Diagnosis of multiple system atrophy

Multiple system atrophy related neurogenic bladder: mechanism and treatment

BACKGROUND

Multiple system atrophy (MSA) is a progressive neurodegenerative disease characterized by its aggressive nature. Its main clinical features include autonomic dysfunction, Parkinson's disease, and cerebellar ataxia.

METHODS

We conducted a comprehensive review of the existing literature, exploring studies and reports related to the mechanisms and treatment of multiple system atrophy related neurogenic bladder. Our aim is to provide a detailed and up-to-date overview of its underlying pathophysiology and current therapeutic strategies.

RESULTS AND CONCLUSION

Neurogenic bladder, a common manifestation of MSA, often goes untreated or mistreated, significantly affecting patients' quality of life. Early-stage bladder dysfunction is frequent in MSA patients and correlates with disease severity. The mechanisms of MSA related neurogenic bladder are related to the autonomic nervous system, somatic nerves, frontal cortex, brainstem, and sacral medulla center. Currently, treatment for MSA related neurogenic bladder is mainly symptomatic, and specific drugs are lacking. Further in-depth research is needed to develop more effective therapeutic options that improve patients' quality of life and reduce the risk of complications.

A strategic approach of the management of sleep-disordered breathing in multiple system atrophy

STUDY OBJECTIVES

Multiple system atrophy (MSA) is a rare neurodegenerative disorder characterized by autonomic dysfunction associated with a combination of cerebellar, parkinsonian, or pyramidal signs. Sleep-disordered breathing such as stridor, obstructive sleep apnea, and central sleep apnea is common in MSA and can impact survival. Several studies have evaluated treatment modalities. However, the optimal strategy often remains unclear in these patients. This review aims to provide an overview of the current evidence on treatment of sleep-disordered breathing in MSA.

METHODS

Systematic review of the current literature through combined keyword search in PubMed, Embase, the Cochrane Library, and cited references: "multiple system atrophy," "stridor," "sleep apnea syndrome," "sleep-disordered breathing," "Shy Drager syndrome."

RESULTS

Twenty-nine papers were included, with a total of 681 patients with MSA and sleep-disordered breathing. Treatment modalities are: continuous positive airway pressure, tracheostomy, tracheostomy-invasive ventilation, noninvasive positive pressure ventilation, adaptive servoventilation, vocal cord surgery, botulinum toxin injections, oral appliance therapy, cervical spinal cord stimulation, selective serotonin reuptake inhibitors.

CONCLUSIONS

Conflicting results on survival are found for continuous positive airway pressure therapy. Tracheostomy has a proven survival benefit. Most beneficial outcomes are seen with tracheostomy-invasive ventilation. Continuous positive airway pressure, other types of positive airway pressure therapy and tracheostomy can adequately control symptoms of obstructive sleep apnea. However, continuous positive airway pressure may exacerbate central sleep apnea. There was a lack of sufficient data regarding servoventilation or noninvasive positive pressure ventilation. Some patients exhibit a floppy epiglottis and require a different approach. In conclusion, due to the complex characteristics of sleep-disordered breathing in MSA, an individualized and multidisciplinary approach is mandatory.

CITATION

Laga A, Bauters F, Hertegonne K, Tomassen P, Santens P, Kastoer C. A strategic approach of the management of sleep-disordered breathing in multiple system atrophy. J Clin Sleep Med. 2025;21(4):703-711.

Differential diagnosis of multiple system atrophy with predominant parkinsonism and Parkinson's disease using neural networks (part II)

Neural networks (NNs) possess the capability to learn complex data relationships, recognize inherent patterns by emulating human brain functions, and generate predictions based on novel data. We conducted deep learning utilizing an NN to differentiate between Parkinson's disease (PD) and the parkinsonian variant (MSA-P) of multiple system atrophy (MSA). The distinction between PD and MSA-P in the early stages presents significant challenges. Considering the recently reported heterogeneity and random distribution of lesions in MSA, we performed an analysis employing an NN with voxel-based morphometry data from the entire brain as input variables. The NN's accuracy in distinguishing MSA-P from PD demonstrates sufficient practicality for clinical application.

Differences Between Patients With Multiple System Atrophy With Predominant Parkinsonism and Parkinson's Disease Based on fNIRS and Gait Analysis

OBJECTIVE

To investigate the differences in gait parameters and cortical activity during a single-task walking (STW) and cognitive dual-task walking (DTW) between multiple system atrophy with predominant parkinsonism (MSA-P) and Parkinson's disease (PD).

METHODS

24 MSA-P patients, 20 PD patients, and 22 healthy controls (HCs) were enrolled. Gait parameters were collected using a portable inertial measurement unit system, and the relative change of oxyhemoglobin (ΔHbO2) in the bilateral frontal and sensorimotor cortex was obtained by functional near-infrared spectroscopy during walking with and without cognitive tasks.

RESULTS

MSA-P patients had increased step length variability and higher ΔHbO2 in the right dorsolateral prefrontal cortex (DLPFC), relative to PD patients and HCs during the DTW condition. Meanwhile, MSA-P patients exhibited higher step length variability and ΔHbO2 in the right DLPFC during DTW compared to STW. Furthermore, mild negative correlations were found between the ΔHbO2 in the right DLPFC and step length, while there was a mild positive correlation between ΔHbO2 and step length variability during the DTW condition. Notably, receiver operating characteristic (ROC) curve analysis uncovered that the areas under the curve (AUCs) of the ΔHbO2 of the right DLPFC and step length variability during DTW were 0.798 (95% confidence interval [CI]: 0.651-0.945, sensitivity = 0.650, specificity = 0.958) and 0.721 (95% CI: 0.570-0.871, sensitivity = 0.625, specificity = 0.800), respectively.

CONCLUSION

MSA-P patients demonstrate more severe gait disturbance and increased DLPFC activity compared with PD patients and HCs. Gait parameters and cortical activity could be a potential features discerning MSA-P patients and PD patients.

Neurofilament Light Chain in Cerebrospinal Fluid and Blood in Multiple System Atrophy: A Systematic Review and Meta-Analysis

Background/Objectives: Multiple system atrophy (MSA) presents a challenging diagnosis due to its clinical overlap with other neurodegenerative disorders, especially other α-synucleinopathies. The main purpose of this systematic review and meta-analysis was to assess neurofilament light chain (NfL) differences in the CSF and blood of patients with MSA versus the healthy control group (HC), patients with Parkinson's disease (PD) and patients with Lewy body dementia (LBD). Secondarily, the diagnostic metrics of CSF and circulating NfL in MSA versus HC, PD, LBD, progressive supranuclear palsy (PSP) and corticobasal degeneration (CBD) were discussed. Methods: MEDLINE and EMBASE were thoroughly searched for relevant case-control studies. Standardized mean differences (SMDs) were calculated separately for CSF and blood NfL per comparison. Statistical heterogeneity was assessed based on the Q and I^2 statistics. Results: Twenty-five relevant studies were retrieved. Quantitative syntheses revealed elevated CSF and circulating NfL levels in individuals with MSA versus HC [SMD = 1.80 (95%CI = 1.66, 1.94) and SMD = 2.00 (95%CI = 1.36, 2.63), respectively] versus PD [SMD = 1.65 (95%CI = 1.26, 2.03) and SMD = 1.63 (95%CI = 0.84, 2.43), respectively] as well as versus LBD [SMD = 1.17, (95%CI = 0.71, 1.63) and SMD = 0.65 (95%CI = 0.30, 1.00), respectively]. Diagnostic accuracy was outstanding for CSF and blood NfL in MSA versus HC and PD, and it was moderate in MSA versus LBD. On the other hand, it was suboptimal in MSA vs. PSP and CBD. Conclusions: Both CSF and circulating NfL levels are elevated in MSA compared to HC, PD and LBD. To achieve optimal diagnostic properties, further work is required in the standardization of processes and the establishment of reference NfL intervals and/or thresholds.

