Diagnostic value of brain MRI and 18F‐FDG PET in the differentiation of parkinsonian type multiple system atrophy from Parkinson’s disease

Background and purpose: Differentiation between parkinsonian type multiple system atrophy (MSA‐P) and Parkinson’s disease (PD) is important but often difficult. We investigated the diagnostic value of brain magnetic resonance imaging (MRI) and ¹⁸F‐fluorodeoxyglucose positron emission tomography (¹⁸F‐FDG PET) in differentiating MSA‐P from PD. Methods: Twenty‐four patients with MSA‐P (16 probable and 8 possible) and eight patients with PD were included in this study. Results: For analysis using the putaminal findings, the sensitivities were 58.3% by visual analysis of brain MRI, 95.8% by visual analysis of ¹⁸F‐FDG PET, and 79.2% by statistical parametric mapping (SPM) analysis of ¹⁸F‐FDG PET in differentiating MSA‐P from PD; the specificity was 100% for each analysis. Using the putaminal findings, visual analysis of ¹⁸F‐FDG PET had a higher sensitivity compared with brain MRI (P = 0.004) and SPM analysis of ¹⁸F‐FDG PET revealed a tendency towards higher sensitivity compared with brain MRI (P = 0.063). For analysis using both putaminal and infratentorial findings, the sensitivities were 79.2% by visual analysis of brain MRI, 95.8% by visual analysis of ¹⁸F‐FDG PET, 95.8% by SPM analysis of ¹⁸F‐FDG PET in differentiating MSA‐P from PD; the specificity was 100% for each analysis. Conclusion: Both brain MRI and ¹⁸F‐FDG PET showed diagnostic usefulness in differentiating MSA‐P from PD, with ¹⁸F‐FDG PET being more sensitive than brain MRI.     

Brain magnetic resonance imaging in multiple-system atrophy and Parkinson disease: a diagnostic algorithm

BACKGROUND: Brain magnetic resonance (MR) imaging offers the potential for objective criteria in the differential diagnosis of multiple system atrophy with predominant parkinsonism (MSA-P) and Parkinson disease (PD), since it frequently shows characteristic abnormalities in patients with MSA-P and is believed to be normal in patients with PD. OBJECTIVE: To determine concordance between clinical and MR imaging-based diagnoses of MSA-P and PD. DESIGN: Two neuroradiologists identified and rated striatal and infratentorial abnormalities in 39 brain MR images and assigned a diagnosis of PD, MSA-P, or MSA with additional marked cerebellar ataxia (MSA-C). SETTING: Academic medical center. PATIENTS: Thirty-nine patients with parkinsonism, including 21 with a clinical diagnosis of PD, 14 with MSA-P, and 4 with MSA-C. RESULTS: All patients with MSA and 14 (67%) of 21 patients with PD had some abnormality on brain MR imaging. Brainstem atrophy was seen in patients with MSA-P and MSA-C. Putaminal atrophy was seen only in MSA-P. Putaminal hypointensity and lateral slitlike hyperintensity were seen in both PD and MSA-P but were always mild in PD. Cerebellar abnormalities, seen in all patients with MSA-C and 11 patients with MSA-P, were also identified in 6 patients with PD, albeit always rated as mild. Nonconcordance between clinical and radiological diagnosis occurred in 2 patients with PD, 5 with MSA-P, and 1 with MSA-C. CONCLUSION: Since several features on brain MR imaging are seen only in MSA-P, a simple diagnostic algorithm may improve the MR imaging diagnosis of MSA-P and PD.     

