多系统萎缩

多系统萎缩是一个与Ｓｈｙ－Ｄｒａｇｅｒ综合征、橄榄桥脑小脑萎缩和纹状体黑质变性相重叠的综合征，临床表现包括帕金森综合征、小脑征、锥体束征和植物神经功能损害。本文回顾性分析了六例多系统损害病例，其中四例在临床上可以诊断为多系统萎缩，另二例则需追踪观察和／或高场强ＭＲＩＴ２加权象才能确诊。本文对多系统萎缩的临床表现、病理改变、神经放射学特征、诊断和鉴别诊断进行了讨论。     

Myeloperoxidase Inhibition Ameliorates Multiple System Atrophy-Like Degeneration in a Transgenic Mouse Model

Multiple system atrophy (MSA) is a rare and fatal α-synucleinopathy characterized by a distinctive oligodendrogliopathy with glial cytoplasmic inclusions and associated neuronal multisystem degeneration. The majority of patients presents with a rapidly progressive parkinsonian disorder and atypical features such as early autonomic failure and cerebellar ataxia. We have previously reported that complete MSA pathology can be modeled in transgenic mice overexpressing oligodendroglial α-synuclein under conditions of oxidative stress induced by 3-nitropropionic acid (3-NP) including striatonigral degeneration, olivopontocerebellar atrophy, astrogliosis, and microglial activation. Here, we show that myeloperoxidase (MPO), a key enzyme involved in the production of reactive oxygen species by phagocytic cells, is expressed in both human and mouse MSA brains. We also demonstrate that in the MSA mouse model, MPO inhibition reduces motor impairment and rescues vulnerable neurons in striatum, substantia nigra pars compacta, cerebellar cortex, pontine nuclei, and inferior olives. MPO inhibition is associated with suppression of microglial activation but does not affect 3-NP induced astrogliosis in the same regions. Finally, MPO inhibition results in reduced intracellular aggregates of α-synuclein. This study suggests that MPO inhibition may represent a novel candidate treatment strategy against MSA-like neurodegeneration acting through its anti-inflammatory and anti-oxidative properties.     

Micturitional Disturbance in Multiple System Atrophy

Abstract: Detailed micturitional histories and urodynamic studies were conducted to investigate the micturitional disturbance in multiple system atrophy (MSA). Eighty-six patients with MSA comprised of 14 with striatonigral degeneration (SND), 42 with olivopontocerebellar atrophy (OPCA) and 30 with Shy-Drager syndrome (SDS). The results were as follows. Micturitional symptoms were noted in over 90% of patients with each type of MSA. Dominant symptoms were irritative ones in SND and OPCA, and a combination of irritative and obstructive ones in SDS. Micturitional symptoms in SDS appeared earlier than those in SND or OPCA. The degree of micturitional disturbance was severer in SDS than in SND or OPCA. Micturitional disturbance tended to become worse as the disease progressed. The responsible sites of lesions of micturitional disturbance seemed to be supra- as well as infranuclear lesions of the pelvic and pudendal nerves in MSA. Infranuclear lesions were more prominent in SDS than in SND or OPCA. Follow-up studies of some of the patients with SDS and OPCA suggested that the responsible sites of pelvic nerve lesions changed from supra- to infranuclear lesions during the course of disease.     

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.     

Current Management and Emerging Therapies in Multiple System Atrophy

Multiple system atrophy (MSA) is a progressive neurodegenerative disease variably associated with motor, nonmotor, and autonomic symptoms, resulting from putaminal and cerebellar degeneration and associated with glial cytoplasmic inclusions enriched with α-synuclein in oligodendrocytes and neurons. Although symptomatic treatment of MSA can provide significant improvements in quality of life, the benefit is often partial, limited by adverse effects, and fails to treat the underlying cause. Consistent with the multisystem nature of the disease and evidence that motor symptoms, autonomic failure, and depression drive patient assessments of quality of life, treatment is best achieved through a coordinated multidisciplinary approach driven by the patient’s priorities and goals of care. Research into disease-modifying therapies is ongoing with a particular focus on synuclein-targeted therapies among others. This review focuses on both current management and emerging therapies for this devastating disease.Electronic supplementary materialThe online version of this article (10.1007/s13311-020-00890-x) contains supplementary material, which is available to authorized users.Key Words: Multiple system atrophy, multidisciplinary care, α-synuclein, symptomatic therapy, disease-modifying     

