Alterations of homotopic functional connectivity and correlates with core neuropsychological impairments in mild cognitive impairment: a resting-state fMRI study.

Abstract

Identifying individuals with mild cognitive impairment (MCI) who are at risk of progressing to Alzheimer's disease (AD) is crucial for early interventions and understanding disease mechanisms. While previous studies using resting-state fMRI (functional magnetic resonance imaging) have identified various neural markers in MCI, there is limited research on alterations in interhemispheric functional interactions. Fifty-three MCI patients and 68 age-, gender-, and education-matched healthy controls were included in the study. Structural cranial MRI and resting-state fMRI data were collected. We investigated voxel-mirrored homotopic connectivity (VMHC) alterations in patients with mild cognitive impairment (MCI) using resting-state fMRI. Functional connectivity was then calculated using the regions with abnormal VMHC as seed points. Correlation analyses were performed to examine the relationship between altered functional connectivity and Core Neuropsychological Test (CNT) scores. Compared to controls, MCI patients exhibited increased VMHC in the bilateral postcentral gyrus. Functional connectivity was enhanced between the bilateral postcentral gyrus and the left cerebellar Crus I, as well as the right inferior temporal gyrus. In contrast, decreased connectivity was observed with the left Gyrus rectus and right supplementary motor area. Correlation analysis revealed a significant negative relationship between VMHC values and CNT scores, as well as with verbal analogy and Chinese word matching scores. MCI patients not only show disrupted interhemispheric VMHC but also demonstrate significant associations with core neuropsychological impairments. These findings provide insights into cognitive changes in MCI and highlight potential biomarkers for early Alzheimer's disease detection.