title: Cognitive decline and amyloid accumulation in patients with mild cognitive impairment.
abstract: OBJECTIVE
  The relationship between baseline (11)C-Pittsburgh compound B ((11)C-PIB) uptake and cognitive decline during a 2-year follow-up was studied in 9 patients with mild cognitive impairment (MCI) who converted to Alzheimer's disease (AD) and 7 who remained with MCI.
  
  
  METHODS
  (11)C-PIB PET scan was conducted at baseline and cognitive assessment both at baseline and at follow-up. To obtain quantitative regional values of (11)C-PIB uptake, automated region of interest analysis was done using spatially normalized parametric ratio (region-to-cerebellar cortex) images.
  
  
  RESULTS
  At baseline, there were statistically significant differences in (11)C-PIB uptake, but not in cognitive test performances between the converters and nonconverters. Memory and executive function declined only in the converters during follow-up. In the converters, lower baseline frontal (11)C-PIB uptake was associated with faster decline in verbal learning. Higher baseline uptake in the caudate nucleus was related to faster decline in memory consolidation, and higher temporal uptake was associated with decline in executive function.
  
  
  CONCLUSIONS
  Higher (11)C-PIB uptake in the caudate nucleus and temporal lobe was related to decline in memory and executive functions, whereas lower frontal uptake was related to decline in verbal learning. The results indicate that in prodromal AD, frontal amyloid accumulation reaches its maximum in the MCI stage, characterized by memory problems without full-blown dementia.
authors.affiliation: Turku PET Centre, University of Turku and Turku University Hospital, Turku, Finland.
authors.forename: Jaana
authors.initials: J
authors.lastname: Koivunen
authors.forename: Mira
authors.initials: M
authors.lastname: Karrasch
authors.forename: Noora M
authors.initials: NM
authors.lastname: Scheinin
authors.forename: Sargo
authors.initials: S
authors.lastname: Aalto
authors.forename: Tero
authors.initials: T
authors.lastname: Vahlberg
authors.forename: Kjell
authors.initials: K
authors.lastname: Någren
authors.forename: Semi
authors.initials: S
authors.lastname: Helin
authors.forename: Matti
authors.initials: M
authors.lastname: Viitanen
authors.forename: Juha O
authors.initials: JO
authors.lastname: Rinne
mesh_terms: D000368:Aged; D000369:Aged, 80 and over; D000544:Alzheimer Disease / Q000000981:diagnostic imaging / Q000378:metabolism / Q000523:psychology; D000682:Amyloid / Q000378:metabolism*; D000814:Aniline Compounds; D002421:Caudate Nucleus / Q000000981:diagnostic imaging; D003071:Cognition / Q000502:physiology; D003072:Cognition Disorders / Q000000981:diagnostic imaging / Q000378:metabolism* / Q000523:psychology*; D060825:Cognitive Dysfunction / Q000000981:diagnostic imaging / Q000378:metabolism* / Q000523:psychology*; D018450:Disease Progression; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D008137:Longitudinal Studies; D008297:Male; D009483:Neuropsychological Tests; D049268:Positron-Emission Tomography; D011594:Psychometrics; D019275:Radiopharmaceuticals; D013702:Temporal Lobe / Q000000981:diagnostic imaging; D013844:Thiazoles
chemical_list: C475519:2-(4'-(methylamino)phenyl)-6-hydroxybenzothiazole; D000682:Amyloid; D000814:Aniline Compounds; D019275:Radiopharmaceuticals; D013844:Thiazoles