高悪性度狭窄症と高ホモシステイン血症を呈する頭蓋内狭窄症と高ホモシステイン血症が急性虚血性脳卒中に伴う皮質くも膜下出血を呈する若年男性

Intracranial High-Grade Stenosis and Hyperhomocysteinemia Presenting as Cortical Subarachnoid Hemorrhage Concomitant with Acute Ischemic Stroke in a Young Man.

• Weiwei Qin
• Weizheng Xie
• Mingrong Xia
• Robert Chunhua Zhao
• Jiewen Zhang

抄録

背景 皮質性くも膜下出血（cSAH）は、原因が異なる稀な臨床症状であるが、急性虚血性脳卒中と併発することはまれである。脳に由来する頭蓋内の高悪性度狭窄は、特に若年成人では珍しい原因と考えられている。CASE REPORT 33歳男性の1例は，軽度の頭痛と自発的な左半身脱力を呈した．脳CT検査では右上前頭溝にcSAHが認められた。MRI，DSA，経食道心エコー検査，腰椎穿刺，血液検査などの神経画像検査を行った．拡散強調画像検査（DWI）では右前頭葉と中大脳動脈（MCA）領域の放射状冠に急性梗塞を認めた．MRアンギオグラフィ（MRA）では右中大脳動脈M1節にフローシグナルは認められなかったが，DSAでは右中大脳動脈M1節に血流遅延が認められ，右中大脳動脈の高悪性度狭窄を示唆していた．臨床検査値は高ホモシステイン血症を示唆し、血栓症、感染症、癌などの原因は除外された。cSAHの発症機序としては，拡張した萎縮性代償性血管の破断によるMCAの重度のアテローム性動脈硬化性狭窄が考えられた．この患者は経過観察で良好な回復を示した。結論 この症例は若年成人の脳卒中患者に急性虚血性脳卒中を合併したcSAHを示した。

BACKGROUND Cortical subarachnoid hemorrhage (cSAH) is a rare clinical presentation with different causes, but rarely happens along with acute ischemic stroke. Intracranial high-grade stenosis originated from brain has been regarded as an unusual cause of cSAH, especially in young adults. CASE REPORT A case of 33-year-old male presented with mild headache and spontaneous left-sided body weakness. Initial brain computed tomography (CT) showed cSAH in the right superior frontal sulcus. Further neuroimaging examinations including magnetic resonance imaging (MRI), digital subtraction angiography (DSA), transesophageal echocardiogram (TEE); in addition, lumbar puncture and blood tests were performed. Diffusion-weighted imaging (DWI) showed an acute infarction in the right frontal lobe and corona radiata of the territory of middle cerebral artery (MCA). The MR angiography (MRA) displayed no flow signal in the right middle cerebral artery M1-segment, while the DSA displayed bloodstream slowness in the right MCA M1-segment which suggested high-grade stenosis of the right MCA. The abnormal laboratory data suggested hyperhomocysteinemia, and excluded causes of thrombosis, infection, or cancer. The mechanism of cSAH may come about in severe atherosclerotic stenosis of MCAs by the broken of expanded tenuous compensatory pial vessels. The patient had good recovered at follow-up. CONCLUSIONS This case demonstrates cSAH with acute ischemic stroke, which is an uncommon complication, in a young adult stroke patient; a high-grade atherosclerotic stenosis of the MCA was identified as the etiology.