Behavioral and psychological symptoms and brain volumes in community-dwelling older persons from the Nakayama Study

The frequency of behavioral and psychological symptoms of dementia (BPSD) is high, and it is a challenge to elucidate its neural substrates underlying their development. In recent years, many findings have been reported on the relationship between BPSD and brain volume in dementia patients. However, the results are not fully conclusive. Furthermore, there have been few population-based studies. Therefore, the relationship between BPSD and brain volume was investigated as an exploratory study. Of the 927 older persons who participated in the fifth Nakayama study, 90 were included in this analysis, consisting of 52 patients with mild cognitive impairment and 38 patients with dementia, with head MRI and the Neuropsychiatric Inventory (NPI) data. Multiple regression analysis was used to examine the association between the total score of each BPSD score on the NPI and brain volume estimated by FreeSurfer. On multivariate adjustment, even after false discovery rate correction, insular cortical volumes decreased significantly as total scores for apathy/indifference increased (p value = 0.002, q-value = 0.01). Similarly, total brain volume decreased significantly as total scores for appetite and eating disturbance increased (p value = 0.03), and parietal, temporal, and hippocampal cortical volumes also decreased significantly as total scores for appetite and eating disturbance increased (all p and q values < 0.05). This study's results suggest that apathy is negatively correlated with insular cortical volume, and that appetite and eating disturbance are also correlated with brain regions, including parietal, temporal, and hippocampal volume in a community-dwelling older population.