Integrative Analysis of Metabolome and Proteome in the Cerebrospinal Fluid of Patients with Multiple System Atrophy

Multiple system atrophy (MSA) is a progressive neurodegenerative synucleinopathy. Differentiating MSA from other synucleinopathies, especially in the early stages, is challenging because of its overlapping symptoms with other forms of Parkinsonism. Thus, there is a pressing need to clarify the underlying biological mechanisms and identify specific biomarkers for MSA. The metabolic profile of cerebrospinal fluid (CSF) is known to be altered in MSA. To further investigate the biological mechanisms behind the metabolic changes, we created a network of altered CSF metabolites in patients with MSA and analysed these changes using bioinformatic software. Acknowledging the limitations of metabolomics, we incorporated proteomic data to improve the overall comprehensiveness of the study. Our in silico predictions showed elevated ROS, cytoplasmic inclusions, white matter demyelination, ataxia, and neurodegeneration, with ATP concentration, neurotransmitter release, and oligodendrocyte count predicted to be suppressed in MSA CSF samples. Machine learning and dimension reduction are important multi-omics approaches as they handle large amounts of data, identify patterns, and make predictions while reducing variance without information loss and generating easily visualised plots that help identify clusters, patterns, or outliers. Thus, integrated multiomics and machine learning approaches are essential for elucidating neurodegenerative mechanisms and identifying potential diagnostic biomarkers of MSA.

Current Landscape of Clinical Diagnosis in Multiple System Atrophy: A 15-Year Analysis From 2008 to 2022

BACKGROUND AND OBJECTIVES

Clinical diagnosis of multiple system atrophy (MSA) is challenging. In 2022, new diagnostic criteria for MSA were proposed. We hypothesized that the positive predictive value (PPV) of clinical diagnosis of MSA improved because of advanced diagnostic tools, including brain MRI. This study aimed to understand temporal changes in PPV of MSA.

METHODS

We conducted a retrospective analysis of patients clinically diagnosed with MSA whose brains were examined in the Mayo Clinic brain bank from 2008 to 2022. PPV was compared between 2 periods (2008-2017 and 2018-2022) and successively with a 4-year moving average. PPV for each clinical subtype (parkinsonism type [MSA-P] and cerebellar type [MSA-C]) was assessed.

RESULTS

This study included 321 patients (136 women, age at death 68 ± 9 years) with a clinical diagnosis of MSA. Among them, 225 were pathologically confirmed as MSA, resulting in an overall PPV of 70%. The remaining 30% had alternative pathologic diagnoses including Lewy body disease (18%), progressive supranuclear palsy (4%), cerebrovascular disease (1%), corticobasal degeneration (1%), and others (6%). PPV improved from 63% in 2008-2017 to 78% in 2018-2022 (odds ratio [OR] 2.0 [1.2-3.5], p = 0.005). Linear analysis also demonstrated increased PPV over time (r = 0.66 [0.14-0.89], p = 0.02). Brain MRI scans were more frequently performed in 2018-2022 compared with 2008-2017 (91% vs 80%; OR 2.4 [1.2-5.0], p = 0.012). PPV was higher in patients with brain MRI compared with those without (73% vs 52%; OR 2.5 [1.3-4.9], p = 0.0057). PPV for MSA-C was similar in both groups (87% in 2008-2017 and 93% in 2018-2022), while that for MSA-P improved from 59% in 2008-2017 to 72% in 2018-2022 (OR 1.8 [1.0-3.2], p = 0.04).

DISCUSSION

This study demonstrates an improvement in the PPV of MSA in recent years, potentially attributed to the increased use of brain MRI. Nevertheless, it also highlights that it remains difficult to make a correct diagnosis for some patients based on their clinical presentation. These findings provide a baseline for future clinicopathologic research on MSA.

A challenging case presentation of multiple system atrophy cerebellar type: A rare case report from Somalia

Multiple system atrophy is a rare and quickly progressing neurological condition characterized by autonomic failure, parkinsonism, or cerebellar ataxia. It is classified into two subtypes: MSA with predominant parkinsonism (MSA-P) and MSA with predominant cerebellar ataxia (MSA-C). We are presenting here a 54-year-old male with parkinsonism, ataxia, and dysarthria. He was diagnosed with parkinson disease and was given a maximum dose of levodopa but has not responded. After a close neurological evaluation with magnetic resonance imaging of the brain, which shows atrophy of the cerebellum and a brainstem with a hot cross bun sign of the pons, suggestive of multiple system atrophy, he was diagnosed with multiple system atrophy cerebellar type, which is the first time to have this diagnosis in Somalia, which is a low-resource country.

Enhanced quantitation of pathological α-synuclein in patient biospecimens by RT-QuIC seed amplification assays

Disease associated pathological aggregates of alpha-synuclein (αSynD) exhibit prion-like spreading in synucleinopathies such as Parkinson's disease (PD) and dementia with Lewy bodies (DLB). Seed amplification assays (SAAs) such as real-time quaking-induced conversion (RT-QuIC) have shown high diagnostic sensitivity and specificity for detecting proteopathic αSynD seeds in a variety of biospecimens from PD and DLB patients. However, the extent to which relative proteopathic seed concentrations are useful as indices of a patient's disease stage or prognosis remains unresolved. One feature of current SAAs that complicates attempts to correlate SAA results with patients' clinical and other laboratory findings is their quantitative imprecision, which has typically been limited to discriminating large differences (e.g. 5-10 fold) in seed concentration. We used end-point dilution (ED) RT-QuIC assays to determine αSynD seed concentrations in patient biospecimens and tested the influence of various assay variables such as serial dilution factor, replicate number and data processing methods. The use of 2-fold versus 10-fold dilution factors and 12 versus 4 replicate reactions per dilution reduced ED-RT-QuIC assay error by as much as 70%. This enhanced assay format discriminated as little as 2-fold differences in αSynD seed concentration besides detecting ~2-16-fold seed reductions caused by inactivation treatments. In some scenarios, analysis of the data using Poisson and midSIN algorithms provided more consistent and statistically significant discrimination of different seed concentrations. We applied our improved assay strategies to multiple diagnostically relevant PD and DLB antemortem patient biospecimens, including cerebrospinal fluid, skin, and brushings of the olfactory mucosa. Using ED αSyn RT-QuIC as a model SAA, we show how to markedly improve the inter-assay reproducibility and quantitative accuracy. Enhanced quantitative SAA accuracy should facilitate assessments of pathological seeding activities as biomarkers in proteinopathy diagnostics and prognostics, as well as in patient cohort selection and assessments of pharmacodynamics and target engagement in drug trials.

Exploring potential circRNA biomarkers for cancers based on double-line heterogeneous graph representation learning

BACKGROUND

Compared with the time-consuming and labor-intensive for biological validation in vitro or in vivo, the computational models can provide high-quality and purposeful candidates in an instant. Existing computational models face limitations in effectively utilizing sparse local structural information for accurate predictions in circRNA-disease associations. This study addresses this challenge with a proposed method, CDA-DGRL (Prediction of CircRNA-Disease Association based on Double-line Graph Representation Learning), which employs a deep learning framework leveraging graph networks and a dual-line representation model integrating graph node features.

METHOD

CDA-DGRL comprises several key steps: initially, the integration of diverse biological information to compute integrated similarities among circRNAs and diseases, leading to the construction of a heterogeneous network specific to circRNA-disease associations. Subsequently, circRNA and disease node features are derived using sparse autoencoders. Thirdly, a graph convolutional neural network is employed to capture the local graph network structure by inputting the circRNA-disease heterogeneous network alongside node features. Fourthly, the utilization of node2vec facilitates depth-first sampling of the circRNA-disease heterogeneous network to grasp the global graph network structure, addressing issues associated with sparse raw data. Finally, the fusion of local and global graph network structures is inputted into an extra trees classifier to identify potential circRNA-disease associations.

RESULTS

The results, obtained through a rigorous five-fold cross-validation on the circR2Disease dataset, demonstrate the superiority of CDA-DGRL with an AUC value of 0.9866 and an AUPR value of 0.9897 compared to existing state-of-the-art models. Notably, the hyper-random tree classifier employed in this model outperforms other machine learning classifiers.

CONCLUSION

Thus, CDA-DGRL stands as a promising methodology for reliably identifying circRNA-disease associations, offering potential avenues to alleviate the necessity for extensive traditional biological experiments. The source code and data for this study are available at https://github.com/zywait/CDA-DGRL .

