Multiple system atrophy: at the crossroads of cellular, molecular and genetic mechanisms.

Multiple system atrophy (MSA) is a rare oligodendroglial α-synucleinopathy characterized by neurodegeneration in striatonigral and olivopontocerebellar regions and autonomic brain centres. It causes complex cumulative motor and non-motor disability with fast progression and effective therapy is currently lacking. The difficulties in the diagnosis and treatment of MSA are largely related to the incomplete understanding of the pathogenesis of the disease. The MSA pathogenic landscape is complex, and converging findings from genetic and neuropathological studies as well as studies in experimental models of MSA have indicated the involvement of genetic and epigenetic changes; α-synuclein misfolding, aggregation and spreading; and α-synuclein strain specificity. These studies also indicate the involvement of myelin and iron dyshomeostasis, neuroinflammation, mitochondrial dysfunction and other cell-specific aspects that are relevant to the fast progression of MSA. In this Review, we discuss these findings and emphasize the implications of the complexity of the multifactorial pathogenic cascade for future translational research and its impact on biomarker discovery and treatment target definitions.

Phenoconversion in pure autonomic failure: a multicentre prospective longitudinal cohort study.

We aimed to describe the clinical features of patients with pure autonomic failure (PAF) preceding phenoconversion that could be useful as predictive markers for advancing α-synuclein-associated neurodegeneration of the brain. Patients diagnosed with PAF were evaluated at eight centres (seven US-based and one European) and enrolled in a longitudinal observational cohort study (NCT01799915). Subjects underwent detailed assessments of motor, sleep, olfactory, cognitive and autonomic function and were followed prospectively to determine whether they developed parkinsonism or dementia for up to 10 years. We identified incident cases of Parkinson's disease (PD), dementia with Lewy bodies (DLB) or multiple system atrophy (MSA) and computed hazard ratios for phenoconversion as functions of clinical features. A total of 209 participants with PAF with a median disease duration of 6 years (IQR: 3-10) were enrolled. Of those, 149 provided follow-up information at an office or telemedicine visit. After a mean follow-up duration of 3 years, 48 (33%) participants phenoconverted (42% to PD, 35% to DLB and 23% to MSA). Faster phenoconversion from study enrolment to any diagnosis was associated with urinary and sexual dysfunction [hazard ratio (HR) 5.9, 95% confidence interval (CI): 1.6-22 and HR: 3.6, 95% CI: 1.1-12] followed by subtle motor signs (HR: 2.7, 95% CI: 1.2-6), trouble swallowing (HR 2.5, 95% CI: 1.4-4.5) and changes in speech (HR:2.4, 95% CI:1.1-4.8) at enrolment. Subjects reporting deterioration of handwriting were more likely to phenoconvert to PD (HR: 2.6, 95% CI: 1.1-5.9) and those reporting difficulty handling utensils were more likely to phenoconvert to DLB (HR: 6.8, 95% CI: 1.2-38). Patients with a younger age of PAF onset (HR: 11, 95% CI: 2.6-46), preserved olfaction (HR: 8.7, 95% CI: 1.7-45), anhidrosis (HR: 1.8, 95% CI: 1-3.1, P = 0.042) and severe urinary problems (HR 1.6, 95% CI: 1-2.5, P = 0.033) were more likely to phenoconvert to MSA. The best autonomic predictor of PD was a blunted heart rate increase during the tilt-table test (HR: 6.1, 95% CI: 1.4-26). Patients with PAF have an estimated 12% (95% CI: 9-15%) per year annual risk following study entry of phenoconverting to a manifest CNS synucleinopathy.

Progressive Brain Atrophy in Multiple System Atrophy: A Longitudinal, Multicenter, Magnetic Resonance Imaging Study.

