Routine MRI for the differential diagnosis of Parkinson's disease,MSA, PSP,and CBD

We assessed the usefulness of routine MRI for the differential diagnosis of Parkinson's disease (PD) with "atypical" parkinsonian syndromes in everyday clinical practice. We studied routinely performed MRI in PD (n = 32), multiple system atrophy (MSA, n = 28), progressive supranuclear palsy (PSP, n = 30), and corticobasal degeneration (CBD, n = 26). From a preliminary analysis of 26 items, 4 independent investigators rated 11 easily recognizable MRI pointers organized as a simple scoring system. The frequency, severity and inter-rater agreement were determined. The total severity score was subdivided into "cortical", "putaminal", "midbrain", and "pontocerebellar" scores. The frequency of putaminal involvement (100%) and vermian cerebellar atrophy (45%) was significantly higher in MSA, but that of cortical atrophy (50%), midbrain atrophy and 3(rd) ventricle enlargement (75%) was higher in PSP and CBD. The median total score fairly differentiated "atypical" parkinsonian syndromes from PD (positive predictive value-PPV-90%). However, the median total score was unable to differentiate atypical parkinsonian syndromes each other. The "cortical" score distinguished CBD and PSP from MSA with a fair PPV (>90%). The PPV of the "putaminal" score was high (70%) for the differential diagnosis of MSA with PSP and CBD. The "midbrain" score was significantly higher in PSP and CBD compared to MSA. These results are in accordance with the underlying pathology found in these disorders and demonstrate that a simple MRI scoring procedure may help the neurologist to differentiate primary causes of parkinsonism in everyday practice.     

Sleep disturbances and brain MRI morphometry in Parkinson's disease,multiple system atrophy and progressive supranuclear palsy – a comparative study

Despite common reports in Parkinson's disease (PD), in other parkinsonian syndromes, sleep disturbances have been less frequently described. This study evaluated and compared sleep disturbances in patients with PD, multiple system atrophy (MSA) and progressive supranuclear palsy (PSP) and analyzed associations with brain magnetic resonance imaging (MRI) morphometry. This was a cross-sectional study of 16 PD cases, 13 MSA, 14 PSP and 12 control. Sleep disturbances were evaluated by Epworth Sleepiness Scale, Pittsburgh Sleep Quality Index (PSQI), Restless Legs Scale and Berlin questionnaire. Pons area, midbrain area, medial cerebellar peduncle (MCP) width, and superior cerebellar peduncle width were measured using MRI. Poor quality sleep, risk of obstructive sleep apnea (OSA) and restless legs syndrome (RLS) were detected in all groups. Patients with MSA showed higher risk of OSA and less frequent RLS. In MSA, a correlation between PSQI scores and Hoehn and Yahr stage was observed (p < 0.05). In PSP, RLS was frequent (57%) and related with reduced sleep duration and efficiency. In PD, excessive daytime sleepiness was related to atrophy of the MCP (p = 0.01). RLS was more frequent in PD and PSP, and in PSP, was associated with reduced sleep efficiency and sleep duration. Brain morphometry abnormalities were found in connection with excessive daytime sleepiness and risk of OSA in PD and PSP suggesting widespread degeneration of brainstem sleep structures on the basis of sleep abnormalities in these patients.     

Apparent diffusion coefficient of the superior cerebellar peduncle differentiates progressive supranuclear palsy from Parkinson's disease

