title: Longitudinal assessment of global and regional atrophy rates in Alzheimer's disease and dementia with Lewy bodies.
abstract: OBJECTIVE
  Percent whole brain volume change (PBVC) measured from serial MRI scans is widely accepted as a sensitive marker of disease progression in Alzheimer's disease (AD). However, the utility of PBVC in the differential diagnosis of dementia remains to be established. We compared PBVC in AD and dementia with Lewy bodies (DLB), and investigated associations with clinical measures.
  
  
  METHODS
  72 participants (14 DLBs, 25 ADs, and 33 healthy controls (HCs)) underwent clinical assessment and 3 Tesla T1-weighted MRI at baseline and repeated at 12 months. We used FSL-SIENA to estimate PBVC for each subject. Voxelwise analyses and ANCOVA compared PBVC between DLB and AD, while correlational tests examined associations of PBVC with clinical measures.
  
  
  RESULTS
  AD had significantly greater atrophy over 1 year (1.8%) compared to DLB (1.0%; p = 0.01) and HC (0.9%; p < 0.01) in widespread regions of the brain including periventricular areas. PBVC was not significantly different between DLB and HC (p = 0.95). There were no differences in cognitive decline between DLB and AD. In the combined dementia group (AD and DLB), younger age was associated with higher atrophy rates (r = 0.49, p < 0.01).
  
  
  CONCLUSIONS
  AD showed a faster rate of global brain atrophy compared to DLB, which had similar rates of atrophy to HC. Among dementia subjects, younger age was associated with accelerated atrophy, reflecting more aggressive disease in younger people. PBVC could aid in differentiating between DLB and AD, however its utility as an outcome marker in DLB is limited.
authors: Department of Psychiatry, University of Cambridge, Cambridge, UK.
authors: Elijah
authors: E
authors: Mak
authors: Department of Psychiatry, University of Cambridge, Cambridge, UK.
authors: Li
authors: L
authors: Su
authors: Wolfson Brain Imaging Centre, UK.
authors: Guy B
authors: GB
authors: Williams
authors: Department of Aged Care, The Royal Melbourne Hospital, Melbourne, Australia ; Institute of Neuroscience, Newcastle University, Campus for Ageing and Vitality, Newcastle, UK.
authors: Rosie
authors: R
authors: Watson
authors: Institute of Neuroscience, Newcastle University, Campus for Ageing and Vitality, Newcastle, UK.
authors: Michael
authors: M
authors: Firbank
authors: Institute of Cellular Medicine & Newcastle Magnetic Resonance Centre, Newcastle University, Newcastle, UK.
authors: Andrew M
authors: AM
authors: Blamire
authors: Department of Psychiatry, University of Cambridge, Cambridge, UK.
authors: John T
authors: JT
authors: O'Brien
mesh_terms: D000368:Aged; D000544:Alzheimer Disease / Q000175:diagnosis*; D001284:Atrophy / Q000473:pathology; D001921:Brain / Q000473:pathology*; D003937:Diagnosis, Differential; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D007090:Image Interpretation, Computer-Assisted; D020961:Lewy Body Disease / Q000175:diagnosis*; D008279:Magnetic Resonance Imaging; D008297:Male
keywords: Alzheimer's disease; Atrophy; Dementia; Lewy bodies; Neuroimaging