OBJECTIVE: To determine the rates of brain atrophy progression in vivo in patients with multiple system atrophy (MSA). BACKGROUND: Surrogate biomarkers of disease progression are a major unmet need in MSA. Small-scale longitudinal studies in patients with MSA using magnetic resonance imaging (MRI) to assess progression of brain atrophy have produced inconsistent results. In recent years, novel MRI post-processing methods have been developed enabling reliable quantification of brain atrophy in an automated fashion. METHODS: Serial 3D-T1-weighted MRI assessments (baseline and after 1 year of follow-up) of 43 patients with MSA were analyzed and compared to a cohort of early-stage Parkinson's disease (PD) patients and healthy controls (HC). FreeSurfer's longitudinal analysis stream was used to determine the brain atrophy rates in an observer-independent fashion. RESULTS: Mean ages at baseline were 64.4 ± 8.3, 60.0 ± 7.5, and 59.8 ± 9.2 years in MSA, PD patients and HC, respectively. A mean disease duration at baseline of 4.1 ± 2.5 years in MSA patients and 2.3 ± 1.4 years in PD patients was observed. Brain regions chiefly affected by MSA pathology showed progressive atrophy with annual rates of atrophy for the cerebellar cortex, cerebellar white matter, pons, and putamen of -4.24 ± 6.8%, -8.22 ± 8.8%, -4.67 ± 4.9%, and - 4.25 ± 4.9%, respectively. Similar to HC, atrophy rates in PD patients were minimal with values of -0.41% ± 1.8%, -1.47% ± 4.1%, -0.04% ± 1.8%, and -1.54% ± 2.2% for cerebellar cortex, cerebellar white matter, pons, and putamen, respectively. CONCLUSIONS: Patients with MSA show significant brain volume loss over 12 months, and cerebellar, pontine, and putaminal volumes were the most sensitive to change in mid-stage disease. © 2023 The Authors. Movement Disorders published by Wiley Periodicals LLC on behalf of International Parkinson and Movement Disorder Society.

Sex-related differences in the clinical presentation of multiple system atrophy.

PURPOSE: To investigate sex-related differences in the clinical presentation of multiple system atrophy (MSA) through a literature review and an analysis of a retrospective cohort. METHODS: The PubMed database was searched for articles including sex-related information in MSA. In a retrospective Innsbruck cohort, we investigated the baseline to last available follow-up clinical-demographic differences between men and women with MSA in a univariate fashion, followed by multivariable binary regression analysis. RESULTS: The literature search yielded 46 publications with sex-related information in MSA. Most studies found comparable survival rates between the sexes, while some recent reports suggested a potential survival benefit for women, possibly due to initial motor onset and overall less severe autonomic failure compared to men. The retrospective Innsbruck MSA cohort comprised 56 female and 60 male individuals with a comparable median follow-up of 27 months. At baseline, female sex was independently associated with depression (odds ratio [OR] 4.7; p = 0.007) and male sex with severe orthostatic hypotension (OR 5.5; p = 0.016). In addition, at last follow-up, female sex was associated with the intake of central nervous system-active drugs (OR 4.1; p = 0.029), whereas male sex was associated with the presence of supine hypertension (OR 3.0; p = 0.020) and the intake of antihypertensive medications (OR 8.7; p = 0.001). Male sex was also associated with initiation of antihypertensive medications over the observation period (OR 12.4; p = 0.004). CONCLUSION: The available literature and findings of the present study indicate sex-related differences in the clinical presentation of MSA and its evolution over time, highlighting the importance of considering sex in symptom exploration, therapeutic decision-making, and future clinical trial design.

The Growing Role of Telerehabilitation and Teleassessment in the Management of Movement Disorders in Rare Neurological Diseases: A Scoping Review.

Background: People with rare neurological diseases (RNDs) often experience symptoms related to movement disorders, requiring a multidisciplinary approach, including rehabilitation. Telemedicine applied to rehabilitation and symptom monitoring may be suitable to ensure treatment consistency and personalized intervention. The objective of this scoping review aimed to emphasize the potential role of telerehabilitation and teleassessment in managing movement disorders within RNDs. By providing a systematic overview of the available literature, we sought to highlight potential interventions, outcomes, and critical issues. Methods: A literature search was conducted on PubMed, Google Scholar, IEEE, and Scopus up to March 2024. Two inclusion criteria were followed: (1) papers focusing on telerehabilitation and teleassessment and (2) papers dealing with movement disorders in RNDs. Results: Eighteen papers fulfilled the inclusion criteria. The main interventions were home-based software and training programs, exergames, wearable sensors, smartphone applications, virtual reality and digital music players for telerehabilitation; wearable sensors, mobile applications, and patient home video for teleassessment. Key findings revealed positive outcomes in gait, balance, limb disability, and in remote monitoring. Limitations include small sample sizes, short intervention durations, and the lack of standardized protocols. Conclusion: This review highlighted the potential of telerehabilitation and teleassessment in addressing movement disorders within RNDs. Data indicate that these modalities may play a major role in supporting conventional programs. Addressing limitations through multicenter studies, longer-term follow-ups, and standardized protocols is essential. These measures are essential for improving remote rehabilitation and assessment, contributing to an improved quality of life for people with RNDs.