Visual event-related potential changes in two subtypes of multiple system atrophy,MSA-C and MSA-P

We investigated the visual event-related potentials (ERPs) in two subtypes of multisystem atrophy (MSA) in 15 MSA-C patients, 12 MSA-P patients, and 21 normal control (NC) subjects. We used a visual oddball task to elicit ERPs. No significant changes were seen in N1 or N2 latency, in either MSA-C or MSA-P, compared with the NC group. An early stage of visual information process related to N1 and a visual discrimination process related to N2 might be preserved in both MSA-C and MSA-P. The P3a peak was more frequently undetectable in MSA than in the NC group. Significant P3a amplitude reduction in both MSA-C and MSA-P suggests impairment of the automatic cognitive processing in both MSA-C and MSA-P. Significant difference was found in P3b latency and P3b amplitude only in MSA-C, compared with the NC group. The result suggests the impairment of the controlled cognitive processing after the visual discrimination process in the MSA-C group. We further investigated the correlation between visual ERP changes and magnetic resonance imaging (MRI) data. Quantitative MRI measurements showed reduced size of the pons, cerebellum, perisylvian cerebral area, and deep cerebral gray matter in both MSA-C and MSA-P, and of the corpus callosum only in MSA-P, as compared to NC group. In both MSA-C and MSA-P, P3b latency was significantly correlated with the size on MRI of the pons and the cerebellum. P3b latency in the whole MSA group was also significantly correlated with the size of the pons and the cerebellum. These results indicate that P3b latency changes in parallel with the volume of the pons and the cerebellum in both MSA-C and MSA-P. Received: 28 August 2001 Received in revised form: 22 January 2002 Accepted: 25 January 2002     

多系统萎缩患者143例临床和影像学特征分析

目的 探讨多系统萎缩(MSA)不同亚型的临床和影像学特征及其相关性.方法 对143例符合1999年Gilman诊断标准的MSA患者进行临床分型和诊断分级,根据Horimoto分期对108例影像学出现异常的患者脑桥十字征和壳核裂隙征进行分析,并探讨不同临床亚型及病程与影像学异常的相关性.结果 143例MSA患者男女比例为1.3:1,其中MSA小脑萎缩型(MSA-C)93例,MSA帕金森型(MSA-P)39例,两者同时出现的即为MSA-P+C型11例;很可能的MSA 90例,可能的MSA 53例.108例MSA患者影像学出现异常,其中MSA-C型患者36例(36/76,47%)出现脑桥十字征,10例(10/76,13%)出现壳核裂隙征;MSA-P型患者6例(6/24,25%)出现脑桥十字征,6例(6/24,25%)出现壳核裂隙征.MSA-C型中病程较短的患者脑桥十字征分期较早.结论 本组病例中MSA-C型患者明显多于MSA-P型,可能与种族遗传背景有关.脑桥十字征和壳核裂隙征为MSA患者的显著影像学特征,MSA临床分型与影像学特征具有一定的相关性,其中脑桥十字征在MSA-C型较为显著,壳核裂隙征在MSA-P型较为显著.     

Individual voxel-based morphometry adjusting covariates in multiple system atrophy

IntroductionThis study aimed to evaluate whether novel individual voxel-based morphometry adjusting covariates (iVAC), such as age, sex, and total intracranial volume, could increase the accuracy of a diagnosis of multiple system atrophy (MSA) and enable the differentiation of MSA from Parkinson's disease (PD).MethodsWe included 53 MSA patients (MSA-C: 33, MSA-P: 20), 53 PD patients, and 189 healthy controls in this study. All participants underwent high-resolution T1-weighted imaging (WI) and T2-WI with a 3.0-T MRI scanner. We evaluated the occurrence of significant atrophic findings in the pons/middle cerebellar peduncle (MCP) and putamen on iVAC and compared these findings with characteristic changes on T2-WI.ResultsOn iVAC, abnormal findings were observed in the pons/MCP of 96.2% of MSA patients and in the putamen of 80% of MSA patients; however, on T2-WI, they were both observed at a frequency of 60.4% in MSA patients. On iVAC, all but one MSA-P patient (98.1%) showed significant atrophic changes in the pons/MCP or putamen. By contrast, 69.8% of patients with MSA showed abnormal signal changes in the pons/MCP or putamen on T2-WI. iVAC yielded 95.0% sensitivity and 96.2% specificity for differentiating MSA-P from PD.ConclusioniVAC enabled us to recognize the morphological characteristics of MSA visually and with high accuracy compared to T2-WI, indicating that iVAC is a potential diagnostic screening tool for MSA.     

