title: Differential putaminal morphology in Huntington's disease, frontotemporal dementia and Alzheimer's disease.
abstract: OBJECTIVE
  Direct neuronal loss or deafferentation of the putamen, a critical hub in corticostriatal circuits, may result in diverse and distinct cognitive and motoric dysfunction in neurodegenerative disease. Differential putaminal morphology, as a quantitative measure of corticostriatal integrity, may thus be evident in Huntington's disease (HD), Alzheimer's disease (AD) and frontotemporal dementia (FTD), diseases with differential clinical dysfunction.
  
  
  METHODS
  HD (n = 17), FTD (n = 33) and AD (n = 13) patients were diagnosed according to international consensus criteria and, with healthy controls (n = 17), were scanned on the same MRI scanner. Patients underwent brief cognitive testing using the Neuropsychiatry Unit Cognitive Assessment Tool (NUCOG). Ten MRI scans from this dataset were manually segmented as a training set for the Adaboost algorithm, which automatically segmented all remaining scans for the putamen, yielding the following subset of the data: 9 left and 12 right putamen segmentations for AD; 25 left and 26 right putamina for FTD; 16 left and 15 right putamina for HD; 12 left and 12 right putamina for controls. Shape analysis was performed at each point on the surface of each structure using a multiple regression controlling for age and sex to compare radial distance across diagnostic groups.
  
  
  RESULTS
  Age, but not sex and intracranial volume (ICV), were significantly different in the segmentation subgroups by diagnosis. The AD group showed significantly poorer performance on cognitive testing than FTD. Mean putaminal volumes were HD < FTD < AD ≤ controls, controlling for age and ICV. The greatest putaminal shape deflation was evident in HD, followed by FTD, in regions corresponding to the interconnections to motoric cortex.
  
  
  CONCLUSIONS
  Differential patterns of putaminal atrophy in HD, FTD and AD, with relevance to corticostriatal circuits, suggest the putamen may be a suitable clinical biomarker in neurodegenerative disease.
authors.affiliation: Research Centre for the Neurosciences of Ageing, Academic Unit of Psychological and Addiction Medicine, Australian National University Medical School, Canberra, Australia. jeffrey.looi@anu.edu.au
authors.forename: Jeffrey C L
authors.initials: JC
authors.lastname: Looi
authors.forename: Priya
authors.initials: P
authors.lastname: Rajagopalan
authors.forename: Mark
authors.initials: M
authors.lastname: Walterfang
authors.forename: Sarah K
authors.initials: SK
authors.lastname: Madsen
authors.forename: Paul M
authors.initials: PM
authors.lastname: Thompson
authors.forename: Matthew D
authors.initials: MD
authors.lastname: Macfarlane
authors.forename: Chris
authors.initials: C
authors.lastname: Ching
authors.forename: Phyllis
authors.initials: P
authors.lastname: Chua
authors.forename: Dennis
authors.initials: D
authors.lastname: Velakoulis
mesh_terms: D000328:Adult; D000367:Age Factors; D000544:Alzheimer Disease / Q000175:diagnosis / Q000473:pathology / Q000503:physiopathology / Q000523:psychology; D001284:Atrophy; D001526:Behavioral Symptoms / Q000473:pathology / Q000503:physiopathology; D003430:Cross-Sectional Studies; D005260:Female; D057180:Frontotemporal Dementia / Q000175:diagnosis / Q000473:pathology / Q000503:physiopathology / Q000523:psychology; D006801:Humans; D006816:Huntington Disease / Q000175:diagnosis / Q000473:pathology / Q000503:physiopathology / Q000523:psychology; D007361:Intelligence Tests; D008279:Magnetic Resonance Imaging / Q000379:methods*; D008297:Male; D008875:Middle Aged; D009044:Motor Cortex / Q000503:physiopathology*; D009434:Neural Pathways / Q000503:physiopathology; D009929:Organ Size; D011699:Putamen / Q000473:pathology / Q000503:physiopathology; D012737:Sex Factors