A Review on the Clinical Diagnosis of Multiple System Atrophy.

Multiple system atrophy (MSA) is a rare, adult-onset, progressive neurodegenerative disorder with major diagnostic challenges. Aiming for a better diagnostic accuracy particularly at early disease stages, novel Movement Disorder Society criteria for the diagnosis of MSA (MDS MSA criteria) have been recently developed. They introduce a neuropathologically established MSA category and three levels of clinical diagnostic certainty including clinically established MSA, clinically probable MSA, and the research category of possible prodromal MSA. The diagnosis of clinically established and clinically probable MSA is based on the presence of cardiovascular or urological autonomic failure, parkinsonism (poorly L-Dopa-responsive for the diagnosis of clinically established MSA), and cerebellar syndrome. These core clinical features need to be associated with supportive motor and non-motor features (MSA red flags) and absence of any exclusion criteria. Characteristic brain MRI markers are required for a diagnosis of clinically established MSA. A research category of possible prodromal MSA is devised to capture patients manifesting with autonomic failure or REM sleep behavior disorder and only mild motor signs at the earliest disease stage. There is a number of promising laboratory markers for MSA that may help increase the overall clinical diagnostic accuracy. In this review, we will discuss the core and supportive clinical features for a diagnosis of MSA in light of the new MDS MSA criteria, which laboratory tools may assist in the clinical diagnosis and which major differential diagnostic challenges should be borne in mind.

Clinical presentation and management strategies of cardiovascular autonomic dysfunction following a COVID-19 infection - A systematic review.

BACKGROUND: Cardiovascular autonomic dysfunction may reportedly occur after a coronavirus-disease-2019 (COVID-19) infection, but the available evidence is scattered. Here we sought to understand the acute and mid-term effects of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection on cardiovascular autonomic function. METHODS: We performed a systematic PubMed, Embase, Web of Science, medRxiv, and bioRxiv search for cases of cardiovascular autonomic dysfunction during an acute SARS-CoV-2 infection or post-COVID-19 condition. The clinical-demographic characteristics of individuals in the acute versus post-COVID-19 phase were compared. RESULTS: We screened 6470 titles and abstracts. Fifty-four full-length articles were included in the data synthesis. One-hundred and thirty-four cases were identified: 81 during the acute SARS-CoV-2 infection (24 thereof diagnosed by history) and 53 in the post-COVID-19 phase. Post-COVID-19 cases were younger than those with cardiovascular autonomic disturbances in the acute SARS-CoV-2 phase (42 vs. 51 years old, p = 0.002) and were more frequently women (68% vs. 49%, p = 0.034). Reflex syncope was the most common cardiovascular autonomic disorder in the acute phase (p = 0.008) and postural orthostatic tachycardia syndrome (POTS) the most frequent diagnosis in individuals with post-COVID-19 orthostatic complaints (p < 0.001). Full recovery was more frequent in individuals with acute versus post-COVID-19 onset of cardiovascular autonomic disturbances (43% vs. 15%, p = 0.002). CONCLUSIONS: There is evidence from the scientific literature about different types of cardiovascular autonomic dysfunction developing during and after COVID-19. More data about the prevalence of autonomic disorders associated with a SARS-CoV-2 infection are needed to quantify its impact on human health.

Impact of the COVID-19 pandemic on clinical autonomic practice in Europe A survey of the European Academy of Neurology (EAN) and the European Federation of Autonomic Societies (EFAS).

OBJECTIVE: To investigate the impact of the coronavirus-disease-2019 (COVID-19) pandemic on European clinical autonomic practice. METHODS: Eighty-four neurology-driven or interdisciplinary autonomic centers in 22 European countries were invited to fill in a web-based survey between September and November 2021. RESULTS: Forty-six centers completed the survey (55%). During the first pandemic year, the number of performed tilt-table tests, autonomic outpatient and inpatient visits decreased respectively by 50%, 45% and 53%, and every-third center reported major adverse events due to postponed examinations or visits. The most frequent newly-diagnosed or worsened cardiovascular autonomic disorders after COVID-19 infection included postural orthostatic tachycardia syndrome (POTS), orthostatic hypotension, and recurrent vasovagal syncope, deemed likely related to the infection by ≥50% of the responders. Forty-seven percent of the responders also reported about people with new-onset of orthostatic intolerance, but negative tilt-table findings, and 16% about people with psychogenic pseudosyncope after COVID-19. Most patients were treated non-pharmacologically and symptomatic recovery at follow-up was observed in ≥45% of cases. By contrast, low frequencies of newly-diagnosed cardiovascular autonomic disorders following COVID-19 vaccination were reported, most frequently POTS and recurrent vasovagal syncope, and most of the responders judged a causal association unlikely. Non-pharmacological measures were the preferred treatment choice, with 50-100% recovery rates at follow-up. CONCLUSIONS: Cardiovascular autonomic disorders may develop or worsen following a COVID-19 infection, while the association with COVID-19 vaccines remains controversial. Despite the severe pandemic impact on European clinical autonomic practice, a specialized diagnostic work-up was pivotal to identify non-autonomic disorders in people with post-COVID-19 orthostatic complaints.