The early diagnosis of progressive supranuclear palsy (PSP) may be challenging, because of clinical overlapping features with Parkinson's disease (PD) and other parkinsonian syndromes such as the Parkinsonian variant of multiple system atrophy (MSA‐P). Conventional MRI can help in differentiating parkinsonian disorders but its diagnostic accuracy is still unsatisfactory. On the basis of the pathological demonstration of superior cerebellar peduncle (SCP) atrophy in patients with PSP, we assessed the SCP apparent diffusion coefficient (ADC) values in patients with PSP, PD, and MSA‐P in order to evaluate its differential diagnostic value in vivo. Twenty‐eight patients with PSP (14 with possible‐PSP and 14 with probable‐PSP), 15 PD, 15 MSA‐P, and 16 healthy subjects were studied by using diffusion weighted imaging (DWI). ADC was calculated in regions of interest defined in the left and right SCP by two clinically blinded operators. Intrarater (r = 0.98, P < 0.001) and interrater reliability (r = 0.97; P < 0.001) for SCP measurements were high. Patients with PSP had higher SCP rADC values (median 0.98 × 10^?3mm²/s) than patients with PD (median 0.79 × 10^?3 mm²/s, P < 0.001), MSA‐P (median 0.79 × 10^?3 mm²/s, P < 0.001), and healthy controls (median 0.80 × 10^?3 mm²/s, P < 0.001). DWI discriminated patients with PSP from PD and healthy subjects on the basis of SCP rADC individual values (100% sensitivity and specificity) and from patients with MSA‐P (96.4% sensitivity and 93.3% specificity). The higher values of rADC in SCP of patients with PSP correspond with the in vivo microstructural feature of atrophy detected postmortem and provide an additional support for early discrimination between PSP and other neurodegenerative parkinsonisms. © 2008 Movement Disorder Society     

Regional brain volumes distinguish PSP, MSA-P, and PD: MRI-based clinico-radiological correlations.

Progressive supranuclear palsy (PSP) and multiple system atrophy (MSA) are neurodegenerative disorders, each with a prevalence of around 5 per 100,000. Regional brain atrophy patterns differ in the two disorders, however, and magnetic resonance imaging is sometimes helpful in distinguishing them in the later stages. We measured whole brain and regional volumes, including cerebellum, pons, midbrain, superior cerebellar peduncle (SCP), and ventricular volumes as well as frontal and posterior-inferior cerebral regions in 18 subjects with PSP, 9 with MSA-P (parkinsonian phenotype), 9 with Parkinson's disease (PD), and 18 healthy controls. Associations between these volumes, cognitive profiles, and clinical measures of disease severity and motor disability were assessed. Mean midbrain volume was 30% smaller in PSP than in PD or controls (P < 0.001) and 15% smaller than in MSA-P (P = 0.009). The mean SCP volume in PSP was 30% smaller than in MSA-P, PD, or controls (P < 0.001). Mean cerebellar volumes in MSA-P were 20% smaller than in controls and PD and 18% smaller than in PSP (P = 0.01). Mean pontine volume in MSA-P was 30% smaller than in PD or controls (P < 0.001) and 25% smaller than in PSP (P = 0.01). Motor disability was most strongly associated with midbrain volume, and more severe executive dysfunction was associated with reduced frontal volume. These distinct patterns of cortical and subcortical atrophy, when considered together rather than independently, better differentiate PSP and MSA-P from each other and also from healthy controls.     

The value of novel MRI techniques in Parkinson-plus syndromes: Diffusion tensor imaging and anatomical connectivity studies