The potential of phosphorylated α-synuclein as a biomarker for the diagnosis and monitoring of multiple system atrophy

INTRODUCTION

Multiple system atrophy (MSA) is a rapidly progressive neurodegenerative disorder characterized by the presence of glial cytoplasmic inclusions (GCIs) containing aggregated α-synuclein (α-Syn). Accurate diagnosis and monitoring of MSA present significant challenges, which can lead to potential misdiagnosis and inappropriate treatment. Biomarkers play a crucial role in improving the accuracy of MSA diagnosis, and phosphorylated α-synuclein (p-syn) has emerged as a promising biomarker for aiding in diagnosis and disease monitoring.

METHODS

A literature search was conducted on PubMed, Scopus, and Google Scholar using specific keywords and MeSH terms without imposing a time limit. Inclusion criteria comprised various study designs including experimental studies, case-control studies, and cohort studies published only in English, while conference abstracts and unpublished sources were excluded.

RESULTS

Increased levels of p-syn have been observed in various samples from MSA patients, such as red blood cells, cerebrospinal fluid, oral mucosal cells, skin, and colon biopsies, highlighting their diagnostic potential. The α-Syn RT-QuIC assay has shown sensitivity in diagnosing MSA and tracking its progression. Meta-analyses and multicenter investigations have confirmed the diagnostic value of p-syn in cerebrospinal fluid, demonstrating high specificity and sensitivity in distinguishing MSA from other neurodegenerative diseases. Moreover, combining p-syn with other biomarkers has further improved the diagnostic accuracy of MSA.

CONCLUSION

The p-syn stands out as a promising biomarker for MSA. It is found in oligodendrocytes and shows a correlation with disease severity and progression. However, further research and validation studies are necessary to establish p-syn as a reliable biomarker for MSA. If proven, p-syn could significantly contribute to early diagnosis, disease monitoring, and assessing treatment response.

Corneal confocal microscopy may help to distinguish Multiple System Atrophy from Parkinson's disease

Multiple system atrophy (MSA) and Parkinson's disease (PD) have clinical overlapping symptoms, which makes differential diagnosis difficult. Our research aimed to distinguish MSA from PD using corneal confocal microscopy (CCM), a noninvasive and objective test. The study included 63 PD patients, 30 MSA patients, and 31 healthy controls (HC). When recruiting PD and MSA, questionnaires were conducted on motor and non-motor functions, such as autonomic and cognitive functions. Participants underwent CCM to quantify the corneal nerve fibers. Corneal nerve fiber density (CNFD) and corneal nerve fiber length (CNFL) values in MSA are lower than PD (MSA vs. PD: CNFD, 20.68 ± 6.70 vs. 24.64 ± 6.43 no./mm2, p < 0.05; CNFL, 12.01 ± 3.25 vs. 14.17 ± 3.52 no./mm2, p < 0.05). In MSA + PD (combined), there is a negative correlation between CNFD and the Orthostatic Grading Scale (OGS) (r = -0.284, p = 0.007). Similarly, CNFD in the only MSA group was negatively correlated with the Unified Multiple System Atrophy Rating Scale I and II (r = -0.391, p = 0.044; r = -0.382, p = 0.049). CNFD and CNFL were inversely associated with MSA (CNFD: β = -0.071; OR, 0.932; 95% CI, 0.872 ~ 0.996; p = 0.038; CNFL: β = -0.135; OR, 0.874; 95% CI, 0.768-0.994; p = 0.040). Furthermore, we found the area under the receiver operating characteristic curve (ROC) of CNFL was the largest, 72.01%. The CCM could be an objective and sensitive biomarker to distinguish MSA from PD. It visually reflects a more severe degeneration in MSA compared to PD.

Smooth Pursuit and Reflexive Saccade in Discriminating Multiple-System Atrophy With Predominant Parkinsonism From Parkinson's Disease

BACKGROUND AND PURPOSE

Performing the differential diagnosis of Parkinson's disease (PD) and multiple-system atrophy of parkinsonian type (MSA-P) is challenging. The oculomotor performances of patients with PD and MSA-P were investigated to explore their potential role as a biomarker for this differentiation.

METHODS

Reflexive saccades and smooth pursuit were examined in 56 patients with PD and 34 with MSA-P in the off-medication state.

RESULTS

Patients with PD and MSA-P had similar oculomotor abnormalities of prolonged and hypometric reflexive saccades. The incidence rates of decreased reflexive saccadic velocity and saccadic smooth pursuit were significantly higher in MSA-P than in PD (p<0.05 for both). Multiple logistic regression analysis indicated that slowed reflexive saccades (odds ratio [OR]=8.14, 95% confidence interval [CI]=1.45-45.5) and saccadic smooth pursuit (OR=5.27, 95% CI=1.24-22.43) were significantly related to MSA-P.

CONCLUSIONS

The distinctive oculomotor abnormalities of saccadic smooth pursuit and slowed reflexive saccades in MSA-P may serve as useful biomarkers for discriminating MSA-P from PD.

3D-CAM: a novel context-aware feature extraction framework for neurological disease classification

In clinical practice and research, the classification and diagnosis of neurological diseases such as Parkinson's Disease (PD) and Multiple System Atrophy (MSA) have long posed a significant challenge. Currently, deep learning, as a cutting-edge technology, has demonstrated immense potential in computer-aided diagnosis of PD and MSA. However, existing methods rely heavily on manually selecting key feature slices and segmenting regions of interest. This not only increases subjectivity and complexity in the classification process but also limits the model's comprehensive analysis of global data features. To address this issue, this paper proposes a novel 3D context-aware modeling framework, named 3D-CAM. It considers 3D contextual information based on an attention mechanism. The framework, utilizing a 2D slicing-based strategy, innovatively integrates a Contextual Information Module and a Location Filtering Module. The Contextual Information Module can be applied to feature maps at any layer, effectively combining features from adjacent slices and utilizing an attention mechanism to focus on crucial features. The Location Filtering Module, on the other hand, is employed in the post-processing phase to filter significant slice segments of classification features. By employing this method in the fully automated classification of PD and MSA, an accuracy of 85.71%, a recall rate of 86.36%, and a precision of 90.48% were achieved. These results not only demonstrates potential for clinical applications, but also provides a novel perspective for medical image diagnosis, thereby offering robust support for accurate diagnosis of neurological diseases.

Infections in the Etiology of Parkinson's Disease and Synucleinopathies: A Renewed Perspective, Mechanistic Insights, and Therapeutic Implications

Increasing evidence suggests a potential role for infectious pathogens in the etiology of synucleinopathies, a group of age-related neurodegenerative disorders including Parkinson's disease (PD), multiple system atrophy and dementia with Lewy bodies. In this review, we discuss the link between infections and synucleinopathies from a historical perspective, present emerging evidence that supports this link, and address current research challenges with a focus on neuroinflammation. Infectious pathogens can elicit a neuroinflammatory response and modulate genetic risk in PD and related synucleinopathies. The mechanisms of how infections might be linked with synucleinopathies as well as the overlap between the immune cellular pathways affected by virulent pathogens and disease-related genetic risk factors are discussed. Here, an important role for α-synuclein in the immune response against infections is emerging. Critical methodological and knowledge gaps are addressed, and we provide new future perspectives on how to address these gaps. Understanding how infections and neuroinflammation influence synucleinopathies will be essential for the development of early diagnostic tools and novel therapies.

Coenzyme Q10: A Biomarker in the Differential Diagnosis of Parkinsonian Syndromes

Multiple system atrophy (MSA) is generally a sporadic neurodegenerative disease which ranks among atypical Parkinson's syndromes. The main clinical manifestation is a combination of autonomic dysfunction and parkinsonism and/or cerebellar disability. The disease may resemble other Parkinsonian syndromes, such as Parkinson's disease (PD) or progressive supranuclear palsy (PSP), from which MSA could be hardly distinguishable during the first years of progression. Due to the lack of a reliable and easily accessible biomarker, the diagnosis is still based primarily on the clinical picture. Recently, reduced levels of coenzyme Q10 (CoQ10) were described in MSA in various tissues, including the central nervous system. The aim of our study was to verify whether the level of CoQ10 in plasma and lymphocytes could serve as an easily available diagnostic biomarker of MSA. The study reported significantly lower levels of CoQ10 in the lymphocytes of patients with MSA compared to patients with PD and controls. The reduction in CoQ10 levels in lymphocytes correlated with the increasing degree of clinical involvement of patients with MSA. CoQ10 levels in lymphocytes seem to be a potential biomarker of disease progression.

