The Correlations between Volume Loss of Temporal and Subcortical Functional Subregions and Cognitive Impairment at Various Stages of Cognitive Decline

Background: The relationship between subregion atrophy in the entire temporal lobe and subcortical nuclei and cognitive decline at various stages of Alzheimer's disease (AD) is unclear.Methods: We selected 711 participants from the AD Neuroimaging Initiative (ADNI) database, which included 195 cases of cognitively normal (CN), 271 cases of early Mild cognitive impairment (MCI) (EMCI), 132 cases of late MCI (LMCI), and 113 cases of AD. we looked at how subregion atrophy in the temporal lobe and subcortical nuclei correlated with cognition at different stages of AD. The volume of the subregions was measured from the human Brainnetome atlas (BNA-246) using voxel-based morphometry and discriminant and correlation analyses were performed.Results: Only the left premotor thalamus demonstrated significant shrinkage in individuals with EMCI (p = 0.012). Discriminant analysis revealed that the left rostral Brodmann area 20 has the highest discriminatory ability among all temporal subregions to distinguish patients with AD from CN. While the left caudal hippocampus can efficiently distinguish patients with LMCI from EMCI. While the right rostral Brodmann area 20 was the most effective in distinguishing AD from LMCI. Correlation analysis revealed that the left nucleus accumbens, left caudal area 35/36, and left sensory thalamus had a mild correlation with cognitive scores measured using the Alzheimer's Disease Assessment Scale-Cognitive (ADAS-cog) 13 and Mini-Mental State Examination (MMSE) scores.Conclusions: Our findings show that the right rostral area 20 in the inferior temporal gyrus plays a significant role in cognitive impairment in AD.