Deep Brain Stimulation of the Globus Pallidus Internus and Externus in Multiple System Atrophy.

BACKGROUND: Multiple system atrophy with parkinsonism (MSA-P) is a progressive condition with no effective treatment. OBJECTIVE: The aim of this study was to describe the safety and efficacy of deep brain stimulation (DBS) of globus pallidus pars interna and externa in a cohort of patients with MSA-P. METHODS: Six patients were included. Changes in Movement Disorders Society Unified Parkinson's Disease Rating Scale Part III (MDS-UPDRS III), Parkinson's Disease Questionnaire (PDQ-39) scores, and levodopa equivalent daily dose were compared before and after DBS. Electrode localization and volume tissue activation were calculated. RESULTS: DBS surgery did not result in any major adverse events or intraoperative complications. Overall, no differences in MDS-UPDRS III scores were demonstrated (55.2 ± 17.6 preoperatively compared with 67.3 ± 19.2 at 1 year after surgery), although transient improvement in mobility and dyskinesia was reported in some subjects. CONCLUSIONS: Globus pallidus pars interna and externa DBS for patients with MSA-P did not result in major complications, although it did not provide significant clinical benefit as measured by MDS-UPDRS III. © 2023 The Authors. Movement Disorders published by Wiley Periodicals LLC on behalf of International Parkinson and Movement Disorder Society.

Prolyl oligopeptidase inhibition reduces alpha-synuclein aggregation in a cellular model of multiple system atrophy.

Multiple system atrophy (MSA) is a fatal neurodegenerative disease where the histopathological hallmark is glial cytoplasmic inclusions in oligodendrocytes, rich of aggregated alpha-synuclein (aSyn). Therefore, therapies targeting aSyn aggregation and toxicity have been studied as a possible disease-modifying therapy for MSA. Our earlier studies show that inhibition of prolyl oligopeptidase (PREP) with KYP-2047 reduces aSyn aggregates in several models. Here, we tested the effects of KYP-2047 on a MSA cellular models, using rat OLN-AS7 and human MO3.13 oligodendrocyte cells. As translocation of p25α to cell cytosol has been identified as an inducer of aSyn aggregation in MSA models, the cells were transiently transfected with p25α. Similar to earlier studies, p25α increased aSyn phosphorylation and aggregation, and caused tubulin retraction and impaired autophagy in OLN-AS7 cells. In both cellular models, p25α transfection increased significantly aSyn mRNA levels and also increased the levels of inactive protein phosphatase 2A (PP2A). However, aSyn or p25α did not cause any cellular death in MO3.13 cells, questioning their use as a MSA model. Simultaneous administration of 10 µM KYP-2047 improved cell viability, decreased insoluble phosphorylated aSyn and normalized autophagy in OLN-AS7 cells but similar impact was not seen in MO3.13 cells.

Clinical features of autopsy-confirmed multiple system atrophy in the Mayo Clinic Florida brain bank.

BACKGROUND: Multiple system atrophy (MSA) presents with various combinations of autonomic dysfunction, parkinsonism, and cerebellar ataxia. Although clinical diagnostic criteria have been widely used, the sensitivity and specificity are suboptimal. This study aims to provide evidence supporting the revision of the current diagnostic criteria for MSA. METHODS: Medical records of 171 patients with autopsy-confirmed MSA in the Mayo Clinic brain bank were reviewed with regard to their clinical features and diagnoses. Pathologic features, including concomitant pathologies (i.e., Alzheimer-related and Lewy-related pathologies), were also assessed. RESULTS: The cohort included 133 MSA-parkinsonian type, 36 MSA-cerebellar type, and 2 unclassified MSA patients who did not show significant motor symptoms. Twenty-three patients (13%) were not clinically diagnosed with MSA, but instead with progressive supranuclear palsy, Parkinson's disease (PD), PD with dementia (PDD), or dementia with Lewy bodies (DLB). Three patients with PDD and DLB also had concomitant Lewy body pathology. Six patients had late-onset MSA, with an age of onset greater than 75 years. Erectile dysfunction was frequent in male patients (60/63; 95%) in all age ranges. REM sleep behavior disorder (RBD) was present in 82 patients (48%) and was the initial symptom in 13 patients. Cognitive impairment was present in 60 patients (35%), but was an initial symptom in only two patients. CONCLUSIONS: Our findings support the conclusion that late-onset presentation should not exclude MSA. The findings of this large autopsy-based cohort provides valuable insights for improving clinical criteria for MSA.