α-Synuclein seed amplification assay as a diagnostic tool for parkinsonian disorders

INTRODUCTION

Synucleinopathies such as Parkinson's disease (PD) and multiple system atrophy (MSA) can be challenging to diagnose due to the symptom overlap with, for example, atypical parkinsonisms like progressive supranuclear palsy (PSP) and corticobasal degeneration (CBD). Seed amplification assays (SAA), developed for the detection of α-synuclein (αSyn) aggregates in CSF, have been successful when used as a biomarker evaluation for synucleinopathies. In this study, we investigated the potential of this assay to not only detect αSyn seeds in CSF, but also discriminate between movement disorders.

METHODS

The αSyn-SAA was tested in a Scandinavian cohort composed of 129 CSF samples from patients with PD (n = 55), MSA (n = 27), CBD (n = 7), and PSP (n = 16), as well as healthy controls (HC, n = 24).

RESULTS

The αSyn seed amplification assay (αSyn-SAA) was able to correctly identify all PD samples as positive (sensitivity of 100%) while also discriminating the PD group from HC (70.8% specificity, p < 0.0001) and tauopathies [CBD (71% specificity) and PSP (75% specificity), p < 0.0001)]. The αSyn-SAA was also able to identify almost all MSA samples as positive for αSyn aggregation (sensitivity of 92.6%). In general, this assay is able to discriminate between the synucleinopathies and tauopathies analyzed herein (p < 0.0001) despite the overlapping symptoms in these diseases.

CONCLUSION

These findings suggest the αSyn-SAA is a useful diagnostic tool for differentiating between different parkinsonian disorders, although further optimization may be needed.

Effects of Rehabilitative Intervention for Augmenting Cough Function in Patients with Multiple System Atrophy

Objectives

One of the causes of death in patients with multiple system atrophy (MSA) is aspiration pneumonia caused by cough dysfunction. This study aimed to identify an effective approach to improve coughing and to explore the establishment of criteria for the use of gastrostomy based on cough and respiratory dysfunctions.

Methods

Eighteen probable MSA patients participated in the study. They were categorized into air stacking and non-air stacking groups. First, we investigated how the inspiration volume changes by applying maximum insufflation capacity (MIC). Second, peak cough flow (PCF) was measured by different cough augmentation methods: 1) spontaneous coughing (SpC); 2) SpC with MIC (SpC + MIC); 3) SpC with manually assisted cough (MAC) (SpC + MAC); and 4) SpC with MIC and MAC (SpC + MIC + MAC). Among these four conditions, PCF values were compared to determine the most effective approach for cough augmentation. Receiver operating characteristic analysis was performed on percent forced vital capacity (%FVC) to determine an index for discriminating PCF below160 L/min, which indicates a high risk of suffocation, involving SpC and SpC + MIC.

Results

Inspiration volume increased significantly with MIC in both groups (P < 0.05), and PCF increased significantly with MIC in the air stacking group (P < 0.01). PCF could not be maintained at 160 L/min when %FVC fell below 59%, even when MIC was applied.

Conclusions

PCF increases with MIC in patients with MSA. It may be meaningful to consider the timing of gastrostomy introduction based on the severity of cough and respiratory dysfunction.

Diagnosing multiple system atrophy: current clinical guidance and emerging molecular biomarkers

Multiple system atrophy (MSA) is a rare and progressive neurodegenerative disorder characterized by motor and autonomic dysfunction. Accurate and early diagnosis of MSA is challenging due to its clinical similarity with other neurodegenerative disorders, such as Parkinson's disease and atypical parkinsonian disorders. Currently, MSA diagnosis is based on clinical criteria drawing from the patient's symptoms, lack of response to levodopa therapy, neuroimaging studies, and exclusion of other diseases. However, these methods have limitations in sensitivity and specificity. Recent advances in molecular biomarker research, such as α-synuclein protein amplification assays (RT-QuIC) and other biomarkers in cerebrospinal fluid and blood, have shown promise in improving the diagnosis of MSA. Additionally, these biomarkers could also serve as targets for developing disease-modifying therapies and monitoring treatment response. In this review, we provide an overview of the clinical syndrome of MSA and discuss the current diagnostic criteria, limitations of current diagnostic methods, and emerging molecular biomarkers that offer hope for improving the accuracy and early detection of MSA.

Prediction of type 1 diabetes with machine learning algorithms based on FTIR spectral data in peripheral blood mononuclear cells

The incidence of autoimmunity is increasing, to ensure timely and comprehensive treatment, there must be a diagnostic method or markers that would be available to the general public. Fourier-transform infrared spectroscopy (FTIR) is a relatively inexpensive and accurate method for determining metabolic fingerprint. The metabolism, molecular composition and function of blood cells vary according to individual physiological and pathological conditions. Thus, by obtaining autoimmune disease-specific metabolic fingerprint markers in peripheral blood mononuclear cells (PBMC) and subsequently using machine learning algorithms, it might be possible to create a tool that will allow the diagnosis of autoimmune diseases. In this preliminary study, it was found that the peak shift at 1545 cm-1 could be considered specific for autoimmune disease type 1 diabetes (T1D), while the shifts at 1070 and 1417 cm-1 could be more attributed to the autoimmune condition per se. The prediction of T1D, despite the small number of participants in the study, showed an inverse AUC = 0.33 ± 0.096, n = 15, indicating a stable trend in the prediction of T1D based on FTIR metabolic fingerprint data in the PBMC.

Sleep Disorders Associated with Neurodegenerative Diseases

Sleep disturbances are common in various neurological pathologies, including amyotrophic lateral sclerosis (ALS), multiple system atrophy (MSA), hereditary ataxias, Huntington's disease (HD), progressive supranuclear palsy (PSP), and dementia with Lewy bodies (DLB). This article reviews the prevalence and characteristics of sleep disorders in these conditions, highlighting their impact on patients' quality of life and disease progression. Sleep-related breathing disorders, insomnia, restless legs syndrome (RLS), periodic limb movement syndrome (PLMS), and rapid eye movement sleep behavior disorder (RBD) are among the common sleep disturbances reported. Both pharmacological and non-pharmacological interventions play crucial roles in managing sleep disturbances and enhancing overall patient care.

Primary lateral sclerosis plus parkinsonism: a case report

BACKGROUND

The standard of diagnosing primary lateral sclerosis, the Pringle criteria, requires three years of purely upper motor neuron symptom presentation before confirming diagnosis. This classic standard has been questioned on occasion due to its restrictive range of both time period and symptomatic exhibition.

CASE PRESENTATION

This case report will review a 57-year-old Caucasian female who presented with pyramidal and extrapyramidal features suggestive of the exceedingly rare disease primary lateral sclerosis plus parkinsonism. We will describe the mixture of upper motor neuron signs and striking parkinsonian symptoms experienced by the patient, as well as the full diagnostic workup leading to her preliminary diagnosis. The details of this case will then be utilized to explore the diagnostic criteria of primary lateral sclerosis, as well as to work through the differential of conditions resembling Parkinson's disease.

CONCLUSIONS

The current criteria to diagnose primary lateral sclerosis may be excluding patients with the disease and is an ongoing area of investigation. A thorough differential including other neurodegenerative conditions is necessary to consider and requires long-term follow-up.

α-Synuclein-carrying astrocytic extracellular vesicles in Parkinson pathogenesis and diagnosis

BACKGROUND

The accumulation of α-synuclein (α-syn), an essential step in PD development and progression, is observed not only in neurons but also in glia, including astrocytes. The mechanisms regulating astrocytic α-syn level and aggregation remain unclear. More recently, it has been demonstrated that a part of α-syn spreading occurs through extracellular vesicles (EVs), although it is unknown whether this process is involved in astrocytes of PD. It is known, however, that EVs derived from the central nervous system exist in the blood and are extensively explored as biomarkers for PD and other neurodegenerative disorders.

