a luminal diameter <2 mm, accompanied by decreased flow in the posterior cerebral circulation, is often used to define vertebral artery hypoplasia

there must be >40% asymmetry to determine that unilateral hypoplasia exists

angiotomography, magnetic resonance angiography, and angiography allow evaluation of the entire course of the vertebral arteries to determine the presence of hypoplasia

the results of the studies published so far suggest a relationship between vertebral artery hypoplasia and an increased risk of ischemic stroke or transient ischemic attack in the posterior vascular area of the brain