title: Multimodal MRI assessment of nigro-striatal pathway in multiple system atrophy and Parkinson disease.
abstract: BACKGROUND
  Parkinson's disease (PD) and multiple system atrophy (MSA) are two neurodegenerative alpha-synucleinopathies characterized by severe impairment of the nigro-striatal pathway. Based on T1-, T2*-, and diffusion-weighted magnetic resonance imaging (MRI), macro-structural and micro-structural abnormalities in these diseases can be detected.
  
  
  OBJECTIVE
  This study was undertaken to compare the nigro-striatal changes that occur in patients with PD with those in patients with both variants of MSA (the parkinsonian variant, MSA-P, and the cerebellar variant, MSA-C), and to explore correlations between different MRI parameters and clinical data.
  
  
  METHODS
  We simultaneously measured volume, T2* relaxation rates, and mean diffusivity in nigro-striatal structures (substantia nigra, caudate nucleus, and putamen) of 26 patients with PD and 29 patients with MSA (16 with MSA-P and 13 with MSA-C).
  
  
  RESULTS
  Significant changes in the putamina in patients with MSA were observed compared with patients with PD. Patients with MSA-P had higher mean diffusivity values in their putamina than did patients with PD or MSA-C. The putamina of both subgroups of MSA had higher T2* relaxation rates values than PD. Remarkably, discriminant analysis showed that using two measurements of microstructural damage (T2* relaxation rates and mean diffusivity in the putamen) allowed 96% accuracy to distinguish patients with PD from those with MSA-P. Correlation analyses between MRI findings and clinical variables revealed that patients with PD showed significant correlations only at the nigra. In patients with MSA, clinical variables correlated with MRI findings in both the nigra and striatum.
  
  
  CONCLUSIONS
  Multimodal MRI reveals different pattern of nigro-striatal involvement in patients with PD and patients with MSA.
authors.affiliation: INSERM, Imagerie Cérébrale et Handicaps Neurologiques, UMR 825, 31059, Toulouse, France.|Université de Toulouse (UPS), Imagerie Cérébrale et Handicaps Neurologiques, Toulouse, France.|Institute of Neurology, University Magna Graecia, Catanzaro, Italy.
authors.forename: Gaetano
authors.initials: G
authors.lastname: Barbagallo
authors.affiliation: Service of Neurology, University Hospital "Marqués de Valdecilla (IFIMAV)," University of Cantabria and "Centro de Investigación Biomédica en Red de Enfermedades Neurodegenerativas (CIBERNED),", Santander, Spain.
authors.forename: Maria
authors.initials: M
authors.lastname: Sierra-Peña
authors.affiliation: Neuroscience Department, Retzius vag 8, Karolinska Institutet, Stockholm, Sweden.
authors.forename: Federico
authors.initials: F
authors.lastname: Nemmi
authors.affiliation: Centre de Référence Atrophie Multisystématisée, Centre Hospitalier Universitaire de Toulouse, Toulouse, France.
authors.forename: Anne Pavy-Le
authors.initials: AP
authors.lastname: Traon
authors.affiliation: Centre de Référence Atrophie Multisystématisée, Centre Hospitalier Universitaire de Bordeaux, Pessac, France.|Service de Neurologie, Centre Hospitalier Universitaire de Bordeaux, Pessac, France.|Université de Bordeaux, Institut des Maladies Neurodégénératives, Bordeaux, France.|CNRS, Institut des Maladies Neurodégénératives, Bordeaux, France.
authors.forename: Wassilios G
authors.initials: WG
authors.lastname: Meissner
authors.affiliation: INSERM, Imagerie Cérébrale et Handicaps Neurologiques, UMR 825, 31059, Toulouse, France.|Université de Toulouse (UPS), Imagerie Cérébrale et Handicaps Neurologiques, Toulouse, France.|Centre de Référence Atrophie Multisystématisée, Centre Hospitalier Universitaire de Toulouse, Toulouse, France.|Département de Pharmacologie Clinique, INSERM CIC1436, Centre Hospitalier Universitaire de Toulouse, Toulouse, France.
authors.forename: Olivier
authors.initials: O
authors.lastname: Rascol
authors.affiliation: INSERM, Imagerie Cérébrale et Handicaps Neurologiques, UMR 825, 31059, Toulouse, France.|Université de Toulouse (UPS), Imagerie Cérébrale et Handicaps Neurologiques, Toulouse, France.
authors.forename: Patrice
authors.initials: P
authors.lastname: Péran
mesh_terms: D000328:Adult; D000368:Aged; D003342:Corpus Striatum / Q000473:pathology* / Q000503:physiopathology; D006801:Humans; D008279:Magnetic Resonance Imaging; D008875:Middle Aged; D019578:Multiple System Atrophy / Q000000981:diagnostic imaging* / Q000503:physiopathology*; D010300:Parkinson Disease / Q000000981:diagnostic imaging* / Q000503:physiopathology*; D011699:Putamen / Q000000981:diagnostic imaging* / Q000503:physiopathology
keywords: Parkinson's disease; multimodal MRI; multiple system atrophy; nigro-striatal pathway