Domain-specific longitudinal associations between brain volume, white matter lesions, and cognitive function changes

We investigated the domain-specific patterns of the association of segmental brain volume and white matter signal abnormality (WMSA) volume with longitudinal changes in cognitive function.

Participants from an institutional health check-up program who were aged >50 years, did not have a confirmed central nervous system disorder and underwent baseline and follow-up evaluations for cognitive function and brain MRI with an interval of at least 1 year were included. Cognitive function was assessed using the Consortium to Establish a Registry for Alzheimer's Disease-Korean version (CERAD-K) assessment battery. Performance changes in each cognitive domain were analyzed for associations with serial data of segmental brain volume and WMSA volume.

A total of 190 subjects were included (115 [60.1 %] females, mean age 68.2 ± 8.2 years [range 50-82 years]). Declines in global cognition were associated with lower baseline (P=0.001) and decreasing volumes (P=0.001) of the hippocampus and amygdala and with increasing total WMSA volumes (P=0.008). Declines in the executive function domain were associated with lower baseline volumes of the hippocampus and amygdala (P = 0.018) and with increasing total WMSA volumes (P=0.015). Declines in the language function and the verbal learning domains were associated with lower baseline (P=0.009 and P=0.002, respectively) and decreasing volumes (P=0.008 and P=0.001, respectively) of the hippocampus and amygdala. Decline in the memory recall was associated with higher total WMSA volumes at baseline (P=0.014). Declines in the recognition memory domains were associated with lower baseline hippocampus and amygdala volume (P = 0.020) and with increases in total WMSA volumes (P=0.012).

The segmental brain volume and the WMSA volume parameters have domain-specific associations with longitudinal cognitive changes, which might reflect the different dependence on the brain reserve according to the cognitive domains.