Conclusions

Carotid atherosclerotic plaque burden, rather than plaque presence alone, is independently associated with possible mild cognitive impairment in older adults, with elevated ICA resistive index providing complementary hemodynamic insight. Associations with visuospatial and language domains may reflect selective vulnerability to vascular pathology. These findings support carotid atherosclerosis—prior to significant stenosis—as a potentially clinically relevant marker associated with poorer cognitive performance. Incorporating carotid ultrasound into cognitive risk assessment may assist in identifying individuals who warrant further assessment. Longitudinal studies are needed to clarify causality, evaluate plaque progression, and assess whether vascular risk modification is linked to subsequent cognitive decline.