title: Reduced striatal volumes in Parkinson's disease: a magnetic resonance imaging study.
abstract: BACKGROUND
  The presence and extent of structural changes in the brain as a consequence of Parkinson's disease (PD) is still poorly understood.
  
  
  METHODS
  High-resolution 3-tesla T1-weighted structural magnetic resonance images in sixty-five PD and 27 age-matched healthy control participants were examined. Putamen, caudate, and intracranial volumes were manually traced in the axial plane of 3D reconstructed images. Striatal nuclei volumes were normalized to intracranial volume for statistical comparison. Disease status was assessed using the Unified Parkinson's Disease Rating Scale and Hoehn and Yahr scale. Cognitive status was assessed using global status tests and detailed neuropsychological testing.
  
  
  RESULTS
  Both caudate and putamen volumes were smaller in PD brains compared to controls after adjusting for age and gender. Caudate volumes were reduced by 11% (p = 0.001) and putamen volumes by 8.1% (p = 0.025). PD striatal volumes were not found to be significantly correlated with cognitive or motor decline.
  
  
  CONCLUSIONS
  Small, but significant reductions in the volume of both the caudate and putamen occur in PD brains. These reductions are independent of the effects of age and gender, however the relation of these reductions to the functional loss of dopamine, which is characteristic of PD, remains unclear.
authors.affiliation: Department of Medicine, University of Otago, Christchurch, New Zealand. toni.pitcher@otago.ac.nz.
authors.forename: Toni L
authors.initials: TL
authors.lastname: Pitcher
authors.forename: Tracy R
authors.initials: TR
authors.lastname: Melzer
authors.forename: Michael R
authors.initials: MR
authors.lastname: Macaskill
authors.forename: Charlotte F
authors.initials: CF
authors.lastname: Graham
authors.forename: Leslie
authors.initials: L
authors.lastname: Livingston
authors.forename: Ross J
authors.initials: RJ
authors.lastname: Keenan
authors.forename: Richard
authors.initials: R
authors.lastname: Watts
authors.forename: John C
authors.initials: JC
authors.lastname: Dalrymple-Alford
authors.forename: Tim J
authors.initials: TJ
authors.lastname: Anderson