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

Abstract

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-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.

Imaging in cell-based therapy for neurodegenerative diseases

“…This differentiation is otherwise difficult due to similar signs and symptoms especially at disease onset. There appears to be a larger decrease in the putaminal volume in MSA-P than in that of PD patients, compared to control [119]. Similar to this, other groups found that differences in the trace of diffusion tensor values or magnetization transfer of the putamen and globus pallidus also successfully differentiate between MSA-P and PD [120,121].…”

Validation of the reference tissue model for estimation of dopaminergic D2-like receptor binding with [18F](N-methyl)benperidol in humans

“…Other studies measuring D 2 -like receptor binding have reported similar levels of variability in BP estimates using Method 3 [44,45]. A study measuring D 2 -like receptor binding using [46].…”

Chromatic pattern-reversal electroretinograms (ChPERGs) are spared in multiple system atrophy compared with Parkinson’s disease

“…In multiple system atrophy (MSA), the visual system is believed to be spared and dopamine deficiency has been hypothesised to be less pronounced than in IPD [9], even though the data in the literature are scarce and not unanimous [10,11] and nothing on retinal dopamine content has been reported. Little information is available on VEPs and pattern electroretinograms (PERGs) in MSA patients [9,12].…”