Abstract WP070: Cognitive Susceptibility to Intracranial Large Artery Enlargement Across Cerebral Small Vessel Disease Subtypes

Background: Brain large artery (LA) dilatation, such as in the basilar or internal carotid artery (BA/ICA), has been linked to dementia risk partly due to changes in brain hemodynamics. Small vessel disease (SVD) is also a contributor to poorer cognition and dementia but the relationship between LA dilatation and SVD on cognition is unclear. We investigated whether the association between LA diameter and cognition differs by SVD presence and subtype. Methods: We analyzed data from a community-based cohort of adults ≥ 50 years without dementia. All participants underwent 3T brain MRI including TOF-MRA. SVD markers-white matter hyperintensities (WMH), lacune, and cerebral microbleed (CMB)-were assessed to classify individuals into four groups: no CSVD, ischemic SVD (WMH ± lacune), mixed CMB, and strictly lobar CMB. Diameters of ICA and BA were measured automatically using LAVA software under a standardized protocol. Cognitive function was tested across memory, language, executive, and visuospatial domains. Multivariable linear regression adjusted for age, sex, and education assessed associations between LA diameters and cognition. A Bonferroni-corrected p-value