Cortical amyloid accumulation is associated with alterations of structural integrity in older people with subjective memory complaints

Abstract We determined the effect of cortical amyloid load using18 F-florbetapir PET on cognitive performance and grey matter structural integrity derived from MRI in 318 cognitively normally performing older people with subjective memory impairment from the INSIGHT-preAD cohort using multivariate partial least square regression. Amyloid uptake was associated with reduced grey matter structural integrity in hippocampus, entorhinal and cingulate cortex, middle temporal gyrus, prefrontal cortex, and lentiform nucleus (p < 0.01, permutation test). Higher amyloid load was associated with poorer global cognitive performance, delayed recall and attention (p < 0.05), independently of its effects on grey matter connectivity. These findings agree with the assumption of a two stage effect of amyloid on cognition, (i) an early direct effect in preclinical stages of Alzheimer’s disease (AD) and (ii) a delayed effect mediated by down-stream effects of amyloid accumulation, such as grey matter connectivity decline.