title: Amyloid, hypometabolism, and cognition in Alzheimer disease: an [11C]PIB and [18F]FDG PET study.
abstract: OBJECTIVE
  To investigate the association between brain amyloid load in Alzheimer disease (AD) measured by [11C]PIB-PET, regional cerebral glucose metabolism (rCMRGlc) measured by [18F]FDG-PET, and cognition.
  
  
  METHODS
  Nineteen subjects with AD and 14 controls had [11C]PIB-PET and underwent a battery of psychometric tests. Twelve of those subjects with AD and eight controls had [18F]FDG-PET. Parametric images of [11C]PIB binding and rCMRGlc were interrogated with a region-of-interest atlas and statistical parametric mapping. [11C]PIB binding and rCMRGlc were correlated with scores on psychometric tests.
  
  
  RESULTS
  AD subjects showed twofold increases in mean [11C]PIB binding in cingulate, frontal, temporal, parietal, and occipital cortical areas. Higher cortical amyloid load correlated with lower scores on facial and word recognition tests. Two patients fulfilling the clinical criteria for AD had normal [11C]PIB at baseline. Over 20 months this remained normal in one but increased in the cingulate of the other. Mean levels of temporal and parietal rCMRGlc were reduced by 20% in AD and these correlated with mini mental scores, immediate recall, and recognition memory test for words. Higher [11C]PIB uptake correlated with lower rCMRGlc in temporal and parietal cortices.
  
  
  CONCLUSIONS
  [11C]PIB-PET detected an increased amyloid plaque load in 89% of patients with clinically probable Alzheimer disease (AD). The high frontal amyloid load detected by [11C]PIB-PET in AD in the face of spared glucose metabolism is of interest and suggests that amyloid plaque formation may not be directly responsible for neuronal dysfunction in this disorder.
authors.affiliation: MRC Clinical Sciences Centre and Division of Neuroscience, Hammersmith Hospital, Imperial College London, London, UK.
authors.forename: P
authors.initials: P
authors.lastname: Edison
authors.forename: H A
authors.initials: HA
authors.lastname: Archer
authors.forename: R
authors.initials: R
authors.lastname: Hinz
authors.forename: A
authors.initials: A
authors.lastname: Hammers
authors.forename: N
authors.initials: N
authors.lastname: Pavese
authors.forename: Y F
authors.initials: YF
authors.lastname: Tai
authors.forename: G
authors.initials: G
authors.lastname: Hotton
authors.forename: D
authors.initials: D
authors.lastname: Cutler
authors.forename: N
authors.initials: N
authors.lastname: Fox
authors.forename: A
authors.initials: A
authors.lastname: Kennedy
authors.forename: M
authors.initials: M
authors.lastname: Rossor
authors.forename: D J
authors.initials: DJ
authors.lastname: Brooks
mesh_terms: D000368:Aged; D000544:Alzheimer Disease / Q000175:diagnosis / Q000378:metabolism* / Q000523:psychology*; D000682:Amyloid / Q000378:metabolism*; D000814:Aniline Compounds; D052160:Benzothiazoles / Q000493:pharmacokinetics; D001921:Brain / Q000378:metabolism*; D002250:Carbon Radioisotopes; D003071:Cognition; D005145:Face; D005260:Female; D019788:Fluorodeoxyglucose F18; D005947:Glucose / Q000378:metabolism*; D006801:Humans; D007802:Language; D008297:Male; D011939:Mental Recall; D008875:Middle Aged; D009483:Neuropsychological Tests; D049268:Positron-Emission Tomography; D019275:Radiopharmaceuticals; D021641:Recognition, Psychology; D013844:Thiazoles
chemical_list: C475519:2-(4'-(methylamino)phenyl)-6-hydroxybenzothiazole; D000682:Amyloid; D000814:Aniline Compounds; D052160:Benzothiazoles; D002250:Carbon Radioisotopes; D019275:Radiopharmaceuticals; D013844:Thiazoles; D019788:Fluorodeoxyglucose F18; D005947:Glucose