意識消失発作で発症した内頸動脈閉塞性疾患の9症例

Carotid Occlusive Disease Presenting with Loss of Consciousness

Ⅰ．はじめに

　意識消失発作を来す原因疾患は多岐にわたるが，循環器系疾患が多いとされている¹⁾．脳血管疾患もその原因の1つとして挙げられているが，その頻度は低いとされており，そのほとんどが椎骨脳底動脈系によるものとされている¹⁾．今回，われわれは意識消失発作で発症した内頸動脈閉塞性疾患の9例を経験したので，臨床所見，画像所見，治療について報告するとともに発作の発現メカニズムについて考察した．

The authors report 9 patients who presented with loss of consciousness (syncope) due to occlusive carotid artery diseases. All patients were males, and their age ranged from 59 to 83 years. The attack was associated with dehydration or hypotension in 5 patients. MRI demonstrated fresh cerebral infarction in the watershed zone. Cerebral angiography revealed occlusion of the unilateral internal carotid artery (ICA) in 7 patients,severe stenosis of the bilateral ICA in one, and occlusion of the unilateral ICA and severe stenosis of the contralateral ICA in one. Single photon emission tomography (SPECT) or positron emission tomography (PET) suggested reduced cerebral perfusion reserve because of inappropriate development of collateral circulation in 4 out of 9 patients. These 4 patients underwent superficial temporal artery to middle cerebral artery anastomosis and/or carotid endarterectomy. Other 5 patients were medically treated. No further episode of syncope occurred in all 9 patients during follow-up periods. The results suggest that occlusive carotid artery diseases should be taken in considerations as a cause of syncope attack.