title: The contribution of cerebellar proton magnetic resonance spectroscopy in the differential diagnosis among parkinsonian syndromes.
abstract: BACKGROUND
  The in vivo differential diagnosis between idiopathic Parkinson's disease (PD) and atypical parkinsonian syndromes (PS), such as multiple system atrophy [MSA with a cerebellar (C) and parkinsonian (P) subtype] and progressive supranuclear palsy - Richardson's Syndrome (PSP-RS) is often challenging. Previous brain MR proton spectroscopy ((1)H-MRS) studies showed biochemical alterations in PS, despite results are conflicting. Cerebellum plays a central role in motor control and its alterations has been already demonstrated in atypical PS. The main aim of this study was to evaluate diagnostic accuracy of cerebellar (1)H-MRS in the differential diagnosis between PD and atypical PS.
  
  
  METHODS
  We obtained (1)H-MRS spectra from the left cerebellar hemisphere of 57 PS (21 PD, and 36 atypical PS) and 14 unaffected controls by using a 1.5 T GE scanner. N-acetyl-aspartate (NAA)/Creatine (Cr), choline-containing compounds (Cho)/Cr, myoinositol (mI)/Cr, and NAA/mI ratios were calculated.
  
  
  RESULTS
  NAA/Cr and NAA/mI ratios were significantly lower (p < 0.01) in atypical PS compared to PD and controls, and in MSA-C compared to PD, MSA-P, PSP-RS and controls. PSP-RS group showed reduced NAA/Cr ratios compared to PD (p < 0.05) and controls (p < 0.05), and reduced NAA/mI compared to controls (p < 0.01). NAA/Cr ratio values higher than 1.016 showed 100% sensitivity and negative predictive value, 62% positive predictive value and 64% specificity in discriminating PD.
  
  
  CONCLUSIONS
  Cerebellar biochemical alterations detected by using (1)H-MRS could represent an adjunctive diagnostic tool to improve the differential diagnosis of PS.
authors.affiliation: Functional MR Unit, Policlinico S. Orsola - Malpighi, Bologna (IT), Via Massarenti 9, 40138 Bologna, Italy; Department of Biomedical and NeuroMotor Sciences, University of Bologna, Bologna (IT), Via U. Foscolo 7, 40123 Bologna, Italy.
authors.forename: Stefano
authors.initials: S
authors.lastname: Zanigni
authors.affiliation: Functional MR Unit, Policlinico S. Orsola - Malpighi, Bologna (IT), Via Massarenti 9, 40138 Bologna, Italy; Department of Biomedical and NeuroMotor Sciences, University of Bologna, Bologna (IT), Via U. Foscolo 7, 40123 Bologna, Italy.
authors.forename: Claudia
authors.initials: C
authors.lastname: Testa
authors.affiliation: Department of Biomedical and NeuroMotor Sciences, University of Bologna, Bologna (IT), Via U. Foscolo 7, 40123 Bologna, Italy; IRCCS Istituto Delle Scienze Neurologiche di Bologna, Bologna (IT), Via Altura 3, 40139 Bologna, Italy.
authors.forename: Giovanna
authors.initials: G
authors.lastname: Calandra-Buonaura
authors.affiliation: Department of Biomedical and NeuroMotor Sciences, University of Bologna, Bologna (IT), Via U. Foscolo 7, 40123 Bologna, Italy; IRCCS Istituto Delle Scienze Neurologiche di Bologna, Bologna (IT), Via Altura 3, 40139 Bologna, Italy.
authors.forename: Luisa
authors.initials: L
authors.lastname: Sambati
authors.affiliation: Neurology Unit, Policlinico S. Orsola - Malpighi, Bologna (IT), Via Massarenti 9, 40138 Bologna, Italy.
authors.forename: Maria
authors.initials: M
authors.lastname: Guarino
authors.affiliation: IRCCS Istituto Delle Scienze Neurologiche di Bologna, Bologna (IT), Via Altura 3, 40139 Bologna, Italy; Neurology Unit, Ospedale Maggiore, Bologna (IT), Via B. Nigrisoli 2, 40133 Bologna, Italy.
authors.forename: Anna
authors.initials: A
authors.lastname: Gabellini
authors.affiliation: Functional MR Unit, Policlinico S. Orsola - Malpighi, Bologna (IT), Via Massarenti 9, 40138 Bologna, Italy; Department of Biomedical and NeuroMotor Sciences, University of Bologna, Bologna (IT), Via U. Foscolo 7, 40123 Bologna, Italy.
authors.forename: Stefania
authors.initials: S
authors.lastname: Evangelisti
authors.affiliation: Department of Biomedical and NeuroMotor Sciences, University of Bologna, Bologna (IT), Via U. Foscolo 7, 40123 Bologna, Italy; IRCCS Istituto Delle Scienze Neurologiche di Bologna, Bologna (IT), Via Altura 3, 40139 Bologna, Italy.
authors.forename: Pietro
authors.initials: P
authors.lastname: Cortelli
authors.affiliation: Functional MR Unit, Policlinico S. Orsola - Malpighi, Bologna (IT), Via Massarenti 9, 40138 Bologna, Italy; Department of Biomedical and NeuroMotor Sciences, University of Bologna, Bologna (IT), Via U. Foscolo 7, 40123 Bologna, Italy. Electronic address: raffaele.lodi@unibo.it.
authors.forename: Raffaele
authors.initials: R
authors.lastname: Lodi
authors.affiliation: Functional MR Unit, Policlinico S. Orsola - Malpighi, Bologna (IT), Via Massarenti 9, 40138 Bologna, Italy; Department of Biomedical and NeuroMotor Sciences, University of Bologna, Bologna (IT), Via U. Foscolo 7, 40123 Bologna, Italy.
authors.forename: Caterina
authors.initials: C
authors.lastname: Tonon
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D002531:Cerebellum / Q000737:chemistry*; D003937:Diagnosis, Differential; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D019578:Multiple System Atrophy / Q000175:diagnosis*; D010300:Parkinson Disease / Q000175:diagnosis*; D066244:Proton Magnetic Resonance Spectroscopy / Q000379:methods*; D013494:Supranuclear Palsy, Progressive / Q000175:diagnosis*; D013577:Syndrome
keywords: Cerebellum; MRS; Multiple system atrophy; Parkinson's disease; Progressive supranuclear palsy