Johnson KA, Gidicsin C, Larvie M, Maye J, Carmasin J, Becker JA, Rentz D, Sperling RA.
Microbleeds and amyloid-s burden in non-demented elderly.
Human Amyloid Imaging 2011 Meeting Abstracts. 2011 Jan 15;
Background: Lobar microbleeds (LMB) are associated with cerebral amyloid-s angiopathy (CAA) and are frequently
observed in Alzheimer's disease (AD) dementia.
Objective: Here we examined the relationship of LMB to in vivo amyloid burden measured with amyloid PET in
Methods: We evaluated 92 non-demented subjects with neuropsychological tests, susceptibility weighted MR
imaging (SWI) and PiB-PET. There were 68 CDR0 subjects, mean age 74} 7y, mean CDR Sum of Boxes (SB)
= 0.02, and 24 CDR0.5, mean age 74} 8y, mean CDR SB = 1.57 (range 0.5 - 3.5). Two readers (K.J. and M.L.)
independently inspected SWI data and identified each microbleed as lobar or non-lobar. Amyloid burden was
evaluated as a dichotomous (non-partial volume corrected mean cortical PiB DVR (mcPiB) cutpoint = 1.15) and a
Results: In the CDR0 group, 51% were classified as PiB positive and 16% had one or more LMB (range 1 - 3). In
the CDR0.5 group, 54% were PiB positive and 13% had one or more LMB (range 1 - 5). Adjusting for age, mcPiB
was associated with number of LMB in both groups (p Conclusions: These data suggest that LMB, frequently observed in non-demented elderly, are related to amyloid-s
burden measured with PET and are a feature of preclinical AD. These findings may have implications for amyloidlowering
treatment trials at earlier stages of the disease.