The North American Multiple System Atrophy Study Group

Summary. The North American Multiple System Atrophy Study Group involves investigators in 12 US medical centers funded by a grant from the National Institutes of Health. The objectives are to examine the environmental and genetic risk factors for MSA; elucidate pathogenic mechanisms underlying the disorder; and refine evaluations used for assessment. During its first year, the group enrolled 87 patients, implemented four cores, and initiated four scientific projects. Most patients among the 87 had parkinsonian features, which frequently began asymmetrically and remained asymmetrical; one-third responded to levodopa and many developed levodopa complications; almost two-thirds of the patients had cerebellar dysfunction, of these 90% had ataxia; urinary incontinence occurred commonly, and sleep disorders affected most. The investigators studied the effects of oxidative and nitrative stress upon the formation of alpha-synuclein inclusions; generated transgenic models of alpha-synuclein accumulation that recapitulate several behavioral and neuropathological features of MSA; and compared the severity of the autonomic features of MSA, Parkinson’s disease and dementia with Lewy bodies.     

Genome-wide estimate of the heritability of Multiple System Atrophy

IntroductionMultiple System Atrophy (MSA) is a neurodegenerative disease which presents heterogeneously with symptoms and signs of parkinsonism, ataxia and autonomic dysfunction. Although MSA typically occurs sporadically, rare pathology-proven MSA families following either autosomal recessive or autosomal dominant patterns have been described, indicating a heritable contribution to the pathogenesis.MethodsWe used Genome-Wide Complex Trait Analysis (GCTA) to estimate the heritable component of MSA due to common coding variability in imputed genotype data of 907 MSA cases and 3866 population-matched controls. GCTA only assesses the effect of putative causal variants in linkage disequilibrium (LD) with all common SNPs on the genotyping platform.ResultsWe estimate the heritability among common variants of MSA in pooled cases at 2.09–6.65%, with a wider range of values in geographic and diagnostic subgroups. Meta-analysis of our geographic cohorts reveals high between-group heterogeneity. Contributions of single chromosomes are generally negligible. We suggest that all calculated MSA heritability among common variants could be explained by the presence of misdiagnosed cases in the clinical subgroup based on a Bayesian estimate using literature-derived rates of misdiagnosis.DiscussionMSA is a challenging disease to study due to high rates of misdiagnosis and low prevalence. Given our low estimates of heritability, common genetic variation appears to play a less prominent role in risk for MSA than in other complex neurodegenerative diseases such as Parkinson's disease, Alzheimer's disease, and Amyotrophic Lateral Sclerosis. The success of future gene discovery efforts rests on large pathologically-confirmed case series and an interrogation of both common and rare genetic variants.     

Nocturnal Pulse Event Frequency Is Reduced in Multiple System Atrophy

Risk of sudden death in multiple system atrophy (MSA) is greatest during sleep with unknown mechanisms. We compared nocturnal pulse event frequency in 46 MSA patients and age-/sex-matched controls undergoing overnight pulse oximetry. Nocturnal oxyhemoglobin desaturation indices and pulse event indices (PEIs) were recorded, and relationships between pulse oximetry variables and survival were analyzed. MSA patients had lower PEI (3.1 ± 5.3 vs. 12.8 ± 10.8, p < 0.001) despite greater hypoxic burden and similar frequency of respiratory events. Nocturnal pulse events were not associated with severity of daytime autonomic failure. Two MSA patients had suspected sudden death, both with severely reduced PEI. MSA patients have fewer nocturnal pulse events compared with controls, despite similar respiratory event frequency, suggesting abnormal cardiac responses to sleep-disordered breathing. Whether this contributes to sudden death in MSA requires further study. ANN NEUROL 2023;93:205–212     

