Multiple System Atrophy With Predominant Parkinsonism Research Articles

Differentiation between Parkinson's Disease and the Parkinsonian Subtype of Multiple System Atrophy Using the Magnetic Resonance T1w/T2w Ratio in the Middle Cerebellar Peduncle.

Multiple system atrophy with predominant parkinsonism (MSA-P) can hardly be distinguished from Parkinson's disease (PD) clinically in the early stages. This study investigated whether a standardized T1-weighted/T2-weighted ratio (sT1w/T2w ratio) can effectively detect degenerative changes in the middle cerebellar peduncle (MCP) associated with MSA-P and PD and evaluated its potential to distinguish between these two diseases. We included 35 patients with MSA-P, 32 patients with PD, and 17 controls. T1w and T2w scans were acquired using a 1.5-T MR system. The MCP sT1w/T2w ratio was analyzed via SPM12 using a region-of-interest approach in a normalized space. The diagnostic performance of the MCP sT1w/T2w ratio was compared between the MSA-P, PD, and controls. Patients with MSA-P had significantly lower MCP sT1w/T2w ratios than patients with PD and controls. Furthermore, MCP sT1w/T2w ratios were lower in patients with PD than in the controls. The MCP sT1w/T2w ratio showed excellent or good accuracy for differentiating MSA-P or PD from the control (area under the curve (AUC) = 0.919 and 0.814, respectively) and substantial power for differentiating MSA-P from PD (AUC = 0.724). Therefore, the MCP sT1w/T2w ratio is sensitive in detecting degenerative changes in the MCP associated with MSA-P and PD and is useful in distinguishing MSA-P from PD.

Abnormal Ocular Movement in the Early Stage of Multiple-System Atrophy With Predominant Parkinsonism Distinct From Parkinson's Disease.

The eye-movement examination can be applied as a noninvasive method to identify multiple-system atrophy (MSA). Few studies have investigated eye movements during the early stage of MSA with predominant parkinsonism (MSA-P). We aimed to determine the characteristic oculomotor changes in the early stage of MSA-P. We retrospectively selected 17 patients with MSA-P and 40 with Parkinson's disease (PD) with disease durations of less than 2 years, and 40 age-matched healthy controls (HCs). Oculomotor performance in the horizontal direction was measured in detail using videonystagmography. We found that the proportions of patients with MSA-P and PD exhibiting abnormal eye movements were 82.4% and 77.5%, respectively, which were significantly higher than that in the HCs (47.5%, p<0.05). Compared with HCs, patients with MSA-P presented significantly higher abnormal proportions of fixation and gaze-holding (17.6% vs. 0%), without-fixation (47.1% vs. 0%), prolonged latency in reflexive saccades (29.4% vs. 5.0%), memory-guided saccades (93.3% vs. 10.0%), and catch-up saccades in smooth-pursuit movement (SPM, 41.2% vs. 0) (all p<0.05). Compared with those with PD, patients with MSA-P presented a significantly higher proportion of catch-up saccades in SPM (41.2% vs. 2.5%, p<0.001). MSA-P presented the characteristic of catch-up saccades in SPM in the early stage, which may provide some value in differentiating MSA-P from PD.

Freezing of gait in Chinese patients with multiple system atrophy: prevalence and risk factors.

