Rotational vertebral artery occlusion

Abstract

Rotational vertebral artery occlusion (RVAO), also known as bow hunter’s syndrome, is rare but clinically important: it carries a risk of impending stroke but can be treated by surgical decompression. Most patients who experience RVAO exhibit a stenosis or vessel malformation (e.g., hypoplasia or termination in the posterior inferior cerebellar artery) of the vertebral artery on the same side as the precipitating horizontal head rotation. This movement compresses the dominant vertebral artery (opposite to the head rotation) and thus interrupts the major blood supply to the vertebrobasilar artery territory. A rotational contralateral vertebral artery occlusion was originally considered physiologic after Toole and Tucker1 found compromised blood flow in vertebral arteries due to head rotation in hemodynamic studies of cadavers. However, this was not supported by vertebral angiography of 39 patients in both the neutral head position and …