Functional neuroimaging and clinical features of drug naive patients with de novo Parkinson's disease and probable RBD.
The association between Parkinson Disease (PD) and REM sleep behavior disorder (RBD) has been related to a specific, malignant clinical phenotype. Definite RBD diagnosis requires video-polysomnography that is often unfeasible. A malignant clinical PD-RBD phenotype could be expected also in PD patients with probable RBD. Aim of this cross-sectional study was to evaluate whether a more severe neuropsychological and functional neuroimaging phenotype can be identified in PD patients with probable RBD.



Thirty-eight de novo, drug naïve PD patients underwent a first-line clinical assessment and a second-line multimodal assessment, including neuropsychological evaluation, (123)I-FP-CIT-SPECT and (18)F-FDG-PET, which were compared between PD patients with (PD + RBD+) and without (PD + RBD-) probable RBD.



On first-line assessment, PD + RBD + patients had significantly more constipation (p = 0.02) and showed worse olfaction (p = 0.01) compared with PD + RBD-while the two groups were similar as for age, presence of orthostatic hypotension, UPDRS-III and MMSE scores. On second-line assessment, PD + RBD + patients showed a worse neuropsychological test profile, more severe nigro-striatal dopaminergic impairment, mainly at caudate level in the less affected hemisphere (p = 0.004) and impaired brain glucose metabolism, with relative hypometabolism in posterior cortical regions and relative hypermetabolism mainly in anterior regions of the more affected hemisphere (p = 0.015).



PD patients with probable RBD are likely to have a more severe neuropsychological and functional brain-imaging phenotype already at the time of diagnosis.
Clinical Neurology, Dept. of Neuroscience (DINOGMI), University of Genoa, IRCCS AOU San Martino-IST, Genoa, Italy. Electronic address: dario.arnaldi@gmail.com.
Dario
D
Arnaldi
Nuclear Medicine, Department of Health Sciences (DISSAL), University of Genoa, IRCCS AOU San Martino-IST, Genoa, Italy.
Silvia
S
Morbelli
Clinical Neurology, Dept. of Neuroscience (DINOGMI), University of Genoa, IRCCS AOU San Martino-IST, Genoa, Italy.
Andrea
A
Brugnolo
Clinical Neurology, Dept. of Neuroscience (DINOGMI), University of Genoa, IRCCS AOU San Martino-IST, Genoa, Italy.
Nicola
N
Girtler
Clinical Neurology, Dept. of Neuroscience (DINOGMI), University of Genoa, IRCCS AOU San Martino-IST, Genoa, Italy.
Agnese
A
Picco
Clinical Neurology, Dept. of Neuroscience (DINOGMI), University of Genoa, IRCCS AOU San Martino-IST, Genoa, Italy.
Michela
M
Ferrara
Clinical Neurology, Dept. of Neuroscience (DINOGMI), University of Genoa, IRCCS AOU San Martino-IST, Genoa, Italy.
Jennifer
J
Accardo
Nuclear Medicine, Department of Health Sciences (DISSAL), University of Genoa, IRCCS AOU San Martino-IST, Genoa, Italy.
Ambra
A
Buschiazzo
Institute of Bioimaging and Molecular Physiology, National Research Council, Genoa, Italy.
Fabrizio
F
de Carli
Institute of Cognitive Sciences and Technologies, National Research Council, Rome, Italy.
Marco
M
Pagani
Clinical Neurology, Dept. of Neuroscience (DINOGMI), University of Genoa, IRCCS AOU San Martino-IST, Genoa, Italy.
Flavio
F
Nobili
D000368:Aged; D001921:Brain / Q000000981:diagnostic imaging*; D005260:Female; D019788:Fluorodeoxyglucose F18 / Q000378:metabolism; D059907:Functional Neuroimaging / Q000379:methods*; D006801:Humans; D008297:Male; D008875:Middle Aged; D009483:Neuropsychological Tests; D010300:Parkinson Disease / Q000000981:diagnostic imaging*; D049268:Positron-Emission Tomography; D020187:REM Sleep Behavior Disorder / Q000000981:diagnostic imaging*; D015899:Tomography, Emission-Computed, Single-Photon; D014326:Tropanes / Q000378:metabolism
D014326:Tropanes; D019788:Fluorodeoxyglucose F18; C087552:2-carbomethoxy-8-(3-fluoropropyl)-3-(4-iodophenyl)tropane
(123)I-FP-CIT-SPECT; (18)F-FDG-PET; Cognitive; PD; RBD