Freezing of gait (FOG) is common in neurodegenerative forms of atypical parkinsonism, but few studies have examined FOG in multiple system atrophy (MSA). In this study, we examined the prevalence of freezing of gait and its relationship to clinical features in a large cohort of Chinese MSA patients. This exploratory study included 202 Chinese patients with probable MSA. FOG was defined as a score ≥ 1 on item 14 of the Unified Parkinson's Disease Rating Scale. Patients with or without FOG were compared in terms of the Unified MSA Rating Scale (UMSARS) as well as cognitive and neuropsychiatric assessments. The frequency of FOG was 48.0, 52.1, and 38.7% in MSA, MSA with predominant parkinsonism (MSA-P), and MSA with predominant cerebellar ataxia (MSA-C), respectively. FOG was associated with worse subscores on parts I, II and IV of the UMSARS as well as worse total UMSARS score; greater likelihood of speech difficulties, falls, gait impairment and balance disorder; more severe symptoms of anxiety and depression; and lower activities of daily living. The binary logistic regression model indicated that higher total UMSARS scores were associated with FOG in MSA, MSA-P, and MSA-C patients. Freezing of gait may be common among Chinese MSA patients, FOG may correlate with severe motor symptoms, anxiety, depression and activities of daily living. Total UMSARS score may be an independent risk factor for FOG.

Plasma Biomarkers and Positron Emission Tomography Tau Pathology in Progressive Supranuclear Palsy.

Development of disease-modifying therapeutic trials of progressive supranuclear palsy (PSP) urges the need for sensitive fluid biomarkers. The objectives of this study were to explore the utility of plasma biomarkers in the diagnosis, differential diagnosis, and assessment of disease severity, brain atrophy, and tau deposition in PSP. Plasma biomarkers were measured using a single-molecule array in a cohort composed of patients with PSP, Parkinson's disease (PD), multiple system atrophy with predominant parkinsonism (MSA-P), and healthy controls (HCs). Plasma neurofilament light chain (NfL) outperformed other plasma makers (ie, glial fibrillary acidic protein [GFAP], phosphorylated-tau 181 [p-tau181], amyloid-β 1-40, amyloid-β 1-42) in identifying PSP from HC (area under the curve [AUC]=0.904) and from MSA-P (AUC=0.711). Plasma GFAP aided in distinguishing PSP from HC (AUC=0.774) and from MSA-P (AUC=0.832). It correlated with brainstem atrophy and higher regional tau accumulation. However, plasma p-tau181 neither helped in diagnosis nor was it associated with clinical or neuroimaging measures. Plasma NfL and GFAP showed different values in differentiating PSP from HC or controls with other forms of neurodegenerative parkinsonism and detecting disease severity, brain atrophy, or tau deposition in PSP. © 2023 International Parkinson and Movement Disorder Society.

Automatic classification of MSA subtypes using Whole-brain gray matter function and Structure-Based radiomics approach

BackgroundThis study aims to develop a radiomics method based on the function and structure of whole-brain gray matter to accurately classify multiple system atrophy with predominant Parkinsonism (MSA-P) or predominant cerebellar ataxia (MSA-C). MethodsWe enrolled 30 MSA-C and 41 MSA-P cases for the internal cohort and 11 MSA-C and 10 MSA-P cases for the external test cohort. We extracted 7,308 features, including gray matter volume (GMV), mean amplitude of low-frequency fluctuation (mALFF), mean regional homogeneity (mReHo), degree of centrality (DC), voxel-mirrored homotopic connectivity (VMHC), and resting-state functional connectivity (RSFC) from 3D-T1 and Rs-fMR data. Feature selection was conducted with t-test and least absolute shrinkage and selection operator (Lasso). Classification was performed using the support vector machine with linear and RBF kernel (SVM-linear/SVM-RBF), random forest and logistic regression. Model performance was assessed via receiver operating characteristic (ROC) curve and compared with DeLong's test. ResultsFeature selection resulted in 12 features, including 1 ALFF, 1 DC and 10 RSFC. All the classifiers showed remarkable classification performance, especially the RF model which exhibited AUC values of 0.91 and 0.80 in the validation and test datasets, respectively. The brain functional activity and connectivity in the cerebellum, orbitofrontal lobe and limbic system were important features to distinguish MSA subtypes with the same disease severity and duration. ConclusionRadiomics approach has the potential to support clinical diagnostic systems and to achieve high classification accuracy for distinguishing between MSA-C and MSA-P patients at the individual level.

