Positional vertebral artery recanalization during neck flexion causing recurrent ischemic stroke

Positional vertebral artery (VA) occlusion is an uncommon etiology of ischemic stroke in the posterior circulation, in which the VA is reversibly occluded due to the neck posture. We present a unique case of positional VA recanalization in which the VA was occluded in the neutral neck position and recanalized by neck flexion. A 70-year-old male presented with repeated cerebral infarction in the posterior circulation. In the neutral position, the patient's left VA was occluded due to the compression by an osteophyte of the C5 vertebral body. However, dynamic cerebral angiography revealed the recanalization of the left VA in the neck flexed posture. The patient remains free from ischemic events 2 years after the initiation of warfarin administration. Positional VA recanalization in which the affected VA is occluded in the neutral position is rare. Dynamic evaluation is important for recurrent ischemic stroke in the posterior circulation, even when VA is occluded in the neutral position.