脳膿瘍破裂により脳幹部梗塞を来たした1例

Fetal brain stem infarction due to rupture of a brain abscess:a case report

I．はじめに

　脳膿瘍と出血の合併には，脳内出血に続発した脳膿瘍と脳膿瘍からの出血の2つの機序が存在するが，いずれも非常に稀である^{1-4,6,7,10-14,16,17,19）}．

　脳膿瘍の死亡原因として，膿瘍そのものによる脳組織の圧排や頭蓋内圧亢進による脳ヘルニアが主なものとして挙げられるが，頻度は少ないものの膿瘍破裂による髄膜炎，脳室上衣炎，急性水頭症が指摘されている^20）．膿瘍内容物自体による急性毒性，脳血管攣縮による脳梗塞の可能性も指摘されている^9）が，詳細な報告は見られない．

We report a case of a brain abscess which initially presented with subcortical hematoma and ultimately re-sulted in fatal brain stem infarction due to its rupure into the subarachnoid space.

A 50-year-old male was admitted to a nearby hospital with complaints of headache, fever, and sensory apha-sia. He had ventricular septal defect found 15 years pre-viously, sinusitis, and liver cirrhosis. Computerized tomographic (CT) scan revealed a left temporal subcor-tical hematoma. Gadolinium-DTPA enhanced magnetic resonance imaging (MRI) showed faint ring-like en-hancement at the margin of the lesion. The left internal carotid angiogram demonstrated the vascular blush and early venous filling of the vein of Labbe.Adminis-tration of antibiotics and predonine resulted in resolu-tion of fever within five days. MRI obtained 17 days af-ter the onset showed typical ring-like enhancement. The mass was just adjacent to the lateral ventricle. The patient was transferred to our hospital for further ex-amination and treatment 21 days after the onset. Fever had recurred 2 days before admission to our hospital. One day after admission, the patient began to vomit. About 15 hours following this symptom, he suddenly became comatose and tetraplegic. CT scan demon-strated a rupture of the abscess. Emergent drainage from the lateral ventricle and the abscess cavity was undertaken. Follow-up CT scan revealed multiple in-farctions involving the upper brain stem and the bilater-al thalamus. He died on the 29th day after the onset. The mechanisms of hemorrhage with a brain abscess and cerebral infarction after rupture of brain abscess are discussed. Hemorrhage with brain abscess is ex-tremely rare. However, brain abscess should be consi-dered as a possible etiology of an atypical hematoma. To avoid fatal rupture of the brain abscess, immediate treatment is essential. Once the rupture of the brain abscess occurs, its contents might cause vasospasm se-vere enough to cause cerebral infarction.