Hyperdense Middle Cerebral Artery Sign

高亮度中大腦血管症狀

顏瑞昇(Zui-Shen Yen) ； 江文莒(Wen-Chu Chiang) ； 陳石池(Shyr-Chyr Chen) ； 陳文鍾(Wen-Jone Chen)

《中華民國急救加護醫學會雜誌》 13卷4期 (2002/12) Pp. 178-180

https://doi.org/10.30018/JECCM.200212.0005

摘要

急性缺血性腦中風是急診常見的急症，頭部電腦斷層檢查是首要的影像學檢查，然而在急性期時頭部電腦斷層可能看不到明顯的變化。在大約12％至２８％以中大腦血管急性缺血性腦中風表現的病人上，頭部電腦斷層會出現高亮度中大腦血管hyperdense middle cerebral artery (HMCA)症狀。高亮度中大腦血管症狀是指在無顯影劑的頭部電腦斷層片子上，中大腦血管會看起來比較白，彷彿打了顯影劑一樣（如Fig. 1）。這個症狀形成的原因是血流速減緩，在中大腦血管中有血栓的形成。在臨床上如果出現高亮度中大腦血管症狀，則暗示病人很可能是大片的中大腦血管梗塞，可能會出現腦水腫的情形。同時有這個症狀的病人其預後會比沒有這個症狀的差。

並列摘要

A 55-year-old male with a history of hyper-tension was sent to the Emergency Department (ED) when he was found unresponsive at home. In the ED, the Glasgow Coma Scale was E3M4V1, the blood pressure was 159/93 mmHg, pulse rate was 58 beats/min. respiratory rate was 20 breaths/min and body temperature was 36.8℃. His right upper and lower limbs could not raise against gravity. Right facial palsy was also found. Noncontrast head com-puter tomography (CT) showed hyperdense middle cerebral artery (HMCA) sign in his left middle ce-rebral artery (MCA) territory (Fig.1). Left middle cerebral ischemic stroke stroke was impressed. Intravenous osmotic diuresis, adequate hydration and 100 mg Aspirin were given. The patient was admitted to Neu-rology Ward. T2-weighted magnetic resonance im-aging showed large infarction area in left middle cerebral artery territory (Fig. 2). His consciousness improved to E4M5V a 3 days later. Global aphasia and right hemiplegia persisted. Rehabilitation pro-gram was initiated one week later.
Emergency CT of the brain is the standard first-step diagnostic procedure for patients with suspect-ed acute ischemic stroke. The HMCA sign, a mark-er of thrombus in the MCA, is a CT predictor of the development of a large cerebral infarction. The fre-quency of HMCA sign in patients with stroke-related symptoms in MCA distribution is about 12-28% The presence of HMCA sign is an early warning of a large infarction, brain edema and poor prognosis in infarction in the MCA area.