Differentiating Parkinson's disease from multiple system atrophy by [123I] meta-iodobenzylguanidine myocardial scintigraphy and olfactory test

We aimed to study whether either [¹²³l] myocardial meta-iodobenzylguanidine (MIBG) myocardial scintigraphy or the odor stick identification test for Japanese (OSIT-J) is effective in differentiating Parkinson’s disease (PD) from multiple system atrophy (MSA). We compared the MIBG accumulation and olfactory score between 42 PD and 42 MSA (19 MSA-P and 23 MSA-C) patients in the early stages. [¹²³l] MIBG myocardial scintigraphy showed higher sensitivity and the olfactory test higher specificity in differentiating PD from MSA. There were significant differences between PD and MSA-C (p = 0.0019) instead of MSA-P (p > 0.05) in the MIBG accumulation, while there were significant differences between PD and MSA-P (p = 0.0003) or MSA-C (p = 0.0003) in the OSIT-J score. Our data suggest that the olfactory test can be useful as a clinical tool with its higher specificity in differentiating PD from MSA in the early stages and, moreover, support the discrimination of PD from MSA-P.     

Potential of a new MRI for visualizing cerebellar involvement in progressive supranuclear palsy

ObjectivesWe assessed the usefulness of differential diagnosis of parkinsonism by evaluating lesions of the decussation of the superior cerebellar peduncle (SCP) in patients with progressive supranuclear palsy (PSP) using a new MRI procedure known as readout segmentation of long variable echo-trains (RESOLVE).MethodsWe evaluated 100 cases, consisting of 20 with PSP, 24 with Parkinson's disease (PD), 13 with multiple system atrophy with predominant parkinsonism (MSA-P), 18 with multiple system atrophy with predominant cerebellar ataxia (MSA-C), and 24 controls. All patients were scored on the Unified Parkinson's Disease Rating Scale Part III and the Scale for the Assessment and Rating Scale of Ataxia, and MRI using RESOLVE was conducted.ResultsImages acquired by this MRI procedure clearly showed high intensity areas corresponding to the decussation of the SCP in all controls, PD, and MSA patients. In contrast, ten of the 20 PSP patients exhibited abnormal iso intensities of the decussation of the SCP, while the other 10 showed high intensity signals. Among the PSP patients, there were no differences in clinical features between those with and those without visualization of the decussation of the SCP. Iso intensity signals had a sensitivity of 50% and a specificity of 100% for differentiating PSP from PD, MSA, and controls.ConclusionThis MRI procedure (RESOLVE) shows a potential for detecting the involvement of the decussation of the SCP in PSP, and can be used for discriminating PSP from PD and MSA-P.     

Multiple regional 1H-MR spectroscopy in multiple system atrophy: NAA/Cr reduction in pontine base as a valuable diagnostic marker

OBJECTIVE: We performed (1)H-MR spectroscopy ((1)H-MRS) on multiple brain regions to determine the metabolite pattern and diagnostic utility of (1)H-MRS in multiple system atrophy (MSA). METHODS: Examining single voxels at 3.0 T, we studied metabolic findings of the putamen, pontine base, and cerebral white matter in 24 MSA patients (predominant cerebellar ataxia (MSA-C), n = 13), parkinsonism (MSA-P), n = 11), in 11 age and duration matched Parkinson's disease patients (PD) and in 18 age matched control subjects. RESULTS: The N-acetylaspartate to creatine ratio (NAA/Cr) in MSA patients showed a significant reduction in the pontine base (p<0.0001) and putamen (p = 0.02) compared with controls. NAA/Cr in cerebral white matter also tended to decline in long standing cases. NAA/Cr reduction in the pontine base was prominent in both MSA-P (p<0.0001) and MSA-C (p<0.0001), and putaminal NAA/Cr reduction was significant in MSA-P (p = 0.009). It was also significant in patients who were in an early phase of their disease, and in those who showed no ataxic symptoms or parkinsonism, or did not show any MRI abnormality of the "hot cross bun" sign or hyperintense putaminal rims. NAA/Cr in MSA-P patients was significantly reduced in the pontine base (p = 0.001) and putamen (p = 0.002) compared with PD patients. The combined (1)H-MRS in the putamen and pontine base served to distinguish patients with MSA-P from PD more clearly. CONCLUSIONS:(1)H-MRS showed widespread neuronal and axonal involvement in MSA. The NAA/Cr reduction in the pontine base proved highly informative in the early diagnosis of MSA prior to MRI changes and even before any clinical manifestation of symptoms.     

