Carotid steal syndrome

Carotid artery steal syndrome occurs when occlusion of one internal carotid artery causes blood from the contralateral internal carotid artery to flow through the anterior communicating artery into the affected side, or blood from the vertebrobasilar system to flow through the ipsilateral posterior communicating artery into the internal carotid artery. This may produce clinical manifestations such as paralysis or sensory disturbance on the same side as the occluded vessel, or vertebrobasilar insufficiency, including hemiplegia, hemisensory disturbance, and aphasia.