Description

A 47-year-old man with a previous remote post-traumatic rotational neck injury with operative repair of a neck laceration and a recent right occipital stroke, presented with syncope when turning his head to the right. Diagnostic cerebral angiography demonstrated an atretic left vertebral artery ending extracranially; in a neutral position, the dominant right vertebral artery exhibited mild stenosis from an osteophyte at C5–6. On rotating the patient's head to the right, the right vertebral artery became occluded (figure 1).