METHODS

Primary astrocytes were transfected with A53T α-syn plasmid or exposed to α-syn aggregates. The level of astrocyte-derived EVs (AEVs) was assessed by nanoparticle tracking analysis and immunofluorescence. The lysosomal function was evaluated by Cathepsin assays, immunofluorescence for levels of Lamp1 and Lamp2, and LysoTracker Red staining. The Apogee assays were optimized to measure the GLT-1+ AEVs in clinical cohorts of 106 PD, 47 multiple system atrophy (MSA), and 103 healthy control (HC) to test the potential of plasma AEVs as a biomarker to differentiate PD from other forms of parkinsonism.

RESULTS

The number of AEVs significantly increased in primary astrocytes with α-syn deposition. The mechanism of increased AEVs was partially attributed to lysosomal dysfunction. The number of α-syn-carrying AEVs was significantly higher in patients with PD than in HC and MSA. The integrative model combining AEVs with total and aggregated α-syn exhibited efficient diagnostic power in differentiating PD from HC with an AUC of 0.915, and from MSA with an AUC of 0.877.

CONCLUSIONS

Pathological α-syn deposition could increase the astrocytic secretion of EVs, possibly through α-syn-induced lysosomal dysfunction. The α-syn-containing AEVs in the peripheral blood may be an effective biomarker for clinical diagnosis or differential diagnosis of PD.

Urinary tract infections trigger synucleinopathy via the innate immune response

Symptoms in the urogenital organs are common in multiple system atrophy (MSA), also in the years preceding the MSA diagnosis. It is unknown how MSA is triggered and these observations in prodromal MSA led us to hypothesize that synucleinopathy could be triggered by infection of the genitourinary tract causing ɑ-synuclein (ɑSyn) to aggregate in peripheral nerves innervating these organs. As a first proof that peripheral infections could act as a trigger in MSA, this study focused on lower urinary tract infections (UTIs), given the relevance and high frequency of UTIs in prodromal MSA, although other types of infection might also be important triggers of MSA. We performed an epidemiological nested-case control study in the Danish population showing that UTIs are associated with future diagnosis of MSA several years after infection and that it impacts risk in both men and women. Bacterial infection of the urinary bladder triggers synucleinopathy in mice and we propose a novel role of ɑSyn in the innate immune system response to bacteria. Urinary tract infection with uropathogenic E. coli results in the de novo aggregation of ɑSyn during neutrophil infiltration. During the infection, ɑSyn is released extracellularly from neutrophils as part of their extracellular traps. Injection of MSA aggregates into the urinary bladder leads to motor deficits and propagation of ɑSyn pathology to the central nervous system in mice overexpressing oligodendroglial ɑSyn. Repeated UTIs lead to progressive development of synucleinopathy with oligodendroglial involvement in vivo. Our results link bacterial infections with synucleinopathy and show that a host response to environmental triggers can result in ɑSyn pathology that bears semblance to MSA.

Dealing with the heterogeneous presentations of freezing of gait: how reliable are the freezing index and heart rate for freezing detection?

BACKGROUND

Freezing of gait (FOG) is an unpredictable gait arrest that hampers the lives of 40% of people with Parkinson's disease. Because the symptom is heterogeneous in phenotypical presentation (it can present as trembling/shuffling, or akinesia) and manifests during various circumstances (it can be triggered by e.g. turning, passing doors, and dual-tasking), it is particularly difficult to detect with motion sensors. The freezing index (FI) is one of the most frequently used accelerometer-based methods for FOG detection. However, it might not adequately distinguish FOG from voluntary stops, certainly for the akinetic type of FOG. Interestingly, a previous study showed that heart rate signals could distinguish FOG from stopping and turning movements. This study aimed to investigate for which phenotypes and evoking circumstances the FI and heart rate might provide reliable signals for FOG detection.

METHODS

Sixteen people with Parkinson's disease and daily freezing completed a gait trajectory designed to provoke FOG including turns, narrow passages, starting, and stopping, with and without a cognitive or motor dual-task. We compared the FI and heart rate of 378 FOG events to baseline levels, and to stopping and normal gait events (i.e. turns and narrow passages without FOG) using mixed-effects models. We specifically evaluated the influence of different types of FOG (trembling vs akinesia) and triggering situations (turning vs narrow passages; no dual-task vs cognitive dual-task vs motor dual-task) on both outcome measures.

RESULTS

The FI increased significantly during trembling and akinetic FOG, but increased similarly during stopping and was therefore not significantly different from FOG. In contrast, heart rate change during FOG was for all types and during all triggering situations statistically different from stopping, but not from normal gait events.

CONCLUSION

When the power in the locomotion band (0.5-3 Hz) decreases, the FI increases and is unable to specify whether a stop is voluntary or involuntary (i.e. trembling or akinetic FOG). In contrast, the heart rate can reveal whether there is the intention to move, thus distinguishing FOG from stopping. We suggest that the combination of a motion sensor and a heart rate monitor may be promising for future FOG detection.

Functional connectome automatically differentiates multiple system atrophy (parkinsonian type) from idiopathic Parkinson's disease at early stages

Differentiating the parkinsonian variant of multiple system atrophy (MSA-P) from idiopathic Parkinson's disease (IPD) is challenging, especially in the early stages. This study aimed to investigate differences and similarities in the brain functional connectomes of IPD and MSA-P patients and use machine learning methods to explore the diagnostic utility of these features. Resting-state fMRI data were acquired from 88 healthy controls, 76 MSA-P patients, and 53 IPD patients using a 3.0 T scanner. The whole-brain functional connectome was constructed by thresholding the Pearson correlation matrices of 116 regions, and topological properties were evaluated through graph theory approaches. Connectome measurements were used as features in machine learning models (random forest [RF]/logistic regression [LR]/support vector machine) to distinguish IPD and MSA-P patients. Regarding graph metrics, early IPD and MSA-P patients shared network topological properties. Both patient groups showed functional connectivity disruptions within the cerebellum-basal ganglia-cortical network, but these disconnections were mainly in the cortico-thalamo-cerebellar circuits in MSA-P patients and the basal ganglia-thalamo-cortical circuits in IPD patients. Among the connectome parameters, t tests combined with the RF method identified 15 features, from which the LR classifier achieved the best diagnostic performance on the validation set (accuracy = 92.31%, sensitivity = 90.91%, specificity = 93.33%, area under the receiver operating characteristic curve = 0.89). MSA-P and IPD patients show similar whole-brain network topological alterations. MSA-P primarily affects cerebellar nodes, and IPD primarily affects basal ganglia nodes; both conditions disrupt the cerebellum-basal ganglia-cortical network. Moreover, functional connectome parameters showed outstanding value in the differential diagnosis of early MSA-P and IPD.

microRNA and circRNA in Parkinson's Disease and atypical parkinsonian syndromes

Multiple System Atrophy (MSA) and Progressive Supranuclear Palsy (PSP) are atypical parkinsonian syndromes (APS) with various clinical phenotypes and considerable clinical overlap with idiopathic Parkinson's disease (iPD). This disease heterogeneity makes ante-mortem diagnosis extremely challenging with up to 24% of patients misdiagnosed. Because diagnosis is predominantly clinical, there is great interest in identifying biomarkers for early diagnosis and differentiation of the different types of parkinsonism. Compared to protein biomarkers, microRNAs (miRNAs) and circularRNAs (circRNAs) are stable tissue-specific molecules that can be accurately measured by reverse transcription-quantitative polymerase chain reaction (RT-qPCR). This chapter critically reviews miRNAs and circRNAs as diagnostic biomarkers and therapeutics to differentiate atypical parkinsonian disorders and their role in disease pathogenesis.

Genetics of Multiple System Atrophy and Progressive Supranuclear Palsy: A Systemized Review of the Literature

Multiple system atrophy (MSA) and progressive supranuclear palsy (PSP) are uncommon multifactorial atypical Parkinsonian syndromes, expressed by various clinical features. MSA and PSP are commonly considered sporadic neurodegenerative disorders; however, our understanding is improving of their genetic framework. The purpose of this study was to critically review the genetics of MSA and PSP and their involvement in the pathogenesis. A systemized literature search of PubMed and MEDLINE was performed up to 1 January 2023. Narrative synthesis of the results was undertaken. In total, 43 studies were analyzed. Although familial MSA cases have been reported, the hereditary nature could not be demonstrated. COQ2 mutations were involved in familial and sporadic MSA, without being reproduced in various clinical populations. In terms of the genetics of the cohort, synuclein alpha (SNCA) polymorphisms were correlated with an elevated likelihood of manifesting MSA in Caucasians, but a causal effect relationship could not be demonstrated. Fifteen MAPT mutations were linked with PSP. Leucine-rich repeat kinase 2 (LRRK2) is an infrequent monogenic mutation of PSP. Dynactin subunit 1 (DCTN1) mutations may imitate the PSP phenotype. GWAS have noted many risk loci of PSP (STX6 and EIF2AK3), suggesting pathogenetic mechanisms related to PSP. Despite the limited evidence, it seems that genetics influence the susceptibility to MSA and PSP. MAPT mutations result in the MSA and PSP pathologies. Further studies are crucial to elucidate the pathogeneses of MSA and PSP, which will support efforts to develop novel drug options.

