We report a case of internal carotid artery (ICA) occlusion caused by en bloc distal embolization of carotid free-floating thrombus (FFT) treated by mechanical thrombectomy.Case presentation: A 57-year-old woman was brought to our hospital with dysarthria, right hemiparesis, and motor aphasia. MRI and MRA revealed acute infarction due to middle cerebral artery occlusion. Carotid ultrasonography demonstrated a pedunculated mobile plaque in the left ICA. We diagnosed embolic infarction due to the carotid FFT and started medical treatment. However, on the second hospital day, the carotid FFT detached from the arterial wall en bloc, resulting in left ICA occlusion. The occluded ICA was successfully recanalized by mechanical thrombectomy. Conclusion:FFT is associated with a high risk of embolic ischemic stroke and the primary treatment strategy must be carefully considered.

Summary:Objective: Most cerebral ischemic attacks in moyamoya disease are attributable to hemodynamic ischemia caused by hypoperfusion. However, in our experience with moyamoya disease, we have encountered several cases of cerebral infarction of an apparent embolic nature. These cases are presented in this manuscript.Patients and methods: Since January 2003, 165 patients with confirmed moyamoya disease have been registered in the moyamoya disease database of our hospital. The initial disease type was cerebral infarction in 36 patients (21.8%), transient ischemic attack in 67 (40.5%), cerebral hemorrhage in 36 (21.8%), cerebral infarction and hemorrhage in 1 (0.6%), headache in 13 (7.8%), asymptomatic in 11 (6.6%), and epilepsy in 1 (0.6%). Four patients with cerebral infarction that was apparently embolic in nature were evaluated retrospectively.Results: The median age of the four patients was 66.5 years (range: 62-84 years). Three (2.9%) of the patients showed cerebral infarction as the initial type of moyamoya disease, and the other patient, who had a bypass surgery 15 years prior, had cerebral infarction on the opposite side this time. Occlusion was present in the posterior cerebral artery of three patients and the anterior cerebral artery of one patient. The patients with occlusion of the posterior cerebral artery had a large infarction extending to the territories of the posterior and middle cerebral arteries. The patient with occlusion of the anterior cerebral artery had severe ischemia bilaterally in the territory of the anterior cerebral artery and on the affected side in the territory of the middle cerebral artery, but recanalization was soon achieved. Cardiogenic embolism was observed in all four patients. Although all four patients had atrial fibrillation, three of them were given antiplatelet therapy. Anticoagulant therapy was given to one patient. Conclusions: Although rare, cerebral infarction of an embolic nature in moyamoya disease tends to be wide ranging because of the associated acute occlusion of the collateral vessels. Anticoagulant therapy may be appropriate, but poses the risk of intracranial hemorrhage. Further research is needed on anticoagulant pharmacotherapy for preventing stroke in moyamoya disease complicated by atrial fibrillation.

No abstract

superficial temporal artery-middle cerebral artery (STA-MCA) bypass 術は 1967 年に Yasargil によって初 めて行われ 7) ，本邦の Japanese EC-IC bypass trial (JET) study によりその優位性が証明された 3) 4

No abstract