急性硬膜下血腫で発症した末梢性前大脳動脈瘤破裂の2例

Ruptured Distal Anterior Cerebral Artery Aneurysms Presenting with Acute Subdural Hematoma:Report of two cases

I．はじめに

　脳動脈瘤破裂により急性硬膜下血腫を生ずる例は，内頸動脈瘤や中大脳動脈瘤破裂に多く，クモ膜下出血や脳内出血に伴って認められることが多いといわれている．この病態には重篤な症例が多く，mass effectに対する急性期減圧血腫除去術などの治療が先行するため，破裂脳動脈瘤の診断治療が大きな問題となる．今回われわれは，急性硬膜下血腫単独で発症した末梢性前大脳動脈瘤破裂の稀な2例を経験し，手術により良好な結果を得たので，文献的考察を加え報告する．

Two cases of ruptured distal anterior cerebral-artery aneurysms presenting with acute subdural hematoma are reported. Case 1 was a 55-year-old male, who showed abrupt disturbance of consciousness. An emergency CT revealed acute subdural hematoma at the right parietal convexity and interhemispheric fis-sure with moderate midline shift. There was no evi-dence of subarachnoid hemorrhage. Right carotid angiography showed an aneurysm at the right distal anterior cerebral artery. An emergency external decom-pression was performed and the aneurysm was clipped successfully through the interhemispheric fissure. In the operative field, subarachnoid hemorrhage could not be seen, and the patient had uneventful recovery. Case 2 was a 66-year-old female, who complained of severe headache. She deteriorated rapidly and become comatous with development of anisocoria. An emergen-cy CT revealed acute subdural hematoma on the bi-lateral parietal convexities and interhemispheric fissure with severe midline shift. There was no evidence of subarachnoid hemorrhage. Carotid angiography showedright distal anterior cerebral artery aneurysm. An emergency external decompression was performed, then the aneurysm was clipped successfully. She reco-vered with disorientation and hemiparesis.

Ruptured distal anterior cerebral artery aneurysms presenting with acute subdural hematoma without sub-arachnoid hemorrhage are rare. It is suggested that CT scans and history of patients are most important but an emergency angiography was prerequisite for correct dia-gnosis. Surgical treatment should be the best manage-ment in such cases.