Value of electrophysiological indicators in differential diagnosis of parkinson's disease and multiple system atrophy

BACKGROUND

We evaluated the value of electrophysiological indicators by external anal sphincter electromyography (EAS-EMG), sympathetic skin response (SSR), R-R interval variation (RRIV), and Bulbocavernosus Reflex (BCR) in differential diagnosis of multiple system atrophy (MSA) and Parkinson's disease (PD).

METHODS

A total of 41 patients with MSA and 32 patients with PD were enrolled. The electrophysiological changes of autonomic dysfunction were assessed with BCR, EAS-EMG, SSR, and RRIV, and the abnormal rate of each indicator was calculated. The diagnostic value of each indicator was analyzed with ROC curve.

RESULTS

The incidence rate of autonomic dysfunction in MSA group was significantly higher than that in PD group (p < 0.05). The abnormal rates of BCR and EAS-EMG indicators in MSA group were higher than those in PD group (p < 0.05). The abnormal rates of SSR and RRIV indicators in MSA group and PD group were high; however, there was no significant difference between MSA and PD groups (p > 0.05). The sensitivity of BCR combined with EAS-EMG indicators in differential diagnosis of MSA and PD were 92.3% in males and 86.7% in females, respectively, and the specificity was 72.7% in males and 90% in females, respectively.

CONCLUSIONS

Combined analysis of BCR and EAS-EMG has high sensitivity and specificity for differential diagnosis of MSA and PD.

The characteristic of nonmotor symptoms with different phenotypes and onsets in multiple system atrophy patients

OBJECTIVES

The characteristic of nonmotor symptoms in patients with multiple system atrophy (MSA) has varied among previous studies. The objective was to investigatethe nonmotor characteristics in MSA patients with different phenotypes, sex and different onset patterns.

METHODS

We performed a retrospective review of 1492 MSA patients. All cases were evaluatedby neurologists and assessed with motormanifestations, nonmotor symptoms, auxiliary examinationand brain MRI scans.

RESULTS

Multiple system atrophy-cerebellar ataxia (MSA-C) was the predominant phenotype in 998 patients. Average age of onset (56.8 ± 9.2 years) was earlier, the disease duration (2.4 ± 2.2 year) was shorter and brain MRI abnormalities (49.2 %) were more frequently in MSA-C (P < 0.001). Multiple system atrophy-parkinsonism (MSA-P) patients were more likely to have nonmotor symptoms. After adjusted significant parameters, urinary dysfunction (OR 1.441, 95 %CI = 1.067-1.946, P = 0.017), constipation (OR 1.482, 95 %CI = 1.113-1.973, P = 0.007), cognitive impairment (OR 1.509, 95 %CI = 1.074-2.121, P = 0.018) and drooling (OR 2.095, 95 %CI = 1.248-3.518, P = 0.005) were associated with the MSA-P phenotype. Males were more likely to have orthostatic hypotension, urinary dysfunction, sexual dysfunction, drooling and females in constipation and probable RBD. In different onset patterns, constipation (59.2 %) and probable RBD (28.4 %) were more frequently in autonomiconset pattern.

CONCLUSIONS

MSA-C is the predominant phenotype in Chinese patients, while many nonmotor symptoms are more common in MSA-P phenotype. Patients with different sex and onset patterns have different nonmotor characteristics. The different clinical features identified could help the physician counseling of MSA patients more easily and more accurately.

[Multiple system atrophy]

The article presents a progressive neurodegenerative disease - multisystem atrophy, characterized by a combination of autonomic failure and various motor disorders, including parkinsonism and/or cerebellar ataxia; etiopathogenetic factors and variants of the clinical picture are described. We describe own clinical observation of a 59-old patient with cerebellar and bulbar syndromes, parkinsonism, pyramidal insufficiency, cognitive deficits, and autonomic dysfunction. The differential diagnosis included a whole range of neurodegenerative and hereditary diseases: Parkinson's disease, vascular parkinsonism, progressive supranuclear palsy, spinocerebellar ataxia, FXTAS, mitochondrial encephalopathies. The moderate severity of parkinsonism and the significant predominance of cerebellar symptoms and autonomic dysfunction make this clinical case difficult to diagnose. However, based on the life and disease history, clinical picture and research methods, a diagnosis of multiple system atrophy, cerebellar type (cerebellar, autonomic, bulbar syndrome, parkinsonism, pyramidal insufficiency and moderate cognitive impairment) was established. Differential search in such patients is a difficult task and includes a whole range of neurodegenerative and hereditary diseases due to the similarity of individual clinical and neuroimaging features and, unfortunately, the limited availability of molecular genetic diagnostic methods. However, earlier diagnosis is necessary to focus in time on the development of a personalized approach to the management of each such patient, taking into account the rate of symptoms development and steady progression, in order to ensure the longest possible survival time with an acceptable level of quality of life.

Exploring the mechanism of astragalus membranaceus in the treatment of multiple system atrophy based on network pharmacology and molecular docking

Multiple system atrophy (MSA) is a fatal neurodegenerative disease, it causes functional degradation of multiple organs and systems throughout the body. Astragalus membranaceus (AM), a well-known traditional Chinese medicine, has been used to improve muscle wasting-related disorders for a long history. In this study, we used network pharmacology and molecular docking to predict the mechanism underlying AM for the treatment of MSA. We screened the active compounds of AM and its related targets, as well as the target proteins of MSA. We made a Venn diagram to obtain the intersecting targets and then constructed a protein-protein interaction network to find the core targets and build an active ingredient-target network map. After subjecting the intersecting targets to gene ontology and Kyoto encyclopedia of genes and genomes analysis, the binding ability of core compounds and core target proteins were validated by molecular docking. A total of 20 eligible compounds and 274 intersecting targets were obtained. The core components of treatment are quercetin, kaempferol, and isorhamnetin, and the core targets are TP53, RELA, and TNF. The main biological processes are related to cellular responses and regulation. Molecular functions are mainly associated with apoptosis, inflammation, and tumorigenesis. Molecular docking results show good and standard binding abilities. This study illustrates that AM treats MSA through multiple targets and pathways, and provides a reference for subsequent research.

Host oligodendrogliopathy and α-synuclein strains dictate disease severity in multiple system atrophy

Multiple system atrophy is a progressive neurodegenerative disease with prominent autonomic and motor features. During early stages, different subtypes of the disease are distinguished by their predominant parkinsonian or cerebellar symptoms, reflecting its heterogeneous nature. The pathognomonic feature of multiple system atrophy is the presence of α-synuclein (αSyn) protein deposits in oligodendroglial cells. αSyn can assemble in specific cellular or disease environments and form αSyn strains with unique structural features, but the ability of αSyn strains to propagate in oligodendrocytes remains elusive. Recently, it was shown that αSyn strains with related conformations exist in the brains of patients. Here, we investigated whether different αSyn strains can influence multiple system atrophy progression in a strain-dependent manner. To this aim, we injected two recombinant αSyn strains (fibrils and ribbons) in multiple system atrophy transgenic mice and found that they determined disease severity in multiple system atrophy via host-restricted and cell-specific pathology in vivo. αSyn strains significantly impact disease progression in a strain-dependent way via oligodendroglial, neurotoxic and immune-related mechanisms. Neurodegeneration and brain atrophy were accompanied by unique microglial and astroglial responses and the recruitment of central and peripheral immune cells. The differential activation of microglial cells correlated with the structural features of αSyn strains both in vitro and in vivo. Spectral analysis showed that ribbons propagated oligodendroglial inclusions that were structurally distinct from those of fibrils, with resemblance to oligodendroglial inclusions, in the brains of patients with multiple system atrophy. This study, therefore, shows that the multiple system atrophy phenotype is governed by both the nature of the αSyn strain and the host environment and that by injecting αSyn strains into an animal model of the disease, a more comprehensive phenotype can be established.

