Rotational vertebral artery occlusion syndrome, also known as bow hunter's syndrome, is a rare form of vertebrobasilar insufficiency secondary to dynamic compression of the usually-dominant vertebral artery.
It has many predisposing etiologies, but is most often due to large osteophytes, atlantoaxial hypermobility, or less often an aberrant course 1.
The significance of bow hunting in particular is that in addition to a stance which mandates right-angle rotation of the head, there is frequently also stabilization of a nocked arrow with the hunter's thumb upon her occiput due to the high force used 2.
The diagnosis is established using provocative digital subtraction cerebral angiography, in which the patient reproduces symptomatic movements, and the site of vertebral artery compression may be identified.
Dynamic Doppler ultrasonography may also be used to establish the diagnosis.