Vertebral artery stump syndrome in acute ischemic stroke.

Although the carotid artery stump as an embolic source for ischemic stroke has been well described, there have been few systematic reports of a similar syndrome in the posterior circulation (PC) after vertebral artery (VA) origin occlusion. The aim of this study was to identify the incidence and characteristics of acute ischemic stroke with VA stump syndrome. Of 3463 consecutive patients who were admitted within 7 days after onset, 865 patients with acute ischemic stroke in the PC were enrolled. The diagnostic criteria of VA stump syndrome included: (1) acute ischemic stroke in the posterior circulation; (2) the VA origin occlusion identified on MRA, duplex ultrasound, CT angiography, and/or conventional angiography; (3) presence of distal antegrade flow in the ipsilateral VA; and (4) absence of other causes of ischemic stroke. Of the 865 patients with PC stroke, 12 (1.4%) were diagnosed as having VA stump syndrome. The ischemic lesions included the cerebellum in all patients. Nine patients had multiple ischemic lesions in the brain stem, thalamus, or posterior lobe other than cerebellum. On duplex ultrasound, a to-and-fro flow pattern was observed in the culprit VA in 10 patients. Three patients had recurrences of ischemic stroke in the PC during the acute phase. VA stump syndrome was not a rare mechanism of PC stroke, and there was a high rate of stroke recurrence during the acute phase. Vascular assessment by a multimodality approach can be used to promptly detect VA stump syndrome.