Anatomical variations

Bow hunter's syndrome in a patient with vertebral artery atresia, an arcuate foramen, and unilateral deafness: a case report

“…The computed tomography angiography findings in our patient revealed a hypoplastic VA that terminated as the posterior inferior cerebellar artery instead of the basilar artery, which meets criteria for the diagnosis of vertebral artery atresia (VAA) [12] . VAA is thought to be relatively rare; one study estimated its prevalence at around 3.4% in the healthy population [15] .…”

“…Upward of 69% of healthy adults are thought to have some degree of size discrepancy between the right and left VAs, with the left being larger than the right in most cases [9] , [10] , [11] . Vertebral artery hypoplasia (VAH) is a condition that occurs when one VA is significantly smaller than the other, but still connects to the basilar artery system [12] . The diameter cut-off used to define VAH varies depending on the study, but generally range from <2 to <3 mm [13] .…”