impression of severity index for PD, the Movement Disorders Society Unified PD Rating Scale Parts II and IV, and the nonmotor symptoms scale. Motor and nonmotor symptoms significantly worsened in the COVID-19 group, requiring therapy adjustment in one third of cases. Clinical deterioration was explained by both infection-related mechanisms and impaired pharmacokinetics of dopaminergic therapy. Urinary issues and fatigue were the most prominent nonmotor issues. Cognitive functions were marginally involved, whereas none experienced autonomic failure.

Abstract The natural pattern of progression of Parkinson’s disease is largely unknown because patients are conventionally followed on treatment. As Parkinson’s disease progresses, the true magnitude of the long-duration response to levodopa remains unknown, because it can only be estimated indirectly in treated patients. We aimed to describe the natural course of motor symptoms by assessing the natural OFF in consecutive Parkinson’s disease patients never exposed to treatment (drug-naïve), and to investigate the effects of daily levodopa on the progression of motor disability in the OFF medication state over a 2-year period. In this prospective naturalistic study in sub-Saharan Africa, 30 Parkinson’s disease patients (age at onset 58 ± 14 years, disease duration 7 ± 4 years) began levodopa monotherapy and were prospectively assessed using the Unified Parkinson’s disease Rating Scale (UPDRS). Data were collected at baseline, at 1-year and 2-years follow-up. First-ever levodopa intake induced a significant improvement in motor symptoms (natural OFF versus ON state UPDRS-III 41.9 ± 15.9 versus 26.8 ± 15.1, respectively; P < 0.001). At 1-year follow-up, OFF state UPDRS-III score after overnight withdrawal of levodopa was considerably lower than natural OFF (26.5 ± 14.9; P < 0 .001). This effect was not modified by disease duration. At the 2-year follow-up, motor signs after overnight OFF (30.2 ± 14.2) were still 30% milder than natural OFF (P = 0.001). The ON state UPDRS-III at the first-ever levodopa challenge was similar to the overnight OFF score at 1-year follow-up and the two conditions were correlated (r = 0.72, P < 0.001). Compared to the natural progression of motor disability, levodopa treatment resulted in a 31% lower annual decline in UPDRS-III scores in the OFF state (3.33 versus 2.30 points/year) with a lower model’s variance explained by disease duration (67% versus 36%). Using the equation regressed on pretreatment data, we predicted the natural OFF at 1-year and 2-year follow-up visits and estimated that the magnitude of the long-duration response to levodopa ranged between 60% and 65% of total motor benefit provided by levodopa, independently of disease duration (P = 0.13). Although levodopa therapy was associated with motor fluctuations, overnight OFF disability during levodopa was invariably less severe than the natural course of the disease, independently of disease duration. The same applies to the yearly decline in UPDRS-III scores in the OFF state. Further research is needed to clarify the mechanisms underlying the long-duration response to levodopa in Parkinson’s disease. Understanding the natural course of Parkinson’s disease and the long-duration response to levodopa may help to develop therapeutic strategies increasing its magnitude to improve patient quality of life and to better interpret the outcome of randomized clinical trials on disease-modifying therapies that still rely on the overnight OFF to define Parkinson’s disease progression.

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Background The differential diagnosis between multiple system atrophy parkinsonism type (MSA‐P) and Parkinson's disease with orthostatic hypotension (PD+OH) is difficult because the 2 diseases have a similar clinical picture. The aim of this study is to distinguish MSA‐P from PD+OH by immunostaining for abnormal phosphorylated α‐synuclein at serine 129 (p‐syn) in cutaneous nerves. Method We recruited 50 patients with parkinsonism and chronic orthostatic hypotension: 25 patients fulfilled the diagnostic criteria for MSA‐P and 25 patients for PD+OH. The patients underwent a skin biopsy from the cervical area, thigh, and leg to analyze somatic and autonomic skin innervation and p‐syn in skin nerves. Results Intraneural p‐syn positivity was found in 72% of patients with MSA‐P, mainly in distal skin sites. More important, p‐syn deposits in MSA‐P differed from PD+OH because they were mainly found in somatic fibers of subepidermal plexi, whereas scant autonomic fiber involvement was found in only 3 patients. All patients with PD+OH displayed widely distributed p‐syn deposits in the autonomic skin fibers of proximal and distal skin sites, whereas somatic fibers were affected only slightly in 4 patients with PD+OH. Skin innervation mirrored p‐syn deposits because somatic innervation was mainly reduced in MSA‐P. Sympathetic innervation was damaged in PD+OH but fairly preserved in MSA‐P. Conclusions The p‐syn in cutaneous nerves allows the differentiation of MSA‐P from PD+OH; MSA‐P mainly shows somatic fiber involvement with relatively preserved autonomic innervation; and by contrast, PD+OH displays prevalent abnormal p‐syn deposits and denervation in autonomic postganglionic nerves. © 2020 International Parkinson and Movement Disorder Society

