Predicting brain atrophy and cognitive aging trajectories with baseline subjective cognitive concerns in cognitively normal older adults

Abstract

Subjective cognitive concerns (SCC) are common even in cognitively normal older adults who lack objectively-detectable deficits on standard neuropsychological evaluation. The clinical relevance of these concerns, particularly considering the nature of concerns (e.g., memory versus non-memory), remains unclear. Thus, we examined whether baseline memory and non-memory SCC relate to longitudinal change in brain volume and neuropsychological test performance in 476 functionally-intact, objectively unimpaired older adults (M_age = 72y, 56 % female, follow-up time = 1 - 9 years). Mixed-effects models revealed that both higher baseline memory and non-memory SCC predicted greater atrophy in total gray matter and dorsolateral prefrontal cortex atrophy over time, while only memory SCC predicted steeper medial temporal lobe atrophy. Regarding neuropsychological performance, higher non-memory SCC predicted decline in processing speed performance, while memory SCC did not predict neuropsychological trajectories. SCC are a risk factor for more adverse brain and cognitive aging trajectories, even in functionally-intact, seemingly cognitively normal older adults.

Keywords: Atrophy; Early detection; Healthy aging; Neuropsychological performance; Subjective cognitive concerns.

Figure 1.

Graphical representation of linear mixed effect model predicting global and regional brain volume trajectories from Baseline ECog Global, Memory, and Non-Memory scores. The X-axis shows years since baseline, and the Y-axis shows either total gray matter volume or regional brain volume. Light blue lines represent high SCC (+1.5SD), dark blue lines represent average SCC (Mean), and black lines represent low SCC (−1.5SD). 95% confidence intervals are shown.

Figure 2.

Graphical representation of linear mixed effect models predicting processing speed composite score trajectories from Baseline ECog Non-Memory domain scores, including Language, Visuospatial, and Executive Function scores. The X-axis shows years since baseline, and the Y-axis shows the processing speed composite score (z). Z-scores were inverted so that higher numbers are equivalent to better task performance. Light blue lines represent high SCC (+1.5SD), dark blue lines represent average SCC (Mean), and black lines represent low SCC (−1.5SD). 95% confidence intervals are shown.