Structural and functional changes related to cognition in patients with early subcortical ischemic vascular disease: A cross-sectional MRI study

Subcortical ischemic vascular disease (SIVD) is a key contributor to vascular cognitive impairment, yet early-stage SIVD is underexplored despite its link to cognitive decline. This study investigates structural and functional changes in SIVD patients with and without cognitive impairment. Twenty-five individuals of subcortical ischemic vascular disease with normal cognition, 25 individuals with subcortical ischemic vascular cognitive impairment (SVCI), and 23 normal controls were enrolled. Voxel-based morphometry was used to assess differences in gray matter volume (GMV) across 3 groups by one-way analysis of variance. Pearson correlation coefficients were computed between voxel-based morphometry-identified seeds and all brain voxels derived from the resting-state functional magnetic resonance imaging analyses to evaluate the alterations of functional connectivity (FC). Spearman correlation analyses were performed to examine the relationships between altered GMV, abnormal FC, and cognitive assessments. Compared with normal controls, the SVCI group showed significant reductions in GMV in prefrontal regions (orbitofrontal cortex, gyrus rectus, inferior frontal gyrus), temporal lobe (olfactory cortex, superior temporal gyrus), insula, and subcortical areas (thalamus, caudate). The subcortical ischemic vascular disease with normal cognition group exhibited GMV loss in the right orbitofrontal cortex. FC analyses revealed hypoconnectivity in cortical-subcortical circuits as well as ipsilateral and contralateral cognitive-related regions. Several GMV and FC alterations in the SVCI group were correlated with neuropsychological assessments, including the Stroop Color-Word Test II and Trail Making Test B. Early-stage SIVD patients exhibit structural and functional abnormalities linked to cognitive deficits. The right orbitofrontal cortex may serve as a potential imaging biomarker for early detection of SIVD.