Marchant N, Reed B, Sanossian N, Madison C, Dhada R, Kriger S, DeCarli C, Weiner M, Chui H, Jagust W.
Contribution of Vascular Brain Injury and Brain Abeta to Cognitive Function.Human Amyloid Imaging Abstract.
2012 Jan 1;
Background: Vascular brain injury (VBI) and brain Abeta deposition frequently co-occur and both may induce cognitive decline in aging. This study evaluated the relative contribution of VBI and Abeta to cognitive function in a cognitively diverse population.
Methods:1 participants (female =8, mean age =7.8), enrolled in a vascular-focused study of aging that recruits cognitively normal and impaired participants (Clinical Dementia Rating [CDR] 0: N =0; .5: N =5; >.5: N =), underwent MRI, PIB-PET imaging, and cognitive testing. MRI images were visually rated for presence and location of infarct (VBI+:4; VBI-:7). PIB-PET DVRs (Logan plotting,5-90min post-injection, grey matter cerebellar reference) were used to create a PIB index by averaging DVRs across frontal, posterior cingulate, precuneus, parietal and lateral temporal cortices. Participants with a PIB index SDs greater than the mean PIB index of a young control group (N =1, mean age =4.5 ±.5) were classified as PIB positive (PIB+: N =9; PIB-: N =2). Standardized composite tests of cognition included measures of Global cognition, Memory, and Executive Functioning.
Results: VBI, particularly when located in subcortical grey matter, was associated with lower cognitive performance in all domains (p’s < 0.08); inclusion of PIB as either a continuous or categorical (PIB+/PIB-) variable did not alter these findings and showed no interaction with VBI.
Conclusions: In this sample of cognitively diverse older adults, VBI played a more influential role than Abeta in cognitive function, and remained a significant predictor of cognition after controlling for the possible influence of Abeta.