Abstract
Bow hunter's stroke is vertebrobasilar insufficiency caused by stenosis of vertebral artery (VA) at the atlantoaxial level by head rotation. A 52-year-old man complained of dizziness during head rotation towards the right. Downbeat nystagmus was noted when his neck was rotated to the right. MRI demonstrated hypoplasia of the right VA. Angiography revealed the right hypoplastic VA ending at the posterior inferior cerebellar artery. The left VA was dominant and had normal flow with the head in the neutral position. Head turning to the right caused complete occlusion of the right VA at the level of the atlas and the patient felt dizziness. Surgical therapy was not performed because he did not agree to the operation.