多系统萎缩不同亚型间的临床特征及脑葡萄糖代谢差异分析

目的分析多系统萎缩-帕金森亚型和多系统萎缩-小脑共济失调亚型患者的临床特征以及18氟-脱氧葡萄糖正电子发射断层(l8F-FDG PET)显像的特征差异。方法收集8例多系统萎缩-帕金森亚型患者和17例多系统萎缩-小脑共济失调亚型患者的临床资料,回顾性分析包括统一帕金森病评定量表-运动部分(UPDRS Ⅲ)评分和Hoehn-Yahr分级的运动症状评估,认知功能、抑郁、嗅觉、快速眼动期睡眠行为紊乱等非运动症状评估,以及基于l8F-FDG PET脑葡萄糖代谢显像的特征差异。结果多系统萎缩-帕金森亚型与多系统萎缩-小脑共济失调亚型患者UPDRS Ⅲ评分(P=0.004)及Hoehn-Yahr分级(P<0.001)比较,差异有统计学意义,而非运动症状组间比较,差异无统计学意义(P>0.05)。多系统萎缩-帕金森亚型在基底节(尤其是后壳核)脑葡萄糖代谢(P<0.001)、小脑及顶枕叶呈低代谢,多系统萎缩-小脑共济失调亚型基底节脑葡萄糖代谢未见减低,仅在小脑和枕叶呈低代谢。结论多系统萎缩的临床特征异质性大,l8F-FDG PET脑葡萄糖代谢显像特征差异可为深入研究多系统萎缩的发病机制、开发更精准治疗奠定基础。     

Magnetic resonance imaging distinguishes progressive supranuclear palsy from multiple system atrophy

Summary. To establish diagnostic magnetic resonance imaging (MRI) criteria for differentiating progressive supranuclear palsy (PSP) from multiple system atrophy (MSA), magnetic resonance images from eight patients with probable PSP, 30 with probable MSA {nine striatonigral degeneration (MSA-P) and 21 olivopontocerebellar atrophy (MSA-C)}, and ten age-matched controls were retrospectively studied. Anteroposterior diameters in the midline sagittal T1-weighted image of the rostral (RMT) and caudal midbrain tegmentum (CMT), caudal pons and medulla were measured. Divergence of the red nuclei (RN) in the axial T2-weighted image was judged. All PSP images had a smaller RMT diameter than the lower limit of the normal range, showed RN divergence, and had a pontine diameter within the normal range. All MSA images had a CMT diameter within the normal range; no MSA images showed divergence of RN. Forty-four percent (4/9) of MSA-P and 76% (16/21) of MSA-C images had a pontine diameter smaller than the lower limit of the normal range. On basis of the results, we propose MRI diagnostic criteria for differentiating PSP from MSA. Received March 23, 2000; accepted June 7, 2000     

Application of the International Cooperative Ataxia Scale rating in multiple system atrophy.

We assessed the International Cooperative Ataxia Scale (ICARS) as a means of extracting and rating cerebellar signs in multiple system atrophy (MSA). Cross-sectional analysis of internal consistency, factor structure, and correlation with parkinsonism severity (Unified Parkinson's Disease Rating Scale [UPDRS] III) of the ICARS, in 50 unselected MSA patients (mean age, 67.6 years; mean disease duration, 5.5 years), 50 age-matched and disease duration-matched Parkinson' disease (PD) patients, and 50 control subjects. Fifteen patients (30%) had MSA-C (cerebellar subtype) and 35 (70%) MSA-P (parkinsonism subtype), and 66% had at least one cerebellar sign. The total ICARS score was much higher (fivefold) in MSA compared to PD patients. The ICARS score was twofold higher in MSA-C than in MSA-P patients. MSA-C patients had a higher score than MSA-P mainly on posture and gait disturbances and kinetic functions subscores. All the ICARS items were significantly more severe in MSA than in PD patients, who in turn scored higher than the controls. In MSA, internal consistency was excellent (Cronbach = 0.93). Factor structure analysis revealed four clinically distinct subscores, in accordance with the scale structure, which accounted for 70% of the variance. The ICARS showed less consistency and accuracy in PD patients; however, the ICARS scores significantly correlated with the UPDRS-III scores in both MSA and PD patients. The ICARS appears a useful tool to extract and rate the severity of cerebellar signs in MSA; however, it is clearly contaminated by parkinsonian features.     

