Subregional Patterns of Preferential Striatal Dopamine Transporter Loss Differ in Parkinson Disease, Progressive Supranuclear Palsy, and Multiple-System Atrophy

Abstract

Parkinson disease (PD), progressive supranuclear palsy (PSP), and multiple-system atrophy (MSA) are known to affect dopaminergic neurons of the brain stem and striatum with different preferential involvement. Here we investigated differences in striatal subregional dopamine transporter loss in PD, PSP, and MSA and assessed the diagnostic value of 18 F-fluorinated-N-3-fluoropropyl-2-b-carboxymethoxy-3-b-(4-iodophenyl)nortropane ( 18 F-FP-CIT) PET in differentiating PSP and MSA from PD. Methods: Forty-nine patients with PD, 19 patients with PSP, 24 patients with MSA, and 21 healthy people (healthy controls) were examined with 18 F-FP-CIT PET. The PET images were spatially normalized and analyzed with 12 striatal subregional volume-of-interest (VOI) templates (bilateral ventral striatum [VS], anterior caudate [AC], posterior caudate, anterior putamen, posterior putamen [PP], and ventral putamen [VP]) and 1 occipital VOI template. The nondisplaceable binding potential (BP ND ) and intersubregional ratio (ISR; defined as the ratio of the BP ND of one striatal subregion to that of another striatal subregion) of subregional VOIs were calculated. Results: The BP ND of all VOIs in the PD, MSA, and PSP groups were significantly lower than those in the healthy controls (P , 0.05). The BP ND of AC and the AC/VS ISR in the PSP group were significantly lower than those in the PD group. The BP ND of VP was significantly lower, but the PP/VP ISR was significantly higher in the MSA group than in the PD group. At the cutoff value for the AC/VS ISR (,0.7), the sensitivity and specificity for differentiating PSP from PD were 94% and 92%, respectively. At the cutoff value for the PP/VP ISR (.0.65), the sensitivity and specificity for differentiating MSA from PD were 90% and 45%, respectively. The diagnostic accuracy of visual analysis was similar to that of quantitative analysis for differentiating PSP from PD but was significantly higher for differentiating MSA from PD. Conclusion: Compared with PD, PSP and MSA showed more prominent and earlier dopamine transporter loss in the AC and VP, respectively. These findings could be useful for suggesting PSP or MSA in parkinsonian cases without characteristic atypical features.

Analysis of Extrastriatal 123I-FP-CIT Binding Contributes to the Differential Diagnosis of Parkinsonian Diseases

“…Already in early disease stages, patients initially diagnosed with PD that later converted to MSA or PSP have lower DAT binding in the caudate nucleus than patients in whom a diagnosis of PD is maintained (4). In addition, our findings in the posterior putamen in the ROI analysis corroborate the results of earlier studies by Oh and Messa (8,9). The automated DAT binding analyses resulted in comparable data, suggesting this type of approach is useful when assessing striatal binding in routine clinical practice.…”

“…Several previous studies have demonstrated lower overall striatal DAT binding in PSP and MSA-P than PD, with relative sparing of the caudate nucleus in PD (4,8,9,14). Already in early disease stages, patients initially diagnosed with PD that later converted to MSA or PSP have lower DAT binding in the caudate nucleus than patients in whom a diagnosis of PD is maintained (4).…”

Metabolic network expression in parkinsonism: Clinical and dopaminergic correlations

“…PSP subjects exhibited significant reductions in DAT binding involving both caudate and putamen, 37 which resulted in higher (more ''normal'') putamen/caudate ratio values relative to the LBD groups. This was consistent with early dopaminergic imaging findings.…”

Segmentation-Based MR Attenuation Correction Including Bones Also Affects Quantitation in Brain Studies: An Initial Result of 18F-FP-CIT PET/MR for Patients with Parkinsonism

“…However, CT images have limitations in PET quantification in the brain structures due to the lack of softtissue differentiation. In brain PET imaging, 18 F-fluoropropylcarbomethoxyiodophenylnortropane ( 18 F-FP-CIT) has been widely used for evaluation of Parkinsonian syndrome as dopaminergic system imaging (3,4). For quantification of dopamine transporter (DAT) density, manually drawn regions of interest or softwarebased coregistered additional MR images have been used to overcome the issues regarding striatal segmentation (5-7).…”