EFAS/EAN survey on the influence of the COVID-19 pandemic on European clinical autonomic education and research.

PURPOSE: To understand the influence of the coronavirus disease 2019 (COVID-19) pandemic on clinical autonomic education and research in Europe. METHODS: We invited 84 European autonomic centers to complete an online survey, recorded the pre-pandemic-to-pandemic percentage of junior participants in the annual congresses of the European Federation of Autonomic Societies (EFAS) and European Academy of Neurology (EAN) and the pre-pandemic-to-pandemic number of PubMed publications on neurological disorders. RESULTS: Forty-six centers answered the survey (55%). Twenty-nine centers were involved in clinical autonomic education and experienced pandemic-related didactic interruptions for 9 (5; 9) months. Ninety percent (n = 26/29) of autonomic educational centers reported a negative impact of the COVID-19 pandemic on education quality, and 93% (n = 27/29) established e-learning models. Both the 2020 joint EAN-EFAS virtual congress and the 2021 (virtual) and 2022 (hybrid) EFAS and EAN congresses marked higher percentages of junior participants than in 2019. Forty-one respondents (89%) were autonomic researchers, and 29 of them reported pandemic-related trial interruptions for 5 (2; 9) months. Since the pandemic begin, almost half of the respondents had less time for scientific writing. Likewise, the number of PubMed publications on autonomic topics showed the smallest increase compared with other neurological fields in 2020-2021 and the highest drop in 2022. Autonomic research centers that amended their trial protocols for telemedicine (38%, n = 16/41) maintained higher clinical caseloads during the first pandemic year. CONCLUSIONS: The COVID-19 pandemic had a substantial negative impact on European clinical autonomic education and research. At the same time, it promoted digitalization, favoring more equitable access to autonomic education and improved trial design.

Sensitivity to Change and Patient-Centricity of the Unified Multiple System Atrophy Rating Scale Items: A Data-Driven Analysis.

BACKGROUND: The Unified Multiple System Atrophy Rating Scale (UMSARS) is a commonly used semiquantitative rating scale to assess symptoms and measure disease progression in multiple system atrophy (MSA). However, it is currently incompletely understood which UMSARS items are the most sensitive to change and most relevant to the patient. OBJECTIVE: The objective of this study was to assess sensitivity to change and patient-centricity of single UMSARS items. METHODS: Data were taken from the European Multiple System Atrophy Study Group Natural History Study and the Rasagiline for Multiple System Atrophy trial. Sensitivity of change of an item of the UMSARS was assessed by calculation of a sensitivity-to-change ratio using its mean slope of progression divided by the standard deviation of the slope when modeling its progression over time. Patient-centricity was assessed through correlation of UMSARS items with quality-of-life measures. RESULTS: Progression rates above the mean in at least one of the two studies examined here were seen for seven items of UMSARS I and 11 items of UMSARS II. These items related to key motor functions such as swallowing, speech, handwriting, cutting food, hygiene, and dressing or walking, whereas items related to autonomic dysfunction were generally less sensitive to change in either data set. More UMSARS I items were identified as patient-centric compared with UMSARS II items, and items most strongly impacting patients' quality of life were those affecting verbal communication skills, personal hygiene, and walking. CONCLUSION: The present results illustrate the potential to optimize the UMSARS to enhance sensitivity to change and patient centricity. © 2022 The Authors. Movement Disorders published by Wiley Periodicals LLC on behalf of International Parkinson and Movement Disorder Society.

Disease Progression in Multiple System Atrophy-Novel Modeling Framework and Predictive Factors.

