Parametric Investigation on Stroke Risks from Carotid Artery Disease*

Embolic Stroke of Undetermined Source continues to account for a significant proportion of all ischemic strokes with a limited ability to identify stroke etiology. Disambiguating embolic stroke etiology is a critical step in improving treatment efficacy and reducing incidence of recurring stroke events. A prominent source of emboli are the carotid arteries, where buildup of atherosclerotic plaques can generate thromboemboli that move into the cerebral arteries. Currently, it is common notion to presume carotid embolization causes stroke events mainly in middle cerebral artery on the same hemisphere (ipsilateral). There have been reported cases where anterior or posterior strokes, and contralateral strokes (on opposite brain hemispheres) occur, which challenges this notion. The role of proximal collateral flow, the influence of stenosis severity and laterality, and embolic particle size effects – these remain challenging to understand in a patient-specific setting. This inspired our in silico investigation, where we develop a patient-specific hemodynamics and embolus transport model based on a heart-brain arterial network, and conduct a set of parametric investigations on flow and carotid embolus distribution in the Circle of Willis.