The Relationship between Vertebrobasilar Circulation Anatomic Variations and Posterior Fossa Stroke

Abstract Background Posterior circulation stroke accounts for 20% of all ischemic strokes and carries a high mortality up to 85%, posterior circulation includes vertebral, basilar arteries and their branches, anatomical variations are very common in the posterior circulation, in particular vertebral arteries, the most common variant is asymmetry, left vertebral artery dominance presents in 50% of the population, right vertebral artery dominance presents in 25% of the population while similar size vertebral arteries present with an only 25% prevalence, other variations of vertebral artery include fenestration and they may vary in origin. Basilar fenestration is the most common intracranial arterial fenestration and the most common congenital anomaly of the basilar artery. This anatomic variation is characterized by duplication of a portion of the artery that is connected proximally and distally, which may predispose to basilar artery aneurysm formation, other variants include persistent carotid-vertebrobasilar anastomoses and basilar artery hypoplasia, anatomic variation of posterior cerebral artery includes fetal posterior cerebral artery incidence reaches 15%, other variations include fenestration. Objective To determine the relationship between anatomic variations of the vertebrobasilar circulation and posterior fossa stroke in patients who underwent MRI brain stroke protocol at our MR unit for evaluation of ischemic stroke. Patients and Methods This study was a retrospective study, and the study was conducted at Ain Shams University Hospitals, radio diagnosis department. The study period 7 months. Including sample of 50 Patients radiologically diagnosed with posterior fossa stroke. Results There was a significant ratio of posterior fossa anatomic variations especially vertebral artery hypoplasia in patients with posterior fossa stroke reaching 66% Conclusion In our study, we demonstrate the high incidence of posterior fossa anatomic variations in patients with posterior fossa stroke.