Cadaveric study of variations in the posterior cerebral and superior cerebellar arteries

Anatomical variations of arteries at the base of the brain may predispose to clinical conditions such as stroke, leading to cognitive and sensorimotor deficits. The aim of this study was to report variant patterns of the vessels at the cerebral arterial circle. In a random sample of 35 fixed human brain dissections, variations of the posterior cerebral artery (PCA) and superior cerebellar artery (SCA) were observed. Variations observed included: unilateral hypoplastic pre-communicating (P1) segment of PCA, bilateral persistent fetal PCA with hypoplasia of its P1 segment (posterior communicating artery contributing to the formation of PCA’s post-communicating (P2) segment), and origination of the PCA in common with the superior cerebellar artery, the latter finding being less common than previously reported variations of the cerebral arterial circle. Hypoplasia was assessed, grossly followed by measurement of the vessels’ diameters using a Dial Caliper, and ultimately by calculation of the statistical significance of the diameter in comparison to normal variants. Our findings suggest that vascular variations at the base of the brain are not uncommon. Ischemic stroke, aneurysms and the potential for compromised collateral blood flow, especially in cases of hypoplasia, are among the clinical implications associated with variations of the arterial network at the base of the brain. Therefore, we recommend paying extra attention to these possibilities when developing overall guidelines for diagnosis and treatment of cerebrovascular pathologies.