Accurate Detection of α-Synuclein Seeds in Cerebrospinal Fluid from Isolated Rapid Eye Movement Sleep Behavior Disorder and Patients with Parkinson's Disease in the DeNovo Parkinson (DeNoPa) Cohort.

BACKGROUND: Misfolded α-synuclein (αSyn) aggregates (αSyn-seeds) in cerebrospinal fluid (CSF) are biomarkers for synucleinopathies such as Parkinson's disease (PD). αSyn-seeds have been detected in prodromal cases with isolated rapid eye movement sleep behavior disorder (iRBD). OBJECTIVES: The objective of this study was to determine the accuracy of the αSyn-seed amplification assay (αS-SAA) in a comprehensively characterized cohort with a high proportion of PD and iRBD CSF samples collected at baseline. METHODS: We used a high-throughput αS-SAA to analyze 233 blinded CSF samples from 206 participants of the DeNovo Parkinson Cohort (DeNoPa) (113 de novo PD, 64 healthy controls, 29 iRBD confirmed by video polysomnography). Results were compared with the final diagnosis, which was determined after up to 10 years of longitudinal clinical evaluations, including dopamine-transporter-single-photon emission computed tomography (DAT-SPECT) at baseline, CSF proteins, Movement Disorder Society-Unified Parkinson's Disease Rating Scale, and various cognitive and nonmotor scales. RESULTS: αS-SAA detected αSyn-seeds in baseline PD-CSF with 98% accuracy. αSyn-seeds were detected in 93% of the iRBD cases. αS-SAA results showed higher agreement with the final than the initial diagnosis, as 14 patients were rediagnosed as non-αSyn aggregation disorder. For synucleinopathies, αS-SAA showed higher concordance with the final diagnosis than DAT-SPECT. Statistically significant correlations were found between assay parameters and disease progression. CONCLUSIONS: Our results confirm αS-SAA accuracy at the first clinical evaluation when a definite diagnosis is most consequential. αS-SAA conditions reported here are highly sensitive, enabling the detection of αSyn-seeds in CSF from iRBD just months after the first symptoms, suggesting that αSyn-seeds are present in the very early prodromal phase of synucleinopathies. Therefore, αSyn-seeds are clear risk markers for synuclein-related disorders, but not for time of phenoconversion. © 2023 The Authors. Movement Disorders published by Wiley Periodicals LLC on behalf of International Parkinson and Movement Disorder Society.

Blood Markers of Inflammation, Neurodegeneration, and Cardiovascular Risk in Early Parkinson's Disease.

BACKGROUND: Recent studies point toward a significant impact of cardiovascular processes and inflammation on Parkinson's disease (PD) progression. OBJECTIVE: The aim of this study was to assess established markers of neuronal function, inflammation, and cardiovascular risk by high-throughput sandwich immune multiplex panels in deeply phenotyped PD. METHODS: Proximity Extension Assay technology on 273 markers was applied in plasma of 109 drug-naive at baseline (BL) patients with PD (BL, 2-, 4-, and 6-year follow-up [FU]) and 96 healthy control patients (HCs; 2- and 4-year FU) from the de novo Parkinson's cohort. BL plasma from 74 individuals (37 patients with PD, 37 healthy control patients) on the same platform from the Parkinson Progression Marker Initiative was used for independent validation. Correlation analysis of the identified markers and 6 years of clinical FU, including motor and cognitive progression, was evaluated. RESULTS: At BL, 35 plasma markers were differentially expressed in PD, showing downregulation of atherosclerotic risk markers, eg, E-selectin and ß2 -integrin. In contrast, we found a reduction of markers of the plasminogen activation system, eg, urokinase plasminogen activator. Neurospecific markers indicated increased levels of peripheral proteins of neurodegeneration and inflammation, such as fibroblast growth factor 21 and peptidase inhibitor 3. Several markers, including interleukin-6 and cystatin B, correlated with cognitive decline and progression of motor symptoms during FU. These findings were independently validated in the Parkinson Progression Marker Initiative. CONCLUSIONS: We identified and validated possible PD plasma biomarker candidates for state, fate, and disease progression, elucidating new molecular processes with reduced endothelial/atherosclerotic processes, increased thromboembolic risk, and neuroinflammation. Further investigations and validation in independent and larger longitudinal cohorts are needed. © 2022 The Authors. Movement Disorders published by Wiley Periodicals LLC on behalf of International Parkinson and Movement Disorder Society.