Structural and metabolic correlates of neuropsychological profiles in multiple system atrophy and Parkinson's disease

BackgroundDespite increased recognition of cognitive impairment in Multiple System Atrophy (MSA), its neuroanatomical correlates are not well defined. We aimed to explore cognitive profiles in MSA with predominant parkinsonism (MSA-P) and Parkinson's disease (PD) and their relationship to frontostriatal structural and metabolic changes. MethodsDetailed clinical and neuropsychological evaluation was performed together with diffusion tensor imaging (DTI) and [18F]-fluoro-deoxyglucose positron emission tomography ([18F]-FDG-PET) in patients with MSA-P (n = 11) and PD (n = 11). We compared clinical and neuropsychological data to healthy controls (n = 9) and correlated neuropsychological data with imaging findings in MSA-P and PD. ResultsPatients with MSA-P showed deficits in executive function (Trail Making Test B-A) and scored higher in measures of depression and anxiety compared to those with PD and healthy controls. Widespread frontostriatal white matter tract reduction in fractional anisotropy was seen in MSA-P and PD compared to an imaging control group. Stroop Test interference performance correlated with [18F]-FDG uptake in the bilateral dorsolateral prefrontal cortex (DLPFC) and with white matter integrity between the striatum and left inferior frontal gyrus (IFG) in PD. Trail Making Test performance correlated with corticostriatal white matter integrity along tracts from the bilateral IFG in MSA-P and from the right DLPFC in both groups. ConclusionExecutive dysfunction was more prominent in patients with MSA-P compared to PD. DLPFC metabolism and frontostriatal white matter integrity seem to be a driver of executive function in PD, whereas alterations in corticostriatal white matter integrity may contribute more to executive dysfunction in MSA-P.

Clinical and Genetic Features of Multiplex Families with Multiple System Atrophy and Parkinson's Disease.

While multiple system atrophy (MSA) has been considered a sporadic disease, there were previously reported multiplex families with MSA. Furthermore, several families with multiple patients with MSA and Parkinson's disease (PD) have been reported. As genetic risk factors for MSA, functionally impaired variants in COQ2 and Gaucher-disease-causing GBA variants have been reported. While it has been established that GBA variants are associated with PD, COQ2 may also be associated with PD. In 672 patients with MSA, we identified 12 multiplex families of patients with MSA and PD in first-degree relatives. We conducted a detailed analysis of the clinical presentations of these patients and genetic analyses of GBA and COQ2. In the multiplex families, a patient with MSA with predominant parkinsonism (MSA-P) was observed in nine families, while a patient with MSA cerebellar subtype (MSA-C) was observed in three families. Six families had siblings with MSA and PD, five families had a parent-offspring pair with MSA and PD, and in one family, a sibling and a parent of an MSA patient had PD. In genetic analyses of these patients, GBA variants were identified in one of the 12 MSA patients and two of the seven PD patients. Functionally impaired variants of COQ2 were identified in two of the 12 MSA patients and not identified in the seven PD patients. This study further emphasizes the occurrence of MSA and PD in first-degree relatives, raising the possibility that a common genetic basis underlies MSA and PD. Even though variants of COQ2 and GBA were identified in some patients in multiplex families with MSA and PD, it is necessary to further explore as yet unidentified genetic risk factors shared by MSA and PD.

Semiautomated Algorithm for the Diagnosis of Multiple System Atrophy With Predominant Parkinsonism.

