Palermo G, Giannoni S, Frosini D, Morganti R, Volterrani D, Bonuccelli U, Pavese N, Ceravolo R. Dopamine Transporter, Age, and Motor Complications in Parkinson's Disease: A Clinical and Single-Photon Emission Computed Tomography Study.
Mov Disord 2020;
35:1028-1036. [PMID:
32154947 DOI:
10.1002/mds.28008]
[Citation(s) in RCA: 12] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/09/2019] [Revised: 01/25/2020] [Accepted: 02/07/2020] [Indexed: 12/16/2022] Open
Abstract
BACKGROUND
Previous molecular imaging studies comparing dopamine function in vivo between early-onset PD and late-onset PD patients have shown contradictory results, presumably attributable to the aging-related decline in nigrostriatal function.
OBJECTIVES
(1) To investigate baseline dopamine transporter availability in early-onset PD (<55 years) and late-onset PD (>70 years) patients, z-scores values of putamen and caudate [123 I]-ioflupane uptake were calculated using the respective age-matched controls in order to correct for early presynaptic compensatory mechanisms and age-related dopamine neuron loss; (2) to examine the associations of such baseline single-photon emission computed tomography measures with the emergence of late-disease motor complications.
METHODS
In this retrospective study, 105 de novo PD patients who underwent [123 I]-ioflupane single-photon emission computed tomography at time of diagnosis were divided into three tertile groups according to age at disease onset (35 early-onset PD and 40 late-onset PD patients). Z-scores were compared between the two groups, and their predictive power for motor complications (during a mean follow-up of 7 years) was evaluated using Cox proportional hazard models.
RESULTS
Despite a less-severe motor phenotype, early-onset PD patients exhibited more reduced [123 I]-ioflupane binding in the putamen and had a higher and earlier risk for developing motor complications than those with late-onset PD. Lower [123 I]-Ioflupane uptake in the putamen and caudate increased the risk of motor complications.
CONCLUSIONS
Our findings indicate that a lower dopamine transporter binding in early-onset PD predicts the later development of motor complications, but it is not related to severity of motor symptoms, suggesting age-related differences in striatal compensatory mechanisms in PD. © 2020 International Parkinson and Movement Disorder Society.
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