Aβ related memory decline and hippocampal volume loss in very mild dementia
Presented at AAIC 2016
Older adults who report a noticeable decline in cognitive abilities are now investigated for early dementia. If this is corroborated by objective evidence of cognitive impairment, individuals can be considered to be in the early stages of dementia. This early stage of dementia is staged clinically at the 0.5 level on the Clinical Dementia Rating (CDR) scale, and has various terms such as ‘very mild dementia’ or ‘mild cognitive impairment’ (MCI). Recent consensus criteria that integrate risk from biomarkers and the amyloid cascade hypothesis stipulate that individuals with a CDR score of 0.5 and who are also Aβ+ can be considered as having prodromal AD. Such criteria also raises the hypothesis that the pathological processes underlying cognitive impairment in individuals who are CDR 0.5 but who have low levels of cerebral Aβ (Aβ-) may reflect neurodegenerative or psychiatric processes other than AD. However, the nature and magnitude of cognitive decline associated with known biomarkers of AD (i.e., cerebral Aβ, hippocampal volume) in individuals with CDR O.S remain poorly defined. In a group of older adults with very mild dementia, we aimed to characterize the nature and magnitude of cognitive decline as measured by the Cogstate Brief Battery, in relation to AP levels and hippocampal volume. Participants were characterized according to their status on the Clinical Dementia Rating (CDR) scale.