[Repeated Bow hunter's stroke by artery-to-artery embolism from the vertebral artery dissecting aneurysm formed by head rotation: A case report].

A 55-year-old woman suffered from diplopia and occipital pain after shoveling snow. She was diagnosed with the right vertebral artery dissecting aneurysm at the level of the axial vertebra and repeatedly had cerebral infarctions in the posterior circulation. She had subluxation of the atlantoaxial vertebra as an underlying disease. Right vertebral angiogram with the head rotated to the left showed the right vertebral artery occlusion and left vertebral angiogram with the head rotated to the right showed stenosis at the C1-C2 level, leading to the diagnosis of Bow hunter's stroke. After wearing a cervical collar and taking 100 ‍mg of aspirin, she had no recurrence of cerebral infarction and later underwent C1-C2 posterior fusion to prevent the recurrence of cerebral infarction. She finished taking aspirin 6 months after the surgery, and there has been no recurrence of cerebral infarction. We report here a case of Bow hunter's stroke, a rare disease, with good clinical outcomes after C1-C2 posterior fusion.