Conventional MRI is a well-described, highly useful tool for the differential diagnosis of degenerative parkinsonian syndromes. Nevertheless, the observed abnormalities may only appear in late-stage disease. Diffusion tensor imaging (DTI) can identify microstructural changes in brain tissue integrity and connectivity. The technique has proven value in the differential diagnosis of multiple system atrophy (MSA), progressive supranuclear palsy (PSP) and Parkinson's disease (PD). Here, we performed a systematic review of the literature on the main corticosubcortical DTI abnormalities identified to date in the context of the diagnosis of MSA and PSP with diffusion-weighted imaging, diffusion tensor imaging and anatomical connectivity studies. In good agreement with the histological data, increased diffusivity in the putamen (in MSA and PSP), in the middle cerebellar peduncles (in MSA) and in the upper cerebellar peduncles (in PSP) has been reported. Motor pathway involvement is characterized by low fraction anisotropy (FA) in the primary motor cortex in MSA-P and PSP, a high apparent diffusion coefficient (ADC) and low FA in the supplementary motor area in PSP. We then outline the value of these techniques in differential diagnosis (especially with respect to PD). Anatomical connectivity studies have revealed a lower number of fibers in the corticospinal tract in MSA and PSP (relative to PD and controls) and fewer tracked cortical projection fibers in patients with PSP or late-stage MSA (relative to patients with early MSA or PD and controls). Lastly, we report the main literature data concerning the value of DTI parameters in monitoring disease progression. The observed correlations between DTI parameters on one hand and clinical scores and/or disease duration on the other constitute strong evidence of the value of DTI in monitoring disease progression. In MSA, the ataxia score was correlated with ADC values in the pons and the upper cerebellar peduncles, whereas both the motor score and the disease duration were correlated with putaminal ADC values. In conclusion, DTI and connectivity studies constitute promising tools for differentiating between “Parkinson-plus” syndromes.     

MRI for the differential diagnosis of neurodegenerative parkinsonism in clinical practice

Parkinson's disease (PD) is the most common neurodegenerative cause of parkinsonism, followed by progressive supranuclear palsy (PSP) and multiple system atrophy (MSA). Despite the publication of consensus operational criteria for the diagnosis of PD and the various atypical parkinsonian disorders (APD) such as PSP, MSA and corticobasal degeneration, an accurate diagnosis of neurodegenerative parkinsonian syndromes remains a challenge for each neurologist. Particularly in the early disease stages the clinical separation of APDs from PD carries a high rate of misdiagnosis. However, an early differentiation between APD and PD, each characterized by completely different natural histories, is crucial for determining the prognosis and choosing a treatment strategy. MRI plays an important role in the exclusion of symptomatic parkinsonism due to other pathologies. Over the past two decades, conventional MRI and advanced MRI techniques, including proton magnetic resonance spectroscopy (1H-MRS), diffusion-weighted imaging (DWI), magnetization transfer imaging (MTI), and magnetic resonance volumetry (MRV) have shown abnormalities in the substantia nigra and basal ganglia, especially in APD. Furthermore, in accordance with neuropathological studies suggesting that the olfactory system is an early target of the disease, recent studies using advanced MRI techniques have shown abnormalities in the olfactory system in the early disease stages of patients with PD. Given that olfactory deficits may be a premotor marker of the disease, such methods may eventually evolve into an early screening tool for PD.     

Reproducible network and regional topographies of abnormal glucose metabolism associated with progressive supranuclear palsy: Multivariate and univariate analyses in American and Chinese patient cohorts

Progressive supranuclear palsy (PSP) is a rare movement disorder and often difficult to distinguish clinically from Parkinson's disease (PD) and multiple system atrophy (MSA) in early phases. In this study, we report reproducible disease‐related topographies of brain network and regional glucose metabolism associated with PSP in clinically‐confirmed independent cohorts of PSP, MSA, and PD patients and healthy controls in the USA and China. Using ¹⁸F‐FDG PET images from PSP and healthy subjects, we applied spatial covariance analysis with bootstrapping to identify a PSP‐related pattern (PSPRP) and estimate its reliability, and evaluated the ability of network scores for differential diagnosis. We also detected regional metabolic differences using statistical parametric mapping analysis. We produced a highly reliable PSPRP characterized by relative metabolic decreases in the middle prefrontal cortex/cingulate, ventrolateral prefrontal cortex, striatum, thalamus and midbrain, covarying with relative metabolic increases in the hippocampus, insula and parieto‐temporal regions. PSPRP network scores correlated positively with PSP duration and accurately discriminated between healthy, PSP, MSA and PD groups in two separate cohorts of parkinsonian patients at both early and advanced stages. Moreover, PSP patients shared many overlapping areas with abnormal metabolism in the same cortical and subcortical regions as in the PSPRP. With rigorous cross‐validation, this study demonstrated highly comparable and reproducible PSP‐related metabolic topographies at network and regional levels across different patient populations and PET scanners. Metabolic brain network activity may serve as a reliable and objective marker of PSP, although cross‐validation applying recent diagnostic criteria and classification is warranted.     