ObjectivePutaminal iron deposition is an important feature that helps differentiate multiple system atrophy with predominant parkinsonism (MSA-p) from Parkinson’s disease (PD). Most previous studies used visual inspection or quantitative methods with manual manipulation to perform this differentiation. We investigated the value of a new semiautomated diagnostic algorithm using 3T-MR susceptibility-weighted imaging for MSA-p.MethodsThis study included 26 MSA-p, 68 PD, and 41 normal control (NC) subjects. The algorithm was developed in 2 steps: 1) determine the image containing the remarkable putaminal margin and 2) calculate the phase-shift values, which reflect the iron concentration. The next step was to identify the best differentiating conditions among several combinations. The highest phase-shift value of each subject was used to assess the most effective diagnostic set.ResultsThe raw phase-shift values were present along the lateral margin of the putamen in each group. It demonstrates an anterior-to-posterior gradient that was identified most frequently in MSA-p. The average of anterior 5 phase shift values were used for normalization. The highest area under the receiver operating characteristic curve (0.874, 80.8% sensitivity, and 86.7% specificity) of MSA-p versus PD was obtained under the combination of 3 or 4 vertical pixels and one dominant side when the normalization methods were applied. In the subanalysis for the MSA-p patients with a longer disease duration, the performance of the algorithm improved.ConclusionThis algorithm detected the putaminal lateral margin well, provided insight into the iron distribution of the putaminal rim of MSA-p, and demonstrated good performance in differentiating MSA-p from PD.

Heterogeneity of Multiple System Atrophy: An Update.

Multiple system atrophy (MSA) is a fatal, rapidly progressing neurodegenerative disease of uncertain etiology, clinically characterized by various combinations of Levodopa unresponsive parkinsonism, cerebellar, autonomic and motor dysfunctions. The morphological hallmark of this α-synucleinopathy is the deposition of aberrant α-synuclein in both glia, mainly oligodendroglia (glial cytoplasmic inclusions /GCIs/) and neurons, associated with glioneuronal degeneration of the striatonigral, olivopontocerebellar and many other neuronal systems. Typical phenotypes are MSA with predominant parkinsonism (MSA-P) and a cerebellar variant (MSA-C) with olivocerebellar atrophy. However, MSA can present with a wider range of clinical and pathological features than previously thought. In addition to rare combined or “mixed” MSA, there is a broad spectrum of atypical MSA variants, such as those with a different age at onset and disease duration, “minimal change” or prodromal forms, MSA variants with Lewy body disease or severe hippocampal pathology, rare forms with an unusual tau pathology or spinal myoclonus, an increasing number of MSA cases with cognitive impairment/dementia, rare familial forms, and questionable conjugal MSA. These variants that do not fit into the current classification of MSA are a major challenge for the diagnosis of this unique proteinopathy. Although the clinical diagnostic accuracy and differential diagnosis of MSA have improved by using combined biomarkers, its distinction from clinically similar extrapyramidal disorders with other pathologies and etiologies may be difficult. These aspects should be taken into consideration when revising the current diagnostic criteria. This appears important given that disease-modifying treatment strategies for this hitherto incurable disorder are under investigation.

The Frontal and Cerebellar Metabolism Related to Cognitive Dysfunction in Multiple System Atrophy.

BackgroundCognitive dysfunctions have been reported in multiple system atrophy (MSA). However the underlying mechanisms remain to be elucidated. This study aimed to explore the possible cerebral metabolism associated with domain-specific cognitive performances in MSA.MethodsA total of 84 patients were diagnosed as probable or possible MSA, comprised of 27 patients as MSA with predominant parkinsonism (MSA-P) and 57 patients as MSA with predominant cerebellar ataxia (MSA-C). The comprehensive neuropsychological tests and 18F-fluorodeoxyglucose (18F-FDG) positron emission tomography (PET) imaging were performed. Z-score was calculated to non-dimensionalize and unify indicators of different tests in the domains of executive function, attention, language, memory, and visuospatial function. Correlations between specific Z-score and cerebral 18F-FDG uptake were analyzed using statistical parametric mapping. The cognition-related metabolic differences between patients with MSA-P and MSA-C were analyzed using the post-hoc test.ResultsZ-scores of the domains including attention, executive function, and language correlated positively with the metabolism in the superior/inferior frontal gyrus and cerebellum, but negatively with that in the insula and fusiform gyrus (p < 0.001). No significant differences in neuropsychological performances and frontal metabolism were found between patients with MSA-P and MSA-C. Only lower metabolism in the cerebellum was observed in MSA-C.ConclusionMetabolic changes in the frontal lobe and cerebellum may participate in the cognitive impairments of patients with MSA. Nevertheless, cognitive and corresponding metabolic differences between the two subtypes of MSA still need more exploration.