Parkinson disease primer, part 1: diagnosis

OBJECTIVE

To provide family physicians an updated approach to the diagnosis of Parkinson disease (PD).

SOURCES OF INFORMATION

Published guidelines on the diagnosis and management of PD were reviewed. Database searches were conducted to retrieve relevant research articles published between 2011 and 2021. Evidence levels ranged from I to III.

MAIN MESSAGE

Diagnosis of PD is predominantly clinical. Family physicians should evaluate patients for specific features of parkinsonism, then determine whether symptoms are attributable to PD. Levodopa trials can be used to help confirm the diagnosis and alleviate motor symptoms of PD. "Red flag" features and absence of response to levodopa may point to other causes of parkinsonism and prompt more urgent referral.

CONCLUSION

Access to neurologists and specialized clinics varies, and Canadian family physicians can be important players in facilitating early and accurate diagnosis of PD. Applying an organized approach to diagnosis and considering motor and nonmotor symptoms can greatly benefit patients with PD. Part 2 in this series will review management of PD.

Comparison of the second consensus statement with the movement disorder society criteria for multiple system atrophy: A single-center analysis

INTRODUCTION

This study aimed at comparing the differences between the second consensus statement and Movement Disorder Society (MDS) criteria for Multiple System Atrophy (MSA) in a single Chinese cohort.

METHODS

We retrospectively reviewed 73 patients with MSA over the past five years. They were categorized as patients with probable and possible MSA according to the second consensus statement in addition to clinically established and clinically probable MSA according to the MDS criteria. The core clinical, supportive clinical, and imaging features were analyzed and compared between the two MSA subtypes.

RESULTS

A total of 40 patients with MSA-P and 33 patients with MSA-C were included in this study. Approximately 78.7% of the category of probable patients in the second consensus statement can be categorized as clinically established MSA in the MDS criteria and five patients with non-supporting features in the second consensus statement criteria can be diagnosed as clinically probable MSA in the MDS criteria. "Rapid progression" and "moderate to severe postural instability" within three years of motor onset dominated among the supportive features. Approximately 78.9% of patients possessed at least one imaging marker with predominant signal decrease of putamen on iron-sensitive sequences (38.0% of patients). Twenty-two patients could not be diagnosed as clinically established MSA mainly due to the lack of supportive or imaging features.

CONCLUSIONS

A high degree of agreement was noticed between the two criteria sets. The supportive and imaging features played important role in the diagnosis of MSA and affected the diagnostic level in the current criteria.

Abécédaire de la maladie de Parkinson, partie 1 : le diagnostic

Objectif

Présenter aux médecins de famille une approche actualisée du diagnostic de la maladie de Parkinson (MP).

Sources de l’information

Les lignes directrices sur le diagnostic et la prise en charge de la MP ont été passées en revue. Des recensions dans les bases de données ont été effectuées pour en extraire les articles de recherche publiés entre 2011 et 2021. Le niveau des données probantes varie entre I et III.

Message principal

Le diagnostic de la MP est principalement d’ordre clinique. Les médecins de famille devraient évaluer les patients en fonction des caractéristiques particulières du parkinsonisme et déterminer ensuite si les symptômes sont attribuables à la MP. Des essais à la lévodopa peuvent servir à confirmer le diagnostic et à atténuer les symptômes moteurs de la MP. Des « signaux d’alerte » et l’absence de réponse à la lévodopa pourraient indiquer d’autres causes du parkinsonisme et inciter à faire une demande de consultation plus urgente.

Conclusion

L’accès à des neurologues et à des cliniques spécialisées est variable, et les médecins de famille canadiens peuvent être des acteurs importants pour faciliter un diagnostic précoce et exact de la MP. La mise en application d’une approche structurée du diagnostic, et la prise en compte des symptômes moteurs et non moteurs peuvent être grandement bénéfiques pour les patients atteints de la MP. La partie 2 de cette série portera sur la prise en charge de la MP.

Synucleinopathies

The α-synucleinopathies include pure autonomic failure, multiple system atrophy, dementia with Lewy bodies, and Parkinson disease. The past two decades have witnessed significant advances in the diagnostic strategies and symptomatic treatment of motor and nonmotor symptoms of the synucleinopathies. This chapter provides an in-depth review of the pathophysiology, pathology, genetic, epidemiology, and clinical and laboratory autonomic features that distinguish the different synucleinopathies with an emphasis on autonomic failure as a common feature. The treatment of the different synucleinopathies is discussed along with the proposal for multidisciplinary, individualized care models that optimally address the various symptoms. There is an urgent need for clinical scientific studies addressing patients at risk of developing synucleinopathies and the investigation of disease mechanisms, biomarkers, potential disease-modifying therapies, and further advancement of symptomatic treatments for motor and nonmotor symptoms.

Aggregated Alpha-Synuclein Inclusions within the Nucleus Predict Impending Neuronal Cell Death in a Mouse Model of Parkinsonism

Alpha-synuclein (aSyn) is a 14 kD protein encoded by the SNCA gene that is expressed in vertebrates and normally localizes to presynaptic terminals and the nucleus. aSyn forms pathological intracellular aggregates that typify a group of important neurodegenerative diseases called synucleinopathies. Previous work in human tissue and model systems indicates that some of these aggregates can be intranuclear, but the significance of aSyn aggregation within the nucleus is not clear. We used a mouse model that develops aggregated aSyn nuclear inclusions. Using aSyn preformed fibril injections in GFP-tagged aSyn transgenic mice, we were able to induce the formation of nuclear aSyn inclusions and study their properties in fixed tissue and in vivo using multiphoton microscopy. In addition, we analyzed human synucleinopathy patient tissue to better understand this pathology. Our data demonstrate that nuclear aSyn inclusions may form through the transmission of aSyn between neurons, and these intranuclear aggregates bear the hallmarks of cytoplasmic Lewy pathology. Neuronal nuclear aSyn inclusions can form rod-like structures that do not contain actin, excluding them from being previously described nuclear actin rods. Longitudinal, in vivo multiphoton imaging indicates that certain morphologies of neuronal nuclear aSyn inclusions predict cell death within 14 days. Human multiple system atrophy cases contain neurons and glia with similar nuclear inclusions, but we were unable to detect such inclusions in Lewy body dementia cases. This study suggests that the dysregulation of a nuclear aSyn function associated with nuclear inclusion formation could play a role in the forms of neurodegeneration associated with synucleinopathy.

Clinical outcomes and cognitive impairments between progressive supranuclear palsy and multiple system atrophy

BACKGROUND

Both progressive supranuclear palsy (PSP) and multiple system atrophy (MSA) belong to atypical parkinsonian syndromes. It is important to differentiate these diseases accurately. We compared clinical outcomes and cognitive impairments between PSP and MSA.

METHODS

Eighty-five MSA parkinsonism type (MSA-P) patients and 76 PSP patients participated in this research. The Montreal Cognitive Assessment (MoCA) and the mini-mental state examination (MMSE) evaluated cognitive function.

RESULTS

MSA-P patients had a significantly higher incidence of dyskinesia, fall, urinary symptoms, and constipation, whereas patients with PSP had a higher incidence of tremor and salivation. MSA-P patients had higher MMSE and MoCA scores than PSP patients. The MMSE score showed a diagnostic cut-off score of 24.5 in PSP versus MSA-P. The MoCA score showed a diagnostic cut-off score of 20.5 in PSP versus MSA-P.

CONCLUSION

In conclusion, patients with PSP had differences in the clinical outcomes and cognitive impairments compared with MSA-P patients. PSP patients had more severe cognitive deficits. The score of MMSE and MoCA could be used in distinguishing MSA-P from PSP.

