Diffusion‐weighted imaging in multiple system atrophy: A comparison between clinical subtypes

Abstract

Multiple system atrophy can be classified into two main types, a Parkinsonian (MSA-P) and a cerebellar (MSA-C) variant based on clinical presentation. We obtained diffusion-weighted magnetic resonance imaging (DWI) in 9 MSA-P and 12 MSA-C patients and 11 controls, and correlated DWI changes with disease duration and severity. We found that Trace (D) values in the entire and anterior putamen were significantly higher in MSA-P than in MSA-C patients and controls, whereas Trace (D) values in the cerebellum and middle cerebellar peduncle (MCP) were significantly higher in MSA-C than in MSA-P patients and controls. Increased disease duration was significantly correlated with increased Trace (D) values in pons of MSA-P patients, and in cerebellum and MCP of MSA-C patients. Both UMSARS and UPDRS motor scores positively correlated with entire and posterior putaminal Trace (D) values in MSA-P patients. The diffusivity changes parallel phenotypical and pathologic differences between MSA-P and MSA-C patients, suggesting that DWI is a feasible tool for in vivo evaluation of neurodegeneration in MSA. Based on our findings, Trace (D) measurements in the putamen and pons in MSA-P patients and in the cerebellum and MCP in MSA-C patients could serve as quantitative markers for microstructural damage in the course of disease.

Diffusion Tensor Imaging in Idiopathic Parkinson's Disease and Multisystem Atrophy (Parkinsonian Type)

“…In some previous studies a significant increase of ADC and decrease of FA in the middle cerebellar peduncle were found in MSAp [10,11,23] but not in others [14,32]. We could not reproduce these findings, presumably due to both image acquisition and post-processing algorithms as discussed in detail below.…”

“…Some of these studies analysed ADC or FA values in manually chosen ROIs [8,9,10,11,23,24], while others employed SPM-style hypothesis-free whole-brain analysis techniques that are especially adequate for analysis of grey matter [14]. …”

“…intra-individual neuronal loss reflecting disease progression in a longitudinal study of patients with Huntington's disease [13] or differentiating MSAp from MSAc (multisystem atrophy of the cerebellar type) [14]. …”

Neuroimaging of Rapidly Progressive Dementias, Part 1: Neurodegenerative Etiologies

“…29 DWI may demonstrate increased diffusivity and ADC within the affected middle cerebellar peduncles, and other authors report decreased fractional anisotropy matching this finding. 34,[40][41][42] Putaminal ADC increases likewise exist in MSA, but not Parkinson disease, and these values also correlate with clinical measures. 41,[43][44][45][46] Therefore, DWI and DTI are essential in improving differentiation between MSA and other similar conditions such as PSP and Parkinson disease.…”

Significance of MRI in Diagnosis and Differential Diagnosis of Parkinson’s Disease

“…The most relevant studies are summarized in table 1 . Several studies performed using ROI could demonstrate that DWI permits to discriminate between MSA-P in early disease stages and PD as well as healthy subjects on the basis of putaminal diffusivity measure values [58,108,114,115,[125][126][127][128][129] . Of particular note, two studies directly compared the value of striatal ADCs or putaminal Trace(D) values using DWI in the differential diagnosis of MSA-P with either dopamine D2 receptor-binding IBZM-SPECT ( 123 I-iodobenzamidesingle-photon emission computed tomography) [115] or cardiac MIBG ( 123 I-meta-iodobenzylguanidine uptake) [128] .…”