Thirugnanachandran T, Beare R, Mitchell M, et al. - Researchers conducted the study for analyzing the role of the circle of Willis (CoW) and leptomeningeal anastomoses in modifying regional variation in infarct topography following occlusion of the anterior cerebral artery and its branches. Participants in the study were 47 patients with a median age of 77.5 years (interquartile range, 68.0–84.5 years). The CoW has traditionally been regarded as the primary collateral system. The computer model, on the other hand, shows that the CoW is only useful in redirecting flow after proximal vessel occlusions (pre-anterior communicating artery). More important are leptomeningeal anastomoses, which influence motor outcome by modifying the posterolateral extent of infarct topography in distal vessel occlusions.