Association between basilar artery hypoplasia and undetermined or lacunar posterior circulation ischemic stroke.

Background And Purpose: The aim of the current study was to determine the prevalence of basilar artery hypoplasia (BAH) and to evaluate whether BAH is a possible risk factor for posterior circulation stroke (PCS).

Methods: Basilar artery diameter was assessed by MRI in 685 consecutive ischemic stroke patients. BAH frequency, defined as a diameter <2 mm, was measured and compared between anterior circulation stroke and PCS groups.