Cerebral atrophy in multiple system atrophy by MRI

Cranial magnetic resonance images (MRI) of the cerebral areas of 40 patients with multiple system atrophy (MSA) and of 61 age-matched controls were analyzed. The cerebral area of MSA patients was 131. 95+/-15.89 cm(2) (mean+/-S.D.), which was significantly smaller than that of normal controls at 149.01+/-10.93 cm(2) (P<0.0001). All 23 MSA cases subjected to the MRI study over a 1-year period showed progressive cerebral atrophy, and the atrophy rate was 2.46+/-1. 66%/year. There were no significant differences within the MSA subtypes or between gender. The progression of cerebral atrophy in MSA correlated more with duration (r=-0.634) than age (r=-0.421). We conclude that MRI findings throughout the course of MSA suggest progressive cerebral atrophy, which is common in all subtypes and reflects duration of the disease rather than age.     

Evaluating posterolateral linearization of the putaminal margin with magnetic resonance imaging to diagnose the Parkinson variant of multiple system atrophy.

The objective was to develop a simple method for evaluating putaminal atrophy in patients with the Parkinson variant of multiple system atrophy (MSA-P). We used magnetic resonance imaging to study 9 patients with MSA-P, 24 patients with cerebellar variants of multiple system atrophy (MSA-C), 38 patients with Parkinson's disease (PD), and 27 healthy control subjects. Posterolateral linearization of the putaminal margin was semiquantitatively scored and the putaminal area per intracranial area was calculated as the adjusted putaminal area. There was a negative correlation between the linearization scores and adjusted putaminal areas (r = -0.43, P < 0.001), such that the mean adjusted putaminal area in the group without putaminal linearization (0.0148 +/- 0.0022) was greater than that of the group with linearization (0.0124 +/- 0.0029, P < 0.005). Moreover, the occurrence of putaminal linearization was significantly higher in MSA-P patients (88.8%) than in MSA-C (8.3%), PD (7.9%) and healthy subjects (7.4%; P < 0.005). Putaminal linearization was a highly sensitive (0.89) and specific (0.91) measure for differentiating MSA-P. Our results suggest that evaluating posterolateral putaminal linearization is useful for assessing putaminal atrophy and for differentiating MSA-P from MSA-C, PD, and healthy subjects.     

Cognitive deficits in multiple system atrophy correlate with frontal atrophy and disease duration

Background and purpose:  Dementia remains an exclusion criterion in diagnosing multiple system atrophy (MSA). This study aimed to determine the cognitive changes and brain atrophy patterns in the Parkinsonian (MSA-P) and cerebellar (MSA-C) variants of MSA.
Methods:  Voxel-based morphometry (VBM) of magnetic resonance imaging (MRI) and neuro-psychological tests were applied to 10 MSA-C and 13 MSA-P patients, and compared to 37 age-matched controls. Correlation analyses were performed between cognitive test results and morphometric data extracted from the VBM data.
Results:  In neuro-psychological testing, the 23 MSA patients scored lower in the Stroop interference test and took longer in the trail-making test as compared with the controls, whereas MSA-C performed worse than MSA-P in the memory scores, Stroop test, and time to complete the trail-making test. MSA, as a group, showed atrophy in the cerebellum, insular cortex, fusiform gyrus, inferior orbito-frontal gyrus, superior temporal gyrus, and caudate nucleus. Memory scores correlated well with pre-frontal lobe atrophy but not in the insular area.
Conclusion:  In conclusion, although dementia is not a typical presenting feature of MSA and is regarded as a sub-cortical movement disorder, frontal atrophy, cognitive changes, and dementia are identifiable as MSA progresses.     

Topography of putaminal degeneration in multiple system atrophy: a diffusion magnetic resonance study.

