脳表と硬膜の吻合血管の解離にて発症した急性硬膜下血腫の1例

A Case of Acute Subdural Hematoma from Dissection of Cortico-dural Anastomosis

Ⅰ．は じ め に

　急性硬膜下血腫の発症要因は，頭部外傷による架橋静脈の破綻や脳挫傷からの出血により形成される外傷性のものがほとんどである．非外傷性急性硬膜下血腫の要因としては，脳動脈瘤の破裂^8,15)，もやもや病からの出血¹¹⁾，出血性素因に伴うもの²⁾などが報告されている．一方，外傷歴のはっきりしない皮質動脈の破綻による急性硬膜下血腫も，急性特発性硬膜下血腫として過去に多く報告されている^{5-7,10,12,14,17,18,20)}．

　過去に，急性特発性硬膜下血腫の原因の1つとして，硬膜と脳表の吻合血管の破綻による硬膜下血腫を論じた報告は散見されるが¹⁰⁾，術中所見およびその病理所見にまで言及した報告はない．今回われわれは，硬膜と脳表の吻合血管の解離により生じた急性硬膜下血腫を経験した．その手術所見，病理所見について若干の考察を加え報告する．

　A case of acute subdural hematoma caused by rupture of a bridging artery between the dura and the cortical surface is reported. A 49-year-old man complained of headache in the left temporal area after he had lifted up a heavy load. His symptom did not improve in spite of taking analgesics, so he was transferred to our hospital. Brain CT disclosed left acute subdural hematoma. Soon after admission, he became comatose and developed right hemiplegia. The cerebral angiogram displayed a tapering occlusion of a branch of the left middle cerebral artery.

　Emergent decompressive craniectomy was performed, and the anastomotic artery between the dura mater and the cortical artery was followed until it appeared normal in the cortical sulcus. Proximal occlusion of the artery was carried out. Pathological examination demonstrated the dissection of the anastomotic artery.

　This is the first reported and pathologically-proven case of acute subdural hematoma caused by dissection of the anastomotic artery between the dura mater and the cortical artery.