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.     

Cerebral peduncle angle: Unreliable in differentiating progressive supranuclear palsy from other neurodegenerative diseases

IntroductionThe significant symptom overlap between progressive supranuclear palsy (PSP) and other parkinsonian neurodegenerative diseases frequently results in misdiagnosis. However, neuroimaging can be used to quantify disease-related morphological changes and specific markers. The cerebral peduncle angle (CPA) has been shown to differentiate clinically diagnosed PSP from other parkinsonian diseases but this result has yet to be confirmed in autopsy-proven disease.MethodsMagnetic resonance imaging (MRI) scans were obtained for 168 patients representing 69 medical facilities. Following randomization, the images were divided into two groups (Type 1 and Type 2) based upon midbrain morphological differences. Two readers were blinded and independently measured the CPA of 146 patients with autopsy-proven progressive supranuclear palsy (PSP; n = 54), corticobasal degeneration (n = 16), multiple system atrophy (MSA; n = 11) and Lewy body disease (n = 65).ResultsApplying two separate measurement techniques revealed no statistically significant differences in CPA measurements among any study groups regardless of classification measurement approach. The interobserver agreement showed significant differences in measurements using the Type 2 approach.ConclusionMeasuring the CPA on MRI is not a reliable way of differentiating among patients with PSP, corticobasal degeneration, MSA, or Lewy body disease.     

Diffusion-weighted magnetic resonance imaging differentiates Parkinsonian variant of multiple-system atrophy from progressive supranuclear palsy.

Progressive supranuclear palsy (PSP) and the parkinsonian variant of multiple-system atrophy (MSA-P) may present with a similar phenotype. Magnetic resonance diffusion-weighted imaging (DWI) has been shown to be a sensitive discriminator of MSA-P from Parkinson's disease (PD). We studied 20 PSP, 11 MSA-P, 12 PD patients and 7 healthy controls in order to investigate whether regional apparent diffusion coefficients (rADCs) help distinguish PSP and MSA-P; whether rADCs are correlated with clinical disease severity scores; and the relationship between brainstem and cerebellar volumes and rADCs in PSP and MSA-P. The Unified Parkinson's Disease Rating Scale, Hoehn and Yahr score, Mini Mental State Examination, and frontal assessment battery were recorded in all patients. Regional ADCs were measured in the middle cerebellar peduncle (MCP), caudal and rostral pons, midbrain, decussating fibers of the superior cerebellar peduncle, thalamus, putamen, globus pallidus, caudate nucleus, corpus callosum, frontal and parietal white matter, as well as the centrum semiovale. In MSA-P, rADCs in the MCP and rostral pons were significantly greater than in PSP (P < 0.001 and 0.009) and PD (P < 0.001 and = 0.002). Stepwise logistic regression revealed that the MCP rADC distinguishes MSA-P from PSP with a sensitivity of 91% and a specificity of 84%. Increased brainstem rADCs were associated with motor deficit in MSA-P and PSP. Increased rADCs in the pons and MCP were associated with smaller pontine and cerebellar volumes in MSA-P. rADCs distinguish MSA-P from PSP. These have a clinical correlate and are associated with reduced brainstem and cerebellar volumes.     