Seeded assembly in vitro does not replicate the structures of α-synuclein filaments from multiple system atrophy.

The propagation of conformational strains by templated seeding is central to the prion concept. Seeded assembly of α-synuclein into filaments is believed to underlie the prion-like spreading of protein inclusions in a number of human neurodegenerative diseases, including Parkinson's disease, dementia with Lewy bodies (DLB) and multiple system atrophy (MSA). We previously determined the atomic structures of α-synuclein filaments from the putamen of five individuals with MSA. Here, we used filament preparations from three of these brains for the in vitro seeded assembly of recombinant human α-synuclein. We find that the structures of the seeded assemblies differ from those of the seeds, suggesting that additional, as yet unknown, factors play a role in the propagation of the seeds. Identification of these factors will be essential for understanding the prion-like spreading of α-synuclein proteinopathies.

Multiple system atrophy pathology is associated with primary Sjögren's syndrome.

BACKGROUNDOur objective was to investigate whether primary Sjögren's syndrome (pSS) is associated with multiple system atrophy (MSA).METHODSWe performed a retrospective cohort study assessing (a) rates of MSA in a cohort of patients with pSS and (b) rates of pSS in a cohort of patients with MSA. These data were compared with rates in respective control groups. We additionally reviewed the neuropathologic findings in 2 patients with pSS, cerebellar degeneration, parkinsonism, and autonomic dysfunction.RESULTSOur cohort of 308 patients with pSS had a greater incidence of MSA compared with 4 large population-based studies and had a significantly higher prevalence of at least probable MSA (1% vs. 0%, P = 0.02) compared with 776 patients in a control cohort of patients with other autoimmune disorders. Our cohort of 26 autopsy-proven patients with MSA had a significantly higher prevalence of pSS compared with a cohort of 115 patients with other autopsy-proven neurodegenerative disorders (8% vs. 0%, P = 0.03). The 2 patients we described with pSS and progressive neurodegenerative disease showed classic MSA pathology at autopsy.CONCLUSIONOur findings provide evidence for an association between MSA and pSS that is specific to both pSS, among autoimmune disorders, and MSA, among neurodegenerative disorders. The 2 cases we describe of autopsy-proven MSA support that MSA pathology can explain neurologic disease in a subset of patients with pSS. These findings together support the hypothesis that systemic autoimmune disease plays a role in neurodegeneration.FUNDINGThe Michigan Brain Bank is supported in part through NIH grant P30AG053760.

MSA: From basic mechanisms to experimental therapeutics.

Multiple system atrophy (MSA) is a rare and fatal neurodegenerative disorder characterized by rapidly progressive autonomic and motor dysfunction. Pathologically, MSA is mainly characterized by the abnormal accumulation of misfolded α-synuclein in the cytoplasm of oligodendrocytes, which plays a major role in the pathogenesis of the disease. Striatonigral degeneration and olivopontecerebellar atrophy underlie the motor syndrome, while degeneration of autonomic centers defines the autonomic failure in MSA. At present, there is no treatment that can halt or reverse its progression. However, over the last decade several studies in preclinical models and patients have helped to better understand the pathophysiological events underlying MSA. The etiology of this fatal disorder remains unclear and may be multifactorial, caused by a combination of factors which may serve as targets for novel therapeutic approaches. In this review, we summarize the current knowledge about the etiopathogenesis and neuropathology of MSA, its different preclinical models, and the main disease modifying therapies that have been used so far or that are planned for future clinical trials.

Traumatic brain injury preceding clinically diagnosed α-synucleinopathies: A case-control study.

OBJECTIVE: To determine the association between traumatic brain injury (TBI) and any clinically diagnosed α-synucleinopathy including Parkinson disease (PD), dementia with Lewy bodies (DLB), PD dementia (PDD), and multiple system atrophy (MSA). METHODS: Using the medical records-linkage system of the Rochester Epidemiology Project, we identified incident cases of α-synucleinopathies in Olmsted County, Minnesota, from 1991 to 2010, matching by age (±1 year) at symptom onset and sex to controls. We reviewed records of cases and controls to detect TBI prior to clinical-motor onset of any α-synucleinopathies. We based severity (possible, probable, and definite) upon the Mayo Classification System for TBI Severity. Using conditional-logistic regression, we calculated the odds ratio (OR) of all α-synucleinopathies and type, adjusting for coffee intake and smoking. RESULTS: TBI frequency was lower among cases (7.0%) than controls (8.2%). No association was found between TBI and all α-synucleinopathies in multivariable analyses (OR 0.90, 95% confidence interval [CI] 0.54-1.52). No association presented when examining the number of TBIs, TBI severity, time between TBI exposure and index date, age at index date, or sex. When stratifying by each individual α-synucleinopathy, we did not identify any associations between TBI and PD, DLB, or PDD. Among the MSA group, 1 (6.4%) and 0 controls experienced a TBI (OR could not be estimated). CONCLUSIONS: In this nested case-control population-based analysis, TBI was not associated with subsequent α-synucleinopathies in general or any individual α-synucleinopathy. This did not change based on the temporality or the severity of the TBI. Our findings may be limited by the study power.