Vascular Risk Factors and Cognition in Multiple System Atrophy.

Objective: Vascular risk factors have been reported to be associated with cognitive impairment (CI) in the general population, but their role on CI in multiple system atrophy (MSA) is unclear. This study aimed to explore the relationship between vascular risk factors and CI in patients with MSA.Methods: The clinical data and vascular risk factors were collected. The Montreal Cognitive Assessment tool was used to test the cognitive function of patients with MSA. Binary logistic regression was used to analyze the correlation between vascular risk factors and CI.Results: A total of 658 patients with MSA with a mean disease duration of 2.55 ± 1.47 years were enrolled. In MSA patients, hypertension was recorded in 20.2%, diabetes mellitus in 10.3%, hyperlipidemia in 10.2%, smoking in 41.2%, drinking in 34.8%, and obesity in 9.6%. The prevalence of CI in patients with MSA, MSA with predominant parkinsonism (MSA-P), and MSA with predominant cerebellar ataxia (MSA-C) was 45.0, 45.1, and 44.9%, respectively. In the binary logistic regression model, patients with more than one vascular risk factors were significantly more likely to have CI in MSA (OR = 4.298, 95% CI 1.456–12.691, P = 0.008) and MSA-P (OR = 6.952, 95% CI 1.390–34.774, P = 0.018), after adjusting for age, sex, educational years, disease duration, and total Unified multiple system atrophy rating scale scores.Conclusion: Multiple vascular risk factors had a cumulative impact on CI in MSA. Therefore, the comprehensive management of vascular risk factors in MSA should not be neglected.

Parkinsonism and dysautonomia with anti-CV2/CRMP5 associated paraneoplastic neurological syndromes mimicking multiple system atrophy: a case report

BackgroundParaneoplastic neurological syndromes (PNSs) are broad-spectrum disorders that can affect any part of the nervous system varying in core symptoms. Onconeural antibodies, including Hu, Yo, Ri, anti-CV2, amphiphysin, Ma2, and Tr are well-characterized and commonly used for the diagnosis of definite PNS. Generally, anti-CV2 antibodies have usually been associated with cerebellar ataxia, chorea, peripheral and autonomic neuropathies, myelopathy, optic neuritis, and retinitis. However, Parkinsonism has not been reported as the core symptom in patients with anti-CV2 antibodies.Case presentationWe report a patient with anti-CV2 antibody manifested as Parkinsonism and autonomic dysfunction, which may lead to the diagnosis of multiple system atrophy with predominant Parkinsonism (MSA-P). A lumbar puncture examination was undergone to find a positive anti-CV2 antibody in cerebrospinal fluid. PET-CT showed no tumor. Immunotherapy was adopted and the symptoms were relieved for 5 months. However, with no evidence of tumor, he died after 8 months.ConclusionsOur findings indicate that PNS with anti-CV2 antibody can be shown as MSA-P mimic. Considering that MSA is a neurodegenerative disease with a poor prognosis, screening for other treatable or controllable factors like PNS presented in this case is necessary when encountering a rapid progressive MSA-mimic patient.

Fatigue in Patients With Multiple System Atrophy: A Prospective Cohort Study.

