くも膜下出血を伴わない急性硬膜下血腫で発症した破裂脳動脈瘤の1例

Glioneuronal Tumor :： An Expanding Spectrum

要旨　くも膜下出血を伴わない急性硬膜下血腫で発症した遠位部前大脳動脈瘤破裂の1例を報告した。症例は63歳女性で，突発する頭痛にて来院し，頭部CTにて右前側頭部，大脳縦裂に硬膜下血腫が認められた。発症様式から破裂脳動脈瘤が疑われたため，脳血管撮影を施行したところ遠位部前大脳動脈瘤がみられ，同日に脳動脈瘤クリッピング術を施行した。手術所見では動脈瘤体部が大脳鎌に強く癒着しており，それにより硬膜下血腫を呈したものと考えられた。文献では，遠位部前大脳動脈瘤破裂は硬膜下血腫を呈しやすいことが示唆された。このことは，本症例では母血管の解剖学的位置と動脈瘤の発育方向が関与していると思われる。

Acute subdural hematoma（ASDH） without subarachnoid or intracerebral hemorrhage following rupture of an intracranial aneurysm is rare. Only 34 cases of pure ASDH resulting from rupture of an intracranial aneurysm, and 5 cases of pure ASDH secondary to rupture of an anterior cerebral artery（ACA）aneurysm, have been reported in the literature. We report a case of a patient with a ruptured distal ACA aneurysm who presented pure ASDH on CT. A 63-year-old woman was admitted with the acute onset of severe headache, nausea, and dizziness. CT showed a right convexity and interhemispheric ASDH in the absence of subarachnoid or intracerebral hemorrhage. Cerebrospinal fluid was clear by lumbar puncture. However, we still suspected a ruptured intracranial aneurysm as the diagnosis. Angiography was performed and demonstrated a right distal ACA aneurysm with a daughter aneurysm. Evacuation of the subdural hematoma, with the clipping of the aneurysm was performed. Intraoperatively, adhesion between the dome of aneurysm and the falx cerebri was observed. The patient was discharged from the hospital without neurological deficits.