L-dopa response pattern in a rat model of mild striatonigral degeneration.

BACKGROUND: Unresponsiveness to dopaminergic therapies is a key feature in the diagnosis of multiple system atrophy (MSA) and a major unmet need in the treatment of MSA patients caused by combined striatonigral degeneration (SND). Transgenic, alpha-synuclein animal models do not recapitulate this lack of levodopa responsiveness. In order to preclinically study interventions including striatal cell grafts, models that feature SND are required. Most of the previous studies focused on extensive nigral and striatal lesions corresponding to advanced MSA-P/SND. The aim of the current study was to replicate mild stage MSA-P/SND with L-dopa failure. METHODS AND RESULTS: Two different striatal quinolinic acid (QA) lesions following a striatal 6-OHDA lesion replicating mild and severe MSA-P/SND, respectively, were investigated and compared to 6-OHDA lesioned animals. After the initial 6-OHDA lesion there was a significant improvement of motor performance after dopaminergic stimulation in the cylinder and stepping test (p<0.001). Response to L-dopa treatment declined in both MSA-P/SND groups reflecting striatal damage of lateral motor areas in contrast to the 6-OHDA only lesioned animals (p<0.01). The remaining striatal volume correlated strongly with contralateral apomorphine induced rotation behaviour and contralateral paw use during L-dopa treatment in cylinder and stepping test (p<0.001). CONCLUSION: Our novel L-dopa response data suggest that L-dopa failure can be induced by restricted lateral striatal lesions combined with dopaminergic denervation. We propose that this sequential striatal double-lesion model replicates a mild stage of MSA-P/SND and is suitable to address neuro-regenerative therapies aimed at restoring dopaminergic responsiveness.

In vitro models of multiple system atrophy from primary cells to induced pluripotent stem cells.

Multiple system atrophy (MSA) is a rare neurodegenerative disease with a fatal outcome. Nowadays, only symptomatic treatment is available for MSA patients. The hallmarks of the disease are glial cytoplasmic inclusions (GCIs), proteinaceous aggregates mainly composed of alpha-synuclein, which accumulate in oligodendrocytes. However, despite the extensive research efforts, little is known about the pathogenesis of MSA. Early myelin dysfunction and alpha-synuclein deposition are thought to play a major role, but the origin of the aggregates and the causes of misfolding are obscure. One of the reasons for this is the lack of a reliable model of the disease. Recently, the development of induced pluripotent stem cell (iPSC) technology opened up the possibility of elucidating disease mechanisms in neurodegenerative diseases including MSA. Patient specific iPSC can be differentiated in glia and neurons, the cells involved in MSA, providing a useful human disease model. Here, we firstly review the progress made in MSA modelling with primary cell cultures. Subsequently, we focus on the first iPSC-based model of MSA, which showed that alpha-synuclein is expressed in oligodendrocyte progenitors, whereas its production decreases in mature oligodendrocytes. We then highlight the opportunities offered by iPSC in studying disease mechanisms and providing innovative models for testing therapeutic strategies, and we discuss the challenges connected with this technique.

α-Synuclein: Multiple System Atrophy Prions.

Multiple system atrophy (MSA) is a rapidly progressive neurodegenerative disease arising from the misfolding and accumulation of the protein α-synuclein in oligodendrocytes, where it forms glial cytoplasmic inclusions (GCIs). Several years of studying synthetic α-synuclein fibrils has provided critical insight into the ability of α-synuclein to template endogenous protein misfolding, giving rise to fibrillar structures capable of propagating from cell to cell. However, more recent studies with MSA-derived α-synuclein aggregates have shown that they have a similar ability to undergo template-directed propagation, like PrP prions. Almost 20 years after α-synuclein was discovered as the primary component of GCIs, α-synuclein aggregates isolated from MSA patient samples were shown to infect cultured mammalian cells and also to transmit neurological disease to transgenic mice. These findings argue that α-synuclein becomes a prion in MSA patients. In this review, we discuss the in vitro and in vivo data supporting the recent classification of MSA as a prion disease.