Nonmotor symptoms are common in patients with multiple system atrophy (MSA), but there is limited knowledge regarding fatigue in MSA. This study aimed to investigate the frequency and evolution of fatigue and the factors related to fatigue and its progression in patients with MSA at an early stage. Patients with probable MSA were comprehensively evaluated at both baseline and the 1-year follow-up, including their motor and nonmotor symptoms. Fatigue and anxiety were assessed using the Fatigue Severity Scale (FSS) and Hamilton Anxiety Rating Scale (HARS), respectively. Orthostatic hypotension (OH) was defined as a decrease in the systolic or diastolic blood pressure by at least 30 and 15 mm Hg, respectively. The binary logistic regression model and linear regression model were used to analyze the factors related to fatigue and its progression, respectively. This study enrolled 146 patients with MSA. The frequency of fatigue was 60.3%, 55.1%, and 64.9% in MSA, MSA with predominant parkinsonism (MSA-P), and MSA with predominant cerebellar ataxia (MSA-C), respectively. The frequency of fatigue and the FSS score in patients with MSA increased from baseline to the 1-year follow-up (p < 0.05). Young age (odds ratio [OR] 0.939, 95% confidence interval [CI] 0.894-0.987), OH (OR 2.806, 95% CI 1.253-6.286), and high HARS score (OR 1.014, 95% CI 1.035-1.177) were associated with fatigue in MSA. OH was associated with fatigue in MSA-P (OR 3.391, 95% CI 1.066-10.788), while high HARS score was associated with fatigue in MSA-C (OR 1.159, 95% CI 1.043-1.287). In addition, only low FSS scores at baseline were associated with the annual progression rate of FSS scores in MSA, MSA-P, and MSA-C (p < 0.05). Neurofilament light chain, α-synuclein, glial fibrillary acidic protein, brain-derived neurotrophic factor, and triggering receptor expressed on myeloid cell-2 were not significantly associated with fatigue and its progression in MSA. Fatigue was prevalent in early-stage MSA, and it increased and remained persistent over time. This study demonstrated that OH and anxiety were associated with fatigue in patients with MSA.

Bereitschaftspotential in Multiple System Atrophy.

Objective: Multiple system atrophy (MSA) is a neurodegenerative disorder manifesting as parkinsonism, cerebellar ataxia, and autonomic dysfunction. It is categorized into MSA with predominant parkinsonism (MSA-P) and into MSA with predominant cerebellar ataxia (MSA-C). The pathophysiology of motor control circuitry involvement in MSA subtype is unclear. Bereitschaftspotential (BP) is a feasible clinical tool to measure electroencephalographic activity prior to volitional motions. We recorded BP in patients with MSA-P and MSA-C to investigate their motor cortical preparation and activation for volitional movement.Methods: We included eight patients with MSA-P, eight patients with MSA-C, and eight age-matched healthy controls. BP was recorded during self-paced rapid wrist extension movements. The electroencephalographic epochs were time-locked to the electromyography onset of the voluntary wrist movements. The three groups were compared with respect to the mean amplitudes of early (1,500–500 ms before movement onset) and late (500–0 ms before movement onset) BP.Results: Mean early BP amplitude was non-significantly different between the three groups. Mean late BP amplitude in the two patient groups was significantly reduced in the parietal area contralateral to the movement side compared with that in the healthy control group. In addition, the late BP of the MSA-C group but not the MSA-P group was significantly reduced at the central parietal area compared with that of the healthy control group.Conclusions: Our findings suggest that patients with MSA exhibit motor cortical dysfunction in voluntary movement preparation and activation. The dysfunction can be practicably evaluated using late BP, which represents the cerebello-dentato-thalamo-cortical pathway.

Plasma Short-Chain Fatty Acids Differences in Multiple System Atrophy from Parkinson's Disease.

