水俣病長期経過による脳病変の推移

A Pathological Study of Long Affected Minamata Disease, especially on the Secondary Degenerative Changes in the Brain

I．はじめに

　昭和28年，最初の水俣病患者の発生をみてより本年で13年が経過した。この間111名の患者発生，内41名の死亡を数えた^7）。このうちわれわれは23例の剖検例を得ている^1）〜7）。昭和35年10月以降は新しい患者の発生をみていないので生存中の70名はすべて少なくとも満5年以上の経過をとつた慢性水俣病患者ということになり，最近の剖検では長期経過の症例が得られるようになつた。われわれは水俣病が長期経過に伴つて脳病変の組織形態学的所見の上にも推移の起こりつつあることに注目し報告してきた^8）。一方立津^9）は臨床的に昭和36年より40年にかけての神経・精神症状の推移を検討し，運動失調，錐体外路症状などは軽快の傾向のいちじるしいこと，構音障害は軽快の傾向が少ないのみならず悪化の例も比較的多いこと，神経症状の軽快，消退に伴つて精神症状が臨床像の前景を占める例のでてきたことを報告した。

　われわれの病理学的研究と立津らの臨床的研究は現在のところそれぞれ別個になされているが，臨床症状は病理形態学的変化の現われであれば，両者は相関すべきものであり，将来この方面の検討もなされねばならない。

In this report, from 23 all autopsy cases of Minamata disease, especially 3 adult cases who had been affecting above more than 4 clinical years were taked up and discussed about the secondary degenerative changes in the brain. The obtainep results were as follows.

1) Neuropathological findings of the 3 cases showed essentially same lesion as the other Minamata disease.

2) As the secondary degenerative changes in the brain, the first, all of 3 cases revealed the diffuse demyelinative changes in the cerebral subcortical white mater which was paralleled disturbances of the cortical nerve cells.

3) The second, there was strikingly chronic neuronal shrinkage. In the cerebellum, dendrites of the Purkinje cell revealed remarkable sclerosis and metamorphosis.

4) In 2 cases who were affected during about 10 years, unusual situation of the Purkinje cell was observed. It was probably produced as a result of regenerative process of the cell degene-rated.

5) Above mentioned degenerative findings were secondary changes which was produced by the disturbances of the nerve cell, and the later were primary and essential changes of the Minamata disease.