title: Enhanced catecholamine transporter binding in the locus coeruleus of patients with early Parkinson disease.
abstract: BACKGROUND
  Studies in animals suggest that the noradrenergic system arising from the locus coeruleus (LC) and dopaminergic pathways mutually influence each other. Little is known however, about the functional state of the LC in patients with Parkinson disease (PD).
  
  
  METHODS
  We retrospectively reviewed clinical and imaging data of 94 subjects with PD at an early clinical stage (Hoehn and Yahr stage 1-2) who underwent single photon computed tomography imaging with FP-CIT ([¹²³I] N-ω-fluoropropyl-2β-carbomethoxy-3β-(4-iodophenyl) tropane). FP-CIT binding values from the patients were compared with 15 healthy subjects: using both a voxel-based whole brain analysis and a volume of interest analysis of a priori defined brain regions.
  
  
  RESULTS
  Average FP-CIT binding in the putamen and caudate nucleus was significantly reduced in PD subjects (43% and 57% on average, respectively; p < 0.001). In contrast, subjects with PD showed an increased binding in the LC (166% on average; p < 0.001) in both analyses. LC-binding correlated negatively with striatal FP-CIT binding values (caudate: contralateral, ρ = -0.28, p < 0.01 and ipsilateral ρ = -0.26, p < 0.01; putamen: contralateral, ρ = -0.29, p < 0.01 and ipsilateral ρ = -0.29, p < 0.01).
  
  
  CONCLUSIONS
  These findings are consistent with an up-regulation of noradrenaline reuptake in the LC area of patients with early stage PD, compatible with enhanced noradrenaline release, and a compensating activity for degeneration of dopaminergic nigrostriatal projections.
authors.affiliation: Dipartimento di Fisiologia Umana, Università degli Studi di Milano, Milano, Italy. ioannis.isaias@unimi.it
authors.forename: Ioannis U
authors.initials: IU
authors.lastname: Isaias
authors.forename: Giorgio
authors.initials: G
authors.lastname: Marotta
authors.forename: Gianni
authors.initials: G
authors.lastname: Pezzoli
authors.forename: Osama
authors.initials: O
authors.lastname: Sabri
authors.forename: Johannes
authors.initials: J
authors.lastname: Schwarz
authors.forename: Paolo
authors.initials: P
authors.lastname: Crenna
authors.forename: Joseph
authors.initials: J
authors.lastname: Classen
authors.forename: Paolo
authors.initials: P
authors.lastname: Cavallari
mesh_terms: D000328:Adult; D000368:Aged; D050483:Dopamine Plasma Membrane Transport Proteins / Q000378:metabolism*; D005260:Female; D049670:History, 17th Century; D006801:Humans; D008125:Locus Coeruleus / Q000000981:diagnostic imaging / Q000378:metabolism*; D008297:Male; D010300:Parkinson Disease / Q000000981:diagnostic imaging / Q000378:metabolism*; D019275:Radiopharmaceuticals; D012189:Retrospective Studies; D015899:Tomography, Emission-Computed, Single-Photon; D014326:Tropanes
chemical_list: D050483:Dopamine Plasma Membrane Transport Proteins; D019275:Radiopharmaceuticals; D014326:Tropanes; C087552:2-carbomethoxy-8-(3-fluoropropyl)-3-(4-iodophenyl)tropane