Study on the correlation of vertebral artery dominance, basilar artery curvature and posterior circulation infarction

Vertebral artery dominance (VAD), which is a common congenital variation of vertebral artery, may be associated with an increased risk of cerebral posterior circulation infarction (PCI). The aims of this study were to investigate the correlation of VAD with incidence and laterality of PCI, and oblige the correlation of VAD and basilar artery (BA) curvature. Incidence of separate territory infarction in posterior circulation and incidence of BA curvature were compared between 78 VAD patients and 68 controls. VA dominance, laterality of BA curvature and separate territory infarction, and their directional relationships were observed in VAD group. The incidence of BA curvature in VAD group was significantly higher than that in controls (P = 0.000). 89.7 % (35/39) of patients had an opposite directional relationship between dominant VA and BA curvature. The total incidence of PCI in VAD group was significantly higher than that in controls (P = 0.001). The incidences of posterior inferior cerebellar artery (PICA) and BA territory infarction were both significantly higher than those in controls [11.5 % (9/78) vs. 1.5 % (1/68), P = 0.016; 20.5 % (16/78) vs. 7.4 % (5/68), P = 0.024]. No differences were found in superior cerebellar artery and posterior cerebral artery territory infarction between two groups. 77.8 % (7/9) of PICA infarction were on the opposite side of dominant VA. 75.0 % (12/16) of BA infarction were on the side of dominant VA. The incidence of PCI in BA curvature patients was significantly higher than that in BA straight patients. The incidence of BA curvature is higher in VAD patients, and BA usually bends to the opposite side of dominant VA. The incidence of PCI is higher in VAD patients, especially in PICA infarction and BA infarction patients.