There is neuropathologic evidence that, in early stages of the Parkinson variant of multiple system atrophy (MSA-P), the putamen shows a distinct topographical pathology affecting predominantly the dorsolateral and caudal regions while leaving the rostral to midparts almost intact. We investigated the topographic profile of putaminal degeneration in MSA-P patients in vivo by means of diffusion-weighted imaging (DWI), which has been shown to reveal abnormalities in the basal ganglia of patients with MSA-P compared to patients with PD and healthy controls. For this purpose, regional trace of the diffusion tensor (rTrace(D)) values were determined in the entire, anterior, and posterior putamen in 15 patients with probable MSA-P, in 20 patients with PD, and in 11 healthy volunteers matched for age and disease duration. MSA-P patients had significantly higher rTrace(D) values in entire, anterior, and posterior putamen compared to both controls and PD patients. Trace(D) values were significantly higher in the posterior compared to the anterior putamen in the MSA-P group. There were no significant differences between posterior and anterior putamen in both the control and PD group. Our study demonstrates prominent involvement of the posterior putamen in early disease stages of MSA-P in vivo by assessing putaminal diffusivity with the help of DWI.     

Quantitative MRI study of progressive cerebral atrophy in multiple system atrophy]

We investigated cerebral atrophy in multiple system atrophy (MSA) by quantitative analysis of MRI. The subjects were 28 patients with MSA (14 striato-nigral degeneration; SND, 14 olivo-ponto-cerebellar atrophy; OPCA. 106 MRI examinations were performed totally) and 85 normal persons for control. The ratios of the ventral pons to the infratentorial space in the sagittal section, the putamen, cerebrum, frontal lobe and parietal & occipital lobes to the intracranial space in the horizontal section, and the temporal lobe to the intracranial space in the coronal section were measured. In the early stage of the disease, OPCA showed significant atrophy of the ventral pons compared with SND, and conversely, SND demonstrated significantly smaller putamen than that in OPCA. According to the progression of the disease, the atrophy of these neural tissues progressed, which resulted in no significant differences between SND and OPCA. The cerebral atrophy was observed in 17 MSA patients. The atrophy of the frontal lobe was much frequent and prominent to that in the temporal lobe and parietal & occipital lobes. SND showed higher incidence of the cerebral atrophy than OPCA in the early stage of the disease. In long period follow-up cases, one case showed cerebral atrophy in earlier stage, and another case in late stage. We indicated the involvement of the cerebral hemispheres in MSA, especially the frontal lobe.     

多系统萎缩的临床与MRI特征

目的探讨多系统萎缩(MSA)的临床与MRI特征及其对临床亚型诊断的意义。方法回顾性分析28例MSA患者的临床及MRI资料。结果橄榄脑桥小脑萎缩(OPCA)以小脑体征(75.0%)突出,MRI表现为脑桥萎缩(91.7%)、小脑蚓部萎缩(91.7%),第四脑室扩大(83.8%),T2WI出现脑桥、小脑对称性高信号(63.6%)及脑桥十字征;纹状体黑质变性(SND)以锥体外系症状(80.0%)明显,MRI改变多位于基底节核团,表现为壳核萎缩(60.0%),T2WI示壳核外侧缘缝隙样高信号(80.0%);ShyDrager综合征(SDS)以自主神经症状(81.8%)为主,出现早且重,MRI未见特异性变化。结论MRI有助于提高MSA及其亚型诊断。脑桥萎缩、T2WI高信号改变,尤其是脑桥十字征的出现有助于OPCA诊断;壳核萎缩与T2WI壳核外侧缘缝隙样高信号改变支持SND诊断。     

Eye of the tiger-like MRI in parkinsonian variant of multiple system atrophy

Parkinsonian variant of multiple system atrophy (MSA-P) clinically presents as autonomic dysfunction with parkinsonian features. Parkinsonian features include bradykinesia, rigidity, tremor, postural instability and poor levo-dopa response. Neuropathologically, MSA-P is characterized by selective neuronal loss and gliosis mainly affecting the putamen and caudate nucleus, substantia nigra, olivopontocerebellar pathway and intermediolateral cell column of the spinal cord. Therefore, the target of magnetic resonance imaging (MRI) is focused on signal changes or volume reduction on putamen, including putaminal slit, gliosis by diffusion studies and reduction of putaminal volume. There have been no reports describing clinical manifestations of MSA-P with imaging abnormalities over globus pallidus. Here, we describe three patients with typical presentations of MSA-P with autonomic dysfunction and disturbances of axial motor function with minimal appendicular symptoms, including postural instability and gait difficulties. MRI showed symmetrical hyperintensity over the center of globus pallidus surrounded by a mild low-signal rims at T2-weighted image that is similar to that of eye of the tiger sign except for the marked hypointense rims. Dopamine transporter scans showed symmetric reduction of uptake over bilateral basal ganglia. This is the first report concerning these unusual imaging findings in MSA-P patients and we believe there is a subgroup of MSA-P with clinical presentation of axial impairment and symmetrically abnormal signal changes of globus pallidus in MRI.     

