Year: 2013
Type: article
Study design: Observational Study
Abstract: We previously reported a relationship between subjective cognitive concerns (SCC) and amyloid burden in a sample of clinically normal (CN) older individuals. In addition to finding a relationship between subjective memory concerns (SCC-M) and amyloid burden, post-hoc analyses also revealed a relationship with subjective concerns in executive function (SCC-E). We sought to further understand the relationship between SCC-E and cortical amyloid burden. We hypothesized that cognitive reserve would modify the relationship between SCC-E and amyloid deposition (in contrast to SCC-M), as these tasks may require higher-level cognitive processes more noticeable to high reserve individuals. We studied 210 CN individuals (Clinical Dementia Rating Scale = 0) who underwent clinical assessment and PiB-PET imaging. Cortical PiB retention was evaluated using a distribution volume ratio (DVR), using cerebellar cortex as tissue reference. SCC was measured by three questionnaires: the Everyday Cognition Scale, the Memory Functioning Questionnaire, and several questions from the Structured Telephone Interview for Dementia Assessment. A composite of SCC-M and SCC-E items were calculated respectively. A composite of verbal intelligence (AMNART IQ) and the Hollingshead scale was used as a proxy for cognitive reserve (CR). Subjects were classified as either low or high CR based on a median split of their composite score. Multivariate models related PiB retention to SCC-M and SCC-E for the low and high reserve groups. Higher PiB retention was associated with greater SCC-M in both high and low reserve groups (High: b =0.98, p=0.006; Low: b =1.12, p=0.013). By contrast, there was a relationship between PiB and SCC-E for the high reserve group (b =0.95, p=0.010), but not the low reserve group (b =0.23, p=0.554). We found a relationship between SCC-M and amyloid burden at all levels of cognitive reserve. However, the relationship between SCC-E and amyloid burden appears more complex, with level of cognitive reserve modulating this relationship. Taken together, SCC-E, in addition to SCC-M, appears to be a potential indicator of early AD pathology, but may depend on level of cognitive reserve.
Source: Alzheimer s & Dementia
Language: English
Subfield: Psychiatry and Mental health
Field: Medicine
Domain: Health Sciences
Open Access status: bronze
OpenAlex ID: W1998355082