アメーバ脳膿瘍の1例

A Case of Amebic Brain Abscess

Ⅰ．はじめに

　アメーバ感染症は，原虫である赤痢アメーバ（Entamoeba histolytica）を経口摂取することで発症する法定感染症である．症状は大腸炎を主体とし，重症例では肝臓，肺などの腸管外病変を示すことがあるが²⁷⁾，アメーバ脳膿瘍の報告は稀である．今回われわれの施設にて手術を行い軽快したアメーバ脳膿瘍の1例を経験したので報告する．

　Amebic brain abscess is a rare and usually fatal complication of Entamoeba histolytica infections. We successfully treated a patient with this infection accompanied by brain, liver and pulmonary abscesses. Treatment consisted of administration of metronidazole through a nasogastric tube, and drainage of the brain abscess.

　A 51-year-old male patient presented with a two-week history of fever, severe back pain, and chest pain. Liver and pulmonary abscesses were drained upon admission. Biopsy of the colon showed infection by Entamoeba histolytica. After oral administration of metronicazole, the patient became somnolent, and neurological examination showed left side weakness. CT scan and MRI of the brain disclosed an abnormal lesion in the right basal ganglia. He was then transferred to our department, where stereotactic aspiration with drainage of the brain abscess was performed. The abscess was filled with reddish purulent material. Treatment with metronidazole (1,200mg daily) for 18 days resulted in almost complete resolution of the intracerebral lesion and survival of the patient without any neurological deficits. His general condition improved dramatically, and he was discharged from our hospital 2 months later.

　Only 14 cases with amebic brain abscess associated with Entamoeba histolytica infection who recovered after treatment have been reported. We suggest amebic brain abscess should be taken into consideration for patients with brain abscess with a history of dysenteric illness especially since early diagnosis and aggressive management is likely to result in a cure.