Comparison of cerebral atrophy evaluated by MRI in Parkinson's disease and multiple system atrophy

Cerebral atrophy was evaluated in 31 patients with Parkinson's disease (PD) and 24 patients with clinically probable multiple system atrophy (MSA). Measurements of ventricular and brainstem areas, obtained from axial and sagittal MRI sections, were performed using a computer digitalizing system. Cortical and cerebellar atrophies were subjectively assessed. All measures were scored by one observer who was blind to the diagnosis (BD). Age, sex, levodopa dosage, baseline motor Parkinsonian disability (i.e. without levodopa treatment) and neuropsychological impairment were not significantly different between the two groups of patients. The total brainstem area (p < 0.001), the mesencephalon (p < 0.05) and the pons (p = 0.05) areas were significantly smaller in MSA as were the lobar (p < 0.05) and the vermian (p < 0.01) parts of the cerebellum. In the MSA group, significant correlations were observed between the brainstem area and items from the motor part of the Unified Parkinson's Disease Rating Scale (dysarthria, posture, arising from a chair), and between the cerebellar atrophy and the gait disturbance. A progressive discriminant analysis using radiologic variables correctly classified 79% of patients in their own diagnosis group with a significant difference (p = 0.01). From these results, it appears that MRI could help to differentiate MSA from PD, especially when MRI detects a severe infratentorial atrophy suggestive of MSA. However, brainstem and cerebellum atrophies are not sufficient criteria to differentiate MSA from PD because they lack both specificity and sensitivity.     

Diagnosing multiple system atrophy at the prodromal stage

Clinical Autonomic Research - Identifying individuals at the earliest disease stage becomes crucial as we aim to develop disease-modifying treatments for neurodegenerative disorders. Prodromal...     

磁共振脑径线测量对多系统萎缩的诊断价值

目的 研究磁共振脑径线测量对于多系统萎缩(MSA)的诊断价值.方法 11例MSA患者,可能MSA 2例,拟诊MSA 9例.其中以帕金森综合征为主要表现(MSA-P)5例,以小脑性共济失调为主要表现(MSA-C)6例.健康对照组6名,病例对照组9例(帕金森病1例、其他类型的帕金森综合征8例).选取反映脑干、小脑和基底节形态学的径线进行测量,计算全脑三维体积,比较各项参数的组间差异.结果 MSA组的脑桥横径(mm,下同)明显短于健康对照组和病例对照组(27.6±2.0、30.5±0.6、29.9±1.1),MSA患者的四脑室前后径(11.9±2.8)明显长于健康对照(9.0±2.1).MSA-C组的脑桥横径明显短于健康对照组和病例对照组(27.2±2.1、30.5±0.6、29.9±1.1).MSA-C患者的四脑室前后径和横径(12.8±2.6和9.0±2.1)明显长于健康对照(17.3±2.1和13.8±1.7).MSA-P患者的脑桥横径较健康对照组短(28.2±1.8、30.5±0.6).MSA-P患者的苍白球最长径(23.7±5.0)和红核直径(6.6±0.8)明显较MSA-C患者(29.7±2.4和8.2±0.4)短.MSA-C患者的第四脑室横径较MSA-P患者宽(17.3±2.1、12.6±2.7),小脑中脚宽度较MSA-P患者缩短(13.3±1.9、15.8±1.2).结论 磁共振脑体积径线测量对于MSA患者脑组织局部萎缩的程度提供了量化的手段.脑桥的横径缩短可以客观地反映MSA患者脑桥的萎缩,但不能用于区分MSA-P和MSA-C.MSA-C患者更易出现第四脑室的扩大和MCP的萎缩,MSA-P患者更易出现红核萎缩.     