Characterization and diagnostic potential of diffusion tractography in multiple system atrophy

IntroductionMicrostructural integrity of the middle cerebellar peduncle (MCP) and the putamen captured by diffusion-tensor imaging (DTI) is differentially affected in the parkinsonian and cerebellar variants of multiple system atrophy (MSA-P, MSA-C) compared to Parkinson's disease (PD). The current study applied DTI and tractography in order to 1) characterize the distribution of DTI metrics along the tracts of the MCP and from the putamen in MSA variants, and 2) evaluate the usefulness of combining these measures for the differential diagnosis of MSA-P against PD in the clinical setting.MethodsTwenty-nine MSA patients (MSA-C, n = 10; MSA-P, n = 19), with a mean disease duration of 2.8 ± 1.7 years, 19 PD patients, and 27 healthy controls (HC) were included in the study. Automatized tractography with a masking procedure was employed to isolate the MCP tracts. DTI measures along the tracts of the MCP and within the putamen were acquired and jointly used to classify MSA vs. PD, and MSA-P vs. PD. Putamen volume was additionally tested as classification feature in post hoc analyses.ResultsDTI measures within the MCP and putamen showed significant alterations in MSA variants compared to HC and PD. Classification accuracy for MSA vs. PD and MSA-P vs PD using diffusion measures was 91.7% and 89.5%, respectively. When replacing the putaminal DTI measure by a normalized measure of putamen volume classification accuracy improved to 95.8% and 94.7%, respectively.ConclusionMultimodal information from MCP tractography and putamen volume yields excellent diagnostic accuracy to discriminate between early-to-moderately advanced patients with MSA and PD.     

Comparison of smooth pursuit eye movement deficits in multiple system atrophy and Parkinson’s disease

Because of the large overlap and quantitative similarity of eye movement alterations in Parkinson’s disease (PD) and multiple system atrophy (MSA), a measurement of eye movement is generally not considered helpful for the differential diagnosis. However, in view of the pathophysiological differences between MSA and PD as well as between the cerebellar (MSA-C) and Parkinsonian (MSA-P) subtypes of MSA, we wondered whether a detailed investigation of oculomotor performance would unravel parameters that could help to differentiate between these entities. We recorded eye movements during sinusoidal pursuit tracking by means of video-oculography in 11 cases of MSA-P, 8 cases of MSA-C and 27 cases of PD and compared them to 23 healthy controls (CTL). The gain of the smooth pursuit eye movement (SPEM) component exhibited significant group differences between each of the three subject groups (MSA, PD, controls) but not between MSA-P and MSA-C. The similarity of pursuit impairment in MSA-P and in MSA-C suggests a commencement of cerebellar pathology in MSA-P despite the lack of clinical signs. Otherwise, SPEM gain was of little use for differential diagnosis between MSA and PD because of wide overlap. However, inspection of the saccadic component of pursuit tracking revealed that in MSA saccades typically correct for position errors accumulated during SPEM epochs (“catch-up saccades”), whereas in PD, saccades were often directed toward future target positions (“anticipatory saccades”). The differences in pursuit tracking between PD and MSA were large enough to warrant their use as ancillary diagnostic criteria for the distinction between these disorders.     

