感染性硬膜下血腫に脳梗塞を併発した1例

A Case of Infected Subdural Hematoma Accompanied by Cerebral Infarction

Ⅰ．はじめに

　硬膜下膿瘍は頭蓋内感染症全体の15～20%を占める疾患である¹⁾．近年の画像診断の進歩により早期診断が可能となり，抗生物質の発達に伴ってその予後は改善しているが¹⁾，初期治療が遅れると今なお致命的となる疾患である．また，既存の慢性硬膜下血腫に遠隔部から感染が波及して生じる感染性硬膜下血腫（infected subdural hematoma：ISH）は硬膜下膿瘍の亜型であるが，病態は異なり報告も少なく，成人例に限れば本例を含め26例の報告^{2,4,6-9,11,13,15,17,18,21,22,24)}のみであった．今回ISHから脳梗塞を併発した1例を経験したが，渉猟し得る限り他に例はなく，極めて稀と思われたため，文献学的考察を加えて報告する．

　Infected subdural hematoma（ISH）is a rare disease caused by hematogenous infection of a preexisting subdural hematoma. We report a rare case of ISH accompanied by cerebral infarction.

　A 76-year-old man who had suffered a closed head injury 3 months before presented fever, headache and left hemiparesis during the medical treatment of acute cholangitis and obstructive jaundice with pancreatic cancer at the department of surgical gastroenterology.

　At the consultation, computed tomography（CT）scan indicated right chronic subdural hematoma. We performed a burr hole opening surgery on the same day. Abscess and hematoma was aspirated from the subdural space, and methicillin-resistant Staphylococcus aureus（MRSA）was detected in this specimen. Thus the diagnosis of the infected subdural hematoma was confirmed. However, despite the antibiotics therapy, follow-up CT showed a low-density area close to the residual abscess, which suggested cerebral infarction. Cerebral angiography showed a vasospasm at the cortical segment of the right middle cerebral artery near the residual abscess. Eventually we carried out a small craniotomy to evacuate the abscess.

　Our case showed that prompt surgical treatment is required in case of ISH and the whole hematoma and abscess should be removed as soon as possible with an image diagnosis and an additional surgical operation.