Consecutive analyses of cerebrospinal fluid axonal and glial markers in Parkinson's disease and atypical parkinsonian disorders

Cerebrospinal fluid (CSF) levels of neurofilament light protein (NFL), a marker of neuronal damage, are normal in Parkinson's disease (PD) but elevated in multiple system atrophy (MSA) and progressive supranuclear palsy (PSP). Therefore, CSF NFL can help differentiate between PD on one hand and MSA/PSP on the other. In the present study of 10 patients with PD, 21 with MSA, 14 with PSP, 11 with corticobasal degeneration (CBD), and 59 healthy controls, this previous observation is confirmed and also extended to include CBD by showing that similarly high CSF NFL levels are seen not only in MSA and PSP but also in CBD. CSF levels of glial fibrillary acidic protein (GFAP), a protein expressed mainly in fibrillary astrocytes, were similar in all investigated groups. In addition, consecutive analyses of CSF NFL and CSF GFAP levels showed relatively stable levels over time in all the investigated parkinsonian disorders, suggesting that the rate of neuronal degeneration is rather constant over time. Our results suggest that measurements of CSF NFL but not GFAP can be useful in the differential diagnosis of PD versus atypical parkinsonian disorders (APD). However they do not help differentiate between the different APD.     

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.     

Progression of falls in postmortem-confirmed parkinsonian disorders.

Although falls are known to occur in several parkinsonian disorders, such as Parkinson's disease (PD), multiple system atrophy (MSA), dementia with Lewy bodies (DLB), corticobasal degeneration (CBD), and progressive supranuclear palsy (PSP), differences in the evolution of this feature have not been studied systematically in pathologically confirmed cases. Seventy-seven cases with pathologically confirmed parkinsonian disorders (PD: n = 11, MSA: n = 15, DLB: n = 14, CBD: n = 13, PSP: n = 24), collected up to 1994, formed the basis for a multicenter clinicopathologic study organized by the National Institute of Neurological Disorders and Stroke to improve differential diagnosis of parkinsonian disorders. In the present study, we determined the time course, that is, the duration from first symptom to onset (latency) and duration from onset to death, of recurrent falls. Furthermore, we analyzed the diagnostic validity of a predefined latency to onset of recurrent falls within 1 year of symptom onset. Significant group differences for latency, but not duration, of recurrent falls were observed. Latencies to onset of falls were short in PSP patients, intermediate in MSA, DLB, and CBD, and long in PD. Recurrent falls occurring within the first year after disease onset predicted PSP in 68% of the patients. Our study demonstrates for the first time that latency to onset, but not duration, of recurrent falls differentiates PD from other parkinsonian disorders. Whereas early falls are important for the diagnosis of PSP, the addition of other features increases its diagnostic predictive value.     

Diagnostic criteria for multiple system atrophy and progressive supranuclear palsy

The atypical parkinsonian disorders (APD) embrace a heterogeneous group of movement disorders all characterized by prominent parkinsonism, accompanied by specific additional features such as cerebellar ataxia, early autonomic dysfunction, early dementia, pyramidal tract signs, myoclonus, supranuclear gaze palsy, apraxia which are atypical for idiopathic Parkinson's disease (PD). Beside these features, rapid disease progression and poor or absent response to L-Dopa therapy both raise the suspicion of an APD. Currently, multiple system atrophy (MSA), progressive supranuclear palsy (PSP), corticobasal degeneration (CBD) and dementia with Lewy bodies (DLB) are referred to as APD. Clinical diagnosis can be difficult in early stages and although the predictive value of the widely established, diagnostic criteria is high at first neurological evaluation sensitivity tends to be poor and may be less than 30%. In this review, we will discuss diagnostic issues in MSA and PSP.     

Neurofilament heavy-chain NfH(SMI35) in cerebrospinal fluid supports the differential diagnosis of Parkinsonian syndromes.