Differentiating multiple system atrophy from Parkinson's disease: contribution of striatal and midbrain MRI volumetry and multi-tracer PET imaging

OBJECTIVES: The differential diagnosis between typical idiopathic Parkinson's disease (PD) and the striatonigral variant of multiple system atrophy (MSA-P) is often difficult because of the presence of signs and symptoms common to both forms of parkinsonism, particularly at symptom onset. This study investigated striatal and midbrain findings in MSA-P and PD patients in comparison with normal controls with the use of positron emission tomography (PET) and three dimensional magnetic resonance imaging (3D MRI) based volumetry to increase the differential diagnostic accuracy between both disease entities. METHODS: Nine patients with MSA-P, 24 patients with PD, and seven healthy controls were studied by MRI and PET with 6-[(18)F]-fluoro-L-dopa (FDOPA), [(18)F]fluoro-deoxyglucose (FDG), and 11-C-Raclopride (RACLO). Striatal and extrastriatal volumes of interest (VOI) were calculated on the basis of the individual MRI data. The PET data were transferred to the VOI datasets and subsequently analysed. RESULTS: MSA-P differed significantly from PD patients in terms of decreased putaminal volume, glucose metabolism, and postsynaptic D2 receptor density. The striatal FDOPA uptake was equally impaired in both conditions. Neither MRI volumetry nor PET imaging of the midbrain region further contributed to the differential diagnosis between PD and MSA-P. CONCLUSIONS: The extent and spatial distribution of functional and morphological changes in the striatum permit the differentiation of MSA-P from PD. Both, multi-tracer PET and 3D MRI based volumetry, may be considered equivalent in the assessment of different striatal abnormality in both disease entities. In contrast, MRI and PET imaging of the midbrain does not provide a further gain in diagnostic accuracy.     

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.     

Cerebellar and parkinsonian phenotypes in multiple system atrophy: similarities,differences and survival

Multiple system atrophy (MSA) is a neurodegenerative disease with two motor phenotypes: parkinsonian (MSA-P) and cerebellar (MSA-C). To elucidate whether in addition to the motor abnormalities there are other significant differences between these phenotypes, we performed a retrospective review of 100 patients (61 males, 39 females) with a diagnosis of possible (12 %), or probable (88 %) MSA. Four patients eventually had post-mortem confirmation (i.e., definite MSA). Sixty percent were classified as having MSA-P and 40 % as MSA-C. MSA-C and MSA-P patients had similar male prevalence (60 %), age of onset (56 ± 9 years), and frequency of OH (69 %). Brain MRI abnormalities were more frequent in MSA-C patients (p < 0.001). Mean survival was 8 ± 3 years for MSA-C and 9 ± 4 years for MSA-P patients (p = 0.22). Disease onset before 55 years predicted longer survival in both phenotypes. Initial autonomic involvement did not influence survival. We conclude that patients with both motor phenotypes have mostly similar survivals and demographic distributions. The differences here identified could help counseling of patients with MSA.     

~(11)C-CFT PET显像评价帕金森病与多系统萎缩P型患者脑内多巴胺转运体分布特点的研究

目的基于~(11)C-CFT正电子发射计算机断层(PET)显像评价帕金森病(PD)与多系统萎缩P型(MSA-P)患者脑内多巴胺转运体(DAT)分布特点,评估~(11)C-CFT PET显像在PD与MSA-P鉴别诊断中的价值。方法回顾性分析年龄、性别和疾病严重程度匹配的32例MSA-P患者(MSA-P组)和56例PD患者(PD组)的临床资料以及~(11)C-CFT PET影像资料;另选择年龄匹配的健康对照者20例为对照组。应用感兴趣区技术获得3组研究对象的尾状核、前壳核和后壳核的DAT分布半定量值,对各感兴趣区的DAT分布半定量值、相互比值和不对称性进行对比研究。建立受试者工作特征曲线(ROL),利用曲线下面积评估基于~(11)C-CFT PET显像所得相关参数对PD和MSA-P的鉴别能力。结果与PD组比较,MSA-P组患者病程更短、进展速度更快(P0.000 1)。与对照组比较,PD组和MSA-P组尾状核、前壳核和后壳核的DAT分布半定量值均显著减低(P0.000 1),且后壳核降低最为显著。PD组和MSA-P组尾状核、前壳核和后壳核的DAT分布半定量值及其不对称指数比较均差异无显著性。PD组和MSA-P组纹状体各感兴趣区DAT分布半定量值中,前壳核/尾状核比值(AP/C)、后壳核/前壳核比值(PP/AP)均差异无显著性;但MSA-P组后壳核/尾状核比值(PP/C)PD组(P0.05),两组PP/C比值的ROL曲线下面积为0.696(P=0.002);以0.611作为PP/C比值的临界值,其对MSA-P和PD鉴别诊断的灵敏度和特异度分别为71.9%和62.5%。结论 ~(11)C-CFT PET显像可以精准显示MSA-P及PD患者脑内多巴胺能神经元的突触前功能损害,但尚不能有效鉴别两种疾病。     