BACKGROUND: Multiple system atrophy (MSA) is a rare and aggressive neurodegenerative disease that typically leads to death 6 to 10 years after symptom onset. The rapid evolution renders it crucial to understand the general disease progression and factors affecting the disease course. OBJECTIVES: The aims of this study were to develop a novel disease-progression model to estimate a population-level MSA progression trajectory and predict patient-specific continuous disease stages describing the degree of progress into the disease. METHODS: The disease-progression model estimated a population-level progression trajectory of subscales of the Unified MSA Rating Scale and the Unified Parkinson's Disease Rating Scale using patients in the European MSA natural history study. The predicted disease continuum was validated via multiple analyses based on reported anchor points, and the effect of MSA subtype on the rate of disease progression was evaluated. RESULTS: The predicted disease continuum spanned approximately 6 years, with an estimated average duration of 51 months for a patient with global disability score 0 to reach the highest level of 4. The predicted continuous disease stages were shown to be correlated with time of symptom onset and predictive of survival time. MSA motor subtype was found to significantly affect disease progression, with MSA-parkinsonian (MSA-P) type patients having an accelerated rate of progression. CONCLUSIONS: The proposed modeling framework introduces a new method of analyzing and interpreting the progression of MSA. It can provide new insights and opportunities for investigating covariate effects on the rate of progression and provide well-founded predictions of patient-level future progressions. © 2022 The Authors. Movement Disorders published by Wiley Periodicals LLC on behalf of International Parkinson and Movement Disorder Society.

Glia Imaging Differentiates Multiple System Atrophy from Parkinson's Disease: A Positron Emission Tomography Study with [11 C]PBR28 and Machine Learning Analysis.

BACKGROUND: The clinical diagnosis of multiple system atrophy (MSA) is challenged by overlapping features with Parkinson's disease (PD) and late-onset ataxias. Additional biomarkers are needed to confirm MSA and to advance the understanding of pathophysiology. Positron emission tomography (PET) imaging of the translocator protein (TSPO), expressed by glia cells, has shown elevations in MSA. OBJECTIVE: In this multicenter PET study, we assess the performance of TSPO imaging as a diagnostic marker for MSA. METHODS: We analyzed [11 C]PBR28 binding to TSPO using imaging data of 66 patients with MSA and 24 patients with PD. Group comparisons were based on regional analysis of parametric images. The diagnostic readout included visual reading of PET images against clinical diagnosis and machine learning analyses. Sensitivity, specificity, and receiver operating curves were used to discriminate MSA from PD and cerebellar from parkinsonian variant MSA. RESULTS: We observed a conspicuous pattern of elevated regional [11 C]PBR28 binding to TSPO in MSA as compared with PD, with "hotspots" in the lentiform nucleus and cerebellar white matter. Visual reading discriminated MSA from PD with 100% specificity and 83% sensitivity. The machine learning approach improved sensitivity to 96%. We identified MSA subtype-specific TSPO binding patterns. CONCLUSIONS: We found a pattern of significantly increased regional glial TSPO binding in patients with MSA. Intriguingly, our data are in line with severe neuroinflammation in MSA. Glia imaging may have potential to support clinical MSA diagnosis and patient stratification in clinical trials on novel drug therapies for an α-synucleinopathy that remains strikingly incurable. © 2021 The Authors. Movement Disorders published by Wiley Periodicals LLC on behalf of International Parkinson and Movement Disorder Society.

The Movement Disorder Society Criteria for the Diagnosis of Multiple System Atrophy.

BACKGROUND: The second consensus criteria for the diagnosis of multiple system atrophy (MSA) are widely recognized as the reference standard for clinical research, but lack sensitivity to diagnose the disease at early stages. OBJECTIVE: To develop novel Movement Disorder Society (MDS) criteria for MSA diagnosis using an evidence-based and consensus-based methodology. METHODS: We identified shortcomings of the second consensus criteria for MSA diagnosis and conducted a systematic literature review to answer predefined questions on clinical presentation and diagnostic tools relevant for MSA diagnosis. The criteria were developed and later optimized using two Delphi rounds within the MSA Criteria Revision Task Force, a survey for MDS membership, and a virtual Consensus Conference. RESULTS: The criteria for neuropathologically established MSA remain unchanged. For a clinical MSA diagnosis a new category of clinically established MSA is introduced, aiming for maximum specificity with acceptable sensitivity. A category of clinically probable MSA is defined to enhance sensitivity while maintaining specificity. A research category of possible prodromal MSA is designed to capture patients in the earliest stages when symptoms and signs are present, but do not meet the threshold for clinically established or clinically probable MSA. Brain magnetic resonance imaging markers suggestive of MSA are required for the diagnosis of clinically established MSA. The number of research biomarkers that support all clinical diagnostic categories will likely grow. CONCLUSIONS: This set of MDS MSA diagnostic criteria aims at improving the diagnostic accuracy, particularly in early disease stages. It requires validation in a prospective clinical and a clinicopathological study. © 2022 The Authors. Movement Disorders published by Wiley Periodicals LLC on behalf of International Parkinson and Movement Disorder Society.