Dynamic interplay of cognitive functioning and depressive symptoms in patients with Parkinson's disease.

OBJECTIVE: We examine the trajectories of and the dynamic interplay between cognitive functioning and depressive symptoms in patients with Parkinson's disease (PD) in comparison to healthy controls (HC) from an intraindividual perspective. METHOD: The DeNoPa study is a single-center, observational, longitudinal study with biennial follow-ups over 8 years. The present analyses are based on 123 PD (79 male) and 107 HC (64 male) with a mean age of 64.1 years (SD = 8.3). PD and HC completed a battery of neuropsychological tests and scales assessing depressive symptoms. We used a random-intercept cross-lagged panel model (RI-CLPM) to study their trajectories and the dynamic interplay. RESULTS: Cognitive abilities of PD were on average d = -0.67 worse at baseline and d = -1.22 at 8-years follow-up in comparison to HC. Depressive symptoms in PD showed large variability and followed a U-shaped trajectory. From an intraindividual perspective, greater impairments in cognitive abilities were subsequently associated with increased depressive symptoms (b = -0.60, p = .03), whereas the effect in the opposite direction was not significant. CONCLUSIONS: We found indication that a decline on a global composite scale of cognition can be seen as a precursor of depressive symptoms in patients with PD. To counter cognitive losses and the subsequent mood deterioration, patient education and early cognitive (and behavioral) enrichment seem promising candidates for treatment. (PsycInfo Database Record (c) 2022 APA, all rights reserved).

Longitudinal Change and Progression Indicators Using the Movement Disorder Society-Unified Parkinson's Disease Rating Scale in Two Independent Cohorts with Early Parkinson's Disease.

BACKGROUND: The MDS-Unified Parkinson's disease (PD) Rating Scale (MDS-UPDRS) is the most used scale in clinical trials. Little is known about the predictive potential of its single items. OBJECTIVE: To systematically dissect MDS-UPDRS to predict PD progression. METHODS: 574 de novo PD patients and 305 healthy controls were investigated at baseline (BL) in the single-center DeNoPa (6-year follow-up) and multi-center PPMI (8-year follow-up) cohorts. We calculated cumulative link mixed models of single MDS-UPDRS items for odds ratios (OR) for class change within the scale. Models were adjusted for age, sex, time, and levodopa equivalent daily dose. Annual change and progression of the square roots of the MDS-UDPRS subscores and Total Score were estimated by linear mixed modeling. RESULTS: Baseline demographics revealed more common tremor dominant subtype in DeNoPa and postural instability and gait disorders-subtype and multiethnicity in PPMI. Subscore progression estimates were higher in PPMI but showed similar slopes and progression in both cohorts. Increased ORs for faster progression were found from BL subscores I and II (activities of daily living; ADL) most marked for subscore III (rigidity of neck/lower extremities, agility of the legs, gait, hands, and global spontaneity of movements). Tremor items showed low ORs/negative values. CONCLUSION: Higher scores at baseline for ADL, freezing, and rigidity were predictors of faster deterioration in both cohorts. Precision and predictability of the MDS-UPDRS were higher in the single-center setting, indicating the need for rigorous training and/or video documentation to improve its use in multi-center cohorts, for example, clinical trials.

Cerebrospinal α-Synuclein Oligomers Reflect Disease Motor Severity in DeNoPa Longitudinal Cohort.

