title: MRI study of caudate nucleus volume in Parkinson's disease with and without dementia with Lewy bodies and Alzheimer's disease.
abstract: OBJECTIVE
  To compare whole brain and caudate volume on MRI in subjects with Parkinson's disease without cognitive impairment (PD), Parkinson's disease with dementia with Lewy bodies (PD + DLB), Alzheimer's disease (AD) and normal control subjects. To examine the relationship between caudate volume and cognitive impairment, depression and movement disorder.
  
  
  METHODS
  Whole brain and caudate volumes were segmented from volumetric 1.5-tesla magnetic resonance imaging (MRI) scans of older subjects with PD (n = 28; mean age 75.5 years), PD + DLB (n = 20; 73.0 years), AD (n = 27; 77.5 years) and normal controls (n = 35; 74.9 years).
  
  
  RESULTS
  Subjects with AD had significantly reduced whole brain and caudate volume compared to controls and those with PD. Caudate atrophy in AD was proportionate to whole brain atrophy. There were no significant differences in whole brain or caudate volume between controls, PD and PD + DLB. There were no significant correlations between caudate volume and either global cognitive function, executive performance or processing speed.
  
  
  CONCLUSIONS
  Caudate atrophy occurs in AD but not PD without dementia. Caudate atrophy is not regionally specific but part of generalised brain volume loss. Structural changes in the caudate, as assessed by in vivo MRI, do not appear to contribute to the cognitive impairment observed amongst patients with PD, PD + DLB or AD. Results indicate that the executive and attentional dysfunctions associated with PD and DLB are unlikely to be a direct and specific consequence of caudate atrophy as assessed on MRI.
authors.affiliation: School of Psychiatry and Clinical Neurosciences, University of Western Australia, Nedlands, Australia.
authors.forename: Osvaldo P
authors.initials: OP
authors.lastname: Almeida
authors.forename: Emma J
authors.initials: EJ
authors.lastname: Burton
authors.forename: Ian
authors.initials: I
authors.lastname: McKeith
authors.forename: Anil
authors.initials: A
authors.lastname: Gholkar
authors.forename: David
authors.initials: D
authors.lastname: Burn
authors.forename: John T
authors.initials: JT
authors.lastname: O'Brien
mesh_terms: D000368:Aged; D000544:Alzheimer Disease / Q000150:complications / Q000000981:diagnostic imaging / Q000473:pathology*; D002421:Caudate Nucleus / Q000000981:diagnostic imaging / Q000473:pathology*; D003704:Dementia / Q000473:pathology*; D005260:Female; D006801:Humans; D016631:Lewy Bodies / Q000473:pathology*; D008279:Magnetic Resonance Imaging; D008297:Male; D010300:Parkinson Disease / Q000150:complications / Q000000981:diagnostic imaging / Q000473:pathology*; D011877:Radionuclide Imaging