Comparison of cerebral glucose metabolism between multiple system atrophy Parkinsonian type and Parkinson's disease

OBJECTIVE: To investigate the difference in the regional cerebral glucose metabolism between multiple system atrophy Parkinsonian type (MSA-P) and Parkinson's disease (PD). MATERIAL AND METHODS: Fifteen patients with MSA-P, 32 patients with PD and eight cases of healthy control underwent positron emission tomography (PET) with (18)F-fluorodeoxyglucose ((18)F-FDG) showing glucose metabolism. Glucose metabolism ratios of various cerebral regions were compared as an indicator of regional cerebral glucose metabolic patterns. RESULTS: The metabolism ratios of frontal lobe/occipital lobe, parietal lobe/occipital lobe, temporal lobe/occipital lobe and corpus striatum/occipital lobe in patients with MSA-P were lower than those in patients with PD and control, respectively (p<0.01). For patients with MSAP, the metabolism ratio in thalamus was higher than those in lenticular nucleus and anterior cortical brain, respectively (p<0.01) and the changes of metabolism ratio in cortex, corpus striatum and thalamus were symmetric. For patients with PD, the metabolism ratio in corpus striatum was higher than that in thalamus and two side of the basal ganglia show asymmetric change of metabolism (p<0.01). CONCLUSION: This study suggests that significant differences exist in the patterns of regional cerebral glucose metabolism between MSA-P and PD. (18)F-FDG PET might be a useful adjunctive method for differential diagnosis between MSA-P and PD.     

Nerve conduction studies in multiple system atrophy

To study the frequency and severity of peripheral neuropathy in multiple system atrophy (MSA), we performed nerve conduction studies in 42 MSA patients suffering from either cerebellar MSA (MSA-C) or parkinsonian MSA (MSA-P). Abnormal nerve conduction was present in 24% of the patients. Abnormalities were significantly more frequent in MSA-P (43%) compared to MSA-C (14%). Motor nerve conduction velocities were reduced in 4% of the MSA-C and in 7% of the MSA-P patients. Abnormal compound muscle action potentials were more frequent in MSA-P (29% versus 7% in MSA-C) pointing to a more pronounced loss of motor axons in this subgroup. Sensory nerve conduction velocities were abnormal in 4% of the MSA-C and 14% of the MSA-P patients, and mean sensory nerve action potentials were normal in all MSA-C and reduced in 7% of the MSA-P patients. The data provide evidence that the peripheral nervous system is differentially affected in MSA-C and MSA-P.     

Evoked potentials in multiple system atrophy (MSA)

OBJECTIVES: To study the involvement of pyramidal tracts and sensory pathways in multiple system atrophy (MSA). MATERIALS AND METHODS: Evoked potential studies were performed in 45 MSA patients suffering from either MSA of cerebellar type (MSA-C) or MSA of parkinsonian type (MSA-P). RESULTS: Motor evoked potentials were normal in all MSA patients, whereas visual and somatosensory evoked potential abnormalities were found in about 40% of the MSA patients with no significant difference between the cerebellar (MSA-C) and parkinsonian (MSA-P) subgroup. Abnormal latencies of wave III in brainstem auditory evoked potentials were significantly more frequent in MSA-C. CONCLUSIONS: Abnormalities of somatosensory, visual and auditory evoked potentials are frequent findings in MSA, whereas abnormal motor evoked potentials are not a characteristic feature of the disease.