[Blunt traumatic dissection in common carotid artery with serial morphological changes detected by carotid ultrasonography in the acute phase].

A 68-year-old man was admitted to our hospital with left hemiparesis, unilateral spatial neglect, and anosognosia at nine hours after blunt neck trauma. Carotid ultrasonography and angiography revealed occlusion of the right common carotid artery. A second ultrasonographic examination detected a double lumen, intimal flap, and a movable thrombus at the occlusion site, with reversed flow in the external cerebral artery and antegrade flow in the internal cerebral artery. Magnetic resonance angiography showed occlusion of the M1 distal section of the right middle cerebral artery. We diagnosed dissection of the right common carotid artery and artery-to-artery embolism from the thrombus in the dissecting common carotid artery. We started anticoagulation on the second hospital day. The patient was able to walk independently at discharge. The finding of carotid dissection on ultrasonography varied during the acute phase. We observed a mural thrombus in the true lumen and vessel recanalization. Treated only by anticoagulants without surgical therapy, the patient had a good outcome without reattack or hyperperfusion syndrome.