We aimed to evaluate the potential of the cerebrospinal fluid (CSF) axonal damage biomarker NfH(SMI35) in the laboratory-supported differential diagnosis of parkinsonian syndromes. Patients with idiopathic Parkinson's disease (PD; n = 22), multiple-system atrophy (MSA; n = 21), progressive supranuclear palsy (PSP; n = 21), corticobasal degeneration (CBD; n = 6), and age-matched controls (n = 45) were included. CSF levels of NfH(SMI35) were measured using ELISA. Levels of CSF NfH(SMI35) were elevated in PSP compared to PD and controls (P < 0.05 each). They were also significantly higher in MSA than in PD and controls (P < 0.05 each). NfH(SMI35) differentiated PD from PSP with a sensitivity of 76.5% and a specificity of 94.4%. Axonal damage as measured by CSF NfH(SMI35) is most prominent in the more rapidly progressive syndromes PSP and MSA as compared to PD or CBD. CSF NfH(SMI35) may therefore be of some value for the laboratory-supported differential diagnosis of atypical parkinsonian syndromes.     

Time course of symptomatic orthostatic hypotension and urinary incontinence in patients with postmortem confirmed parkinsonian syndromes: a clinicopathological study

OBJECTIVE: Although both orthostatic hypotension and urinary incontinence have been reported in a number of parkinsonian syndromes, such as Parkinson's disease (PD), multiple system atrophy (MSA), dementia with Lewy bodies (DLB), corticobasal degeneration (CBD), and progressive supranuclear palsy (PSP), differences in the evolution of these features have not been studied systematically in pathologically confirmed cases. METHODS: 77 cases with pathologically confirmed parkinsonian syndromes (PD, n=11; MSA, n=15; DLB, n=14; CBD, n=13; PSP, n=24), collected up to 1994, formed the basis for a multicentre clinicopathological study organised by the NINDS to improve the differential diagnosis of parkinsonian disorders. The present study determined the time course-that is, latency to onset and duration from onset to death, of symptomatic orthostatic hypotension, and urinary incontinence in the NINDS series. Furthermore, the diagnostic validity of a predefined latency to onset within 1 year of disease onset of symptomatic orthostatic hypotension or urinary incontinence was analysed. RESULTS: Significant group differences for latency, but not duration, of symptomatic orthostatic hypotension and urinary incontinence were found. Latencies to onset of either feature were short in patients with MSA, intermediate in patients with DLB, CBD, and PSP, and long in those with PD. Symptomatic orthostatic hypotension occurring within the first year after disease onset predicted MSA in 75% of cases; early urinary incontinence was less predictive for MSA (56%). CONCLUSION: Latency to onset, but not duration, of symptomatic orthostatic hypotension or urinary incontinence differentiates PD from other parkinsonian syndromes, particularly MSA.     

Conventional magnetic resonance imaging in confirmed progressive supranuclear palsy and multiple system atrophy

Conventional magnetic resonance imaging (cMRI) is often used to aid the diagnosis of progressive supranuclear palsy (PSP) and multiple system atrophy (MSA), but its ability to predict the histopathological diagnosis has not been systematically studied. cMRI from 48 neuropathologically confirmed cases, including PSP (n = 22), MSA (n = 13), Parkinson's disease (PD) (n = 7), and corticobasal degeneration (n = 6), and controls (n = 9) were assessed blinded to clinical details and systematically rated for reported abnormalities. Clinical diagnosis and macroscopic postmortem findings were retrospectively assessed. Radiological assessment of MRI was correct in 16 of 22 (72.7%) PSP cases and 10 of 13 (76.9%) MSA cases with substantial interrater agreement (Cohen's kappa 0.708; P < .001); no PSP case was misclassified as MSA or vice versa. MRI was less sensitive but more specific than clinical diagnosis in PSP and both more sensitive and specific than clinical diagnosis in MSA. The “hummingbird” and “morning glory” signs were highly specific for PSP, and “the middle cerebellar peduncle sign” and “hot cross bun” for MSA, but sensitivity was lower (up to 68.4%) and characteristic findings may not be present even at autopsy. cMRI, clinical diagnosis, and macroscopic examination at postmortem have similar sensitivity and specificity in predicting a neuropathological diagnosis. We have validated specific radiological signs in pathologically confirmed PSP and MSA. However, the low sensitivity of these and macroscopic findings at autopsy suggest a need for imaging techniques sensitive to microstructural abnormalities without regional atrophy. © 2012 Movement Disorder Society     

