一酸化炭素中毒の脳波による予後判定—初期の脳波と2年目の症状との関係

THE EEG AND PROGNOSIS IN CARBON MONOXIDE POISONING:SERIAL OBSERVATION FOR TWO YEARS

I．はじめに

　1963年11月9日，福岡県三池三川鉱で，炭塵爆発によつて，多数の一酸化炭素中毒（以下CO—中毒と略す）による犠牲者が発生した。死をまぬがれた人々のうちにも2年後の現在なお症状を残している人々が多くいて治療はつづけられている。このように多数のしかも同一条件で発生したCO—中毒例についての組織的な臨床的研究の報告は本災害以外はみられず，本災害における経験は，臨床的にも脳波学的にもきわめて貴重である。すでに，これらの研究結果については数回報告されてきたが（第61,62回日本精神神経学会および第13,14回日本脳波学会），ここでは初期の脳波と2年目の後遺症状との関係を追求し，初期の脳波所見から予後が判定できるか否かについて検討してみたい。これらの研究が，今後のCO—中毒の診療や予後判定にわずかでも貢献するところがあるとすれば，それは尊い犠牲者に対するささやかなはなむけとなろう。

The EEG was examined successively for two years in 56 patients with cabon monoxide poisoning, which broke out in the group owing to coal dust explosion in Miike-Mikawa Mine on November 9, 1963.

1) Between the 19th and the 26th days after poi-soning, the EEG was regarded as abnormal in 89.2 per cent of the cases examined; borderline in 8.9 per cent; and normal in 1.7 per cent. Three main fea-tures were noticed: appearance of slow wave (62.5%); low voltage (76.7%); and frontal dominancy in voltage (30.7%).

2) In regard to correlation between the EEG in the early stage and prognosis for the next two years, severe suquelae developed in the cases that had shown marked low voltage and slowing. The prognosis of cases with flat EEG was especially grave.

3) The cases with symptoms similar to the dece-rebrated state showed flat EEG in the early stage. While cases with dementia, focal signs and neurological symptoms also showed marked low voltage and high amount of slow component in EEG. The severity of intellectual disturbance was parallel to the abnormaltity in EEG in the early stage. The reverse relation was seen between the severity of subjective complaints and the abnormality of EEG.

4) The prognosis of cases with frontal dominancy in voltage was also grave. The cases often continued to show neurological symptoms, focal signs and de-mentia.

5) The prognosis was favorable in cases which recovered amplitude with reduction of slow waves in the lapses of time, while it was unfavorable in those who showed neither increase in amplitude nor decrease in slow waves over a long period of time.