Glutathione Depletion and MicroRNA Dysregulation in Multiple System Atrophy: A Review

Multiple system atrophy (MSA) is a rare neurodegenerative disease characterized by parkinsonism, cerebellar impairment, and autonomic failure. Although the causes of MSA onset and progression remain uncertain, its pathogenesis may involve oxidative stress via the generation of excess reactive oxygen species and/or destruction of the antioxidant system. One of the most powerful antioxidants is glutathione, which plays essential roles as an antioxidant enzyme cofactor, cysteine-storage molecule, major redox buffer, and neuromodulator, in addition to being a key antioxidant in the central nervous system. Glutathione levels are known to be reduced in neurodegenerative diseases. In addition, genes regulating redox states have been shown to be post-transcriptionally modified by microRNA (miRNA), one of the most important types of non-coding RNA. miRNAs have been reported to be dysregulated in several diseases, including MSA. In this review, we focused on the relation between glutathione deficiency, miRNA dysregulation and oxidative stress and their close relation with MSA pathology.

Multiple system atrophy: α-Synuclein strains at the neuron-oligodendrocyte crossroad

The aberrant accumulation of α-Synuclein within oligodendrocytes is an enigmatic, pathological feature specific to Multiple system atrophy (MSA). Since the characterization of the disease in 1969, decades of research have focused on unravelling the pathogenic processes that lead to the formation of oligodendroglial cytoplasmic inclusions. The discovery of aggregated α-Synuclein (α-Syn) being the primary constituent of glial cytoplasmic inclusions has spurred several lines of research investigating the relationship between the pathogenic accumulation of the protein and oligodendrocytes. Recent developments have identified the ability of α-Syn to form conformationally distinct “strains” with varying behavioral characteristics and toxicities. Such “strains” are potentially disease-specific, providing insight into the enigmatic nature of MSA. This review discusses the evidence for MSA-specific α-Syn strains, highlighting the current methods for detecting and characterizing MSA patient-derived α-Syn. Given the differing behaviors of α-Syn strains, we explore the seeding and spreading capabilities of MSA-specific strains, postulating their influence on the aggressive nature of the disease. These ideas culminate into one key question: What causes MSA–specific strain formation? To answer this, we discuss the interplay between oligodendrocytes, neurons and α-Syn, exploring the ability of each cell type to contribute to the aggregate formation while postulating the effect of additional variables such as protein interactions, host characteristics and environmental factors. Thus, we propose the idea that MSA strain formation results from the intricate interrelation between neurons and oligodendrocytes, with deficits in each cell type required to initiate α-Syn aggregation and MSA pathogenesis.

Graphical Abstract

Case report: Combined therapy of bilateral subthalamic nucleus deep brain stimulation and spinal cord stimulation significantly improves motor function in a patient with multiple system atrophy with predominant parkinsonism

Multiple system atrophy with predominant parkinsonism (MSA-P) is a highly incapacitating disease with a short life expectancy and symptomatic therapy is still limited. In this report, we presented the case of a 65-year-old woman with a 3-year history of severe rigidity, bradykinesia, and gait dysfunction alongside severe freezing of gait diagnosed with MSA-P. She underwent combined therapy of bilateral subthalamic nucleus deep brain stimulation (DBS) and low-thoracic spinal cord stimulation (SCS). The double-blind evaluation of the Movement Disorder Society Sponsored Revision of the Unified Parkinson's Disease Rating Scale part III and 7-m Timed Up and Go at follow-ups showed her cardinal parkinsonian symptoms benefit significantly from DBS stimulation, while the improvement of SCS was mainly embodied in lower-limb symptoms. The combined stimulation achieved a better improvement of motor function than either DBS or SCS stimulation alone. Most notably, the improvement of lower-limb symptoms was significantly enhanced by the combined stimulation.

Differential diagnosis of patients with atypical Parkinsonian syndrome using 18F-FDG and 18F-FP CIT PET: A report of five cases

We describe 5 cases of patients who presented atypical parkinsonian syndrome (APS), including gait disturbance, postural instability, decreasing facial expression, dyskinesia, and subjective cognitive impairment. The patients underwent 18F-FP-CIT PET and 18F-FDG PET consecutively for differential diagnosis of APS. Through PET imaging examination, it was possible to offer a suggestive diagnosis and determine individual strategic management for patients with APS.

Clinical and pathological characteristics of later onset multiple system atrophy

BACKGROUND

In the current consensus criteria, onset after age 75 is considered as non-supporting for diagnosis of multiples system atrophy (MSA); however, some MSA patients present after age 75. Clinical and pathological characteristics of such later onset MSA (LO-MSA) compared to usual onset MSA (UO-MSA) remain poorly understood.

METHODS

The clinical cohort included patients from Kobe University Hospital and Amagasaki General Medical Center Hospital, while the autopsy cohort was from the brain bank at Mayo Clinic Florida. We identified 83 patients in the clinical cohort and 193 patients in the autopsy cohort. We divided MSA into two groups according to age at onset: UO-MSA (≤ 75) and LO-MSA (> 75). We compared clinical features and outcomes between the two groups in the clinical cohort and compared the findings to the autopsy cohort.

RESULTS

LO-MSA accounted for 8% in the clinical cohort and 5% in the autopsy cohort. The median time from onset to death or to life-saving tracheostomy was significantly shorter in LO-MSA than in UO-MSA in both cohorts (4.8 vs 7.9 years in the clinical cohort and 3.9 vs 7.5 years in the autopsy cohort; P = 0.043 and P < 0.0001, respectively). The median time from diagnosis to death was less than 3 years in LO-MSA in the clinical cohort.

CONCLUSIONS

Some MSA patients have late age of onset and short survival, limiting time for clinical decision making. MSA should be considered in the differential diagnosis of elderly patients with autonomic symptoms and extrapyramidal and/or cerebellar syndromes.

Adverse Events of Physiotherapy Interventions in Parkinsonian Patients

Background

Physiotherapists have an ethical, professional, and regulatory responsibility for safety in all aspects of patient care. Notwithstanding, the adverse events issue has been inadequately addressed in the rehabilitation research field.

Objectives

To determine the frequency and characterize the adverse events that occur during or in between physiotherapy sessions for parkinsonian syndromes.

Methods

An exploratory clinical study was conducted. Physiotherapists were asked to actively report the adverse events that occurred during or between sessions for parkinsonian syndromes.

Results

A total of 100 patients were enrolled in the study, which resulted in 1845 sessions. The most common adverse events reported were falls, pain/discomfort, and hypotension, with a total of 128 adverse events reported.

Conclusions

During the physiotherapy sessions, adverse events do occur. Future research should clarify the relationship between AE occurrence and the type of intervention as well as causality and risk-minimization strategies.

Alpha-Synuclein Strain Variability in Body-First and Brain-First Synucleinopathies

Pathogenic alpha-synuclein (asyn) aggregates are a defining feature of neurodegenerative synucleinopathies, which include Parkinson's disease, Lewy body dementia, pure autonomic failure and multiple system atrophy. Early accurate differentiation between these synucleinopathies is challenging due to the highly heterogeneous clinical profile at early prodromal disease stages. Therefore, diagnosis is often made in late disease stages when a patient presents with a broad range of motor and non-motor symptoms easing the differentiation. Increasing data suggest the clinical heterogeneity seen in patients is explained by the presence of distinct asyn strains, which exhibit variable morphologies and pathological functions. Recently, asyn seed amplification assays (PMCA and RT-QuIC) and conformation-specific ligand assays have made promising progress in differentiating between synucleinopathies in prodromal and advanced disease stages. Importantly, the cellular environment is known to impact strain morphology. And, asyn aggregate pathology can propagate trans-synaptically along the brain-body axis, affecting multiple organs and propagating through multiple cell types. Here, we present our hypothesis that the changing cellular environments, an asyn seed may encounter during its brain-to-body or body-to-brain propagation, may influence the structure and thereby the function of the aggregate strains developing within the different cells. Additionally, we aim to review strain characteristics of the different synucleinopathies in clinical and preclinical studies. Future preclinical animal models of synucleinopathies should investigate if asyn strain morphology is altered during brain-to-body and body-to-brain spreading using these seeding amplification and conformation-specific assays. Such findings would greatly deepen our understanding of synucleinopathies and the potential link between strain and phenotypic variability, which may enable specific diagnosis of different synucleinopathies in the prodromal phase, creating a large therapeutic window with potential future applications in clinical trials and personalized therapeutics.