Differentiation of Progressive Supranuclear Palsy: clinical,imaging and laboratory tools

Progressive supranuclear palsy (PSP) is the most common atypical parkinsonian syndrome comprising two main clinical subtypes: Richardson's syndrome (RS), characterized by prominent postural instability, supranuclear vertical gaze palsy and frontal dysfunction; and PSP‐parkinsonism (PSP‐P) which is characterized by an asymmetric onset, tremor and moderate initial therapeutic response to levodopa. The early clinical features of PSP‐P are often difficult to discern from idiopathic Parkinson's disease (PD), and other atypical parkinsonian disorders, including multiple system atrophy (MSA) and corticobasal syndrome (CBS). In addition, rare PSP subtypes may be overlooked or misdiagnosed if there are atypical features present. The differentiation between atypical parkinsonian disorders and PD is important because the prognoses are different, and there are different responses to therapy. Structural and functional imaging, although currently of limited diagnostic value for individual use in early disease, may contribute valuable information in the differential diagnosis of PSP. A growing body of evidence shows the importance of CSF biomarkers in distinguishing between atypical parkinsonian disorders particularly early in their course when disease‐modifying therapies are becoming available. However, specific diagnostic CSF biomarkers have yet to be identified. In the absence of reliable disease‐specific markers, we provide an update of the recent literature on the assessment of clinical symptoms, pathology, neuroimaging and biofluid markers that might help to distinguish between these overlapping conditions early in the course of the disease.     

Magnetic resonance imaging in Parkinson's disease and parkinsonian syndromes

High field strength magnetic resonance imaging (MRI) provides a noninvasive means of evaluating patients with parkinsonism. Using strict clinical criteria, we began a prospective study of patients with Parkinson's disease (PD) and parkinsonian syndromes (PS) including progressive supranuclear palsy (PSP), multiple system atrophy (MSA), and atypical parkinsonism (ATYP). We detected moderate to severe putaminal hypointensity more frequently in PS than in PD and controls, although putaminal hypointensity did not distinguish between MSA, PSP, or ATYP. Signal intensity in the lateral substantia nigra did not differ significantly among patients with PD, PS, or controls and was therefore not a useful MRI marker. Pars compacta width was significantly narrower in both PD and PS. Subcortical and periventricular hyperintense foci were more abundant in PD and PS than controls. Atrophy of the brainstem occurred only in patients with PS.     

进行性核上性麻痹与多系统萎缩的头部MRI和FDG-PET比较

目的对比研究进行性核上性麻痹(PSP)与多系统萎缩(MSA)的脑干MRI表现和头部葡萄糖代谢特征。方法对11例PSP患者、37例MSA患者和43例健康对照进行头部MRI平扫检查,并计算MRI正中矢状面T1加权像上中脑截面面积,其中5例PSP和19例MSA进行了18F-FDG PET检查。结果(1)MRI:11例PSP正中矢状位T1加权像均可见中脑上缘平坦或凹陷表现,呈"蜂鸟征",而MSA患者和健康对照组未见上述表现。37例MSA患者中有34例轴位T2加权像桥脑可见"十字征"样长T2异常信号。PSP患者正中矢状位T1加权像上中脑截面面积分别低于MSA组和健康对照组(P<0.01)。(2)PET:PSP组主要表现为对称性额叶低代谢;MSA组主要表现为额、顶、颞叶普遍低代谢,纹状体对称性代谢降低,丘脑代谢高于纹状体。结论PSP中脑MRI特征和头部葡萄糖代谢特征与MSA和健康对照有明确差异,有助于PSP与MSA的鉴别诊断。