Multiple system atrophy (MSA) and Parkinson's disease (PD) have overlapping symptoms, making diagnosis challenging. Short-chain fatty acids (SCFAs) are produced exclusively by gut microbiota and were reduced in feces of MSA patients. However, plasma SCFA concentrations in MSA patients have not been investigated. We aimed to investigate the plasma SCFAs in MSA patients and to identify the potential differential diagnostic ability. Plasma SCFA were measured in 25 MSA patients, 46 healthy controls, and 46 PD patients using gas chromatography-mass spectrometry. Demographic and clinical characteristics of the participants were evaluated. Acetic acid concentration was lower in MSA patients than in healthy controls. Acetic acid and propionic acid concentrations were lower in MSA and MSA with predominant parkinsonism (MSA-P) patients than in PD patients. A receiver operating characteristic curve (ROC) analysis revealed reduced acetic acid concentration discriminated MSA patients from healthy controls with 76% specificity but only 57% sensitivity and an area under the curve (AUC) of 0.68 (95% confidence interval (CI): 0.55-0.81). Combined acetic acid and propionic acid concentrations discriminated MSA patients from PD patients with an AUC of 0.82 (95% CI: 0.71-0.93), 84% specificity and 76% sensitivity. Especially, with combined acetic acid and propionic acid concentrations, MSA-P patients were separated from PD patients with an AUC of 0.89 (95% CI: 0.80-0.97), 91% specificity and 80% sensitivity. Plasma SCFAs were decreased in MSA patients. The combined acetic acid and propionic acid concentrations may be a potential biomarker for differentiating MSA patients from PD patients.

A study on the characteristics of cognitive function in patients with multiple system atrophy in China

Nonmotor symptoms in patients with multiple system atrophy (MSA) have received an increasing amount of attention in recent years, but no research on MSA patients' cognitive characteristics has been conducted in China. To evaluate the cognitive function of MSA patients in China. Using a case–control study design, 256 MSA patients and 64 controls were evaluated by the Montreal cognitive assessment (MoCA) scale to characterize their cognitive function. Like the controls, 60.5% of the patients with MSA had cognitive impairment, but the characteristics of cognitive impairment between the two groups were different. The cognitive impairment in MSA patients was prominent in the cognitive domains of visuospatial/executive functions, naming, attention, and orientation; particularly, the visuospatial/executive functions were the most significantly impaired, while impairment in language function was mainly seen in the controls. Besides, impairments in visuospatial/executive functions, attention, language, and orientation were more prominent in MSA-P (MSA with predominant Parkinsonism) patients than in MSA-C (MSA with predominant cerebellar ataxia). The cognitive impairments were more severe in patients with probable MSA than in patients with possible MSA. In addition, the results showed that the level of cognitive function was negatively correlated with the severity of MSA. This study, which characterized the cognitive function of MSA patients with the largest sample size known so far in China, found that patients with MSA do have cognitive impairment and display specific characteristics. Therefore, the cognitive impairment of MSA should be paid more attention.The study has been registered in the Chinese Clinical Trial Registry (ChiCTR) (Registration No: ChiCTR1900022462).

Differences of cerebral perfusion between subtype of multiple system atrophy with predominant cerebellar ataxia and with predominant parkinsonism

Objective: The abnormally low regional cerebral blood flow (rCBF) in multiple system atrophy (MSA) has been reported in the cerebellum, pons, and the striatum. The aim of the present study was to investigate the difference of rCBF between MSA with predominant cerebellar ataxia (MSA-C) and MSA with predominant parkinsonism (MSA-P).

Effectiveness of Levodopa in Patients with Multiple System Atrophy and Associated Clinicopathological Features.

