脳日本住血吸虫症について—1手術症例と文献的考察

CEREBRAL SCHISTOSOMIASIS:REPORT OF AN OPERATED CASE AND REVIEW OF LITERATURES

I．はじめに

　日本住血吸虫はアジアに広く分布し，特定河川の流域で地方病の原因として恐れられてきた。このアジア最大の風土病のひとつである日本住血吸虫症は本邦において，すでに1847年（文化4年）に藤井により"片山記"として記載されている。その後，桂田や宮入などの研究により本症の解明がなされ，その予防法や治療法の進歩により次第に減少の傾向にある。しかし，第2次大戦後に行なわれた，中間宿主である宮入貝の大規模な撲滅計画の実施にもかかわらず，本寄生虫の絶滅は極めて困難なのが現状である。

　日本住血吸虫に感染すると門脈系に成虫が寄生し，肝硬変症へと進展するのであるが，時に脳内に虫卵が迷入して，脳日本住血吸虫症をおこすことがある。この脳日本住血吸虫症については1889年に山極^1）が"ジャクソン氏巓癇原因追加（「ジストマ」虫卵に因する大脳皮質の病変）"と題する論文を発表したが，後にこれが日本住血吸虫卵に起因することが確認され，脳日本住血吸虫症の最初の報告例となつた。その後，本症について可成りの症例報告がみられるようになつたが，現在なお稀な疾患のひとつである。

An extremely rare case of cerebral schistosomalgranuloma was treated operatively. Patient is 8year-old Japanese male who is suffering from inter-mittent headache, vomiting and visual disturbance.Neurological examination revealed no obvious path-ological findings except bilateral chocked disc.

Hematological examination showed eosinophilia.Stool examination was negative for occult bloodand there were no ova or parasites. The skin testfor schistosomiasis was 10×12/30×25 and for para-gonimiasis 8×10/8×10 respectively. Plane skullfilm revealed no pathological calcification nor otherabnormal findings. The chest X-ray was normal.Lumbar puncture revealed crystal clear fluid ofopening pressure of 260 mm in water. The fluidcontained 22 cells per cubic millimeter, all of whichwas monocytes, 50mg/dl sugar and 35mg/dl protein.Right carotid angiogram showed mass lesion inright frontal lobe. He was operated under the di-agnosis of parasitic cerebral granuloma. Schisto-somal ova was founded histologically in sectionsof the granuloma. He is well at present two yearsand six months after discharge.

From the first report of Yamagiwa's on cerebralschistosomiasis in 1889 to our case in 1974, 179cases were reported including our case up to thepresent time. In these cases, 50 cases were provenby operation or autopsy, but 129 cases were pre-sumptive.

Symptoms and signs of intracranial hypertension,for example, headache, vomiting and chocked discare most common in cerebral schistosomiasis.Convulsive seizure, especially Jacksonian seizure, isappeared frequently. Other symptoms and signsare pyramidal sign, sensory disturbance, visual dis-turbance and so on.

To diagnose this disease, there are several im-portant problems as follows. That is whether hehad been in epidemic area of the schistosomiasis,eosinophilia in blood, pleocytosis and elevated pro-tein level in CSF, intracranial hypertension, con-vulsive seizure especially Jacksonian seizure, schisto-somal ova in stool and so on. It is exactly diagnosedby the presence of schistosomal ova in brain tissueBut it is most important to distinguish the ovaof schistosoma japonica from it of ParagonimusWestermanii.

A case of cerebral schistosomal granuloma ispresented and symptomes, histological study, diag-nosis and treatment of cerebral schistosomiasis arediscussed.