title: A functional neuroimaging study of appetite loss in Alzheimer's disease.
abstract: BACKGROUND
  Alzheimer's Disease (AD) is frequently associated with changes in appetite. This study investigated the relationship between regional cerebral perfusion and appetite loss in AD.
  
  
  METHODS
  64 patients with possible or probable AD were characterized as being with (n=22) or without (n=44) appetite loss based on the Neuropsychiatric Inventory (NPI) Appetite subscale. 99mTc-ECD SPECT scans were coregistered to a standardized template in Talairach space generating mean ratios of uptake referenced to the cerebellum. Regions of interest (ROIs) included anterior cingulate cortex (ACC), middle mesial temporal cortex (MTC-m), inferior mesial temporal cortex (MTC-i), insula (INS), orbitofrontal cortex (OFC) and thalamus-hypothalamus (THAL).
  
  
  RESULTS
  Backward stepwise logistic regression analysis of these ROIs showed hypoperfusion in the L-ACC (p=0.015) and L-OFC (p=0.015), relative sparing of perfusion in the R-ACC (p=0.010), R-OFC (p=0.010) and L-MTC-m (p=0.006), and greater anxiety (p=0.005) independently predicted loss of appetite (chi(2)=22.24, p=0.001, Nagelkerke R(2)=0.41).
  
  
  CONCLUSIONS
  Hypoperfusion in the left anterior cingulate and left orbitofrontal cortices, and relative sparing of perfusion in the right anterior cingulate, right orbitofrontal and left middle mesial temporal cortices emerged as predictors of appetite loss in this sample of patients. These findings are consistent with impairments in the extrinsic motivational pathways of eating and impaired reward value of food as components of appetite loss in AD.
authors.affiliation: Sunnybrook Health Sciences Centre, Toronto, Ontario, Canada.
authors.forename: Zahinoor
authors.initials: Z
authors.lastname: Ismail
authors.forename: Nathan
authors.initials: N
authors.lastname: Herrmann
authors.forename: Lana S
authors.initials: LS
authors.lastname: Rothenburg
authors.forename: Adolfo
authors.initials: A
authors.lastname: Cotter
authors.forename: Farrell S
authors.initials: FS
authors.lastname: Leibovitch
authors.forename: Shahryar
authors.initials: S
authors.lastname: Rafi-Tari
authors.forename: Sandra E
authors.initials: SE
authors.lastname: Black
authors.forename: Krista L
authors.initials: KL
authors.lastname: Lanctôt
mesh_terms: D000368:Aged; D000369:Aged, 80 and over; D000544:Alzheimer Disease / Q000150:complications* / Q000000981:diagnostic imaging*; D000855:Anorexia / Q000000981:diagnostic imaging* / Q000209:etiology*; D001931:Brain Mapping; D005260:Female; D006801:Humans; D007091:Image Processing, Computer-Assisted; D008279:Magnetic Resonance Imaging / Q000379:methods; D008297:Male; D015999:Multivariate Analysis; D011237:Predictive Value of Tests; D012720:Severity of Illness Index; D015899:Tomography, Emission-Computed, Single-Photon