後頭蓋窩硬膜下血腫—その診断と硬膜外血腫との鑑別

TRAUMATIC SUBDURAL HEMATOMA OF THE POSTERIOR FOSSA:CASE REPORT

まえがき

　後頭蓋窩血腫の中で，硬膜下血腫の発生頻度は，硬膜外血腫にくらべてはるかにすくない^{1）3）5）7）8）}。外科的治療に成功した例は，Coblenz^2）（1940）の新生児の例が最初である。全硬膜下血腫中での頻度は，Munro^6）によると62例中1例（1.1％），McKissockら^5）によると389例中2例（0.5％），Ciembroniewicz^1）によると535例中3例（0.6％）であり，Wright^8）によると重症頭部外傷361例中，後頭蓋窩硬膜下血腫は5例（1.4％）であった。本邦では佐藤ら^7）および平井ら^4）が，各1例報告している。著者らは，さきに後頭蓋窩硬膜外血腫について報告し^9），椎骨動脈写の有用性を強調したが，最近示唆に富む経過をとつた後頭蓋窩硬膜下血腫の1例を経験し，術前に椎骨動脈写により，硬膜外血腫との鑑別も可能であつたので，主としてその椎骨動脈写の所見を中心に報告する。

We have reported the successful surgical treat-ment of a patient with traumatic posterior fossa subdural hematoma.

A five-year-old boy sustained traumatic supraten-torial hydroma, suffering from conscious disorder and motor signs. The evacuation of hydroma re-sulted in marked improvement of the motor deficits.

Because of delaying recovery of the conscious status, a left vertebral angiography was repeated ten days after the head injury, and revealed anavascular area of the posterior fossa, which had not been demonstrated in angiographies performed immediately after the injury. A craniectomy of posterior fossa uncovered subdural hematoma com-bined with hydroma. There was rapid improvement of the conscious disorder following evacuation of the mass.

When a head-injured patient sustained persisting conscious disorder without any focal neurological signs, vertebral angiography should be performed to exclude a posterior fossa lesion even in the early stage of injury. We could make a complete pre-operative diagnosis of localized infratentorial sub-dural hematoma and also a strict operative program concerning decision upon whether emergency case or not, type of skin incision, necessity of blood transfusion etc. on the ground of angiographic findings.