T2*-weighted MRI in diagnosis of multiple system atrophy

Abstract Background Putaminal iron deposition is a histopathological feature of multiple system atrophy (MSA), which is not observed in patients with idiopathic Parkinson's disease (PD). T2*-weighted magnetic resonance imaging (MRI) gradient echo (GE) sequences are sensitive for paramagnetic susceptibility changes and therefore may support the clinical differential diagnosis between MSA and PD. Methods We evaluated putaminal signal intensities on 1.0 Tesla scans of 52 MSA patients, 88 patients with PD and 29 healthy control subjects. Results The typical finding in T2* GE sequences of MSA patients was a signal loss of the dorsolateral putamen, which showed a high specificity (>0.91), but was present in only a subpopulation of patients (sensitivity 0.64–0.69). The combination of the latter with additional presence of a hyperintense lateral rim in fluid attenuated inversion recovery (FLAIR) sequences increased the specificity to 0.97. Using a quantitative evaluation of putaminal signal intensities in defined regions of interest MSA and PD could be discriminated with a diagnostic accuracy (r) of up to 0.82. Conclusion Although the separation of groups remains incomplete, the use of T2*-weighted GE sequences combined with FLAIR may be helpful for the differential diagnosis of MSA versus PD considering its fast application, easy evaluation, broad availability, the specificity of findings and the presence of putaminal signal loss already at early disease stages.     

Delineating the sites and progression of in vivo atrophy in multiple system atrophy using fluid-registered MRI.

We describe the pattern and progression of atrophy delineated using fluid registration of serial magnetic resonance imaging scans in a case of multiple system atrophy (MSA). The in vivo findings were consistent with those found at postmortem, including significant supratentorial atrophy concurrent with an unusual degree of cognitive impairment for MSA.     

Hemi-parkinsonism in multiple system atrophy: a PET and MRI study

We selected 6 patients presenting with hemi-parkinsonism from a total of 20 patients with probable multiple system atrophy (MSA) and studied their nigrostriatal lesions using magnetic resonance (MR) imaging and positron emission tomography (PET) with ¹⁸F-labeled 2-deoxy-2-fluoro- -glucose (FDG). T₂ weighted MR images demonstrated a decreased signal intensity in the putamen of all patients. This decreased signal was more intense in the nucleus contralateral to the affected body side in 5 patients. A decreased signal in the substantia nigra was found, expanding more on the contralateral side in 3 patients. T₁-weighted images showed that the contralateral putamen was smaller in size than the ipsilateral. These findings indicated that the iron deposit and the neuronal cell loss in the degenerative process were more remarkable in the contralateral nuclei. FDG uptake in 5 patients had likewise declined more in the contralateral than in the ipsilateral putamen. The study shows that these patients have the nigrostriatal lesions as described in previous reports on MSA and that an asymmetric lesion relating to clinical signs is present in the nigrostriatal system. When a patient presents with hemi-parkinsonism alone, MR imaging and PET/FDG are useful for the clinical diagnosis of MSA.     

Longitudinal quantitative MRI in multiple system atrophy and progressive supranuclear palsy

ObjectiveMRI has been used in parkinsonism to assess atrophy, tissue water diffusivity, and mineral deposition but usually at a single time-point. However, multiple system atrophy (MSA) and progressive supranuclear palsy (PSP) are progressive diseases. This study assessed the value of longitudinal MRI in characterizing the time course of the degenerative process.MethodsTwo serial MRIs (mean 23 months apart) were retrospectively analyzed in 12 MSA, 6 PSP, and 18 age and sex matched controls. Assessment included selected cross-sectional areas, regional apparent diffusion coefficient (ADC) and gradient echo (GRE) intensity ratios of the lateral ventricles, caudate, putamen, middle cerebellar peduncle, pons and midbrain.ResultsOn follow-up imaging, there was a larger ADC increase in the putamen in PSP over time compared to controls (p = 0.02). In MSA there was greater volume loss in the pons over time compared to controls (p = 0.002). In MSA the changes in middle cerebellar peduncle ADC were correlated with motor symptom severity according to the Unified Parkinson's Disease Rating Scale Part III (p = 0.005).ConclusionsEvidence of progressive neurodegeneration can be observed on MRI in MSA and PSP within two years consisting of increasing putaminal ADC in PSP and pontine atrophy in MSA.     