ObjectiveTo provide a variant-specific estimate of incidence, penetrance, sex distribution, and association with dementia of the 4 most common Parkinson disease (PD)-associated GBA variants, we analyzed a large cohort of 4,923 Italian unrelated patients with primary degenerative parkinsonism (including 3,832 PD) enrolled in a single tertiary care center and 7,757 ethnically matched controls.MethodsThe p.E326K, p.T369M, p.N370S, and p.L444P variants were screened using an allele-specific multiplexed PCR approach. All statistical procedures were performed using R or Plink v1.07.ResultsAmong the 4 analyzed variants, the p.L444P confirmed to be the most strongly associated with disease risk for PD, PD dementia (PDD), and dementia with Lewy bodies (DLB) (odds ratio [OR] for PD 15.63, 95% confidence interval [CI] = 8.04–30.37, p = 4.97*10−16; OR for PDD 29.57, 95% CI = 14.07–62.13, p = 3.86*10−19; OR for DLB 102.7, 95% CI = 31.38–336.1, p = 1.91*10−14). However, an unexpectedly high risk for dementia was conferred by p.E326K (OR for PDD 4.80, 95% CI = 2.87–8.02, p = 2.12*10−9; OR for DLB 12.24, 95% CI = 4.95–30.24, p = 5.71*10−8), which, on the basis of the impact on glucocerebrosidase activity, would be expected to be mild. The 1.5–2:1 male sex bias described in sporadic PD was lost in p.T369M carriers. We also showed that PD penetrance for p.L444P could reach the 15% at age 75 years.ConclusionsWe report a large monocentric study on GBA-PD assessing mutation-specific data on the sex distribution, penetrance, incidence, and association with dementia of the 4 most frequent deleterious variants in GBA.

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Background: Although abnormalities in gut microbiota are hypothesized to influence the pathogenesis and clinical phenotype of Parkinson’s disease (PD), prospective studies on de novo patients are lacking. Objective: To preliminarily investigate whether gut microbiota in early untreated PD may predict motor and non-motor features progression over a 3-year period. Methods: 16S ribosomal RNA gene amplicons were sequenced on fecal samples of 39 de novo PD patients. Multiple confounders were taken into account, including dietary habits. Motor and non-motor symptoms were assessed using validated scales at baseline and followed-up yearly for 3 years. At last follow-up, a detailed neuropsychological assessment was additionally performed. A general linear model for repeated measurements— adjusted by dopaminergic therapy at follow-up— was used to investigate the relationship between bacterial taxa abundance at baseline (stratified by the median of distribution at baseline) and outcome variables. Results: Twenty-five patients were included (11 refused, 2 lost at follow-up, 1 died). Lower abundance of Roseburia (Firmicutes phylum) at baseline was associated with worse evolution of motor, non-motor and cognitive functions at 3-year follow-up. Similarly, lower abundance of Ruminococcaceae and Actinobacteria at baseline was associated with faster worsening of global cognitive functions. At follow-up, frontal lobe functions were the features most robustly associated with baseline microbial abnormalities. Conclusion: In the present exploratory study on de novo PD, we found an association between abnormal distribution of specific bacterial taxa and the progression of motor and non-motor features over a 3-year period. This proof-of-principle study supports the design of a larger observational study aiming to determine whether these differences survive multiple-comparison correction and define microbiota-specific subgroups suitable for therapeutic targeting.

Background To date, variants in the GBA gene represent the most frequent large‐effect genetic factor associated with Parkinson's disease (PD). However, the reason why individuals with the same GBA variant may or may not develop neurodegeneration and PD is still unclear. Objectives Therefore, we evaluated the contribution of rare variants in genes responsible for lysosomal storage disorders (LSDs) to GBA‐PD risk, comparing the burden of deleterious variants in LSD genes in PD patients versus asymptomatic subjects, all carriers of deleterious variants in GBA. Methods We used a custom next‐generation sequencing panel, including 50 LSD genes, to screen 305 patients and 207 controls (discovery cohort). Replication and meta‐analysis were performed in two replication cohorts of GBA‐variant carriers, of 250 patients and 287 controls, for whom exome or genome data were available. Results Statistical analysis in the discovery cohort revealed a significantly increased burden of deleterious variants in LSD genes in patients (P = 0.0029). Moreover, our analyses evidenced that the two strongest modifiers of GBA penetrance are a second variation in GBA (5.6% vs. 1.4%, P = 0.023) and variants in genes causing mucopolysaccharidoses (6.9% vs. 1%, P = 0.0020). These results were confirmed in the meta‐analysis, where we observed pooled odds ratios of 1.42 (95% confidence interval [CI] = 1.10–1.83, P = 0.0063), 4.36 (95% CI = 2.02–9.45, P = 0.00019), and 1.83 (95% CI = 1.04–3.22, P = 0.038) for variants in LSD genes, GBA, and mucopolysaccharidosis genes, respectively. Conclusion The identification of genetic lesions in lysosomal genes increasing PD risk may have important implications in terms of patient stratification for future therapeutic trials. © 2022 The Authors. Movement Disorders published by Wiley Periodicals LLC on behalf of International Parkinson Movement Disorder Society.