脳虚血症状で発症した急性大動脈解離の1例―急性期脳卒中診断における三次元CT血管造影とCT灌流画像の有用性

A Case of Acute Aortic Dissection Presenting with Cerebral Ischemic Symptoms: Utility of 3D CT Angiography and CT Perfusion for the Diagnosis of Acute Stroke

76歳女性が，意識障害，構音障害，左上肢麻痺の症状で救急搬送された。頭部単純CTでは異常所見を認めなかった。三次元CT血管造影，CT灌流画像で，右大脳半球の広範な血流低下を認め，右総頸動脈を含むStanford A型の大動脈解離と診断した。直ちに上行大動脈置換術を施行し，術後数日で神経所見は軽快した。大動脈解離は，胸背部痛，脈圧の左右差や縦隔の拡大などの典型的所見がなく，脳卒中で発症することがある。三次元CT血管造影，CT灌流画像は正確な脳卒中診断に有用である。

Abstract

A 76-year-old woman presented at our hospital complaining of loss of consciousness, dysarthria, and upper extremity paresis. Head CT showed no remarkable findings. 3D CT angiography (CTA) and CT perfusion (CTP) revealed acute aortic dissection (AAD) involving the innominate artery and decreased cerebral blood flow in the right cerebral hemisphere, although there were no clinical signs of AAD. The patient underwent emergency allograft replacement performed by cardiovascular surgeons. The symptoms disappeared within several days and no cerebral infarction developed. Although patients with AAD and neurological symptoms can show a fatal course when they receive tissue plasminogen activator (tPA), it is difficult to exclude patient with AAD as candidates for tPA treatment. Routine use of 3D CTA and CTP in the diagnosis of acute stroke may help overcome the above problem.

(Received October 7, 2013; Accepted January 17, 2014; Published August 1, 2014)