title: Magnetic resonance imaging markers of Parkinson's disease nigrostriatal signature.
abstract: One objective of modern neuroimaging is to identify markers that can aid in diagnosis, disease progression monitoring and long-term drug impact analysis. In this study, Parkinson-associated physiopathological modifications were characterized in six subcortical structures by simultaneously measuring quantitative magnetic resonance parameters sensitive to complementary tissue characteristics (i.e. volume atrophy, iron deposition and microstructural damage). Thirty patients with Parkinson's disease and 22 control subjects underwent 3-T magnetic resonance imaging with T₂*-weighted, whole-brain T₁-weighted and diffusion tensor imaging scans. The mean R₂* value, mean diffusivity and fractional anisotropy in the pallidum, putamen, caudate nucleus, thalamus, substantia nigra and red nucleus were compared between patients with Parkinson's disease and control subjects. Comparisons were also performed using voxel-based analysis of R₂*, mean diffusivity and fractional anisotropy maps to determine which subregion of the basal ganglia showed the greater difference for each parameter. Averages of each subregion were then used in a logistic regression analysis. Compared with control subjects, patients with Parkinson's disease displayed significantly higher R₂* values in the substantia nigra, lower fractional anisotropy values in the substantia nigra and thalamus, and higher mean diffusivity values in the thalamus. Voxel-based analyses confirmed these results and, in addition, showed a significant difference in the mean diffusivity in the striatum. The combination of three markers was sufficient to obtain a 95% global accuracy (area under the receiver operating characteristic curve) for discriminating patients with Parkinson's disease from controls. The markers comprising discriminating combinations were R₂* in the substantia nigra, fractional anisotropy in the substantia nigra and mean diffusivity in the putamen or caudate nucleus. Remarkably, the predictive markers involved the nigrostriatal structures that characterize Parkinson's physiopathology. Furthermore, highly discriminating combinations included markers from three different magnetic resonance parameters (R₂*, mean diffusivity and fractional anisotropy). These findings demonstrate that multimodal magnetic resonance imaging of subcortical grey matter structures is useful for the evaluation of Parkinson's disease and, possibly, of other subcortical pathologies.
authors.affiliation: Department of Radiology, I.R.C.C.S. Foundation Santa Lucia, Via Ardeatina 306, 00179 Rome. p.peran@hsantalucia.it
authors.forename: Patrice
authors.initials: P
authors.lastname: Péran
authors.forename: Andrea
authors.initials: A
authors.lastname: Cherubini
authors.forename: Francesca
authors.initials: F
authors.lastname: Assogna
authors.forename: Fabrizio
authors.initials: F
authors.lastname: Piras
authors.forename: Carlo
authors.initials: C
authors.lastname: Quattrocchi
authors.forename: Antonella
authors.initials: A
authors.lastname: Peppe
authors.forename: Pierre
authors.initials: P
authors.lastname: Celsis
authors.forename: Olivier
authors.initials: O
authors.lastname: Rascol
authors.forename: Jean-François
authors.initials: JF
authors.lastname: Démonet
authors.forename: Alessandro
authors.initials: A
authors.lastname: Stefani
authors.forename: Mariangela
authors.initials: M
authors.lastname: Pierantozzi
authors.forename: Francesco Ernesto
authors.initials: FE
authors.lastname: Pontieri
authors.forename: Carlo
authors.initials: C
authors.lastname: Caltagirone
authors.forename: Gianfranco
authors.initials: G
authors.lastname: Spalletta
authors.forename: Umberto
authors.initials: U
authors.lastname: Sabatini
mesh_terms: D000368:Aged; D015415:Biomarkers; D003342:Corpus Striatum / Q000473:pathology*; D005260:Female; D006801:Humans; D008279:Magnetic Resonance Imaging / Q000379:methods; D008297:Male; D008875:Middle Aged; D010300:Parkinson Disease / Q000473:pathology* / Q000503:physiopathology; D013378:Substantia Nigra / Q000473:pathology*
chemical_list: D015415:Biomarkers