Cognition and amyloid load in Alzheimer disease imaged with florbetapir F 18(AV-45) positron emission tomography.
Rosenberg PB., Wong DF., Edell SL., Ross JS., Joshi AD., Brašić JR., Zhou Y., Raymont V., Kumar A., Ravert HT., Dannals RF., Pontecorvo MJ., Skovronsky DM., Lyketsos CG.
OBJECTIVE: To examine the association between regional brain uptake of a novel amyloid positron emission tomography (PET) tracer florbetapir F 18 ([(18)F]-AV-45) and cognitive performance in a pilot study. DESIGN: Cross-sectional comparison of [(18)F]-AV-45 in AD patients versus controls. SETTING: Three specialty memory clinics. PARTICIPANTS: Eleven participants with probable Alzheimer disease (AD) by NINDS/ADRDA criteria and 15 healthy comparison (HC) participants. MEASUREMENTS: Participants underwent PET imaging following a 370 MBq (10 mCi) intravenous administration of [(18)F]-AV-45. Regional/cerebellar standardized uptake value ratios (SUVRs) were calculated. Cognition was assessed using Mini-Mental State Examination, Alzheimer's Disease Assessment Scale-Cognitive subscale (ADAS-Cog), Wechsler Logical Memory IA (immediate recall) test (LMIA), and verbal category fluency. RESULTS: Greater [(18)F]-AV-45 SUVR was associated with poorer performance on all cognitive tests. In the HC group, occipital, parietal, precuneus, temporal, and cortical average SUVR was associated with greater ADAS-Cog, and greater anterior cingulate SUVR was associated with lower LMIA. Two HC participants had [(18)F]-AV-45 cortical/cerebellar SUVR greater than 1.5, one of whom had deficits in episodic recall and on follow-up met criteria for amnestic mild cognitive impairment. CONCLUSION: [(18)F]-AV-45 SUVR in several brain regions was associated with worse global cognitive performance particularly in HC, suggesting its potential as a marker of preclinical AD.