Clinical Trial-Ready Patient Cohorts for Multiple System Atrophy: Coupling Biospecimen and iPSC Banking to Longitudinal Deep-Phenotyping.

Multiple system atrophy (MSA) is a fatal neurodegenerative disease of unknown etiology characterized by widespread aggregation of the protein alpha-synuclein in neurons and glia. Its orphan status, biological relationship to Parkinson's disease (PD), and rapid progression have sparked interest in drug development. One significant obstacle to therapeutics is disease heterogeneity. Here, we share our process of developing a clinical trial-ready cohort of MSA patients (69 patients in 2 years) within an outpatient clinical setting, and recruiting 20 of these patients into a longitudinal "n-of-few" clinical trial paradigm. First, we deeply phenotype our patients with clinical scales (UMSARS, BARS, MoCA, NMSS, and UPSIT) and tests designed to establish early differential diagnosis (including volumetric MRI, FDG-PET, MIBG scan, polysomnography, genetic testing, autonomic function tests, skin biopsy) or disease activity (PBR06-TSPO). Second, we longitudinally collect biospecimens (blood, CSF, stool) and clinical, biometric, and imaging data to generate antecedent disease-progression scores. Third, in our Mass General Brigham SCiN study (stem cells in neurodegeneration), we generate induced pluripotent stem cell (iPSC) models from our patients, matched to biospecimens, including postmortem brain. We present 38 iPSC lines derived from MSA patients and relevant disease controls (spinocerebellar ataxia and PD, including alpha-synuclein triplication cases), 22 matched to whole-genome sequenced postmortem brain. iPSC models may facilitate matching patients to appropriate therapies, particularly in heterogeneous diseases for which patient-specific biology may elude animal models. We anticipate that deeply phenotyped and genotyped patient cohorts matched to cellular models will increase the likelihood of success in clinical trials for MSA.

Sudomotor dysfunction in people with neuromyelitis optica spectrum disorders.

BACKGROUND AND PURPOSE: The aim was to determine the extent of sudomotor dysfunction in people with neuromyelitis optica spectrum disorder (pwNMOSD) and to compare findings with a historical cohort of people with relapsing-remitting multiple sclerosis (pwRRMS). METHODS: Forty-eight pwNMOSD were enrolled from four clinical centers. All participants completed the Composite Autonomic Symptom Score 31 to screen for symptoms of sudomotor dysfunction. Sudomotor function was assessed using the quantitative sudomotor axon reflex test. The results were compared with a historical cohort of 35 pwRRMS matched for age, sex and disease duration. RESULTS: Symptoms of sudomotor dysfunction, defined by a score in the Composite Autonomic Symptom Score 31 secretomotor domain >0, were present in 26 (54%) of pwNMOSD. The quantitative sudomotor axon reflex test confirmed a sudomotor dysfunction in 25 (52.1%) of pwNMOSD; in 14 of them (29.2%) sudomotor dysfunction was moderate or severe. No difference was observed between pwNMOSD and pwRRMS in any of the studied parameters. However, symptomatic sudomotor dysfunction was more frequent in pwNMOSD (n = 8, 22.9%) compared to pwRRMS (n = 1, 3%; p = 0.028). In a multivariable logistic regression analysis, statistically significant predictors for symptomatic sudomotor failure were age and diagnosis of neuromyelitis optica spectrum disorder. CONCLUSIONS: Sudomotor dysfunction is common in pwNMOSD and more often symptomatic compared to pwRRMS.

Clinical autonomic nervous system laboratories in Europe: A joint survey of the European Academy of Neurology and the European Federation of Autonomic Societies: A joint survey of the European Academy of Neurology and the European Federation of Autonomic Societies.

