What would be a consequence of an anomaly in the Circle of Willis?

An anomaly in the Circle of Willis can lead to possible ischemic changes during carotid occlusion because the Circle of Willis, by design, acts as a crucial anastomotic network that provides collateral blood flow to the brain. If there are abnormalities, such as underdeveloped or absent arteries, the capacity for collateral circulation diminishes. In situations where there is an occlusion, particularly in the carotid arteries, the compromised Circle of Willis may fail to provide adequate blood supply to regions of the brain that would otherwise benefit from this collateral flow. This can result in ischemia—an insufficient blood supply to meet the metabolic demands of brain tissue, potentially leading to effects such as stroke. Thus, the consequence of an anomaly in this arterial circle directly impacts the brain's vascular resilience during episodes of arterial blockage.