RT Journal Article SR Electronic T1 Potential collateral circulation to the human cerebral cortex JF Neurology JO Neurology FD Lippincott Williams & Wilkins SP 941 OP 941 DO 10.1212/WNL.24.10.941 VO 24 IS 10 A1 LOIS A. GILLILAN YR 1974 UL http://n.neurology.org/content/24/10/941.abstract AB The circle of Willis is a potential collateral circuit supplying the three cerebral arteries. If one of these arteries becomes occluded, preexisting anastomoses between their terminal branches or the arteriolar plexus between adjacent branches may enlarge, providing collateral circulation. Anastomoses between dural and cerebral arteries also may enlarge over the vertex. In occlusion of an internal carotid, extracranial vessels can resupply the cerebral cortex via the orbital plexus and ophthalmic artery. In slowly progressive bilateral internal carotid occlusions, a rete mirabile caroticum may develop and subsequently interconnect the ascending pharyngeal/internal maxillary and internal carotid arteries distal to the occlusion.