Differential diagnosis of parkinsonism: a head-to-head comparison of FDG PET and MIBG scintigraphy

Abstract

Abstract[18F]fluorodeoxyglucose (FDG) PET and [123I]metaiodobenzylguanidine (MIBG) scintigraphy may contribute to the differential diagnosis of neurodegenerative parkinsonism. To identify the superior method, we retrospectively evaluated 54 patients with suspected neurodegenerative parkinsonism, who were referred for FDG PET and MIBG scintigraphy. Two investigators visually assessed FDG PET scans using an ordinal 6-step score for disease-specific patterns of Lewy body diseases (LBD) or atypical parkinsonism (APS) and assigned the latter to the subgroups multiple system atrophy (MSA), progressive supranuclear palsy (PSP), or corticobasal syndrome. Regions-of-interest analysis on anterior planar MIBG images served to calculate the heart-to-mediastinum ratio. Movement disorder specialists blinded to imaging results established clinical follow-up diagnosis by means of guideline-derived case vignettes. Clinical follow-up (1.7 ± 2.3 years) revealed the following diagnoses: n = 19 LBD (n = 17 Parkinson’s disease [PD], n = 1 PD dementia, and n = 1 dementia with Lewy bodies), n = 31 APS (n = 28 MSA, n = 3 PSP), n = 3 non-neurodegenerative parkinsonism; n = 1 patient could not be diagnosed and was excluded. Receiver operating characteristic analyses for discriminating LBD vs. non-LBD revealed a larger area under the curve for FDG PET than for MIBG scintigraphy at statistical trend level for consensus rating (0.82 vs. 0.69, p = 0.06; significant for investigator #1: 0.83 vs. 0.69, p = 0.04). The analysis of PD vs. MSA showed a similar difference (0.82 vs. 0.69, p = 0.11; rater #1: 0.83 vs. 0.69, p = 0.07). Albeit the notable differences in diagnostic performance did not attain statistical significance, the authors consider this finding clinically relevant and suggest that FDG PET, which also allows for subgrouping of APS, should be preferred.

An Update on Gene Therapy Approaches for Parkinson’s Disease: Restoration of Dopaminergic Function

“…Integration of technology, multimodal imaging, and other ancillary studies to distinguish PD from other parkinsonisms are important design elements to consider in PD gene therapy studies, particularly for studies enrolling participants with early or de novo PD. The use of FDG PET with MIBG cardiac scintigraphy, other imaging of the DAergic system, or MRI findings can support clinical impressions to bolster diagnostic certainty and to differentiate PD from atypical parkinsonisms [ 53, 54 ]. Other “low-tech” assessments like olfactory testing can also easily be included to distinguish PD from other atypical forms [ 55 ].…”

The potential role of the cardiac MIBG scan in differentiating the drug-induced Parkinsonism from Parkinson’s disease

“…Our results indicated 84.4% sensitivity and 86.4% specificity for MIBG scan in differentiating the PD, which is close to the results from similar works [9] , [17] , [20] . Also, the competitiveness of the MIBG scan with other nuclear scans is differentiating the neurodegenerative PD [21] from other parkinsonian disorders, emphasizing the considerable utility of the MIBG scan. In this regard, there are few head-to-head comparisons between the MIBG scan and dopamine transporter (DAT) scan to differentiate patients with PD from other parkinsonian syndromes, including DIP.…”

Update on neuroimaging in non-Alzheimer's disease dementia: a focus on the Lewy body disease spectrum

“…MIBG myocardial scintigraphy detects early disturbances of the sympathetic nervous system in LBD and is useful for differentiating this dementia from AD [15]. However, recent studies have underlined the importance of a methodological standardization and cut-off setting for 123I-MIBG [15][16][17].…”