Diffusion-weighted MRI differentiates the Parkinson variant of multiple system atrophy from PD

OBJECTIVE AND BACKGROUND: Routine MRI as well as MR volumetry and MRS have been shown to contribute to the differential diagnosis of the Parkinson variant of multiple system atrophy (MSA-P) and PD. However, it is currently unknown whether diffusion-weighted imaging (DWI) discriminates these disorders. METHODS: Ten patients with MSA-P (mean age, 64 years) were studied, 11 with PD (mean age, 64 years), and seven healthy volunteers (mean age, 59 years) matched for age and disease duration. Regional apparent diffusion coefficients (rADC) were determined in different brain regions including basal ganglia, gray matter, white matter, substantia nigra, and pons. RESULTS: Patients with MSA-P had higher putaminal rADC (median 0.791 x 10(3)/mm(2)/s) than both patients with PD (median 0.698 x 10(3)/mm(2)/s, p < 0.001) and healthy volunteers (median 0.727 x 10(3)/mm(2)/s, p < 0.001). There were no significant differences in putaminal rADC between patients with PD and healthy volunteers. Moreover, none of the putaminal rADC values in the PD and control group surpassed the lowest value in the MSA-P group. There were no significant group differences in the rADC values in other brain regions such as pons, substantia nigra, globus pallidus, caudate nucleus, thalamus, or gray and white matter. Putaminal rADC values correlated significantly with Unified PD Rating Scale OFF scores in patients with MSA as measured by the Spearman rank test. CONCLUSION: DWI, even if measured in the slice direction only, is able to discriminate MSA-P and both patients with PD and healthy volunteers on the basis of putaminal rADC values. The increased putaminal rADC values in Parkinson variant of multiple system atrophy are likely to reflect ongoing striatal degeneration, whereas most neuropathologic studies reveal intact striatum in PD. Diffusion-weighted imaging may represent a useful diagnostic tool that can provide additional support for a diagnosis of Parkinson variant of multiple system atrophy.     

Spatial correlation and segregation of multimodal MRI abnormalities in multiple system atrophy

Objective

The variability of the severity and regional distribution of pathological process in basal ganglia (BG) and brainstem–cerebellar systems results in clinical heterogeneity and represents the motor subtype of multiple system atrophy (MSA). This study aimed to quantify spatial patterns of multimodal MRI abnormalities in BG and stem-CB regions and define structural MRI findings that correlate with clinical characteristics.

Methods

We simultaneously measured R2*, mean diffusivity (MD), and volume in the subcortical structures (BG, thalamus, brainstem–cerebellar regions) of 39 probable MSA and 22 control subjects. Principal component analysis (PCA) and structural equation modeling (SEM) were performed to show a model consisting of multiple inter-dependencies.

Results

Structural MRI alterations were found to be significantly interrelated within BG as well as brainstem–cerebellar regions in MSA patients. PCA extracted four factors: three factors reflected alterations in R2*, MD and volume of the BG region including the caudate nucleus, putamen, and pallidum, and the remaining one factor represented degenerative changes in MD and volume of stem-CB region. In SEM, a latent variable reflecting brainstem–cerebellar degeneration did not show a significant correlation with the other latent variables associated with BG degeneration. Putaminal MD values and a PCA-driven factor reflecting MD values in the BG showed a significant correlation with UPDRS and UMSARS scores.

Conclusion

Multimodal structural MRI abnormalities in MSA appear to be segregated into BG and stem-CB-related factors that can be associated with the clinical phenotype and motor severity.