Claudio Liguori1, Roberta Ruffini2, Enrica Olivola3, Agostino Chiaravalloti4, Francesca Izzi2, Alessandro Stefani5, Mariangela Pierantozzi6, Nicola Biagio Mercuri7, Nicola Modugno3, Diego Centonze8, Orazio Schillaci4, Fabio Placidi2. 1. Sleep Medicine Centre, Department of Systems Medicine, University of Rome 'Tor Vergata", Rome, Italy. Electronic address: liguori@med.uniroma2.it. 2. Sleep Medicine Centre, Department of Systems Medicine, University of Rome 'Tor Vergata", Rome, Italy. 3. IRCSS Neuromed, Pozzilli, Italy. 4. IRCSS Neuromed, Pozzilli, Italy; Department of Biomedicine and Prevention, University of Rome 'Tor Vergata', Rome, Italy. 5. Parkinson's Disease Centre, Neurology Unit, Department of Systems Medicine, University of Rome "Tor Vergata", Rome, Italy. 6. Neurology Unit, Department of Systems Medicine, University of Rome "Tor Vergata", Rome, Italy. 7. Neurology Unit, Department of Systems Medicine, University of Rome "Tor Vergata", Rome, Italy; IRCCS Fondazione Santa Lucia, Rome, Italy. 8. IRCSS Neuromed, Pozzilli, Italy; Neurology Unit, Department of Systems Medicine, University of Rome "Tor Vergata", Rome, Italy.
Abstract
INTRODUCTION: Several longitudinal studies revealed that patients affected by idiopathic REM behavior disorder (iRBD) trend to convert to α-synucleinopathies at follow-up, although the time and direction of conversion is currently unpredictable. This study aimed at evaluating brain glucose metabolism, measured by [18F]FDG-PET, in patients affected by iRBD and compared to Parkinson's Disease (PD), Lewy Body Dementia (DLB), Alzheimer's Disease (AD), and controls. METHODS: Differences in brain [18F]FDG uptake were analyzed using statistical parametric mapping implemented in Matlab R2012b among iRBD, PD, DLB, AD, and controls. RESULTS: Fifty-four iRBD, 28 PD, 10 DLB, 55 AD, and 35 controls were included in this study. iRBD patients presented an altered [18F]FDG uptake, since the increased [18F]FDG uptake in the brainstem and the reduced [18F]FDG uptake in temporal and parietal regions compared to controls. Moreover, iRBD patients showed several differences in [18F]FDG uptake than PD, DLB, or AD groups, with the main differences documented in the comparison with AD patients. CONCLUSIONS: This study documented the alteration of brain [18F]FDG uptake in brainstem and cortical areas of iRBD patients compared to controls. Moreover, the cerebral [18F]FDG uptake of iRBD patients resulted different from that presented by AD, further supporting the hypothesis that tau-related neurodegeneration may not induce RBD manifestations. However, brain [18F]FDG uptake of iRBD patients also differed from that of DLB and PD patients. Hence, these findings further support the hypothesis that iRBD may represent a very early stage of α-synucleinopathy in which biomarkers changes already occur but not allow the prediction of phenoconversion.
INTRODUCTION: Several longitudinal studies revealed that patients affected by idiopathic REM behavior disorder (iRBD) trend to convert to α-synucleinopathies at follow-up, although the time and direction of conversion is currently unpredictable. This study aimed at evaluating brain glucose metabolism, measured by [18F]FDG-PET, in patients affected by iRBD and compared to Parkinson's Disease (PD), Lewy Body Dementia (DLB), Alzheimer's Disease (AD), and controls. METHODS: Differences in brain [18F]FDG uptake were analyzed using statistical parametric mapping implemented in Matlab R2012b among iRBD, PD, DLB, AD, and controls. RESULTS: Fifty-four iRBD, 28 PD, 10 DLB, 55 AD, and 35 controls were included in this study. iRBD patients presented an altered [18F]FDG uptake, since the increased [18F]FDG uptake in the brainstem and the reduced [18F]FDG uptake in temporal and parietal regions compared to controls. Moreover, iRBD patients showed several differences in [18F]FDG uptake than PD, DLB, or AD groups, with the main differences documented in the comparison with ADpatients. CONCLUSIONS: This study documented the alteration of brain [18F]FDG uptake in brainstem and cortical areas of iRBD patients compared to controls. Moreover, the cerebral [18F]FDG uptake of iRBD patients resulted different from that presented by AD, further supporting the hypothesis that tau-related neurodegeneration may not induce RBD manifestations. However, brain [18F]FDG uptake of iRBD patients also differed from that of DLB and PDpatients. Hence, these findings further support the hypothesis that iRBD may represent a very early stage of α-synucleinopathy in which biomarkers changes already occur but not allow the prediction of phenoconversion.
Authors: Michael J Firbank; John T O'Brien; Rory Durcan; Louise M Allan; Sally Barker; Joanna Ciafone; Paul C Donaghy; Calum A Hamilton; Sarah Lawley; Jim Lloyd; Gemma Roberts; John-Paul Taylor; Alan J Thomas Journal: J Neurol Date: 2020-10-21 Impact factor: 4.849