Objective To determine the clinicopathological features of levodopa or dopamine agonist (DA) responders with multiple system atrophy (MSA), an autopsy-confirmed diagnosis is vital due to concomitant cases of MSA and Parkinson's disease (PD). We therefore aimed to investigate the effectiveness of levodopa and DA in autopsy cases of MSA without PD and thereby clarify the clinical course, magnetic resonance imaging (MRI) findings, and pathological features of levodopa-responsive MSA cases. Methods The medical records (clinical data, MRI findings, and pathological findings) of 12 patients with MSA were obtained, and the patients were pathologically confirmed to not have PD. The clinical diagnoses of the patients were MSA with predominant parkinsonism (MSA-P) (n=7), MSA with predominant cerebellar ataxia (MSA-C) (n=4), and progressive supranuclear palsy (PSP) with a concomitant pathology of MSA (n=1). Results Nine patients received a maximum dose of 300-900 mg of levodopa as treatment, which was effective in two MSA-P patients and mildly effective in another two MSA-P patients. DA was mildly effective in one MSA-C patient. The levodopa responders showed marked autonomic dysfunction relatively late and became bedridden after 10 years. Additionally, they exhibited bilateral hyperintense putaminal rims in MRIs after six and nine years, respectively, after disease onset. One levodopa responder and one DA mild responder showed relatively mild neurodegeneration of the putamen. Conclusion Levodopa responders, despite having MSA-P, may show a relatively slow progression in putaminal neurodegeneration, and might maintain prolonged daily life activities in cases without an early occurrence of autonomic dysfunction.

Comparison of Neuropathological Characteristics between Multiple System Atrophy Cerebellar Type and Parkinsonian Type

Background: Multiple system atrophy (MSA) is a sporadic neurodegenerative disease characterized by various combinations of parkinsonism, cerebellar ataxia, autonomic dysfunction and pyramidal signs. Two clinical subtypes are recognized: MSA with predominant cerebellar ataxia (MSA-C) and MSA with predominant parkinsonism (MSA-P). The aim of this study was to compare pathological features between MSA-C and MSA-P.Methods: Two autopsy confirmed cases with MSA were included from the Pusan National University Hospital Brain Bank. Case 1 had been clinically diagnosed as MSA-C and case 2 as MSA-P. The severity of neuronal loss and gliosis as well as the glial and neuronal cytoplasmic inclusions were semiquantitatively assessed in both striatonigral and olivopontocerebellar regions. Based on the grading system, pathological phenotypes of MSA were classified as striatonigral degeneration (SND) predominant (SND type), olivopontocerebellar degeneration (OPC) predominant (OPC type), or equivalent SND and OPC pathology (SND=OPC type).Results: Both cases showed widespread and abundant α-synuclein positive glial cytoplasmic inclusions in association with neurodegenerative changes in striatonigral or olivopontocerebellar structures, leading to the primary pathological diagnosis of MSA. Primary age-related tauopathy was incidentally found but Lewy bodies were not in both cases. The pathological phenotypes of MSA were MSA-OPC type in case 1 and MSA-SND=OPC type in case 2.Conclusions: Our data suggest that clinical phenotypes of MSA reflect the pathological characteristics.

Intrafamilial phenotypic variation in spinocerebellar ataxia type 23

BackgroundSpinocerebellar ataxia type 23 (SCA23) is an autosomal dominant cerebellar ataxia caused by pathogenic variants in the prodynorphin gene (PDYN). The frequency of PDYN variants is reportedly very low (~ 0.1%) in several ataxia cohorts screened to date.Case presentationsWe found five cases of SCA23 in two families (mean age at onset: 37.8 ± 5.5 years; mean age at examination: 64.2 ± 12.3 years) with a novel PDYN variant (c.644G > A:p.R215H). We identified marked heterogeneity in the clinical features in Family 1: the proband showed clinical and neuroimaging features suggestive of multiple system atrophy with predominant parkinsonism (MSA-P). Conversely, the proband’s mother with the PDYN p.R215H variant had no subjective symptoms; she had not come to medical attention before our survey, although she showed apparent cerebellar atrophy on brain magnetic resonance imaging (MRI). The other two patients in Family 1 and a patient in Family 2 showed slowly progressive cerebellar ataxia.ConclusionsWe here report two Japanese families with SCA23, one of which showed considerable phenotypic variation in affected members. Our findings support that SCA23 can phenotypically overlap with MSA.