BACKGROUND AND PURPOSE: Disorders of the autonomic nervous system (ANS) are common conditions, but it is unclear whether access to ANS healthcare provision is homogeneous across European countries. The aim of this study was to identify neurology-driven or interdisciplinary clinical ANS laboratories in Europe, describe their characteristics and explore regional differences. METHODS: We contacted the European national ANS and neurological societies, as well as members of our professional network, to identify clinical ANS laboratories in each country and invite them to answer a web-based survey. RESULTS: We identified 84 laboratories in 22 countries and 46 (55%) answered the survey. All laboratories perform cardiovascular autonomic function tests, and 83% also perform sweat tests. Testing for catecholamines and autoantibodies are performed in 63% and 56% of laboratories, and epidermal nerve fiber density analysis in 63%. Each laboratory is staffed by a median of two consultants, one resident, one technician and one nurse. The median (interquartile range [IQR]) number of head-up tilt tests/laboratory/year is 105 (49-251). Reflex syncope and neurogenic orthostatic hypotension are the most frequently diagnosed cardiovascular ANS disorders. Thirty-five centers (76%) have an ANS outpatient clinic, with a median (IQR) of 200 (100-360) outpatient visits/year; 42 centers (91%) also offer inpatient care (median 20 [IQR 4-110] inpatient stays/year). Forty-one laboratories (89%) are involved in research activities. We observed a significant difference in the geographical distribution of ANS services among European regions: 11 out of 12 countries from North/West Europe have at least one ANS laboratory versus 11 out of 21 from South/East/Greater Europe (p = 0.021). CONCLUSIONS: This survey highlights disparities in the availability of healthcare services for people with ANS disorders across European countries, stressing the need for improved access to specialized care in South, East and Greater Europe.

Cardiac sympathetic innervation in Parkinson's disease versus multiple system atrophy.

PURPOSE: The aims of this study were to evaluate the diagnostic accuracy of the dual imaging method combining cardiac iodine-123-metaiodobenzylguanidine single-photon emission computed tomography combined with low-dose chest computed tomography compared to routine cardiac scintigraphy, and assess regional differences in tracer distribution and the relationships between imaging and autonomic function in Parkinson's disease and multiple system atrophy. METHODS: A prospective study including 19 Parkinson's disease and 12 multiple system atrophy patients was performed. Patients underwent clinical evaluation, iodine-123-metaiodobenzylguanidine single-photon emission computed tomography combined with chest computed tomography, planar scintigraphy, and cardiovascular autonomic function tests. RESULTS: Co-registration of single-photon emission computed tomography and chest computed tomography resulted in three groups with distinct patterns of tracer uptake: homogeneous, non-homogeneously reduced and absent. There was a significant difference in group allocation among patients with multiple system atrophy and Parkinson's disease (p = 0.001). Most multiple system atrophy patients showed homogeneous uptake, and the majority of Parkinson's disease patients showed absent cardiac tracer uptake. We identified a pattern of heterogeneous cardiac tracer uptake in both diseases with reductions in the apex and the lateral myocardial wall. Sympathetic dysfunction reflected by a missing blood pressure overshoot during Valsalva manoeuvre correlated with cardiac tracer distribution in Parkinson's disease patients (p < 0.001). CONCLUSIONS: The diagnostic accuracy of the dual imaging method and routine cardiac scintigraphy were similar. Anatomical tracer allocation provided by the dual imaging method of cardiac iodine-123-metaiodobenzylguanidine single-photon emission computed tomography and chest computed tomography identified a heterogeneous subgroup of Parkinson's disease and multiple system atrophy patients with reduced cardiac tracer uptake in the apex and the lateral wall. Sympathetic dysfunction correlated with cardiac imaging in Parkinson's disease patients.

The role of cardiovascular autonomic failure in the differential diagnosis of α-synucleinopathies.

The α-synucleinopathies comprise a group of adult-onset neurodegenerative disorders including Parkinson's disease (PD), multiple system atrophy (MSA), dementia with Lewy bodies (DLB,) and - as a restricted non-motor form - pure autonomic failure (PAF). Neuropathologically, the α-synucleinopathies are characterized by aggregates of misfolded α-synuclein in the central and peripheral nervous system. Cardiovascular autonomic failure is a common non-motor symptom in people with PD, a key diagnostic criterion in MSA, a supportive feature for the diagnosis of DLB and disease-defining in PAF. The site of autonomic nervous system lesion differs between the α-synucleinopathies, with a predominantly central lesion pattern in MSA versus a peripheral one in PD, DLB, and PAF. In clinical practice, overlapping autonomic features often challenge the differential diagnosis among the α-synucleinopathies, but also distinguish them from related disorders, such as the tauopathies or other neurodegenerative ataxias. In this review, we discuss the differential diagnostic yield of cardiovascular autonomic failure in individuals presenting with isolated autonomic failure, parkinsonism, cognitive impairment, or cerebellar ataxia.

