Angiographic Assessment of Rotational Vertebral Artery Syndrome (Bow Hunter's Syndrome): A Case Series

Rotational vertebral artery syndrome or bow hunter's syndrome is a rare and potentially underdiagnosed condition in which vertebral artery flow is compromised by positional rotation of the neck in the setting of absent alternative pathways of flow. Rotational vertebral artery syndrome has previously been described in case reports and small case series, but these reports have had limited focus on imaging findings. Three patients with rotational vertebral artery syndrome presented with transient ischemic attack-like symptoms that included presyncope. The etiologies included hypermobility in the C1‐2 joint and, in 2 cases, large compressive osteophytes in the midcervical spine. Each patient underwent catheter angiography, which effectively identified the site of compression. Angiography with the head in the neutral position was performed as a baseline, and incremental angiographic images were obtained through a range of positions of the neck until the patient became symptomatic. Hesitant or reluctant patients were exhorted to provoke their symptoms, even at considerable discomfort to themselves, with the explanation that their surgical cure depended on these images. CT angiography was also performed for surgical planning, which was particularly useful to evaluate and plan treatment in the 2 patients with spondylosis with compression in the midcervical spine. All 3 patients were managed with surgical fusions. All patients had excellent outcomes by the Glasgow Outcome Sore and resolution of presyncopal symptoms. A well-executed catheter angiogram can effectively localize the site of vertebral artery compression and facilitate surgical planning. CT angiography adds valuable anatomic detail that allows precise surgical planning in patients with rotational vertebral artery syndrome secondary to spondylosis.