Viral-mediated oligodendroglial alpha-synuclein expression models multiple system atrophy.

BACKGROUND: MSA is a fatal neurodegenerative disorder characterized by a combination of autonomic dysfunction, cerebellar ataxia, and l-dopa unresponsive parkinsonism. The hallmark of MSA is the accumulation of α-synuclein, forming cytoplasmic inclusions in oligodendrocytes. Adeno-associated viruses allow efficient targeting of disease-associated genes in selected cellular ensembles and have proven efficient for the neuronal overexpression of α-synuclein in the substantia nigra in the context of PD. OBJECTIVES: We aimed to develop viral-based models of MSA. METHODS: Chimeric viral vectors expressing either human wild-type α-synuclein or green fluorescent protein under the control of mouse myelin basic protein were injected in the striatum of rats and monkeys. Rats underwent a longitudinal motor assessment before histopathological analysis at 3 and 6 months. RESULTS: Injection of vectors expressing α-synuclein in the striatum resulted in >80% oligodendroglial selectivity in rats and >60% in monkeys. Rats developed progressive motor deficits that were l-dopa unresponsive when assessed at 6 months. Significant loss of dopaminergic neurons occurred at 3 months, further progressing at 6 months, together with a loss of striatal neurons. Prominent α-synuclein accumulation, including phosphorylated and proteinase-K-resistant α-synuclein, was detected in the striatum and substantia nigra. CONCLUSIONS: Viral-mediated oligodendroglial expression of α-synuclein allows replicating some of the key features of MSA. This flexible strategy can be used to investigate, in several species, how α-synuclein accumulation in selected oligodendroglial populations contributes to the pathophysiology of MSA and offers a new framework for preclinical validation of therapeutic strategies. © 2017 International Parkinson and Movement Disorder Society.

Multiple System Atrophy - State of the Art.

Multiple system atrophy (MSA) is a rare and fatal neurodegenerative disorder that is characterized by a variable combination of parkinsonism, cerebellar impairment, and autonomic dysfunction. Some symptomatic treatments are available while neuroprotection or disease-modification remain unmet treatment needs. The pathologic hallmark is the accumulation of aggregated alpha-synuclein (α-syn) in oligodendrocytes forming glial cytoplasmic inclusions, which qualifies MSA as synucleinopathy together with Parkinson's disease and dementia with Lewy bodies. Despite progress in our understanding of the pathogenesis of MSA, the origin of α-syn aggregates in oligodendrocytes is still a matter of an ongoing debate. We critically review here studies published in the field over the past 5 years dealing with pathogenesis, genetics, clinical signs, biomarker for improving diagnostic accuracy, and treatment development.

Treatment of Advanced Parkinson Disease and Related Disorders.

PURPOSE OF REVIEW: Parkinson disease often spans decades of a patient's lifetime. Over time, nonmotor symptoms predominate and may limit dopaminergic therapy. Neurologists continue to play a vital role in treatment. In addition to balancing neurobehavioral complications of Parkinson disease with motor benefit, addressing nonmotor symptoms common in the advanced stage may improve quality of life and reduce symptom burden. Symptoms such as dysphagia, constipation, urinary dysfunction, orthostatic hypotension, and pain respond to nonpharmacologic and pharmacologic therapies. RECENT FINDINGS: Evidence for treatment of many nonmotor symptoms is weak or lacking. The evidence for treatment of the atypical parkinsonian syndromes (progressive supranuclear palsy, multiple system atrophy, and corticobasal degeneration) in advanced stages is even more scant. SUMMARY: Engaging palliative care physicians in the joint care of patients can provide patients with access to expertise in end-of-life issues. Neurologic illnesses have specific hospice criteria to guide clinicians for referrals. Evidence supports that assisting patients with advance directives can result in improved satisfaction with care and improved quality of life in the last weeks of life. Neurologists can remain engaged in their patients' care throughout the course of illness.

Use of a new generation of adaptive servo ventilation for sleep-disordered breathing in patients with multiple system atrophy.