Non-Motor Symptoms in Parkinson's Disease are Reduced by Nabilone.

OBJECTIVE: The objective of this study was to assess the efficacy and safety of nabilone, a synthetic tetrahydrocannabinol analogue, as a treatment for non-motor symptoms (NMS) in Parkinson's disease (PD). METHODS: This was a phase II placebo-controlled, double-blind, parallel-group, enriched enrollment randomized withdrawal trial conducted at the Medical University Innsbruck. A random sample of 47 patients with PD with stable motor disease and disturbing NMS defined by a score of ≥4 points on the Movement Disorder Society - Unified PD Rating Scale-I (MDS-UPDRS-I) underwent open-label nabilone titration (0.25 mg once daily to 1 mg twice daily, phase I). Responders were randomized 1:1 to continue with nabilone or switch to placebo for 4 weeks (phase II). The primary efficacy criterion was the change of the MDS-UPDRS-I between randomization and week 4. Safety was analyzed in all patients who received at least one nabilone dose. RESULTS: Between October 2017 and July 2019, 19 patients received either nabilone (median dose = 0.75 mg) or placebo. At week 4, mean change of the MDS-UPDRS-I was 2.63 (95% confidence interval [CI] 1.53 to 3.74, p = 0.002, effect size = 1.15) in the placebo versus 1.00 (95% CI -0.16 to 2.16, p = 0.280, effect size = 0.42) in the nabilone-group (difference: 1.63, 95% CI 0.09 to 3.18, p = 0.030, effect size = 0.66). Seventy-seven percent of patients had adverse events (AEs) during open-label titration, most of them were transient. In the double-blind phase, similar proportions of patients in each group had AEs (42% in the placebo group and 32% in the nabilone group). There were no serious AEs. INTERPRETATION: Our results highlight the potential efficacy of nabilone for patients with PD with disturbing NMS, which appears to be driven by positive effects on anxious mood and night-time sleep problems. TRIAL REGISTRY: ClinicalTrials.gov (NCT03769896) and EudraCT (2017-000192-86). ANN NEUROL 2020;88:712-722.

Automated Analysis of Diffusion-Weighted Magnetic Resonance Imaging for the Differential Diagnosis of Multiple System Atrophy from Parkinson's Disease.

BACKGROUND: Manual region-of-interest analysis of putaminal and middle cerebellar peduncle diffusivity distinguishes patients with multiple system atrophy (MSA) and Parkinson's disease (PD) with high diagnostic accuracy. However, a recent meta-analysis found substantial between-study heterogeneity of diagnostic accuracy due to the lack of harmonized imaging protocols and standardized analyses pipelines. OBJECTIVE: Evaluation of diagnostic accuracy of observer-independent analysis of microstructural integrity as measured by diffusion-tensor imaging in patients with MSA and PD. METHODS: A total of 29 patients with MSA and 19 patients with PD (matched for age, gender, and disease duration) with 3 years of follow-up were investigated with diffusion-tensor imaging and T1-weighted magnetic resonance imaging. Automated localization of relevant brain regions was obtained, and mean diffusivity and fractional anisotropy values were averaged within the regions of interest. The classification was performed using a C5.0 hierachical decision tree algorithm. RESULTS: Mean diffusivity of the middle cerebellar peduncle and cerebellar gray and white matter compartment as well as the putamen were significantly increased in patients with MSA and showed superior effect sizes compared to the volumetric analysis of these regions. A classifier model identified mean diffusivity of the middle cerebellar peduncle and putamen as the most predictive parameters. Cross-validation of the classification model yields a Cohen's κ and overall diagnostic accuracy of 0.823 and 0.914, respectively. CONCLUSION: Analysis of microstructural integrity within the middle cerebellar peduncle and putamen yielded a superior effect size compared to the volumetric measures, resulting in excellent diagnostic accuracy to discriminate patients with MSA from PD in the early to moderate disease stages. © 2020 The Authors. Movement Disorders published by Wiley Periodicals LLC on behalf of International Parkinson and Movement Disorder Society.