Hippocampal Volume Loss as A Marker of Cognitive Decline in Dementia and Mild Cognitive Impairment: A Comprehensive Prospective Study

Background: Hippocampal atrophy is a hallmark of cognitive decline observed in dementia and mild cognitive impairment (MCI). This study investigated hippocampal volumes across individuals with dementia, MCI, and healthy controls to explore structural changes and their association with cognitive performance. Methods: The present study included 62 participants categorized into three groups: dementia (DEM, N=22), MCI (N=15), and healthy controls (N=25). Hippocampal volumes were measured using 1.5 Tesla MRI. Cognitive function was assessed with the Mini-Mental State Examination (MMSE). Pearson correlation and ANOVA with post hoc Tukey's HSD tests were performed to analyze group differences and relationships between hippocampal volume and cognitive parameters. Results: The mean hippocampal volumes were significantly smaller in the DEM group compared to the MCI and healthy groups (P <0.0001). Right hippocampal volumes were 1.69 ± 0.47 cm³ in the DEM group, 2.12 ± 0.23 cm³ in MCI, and 2.64 ± 0.33 cm³ in healthy participants. A progressive hippocampal volume loss of 34.7% from MCI to DEM was observed. Significant differences in MMSE scores were found between groups (P < 0.005). A strong positive correlation between MMSE scores and hippocampal volumes was noted in the DEM group (r = 0.55, P <0.05). Conclusions: The findings confirm that hippocampal atrophy is a key feature of cognitive decline, with substantial volume loss observed in dementia patients compared to MCI and healthy individuals. The strong correlation between hippocampal volume and cognitive performance in dementia underscores the role of hippocampal measurements as potential diagnostic and monitoring biomarkers.