A 70-year-old man (case 1) and a 64-year-old woman (case 2) with multiple system atrophy (MSA) and snoring were admitted for polysomnography. Their awake PaCO2 indicated normocapnia. Apnoea-hypopnoea index (AHI), max transcutaneous carbon dioxide partial pressure (PtcCO2) and ΔPtcCO2 (max PtcCO2 (during sleep)-baseline PtcCO2 (while awake)) were 11.4/h, 63 mm Hg and 18 mm Hg, respectively, in case 1 and 53.1/h, 59 mm Hg and 13 mm Hg, respectively, in case 2. Their sleep-disordered breathing (SDB) was diagnosed as obstructive sleep apnoea with hypoventilation. We thought that variable expiratory positive airway pressure and pressure support ventilation (advanced-adaptive servo ventilation (ASV)) might be favourable for their SDB. Polysomnography after introducing advanced-ASV revealed that AHI, max PtcCO2 and ΔPtcCO2 were 0.2/h, 53 mm Hg and 5 mm Hg, respectively, in case 1 and 1.5/h, 56 mm Hg and 9 mm Hg, respectively, in case 2. Advanced-ASV for treating Cheyne-Stokes breathing may be helpful in SDB in patients with MSA.

Plasma Homocysteine, Vitamin B12 and Folate Levels in Multiple System Atrophy: A Case-Control Study.

BACKGROUND: Multiple system atrophy (MSA) is a neurodegenerative disease, and its pathological hallmark is the accumulation of α-synuclein proteins. Homocysteine (Hcy) is an intermediate amino acid generated during the metabolism of methionine. Hcy may contribute to the pathogenesis of neurodegenerative disorders. Vitamin B12 and folate are cofactors necessary for the methylation of homocysteine. METHODS: This study compared the levels of serum Hcy, vitamin B12 and folate in patients with MSA with those in healthy people to reveal the possible association between MSA and plasma levels of Hcy, vitamin B12 and folate. We enrolled 161 patients with MSA and 161 healthy people in this study. The association between MSA and the levels of Hcy, vitamin B12 and folate were analyzed using binary logistic regression. RESULTS: The mean level of Hcy in patients with MSA was significantly higher than that in healthy controls (16.23 ± 8.09 umol/l vs 14.04 ± 4.25 umol/l, p < 0.05). After adjusting for age, sex and medical history, the odds ratio for Hcy was 1.07 (95% CI = 1.01-1.13, p < 0.05) for patients with MSA. Vitamin B12 and folate levels were not significantly different between patients with MSA and controls. CONCLUSION: Our data suggest that higher levels of Hcy may be associated with an increased risk for MSA.

[Multiple system atrophy and autophagy].

Macroautophagy is a dynamic process whereby cytoplasmic molecules are sequestered within autophagosomes. There exist two groups of mammalian autophagy-related gene (Atg) 8 homologues (LC3 and GABARAPs), which play essential role in autophagosomal formation. We determined whether Atg8 homologues are affected in Lewy body disease (LBD) and multiple system atrophy (MSA). The level of LC3 was increased in an insoluble fraction from the brain of patients with LBD, whereas the level of GABARAPs was decreased in LBD. The level of matured GABARAPs was significantly decreased in the cerebellum of MSA, and that the higher levels of matured and lipidated LC3 were detected in detergent-insoluble fraction of MSA. Furthermore, immunohistochemical staining revealed that both LC3 and GABARAPs were localized in Lewy bodies and glial cytoplasmic inclusions in MSA were positive for LC3. These findings suggest that autophagic function is impaired through alteration of Atg8 homologues in LBD and MSA. Autophagy-enhancing strategies can therefore have therapeutic efficacy for various neurodegenerative diseases including LBD and MSA.

XIAP immunoreactivity in glial and neuronal cytoplasmic inclusions in multiple system atrophy.

X-linked inhibitor of apoptosis protein (XIAP) selectively binds to caspases-3, -7 and -9, and inhibits the activities of these caspases. To elucidate the role of XIAP in patients with multiple system atrophy (MSA), we performed immunohistochemical studies on XIAP in formalin-fixed, paraffin-embedded sections from 8 normal subjects and 10 patients with MSA. In normal brains, several types of neurons were immunostained for XIAP, and XIAP-immunopositive oligodendrocytes were scattered throughout the cerebral and cerebellar white matter. In the MSA brains, neuronal XIAP immunoreactivity was spared even in the severely-affected lesions, and glial cytoplasmic inclusions (GCIs), neuronal cytoplasmic inclusions (NCIs) and dystrophic neurites were all intensely immunoreactive for XIAP. A semiquantitative analysis of mid-pons sections double-immunostained for XIAP and α-synuclein demonstrated that the average percentages of XIAP-immunopositive GCIs and NCIs in the pontine nucleus were 70.2% and 82.2%, respectively. Our results suggest that a widespread accumulation of XIAP may occur in brains with MSA, and that XIAP may be partially associated with the pathogenesis of MSA.