BACKGROUND: Tangible efforts have been made to identify biomarkers for Parkinson's disease (PD) diagnosis and progression, with α-synuclein (α-syn) related biomarkers being at the forefront. OBJECTIVES: The objectives of this study were to explore whether cerebrospinal fluid (CSF) levels of total, oligomeric, phosphorylated Ser 129 α-synuclein, along with total tau, phosphorylated tau 181, and ß-amyloid 1-42 are (1) informative as diagnostic markers for PD, (2) changed over disease progression, and/or (3) correlated with motor and cognitive indices of disease progression in the longitudinal De Novo Parkinson cohort. METHODS: A total of 94 de novo PD patients and 52 controls at baseline and 24- and 48-month follow-up were included, all of whom had longitudinal lumbar punctures and clinical assessments for both cognitive and motor functions. Using our in-house enzymelinked immunosorbent assays and commercially available assays, different forms of α-synuclein, tau, and ß-amyloid 1-42 were quantified in CSF samples from the De Novo Parkinson cohort. RESULTS: Baseline CSF total α-synuclein was significantly lower in early de novo PD compared with healthy controls, whereas the ratio of oligomeric/total and phosphorylated/total were significantly higher in the PD group. CSF oligomeric-α-synuclein longitudinally increased over the 4-year follow-up in the PD group and correlated with PD motor progression. Patients at advanced stages of PD presented with elevated CSF oligomeric-α-synuclein levels compared with healthy controls. CONCLUSIONS: Longitudinal transitions of CSF biomarkers over disease progression might not occur linearly and are susceptible to disease state. CSF oligomeric-α-synuclein levels appear to increase with diseases severity and reflect PD motor rather than cognitive trajectories. © 2021 The Authors. Movement Disorders published by Wiley Periodicals LLC on behalf of International Parkinson and Movement Disorder Society.

Baseline predictors for progression 4 years after Parkinson's disease diagnosis in the De Novo Parkinson Cohort (DeNoPa).

OBJECTIVES: The objectives of this study were to investigate (1) the annual rate of progression of motor and cognitive symptoms and (2) baseline predictors of different modalities for this progression in early Parkinson's disease (PD) when compared with healthy controls. METHODS: A total of 135 de novo PD and 109 healthy controls (of the De Novo Parkinson cohort) were investigated at baseline and after 24 and 48 months. To delineate motor progression and cognitive decline, the Movement Disorder Society-Unified Parkinson's Disease Rating Scale part III (MDS-UPDRS III) and the Mini-Mental Status Examination (MMSE) were selected. Baseline variables used to predict progression included sociodemographic factors, comorbidities, motor/nonmotor symptoms, polysomnography, MRI, and laboratory biomarkers in serum and CSF. RESULTS: Symptoms worsened over 4 years in PD with an annual change of 1.8 points on the MDS-UPDRS III and 0.2 points on the MMSE. Baseline predictors of worse progression of motor symptoms in PD included male sex, orthostatic blood pressure drop, diagnosis of coronary artery disease, arterial hypertension, elevated serum uric acid, and CSF neurofilament light chain. Predictors of cognitive decline in PD included previous heavy alcohol abuse, current diagnoses of diabetes mellitus, arterial hypertension, elevated periodic limb movement index during sleep, decreased hippocampal volume by MRI, higher baseline levels of uric acid, C-reactive protein, high density lipoprotein (HDL) cholesterol, and glucose levels. CONCLUSION: Cardiovascular risk factors, deregulated blood glucose, uric acid metabolism, and inflammation were identified as risk markers for faster disease progression. Our panel of risk parameters needs validation during our continuing follow-up and also in independent patient cohorts. © 2018 International Parkinson and Movement Disorder Society.

The nasal and gut microbiome in Parkinson's disease and idiopathic rapid eye movement sleep behavior disorder.

BACKGROUND: Increasing evidence connects the gut microbiota and the onset and/or phenotype of Parkinson's disease (PD). Differences in the abundances of specific bacterial taxa have been reported in PD patients. It is, however, unknown whether these differences can be observed in individuals at high risk, for example, with idiopathic rapid eye movement sleep behavior disorder, a prodromal condition of α-synuclein aggregation disorders including PD. OBJECTIVES: To compare microbiota in carefully preserved nasal wash and stool samples of subjects with idiopathic rapid eye movement sleep behavior disorder, manifest PD, and healthy individuals. METHODS: Microbiota of flash-frozen stool and nasal wash samples from 76 PD patients, 21 idiopathic rapid eye movement sleep behavior disorder patients, and 78 healthy controls were assessed by 16S and 18S ribosomal RNA amplicon sequencing. Seventy variables, related to demographics, clinical parameters including nonmotor symptoms, and sample processing, were analyzed in relation to microbiome variability and controlled differential analyses were performed. RESULTS: Differentially abundant gut microbes, such as Akkermansia, were observed in PD, but no strong differences in nasal microbiota. Eighty percent of the differential gut microbes in PD versus healthy controls showed similar trends in idiopathic rapid eye movement sleep behavior disorder, for example, Anaerotruncus and several Bacteroides spp., and correlated with nonmotor symptoms. Metagenomic sequencing of select samples enabled the reconstruction of genomes of so far uncharacterized differentially abundant organisms. CONCLUSION: Our study reveals differential abundances of gut microbial taxa in PD and its prodrome idiopathic rapid eye movement sleep behavior disorder in comparison to the healthy controls, and highlights the potential of metagenomics to identify and characterize microbial taxa, which are enriched or depleted in PD and/or idiopathic rapid eye movement sleep behavior disorder. © 2017 The Authors. Movement Disorders published by Wiley Periodicals, Inc. on behalf of International Parkinson and Movement Disorder Society.

