Extracranial Carotid Artery Disease is Associated with Decreased Ipsilateral Cortical Surface Area in Regions Relevant to Cognitive Decline

Motivation: The impact of asymptomatic extracranial carotid artery disease (aECAD) on brain structure, specifically cortical surface area (SA) and thickness, remains underexplored, yet may clarify aECAD's role in dementia risk. Goal(s): This study investigates how aECAD affects SA and thickness in brain regions vulnerable in neurodegenerative disease, specifically the Default Mode Network (DMN) and AD Signature. Approach: SA and thickness were calculated via FreeSurfer in 140 adults with aECAD / cardiovascular risk factors, and analyzed in DMN and AD Signature ipsilateral and contralateral to side of stenosis. Results: Significant ipsilateral SA reductions suggest a localized vascular mechanism distinct from age- or disease-related cortical thinning. Impact: Findings highlight that aECAD impacts cortical surface area rather than thickness, revealing a distinct vascular pathway to dementia. This insight points to potential targets for early intervention in high-risk individuals and suggests further research into vascular health's role in neurodegeneration.