[Basilar artery occlusion due to embolism from the vertebral artery: three case reports].

Without early recanalization, it is well known that acute basilar artery occlusion almost always results in death or severe disability. We report three cases of basilar artery occlusion due to vertebral artery thrombo-embolism. In all cases, the cause of the strokes was artery to artery embolism from the vertebral artery origin. In case 1 and 3, despite complete occlusion of the vertebral artery origin, the thrombus was drained into the basilar artery through collateral flow from the external carotid artery. Atherosclerotic lesion of the vertebral artery origin is one of the main embolic sources of basilar artery, in which case, angioplasty or stent placement of the vertebral artery origin should be considered in addition to thrombolysis of the basilar artery.