Monitoring of 30 marker candidates in early Parkinson disease as progression markers.

OBJECTIVE: This was a longitudinal single-center cohort study to comprehensively explore multimodal progression markers for Parkinson disease (PD) in patients with recently diagnosed PD (n = 123) and age-matched, neurologically healthy controls (HC; n = 106). METHODS: Thirty tests at baseline and after 24 months covered nonmotor symptoms (NMS), cognitive function, and REM sleep behavior disorder (RBD) by polysomnography (PSG), voxel-based morphometry (VBM) of the brain by MRI, and CSF markers. Linear mixed-effect models were used to estimate differences of rates of change and to provide standardized effect sizes (d) with 95% confidence intervals (CI). RESULTS: A composite panel of 10 informative markers was identified. Significant relative worsening (PD vs HC) was seen with the following markers: the Unified Parkinson's Disease Rating Scale I (d 0.39; CI 0.09-0.70), the Autonomic Scale for Outcomes in Parkinson's Disease (d 0.25; CI 0.06-0.46), the Epworth Sleepiness Scale (d 0.47; CI 0.24-0.71), the RBD Screening Questionnaire (d 0.44; CI 0.25-0.64), and RBD by PSG (d 0.37; CI 0.19-0.55) as well as VBM units of cortical gray matter (d -0.2; CI -0.3 to -0.09) and hippocampus (d -0.15; CI -0.27 to -0.03). Markers with a relative improvement included the Nonmotor Symptom (Severity) Scale (d -0.19; CI -0.36 to -0.02) and 2 depression scales (Beck Depression Inventory d -0.18; CI -0.36 to 0; Montgomery-Åsberg Depression Rating Scale d -0.26; CI -0.47 to -0.04). Unexpectedly, cognitive measures and select laboratory markers were not significantly changed in PD vs HC participants. CONCLUSIONS: Current CSF biomarkers and cognitive scales do not represent useful progression markers. However, sleep and imaging measures, and to some extent NMS, assessed using adequate scales, may be more informative markers to quantify progression.

Nonmotor and diagnostic findings in subjects with de novo Parkinson disease of the DeNoPa cohort.

OBJECTIVE: To determine nonmotor signs (NMS) and evaluate the utility of several diagnostic tools in patients with de novo Parkinson disease (PD). METHODS: This is a large single-center study of the DeNoPa cohort, including frequency-matched healthy controls. This study covers motor signs, NMS, and a combination of diagnostic tests including olfactory testing, transcranial sonography of substantia nigra (TCS), and polysomnography (PSG). We report the frequency and characteristics of NMS and the outcomes of nonmotor tests at the time of diagnosis. RESULTS: Cross-sectional analyses of baseline investigations identified significant differences in the NMS Questionnaire (NMSQuest) and the Scopa-AUT Gastrointestinal score in 159 drug-naïve PD patients vs 110 controls. In addition, patients with PD showed reduced olfactory function, hyperechogenicity on TCS, and higher frequency of REM sleep behavior disorder (RBD). In exploring predictive markers, we found that the combination of several investigations, i.e., the NMSQuest, Scopa-AUT Gastrointestinal score, and Smell Identification Test reached an area under the receiver operating characteristic curve (AUC) of 0.913 (95% confidence interval [CI] 0.878-0.948). With the addition of serum cholesterol and mean heart rate values, the AUC value reached 0.919 (95% CI 886-0.953); when TCS and PSG were added, the AUC increased to 0.963 (95% CI 0.943-0.982). CONCLUSIONS: We show feasibility and utility of standardized data acquisition in a large, single-center cohort of patients with de novo PD and matched healthy controls. The baseline results from our prospective investigations reached a value of >0.9 sensitivity and specificity for biological markers when we added routine laboratory investigations and quantified nonmotor features including sleep.