胸部大動脈解離による一過性脳虚血発作の1例

Transient Ischemic Attack Due to Thoracic Aortic Dissection : Report of a Case

　Ⅰ．はじめに

胸部大動脈解離は診断が遅れると致死率の高い疾患であるが，約10％は特徴的疼痛を欠くといわれている⁴⁾．また，神経症候の合併も稀ではなく，典型的疼痛を欠き，神経症候のみを呈する例も報告されている^2,5,8-10)．頸部血管エコー検査は頸部血管を非侵襲的に迅速に診断することが可能な検査である．近年，頸部血管エコー検査にて診断された疼痛を伴わない大動脈解離による脳血管障害の報告が散見されるようになった^5,8-10)．今回，われわれは頸部血管エコー検査にて総頸動脈起始部のintimal flapと総頸動脈の狭窄を認め，一過性脳虚血発作で発症した胸部大動脈解離の1例を経験した．

　We report a case of a 73-year-old woman with transient left hemiparesis and dysarthria. Neurological signs and symptoms gradually improved over a period of 30 minutes. Carotid sonography revealed common carotid artery (CCA) stenosis and mobile flap at the origin of CCA. On thoracic computed tomography the patient was shown to have dissection of De Bakey type I. She was diagnosed as having a transient ischemic attack due to aortic dissection. Furthermore,it was suggested that the embolic mechanism had occurred from the CCA flap. After replacing the aortic arch,both CCA stenosis and flap had disappeared on carotid sonography.

　Carotid sonography was useful not only for diagnosis of aortic and common carotid dissections,but also because it contributed to speculation concerning its mechanisms and suggesting its relation to ischemic stroke.