[Relation between various pathways of collateral circulation and cerebral circulatory disorders resulting from extracranial occlusion of one of the vertebral arteries].

The data obtained during angiographic and clinical examination of 35 patients with extracranial occlusion of one vertebral artery (VA) have been compared. The clinical picture of extracranial occlusion of one VA may vary. Also, the disease may run an asymptomatic course. The clinical symptoms of injuries to the vertebro-basilar vessels are less pronounced during noticeable occlusive alterations within the system of the carotid arteries. The main pathways of collateral circulation in extracranial occlusion of one VA involve intrasystemic anastomoses (within the system of the subclavian arteries). Of the greatest functional importance is the unoccluded VA.