Optimizing Parkinson’s disease diagnosis: the role of a dual nuclear imaging algorithm

MIBG-DAT dual imaging diagnostic algorithm. MIBG abnormality separates multisystem Lewy body disease (MLBD) pathologies, including idiopathic Parkinson’s disease (PD) and dementia with Lewy bodies (DLB) from other types of parkinsonism. 123I-Ioflupane measures the integrity of nigrostriatal dopamine projections. Low dopamine transporter (DAT) levels in the caudate, putamen or both, in either brain hemisphere, are consistent with a parkinsonian disorder, independently of its nature. In subjects with appropriate symptoms and signs, the combination of the two imaging modalities allows discriminating four distinct pathologies: (1) non-parkinsonian disorders (upper left quadrant, dual test normality); (2) atypical non-Lewy body parkinsonism (upper right quadrant, normal MIBG, and abnormal DAT); (3) early-stage MLBD or pre-symptomatic parkinsonism (lower left quadrant, abnormal MIBG and normal DAT); (4) MLBD, either DLB or PD (lower right quadrant, abnormal MIBG, and DAT