Intrathecal Baclofen Therapy Slows Progressive Disability in Multiple System Atrophy

Objectives: Evaluate the benefit of intrathecal baclofen (ITB) therapy on function, quality of life, and progression in patients with multiple system atrophy (MSA). Methods: We report on three MSA patients at different stages treated with ITB therapy. MSA patients were staged using Watanabe et al. ADL milestones for disease progression and by scales for tone (modified Ashworth scale) ambulation (Hauser ambulation index) and disability (expanded disability status scale) Results: All three patients had an improvement in the modified Ashworth scale and none had progression in their disability or ambulatory outcomes and did not progress as predicted by Watanabe et al. Conclusions: Our results suggest that ITB can maintain (or improve function) and maintain quality of life in patients with MSA. ITB is currently not indicated for patients with MSA but should be studied further for the quality of life benefits and delay in disease progression it potentially provides.     

多发性硬化伴肌萎缩

本文报道２例多发性硬化（ｍｕｔｉｐｌｅｓｃｌｅｒｏｓｉｓ，ＭＳ）伴肌肉萎缩患者，发现这种萎缩以出现早、较局限、以手肌最早受累为特点。结合国外有关研究及本组电生理检查，推测ＭＳ伴肌萎缩的原因有两种：（１）中枢性萎缩；（２）前角及前根髓内病变。临床上应注意与肌萎缩侧索硬化相鉴别。     

Multiple System Atrophy: Recent Developments and Future Perspectives

Multiple system atrophy (MSA) is a rare and fatal neurodegenerative disorder characterized by a variable combination of parkinsonism, cerebellar impairment, and autonomic dysfunction. The pathologic hallmark is the accumulation of aggregated α‐synuclein in oligodendrocytes, forming glial cytoplasmic inclusions, which qualifies MSA as a synucleinopathy together with Parkinson's disease and dementia with Lewy bodies. The underlying pathogenesis is still not well understood. Some symptomatic treatments are available, whereas neuroprotection remains an urgent unmet treatment need. In this review, we critically appraise significant developments of the past decade with emphasis on pathogenesis, diagnosis, prognosis, and treatment development. We further discuss unsolved questions and highlight some perspectives. © 2019 International Parkinson and Movement Disorder Society     

Association of Metallothionein-III with Oligodendroglial Cytoplasmic Inclusions in Multiple System Atrophy

Multiple system atrophy (MSA) is an adult-onset neurodegenerative disease characterised by Parkinsonian and autonomic symptoms and by widespread intracytoplasmic inclusion bodies in oligodendrocytes. These glial cytoplasmic inclusions (GCIs) are comprised of 9–10 nm filaments rich in the protein alpha-synuclein, also found in neuronal inclusion bodies associated with Parkinson’s disease. Metallothioneins (MTs) are a class of low-molecular weight (6–7 kDa), cysteine-rich metal-binding proteins the expression of which is induced by heavy metals, glucocorticoids, cytokines and oxidative stress. Recent studies have shown a role for the ubiquitously expressed MT-I/II isoforms in the brain following a variety of stresses, whereas, the function of the brain-specific MT isoform, MT-III, is less clear. MT-III and MT-I/II immunostaining of post-mortem tissue in MSA and normal control human brains showed that the number of MT-III-positive cells is significantly increased in MSA in visual cortex, whereas MT-I/II isoforms showed no significant difference in the distribution of immunopositive cells in MSA compared to normal tissue. GCIs were immunopositive for MT-III, but were immunonegative for the MT-I/II isoforms. Immunofluorescence double labelling showed the co-localisation of alpha-synuclein and MT-III in GCIs in MSA tissue. In isolated GCIs, transmission electron microscopy demonstrated MT-III immunogold labelling of the amorphous material surrounding alpha-synuclein filaments in GCIs. High-molecular weight MT-III species in addition to MT-III monomer were detected in GCIs by Western analysis of the detergent-solubilised proteins of purified GCIs. These results show that MT-III, but not MT-I/II, is a specific component of GCIs, present in abnormal aggregated forms external to the alpha-synuclein filaments.