急性一酸化炭素中毒不全間歇型の1例の脳波推移

SERIAL CHANGES OF EEG ABNORMALITIES OBSERVED IN A CASE OF CARBON MONOXIDE POISONING (IMCOMPLETE INTERMITTENT FORM)

I．はじめに

　急性一酸化炭素中毒（以下急性CO中毒と略）について脳波学的には既に多くの業績があり，中でもLennox　and Petersen^11），　Bokonjić^1），稲永ら^7），立津ら^19）の研究はよく知られているが，間歇型の成因についてなど一致した見解が得られていない部分もあり，尚研究の発展が望まれている。わが国では，佐々木ら^17），永松ら^13），藤田ら^5），古賀ら^9），小川ら^14）が，初期意識障害時脳波と間歇型症例の脳波について知見を加えているが，我々も急性CO中毒の極く初期から脳波を観察しえた不金間歇型の1例を経験したので，初期意識障害時脳波と再燃時脳波を中心に考察を加えて報告する。

A case of 61 years old male who inhalated carbon monoxide accidentally is reported. He was un-conscious 88 hours after the accident. Following several days, he remained rather clear but dis-orientation, memory disturbance and Gerstmann's syndrome were noted. On the 9th day he relapsed and remained in apallic state with consciousness disturbance for about 30 days. Then crowding of consciousness progressed gradually and he died on the 123rd day.

EEG's were recorded 9 times through the course. The EEG on the first day showed 5-8 Hz and 1-2 Hz activities prominently in the frontal and central areas. It supported the findings of Bokonjić(1963).The second day EEG revealed increase of delta waves in spite of the recovery of consciousness. Spindle-like activities (8-10 Hz) and mitten patterns with 9 Hz thumbs were observed, too. When he was considerably alert, his EEG showed posterior 8 Hz alpha activities and 1.5-2 Hz frontal mono-rhythmic deltas. At relapse phase delta waves increased predominantly in the frontal area. The EEG characteristics seemed to be related with brain edema and dysfunctions of the mid-brain and neighboring regions. Subsequent serial EEG's were further dominated by low voltage delta waves. It was peculiar that on the 51st day EEG bitemporal sharp wave foci were demonstrated.

On the histopathological examination, typical lesions of CO poisoning were found.

The pathogenesis of intermittent form CO poison-ing has been in dispute, while detailed EEG studies are relatively uncommon. In this paper serial EEG changes of a case are discussed, referring to three other cases previously reported by other authors. Following characteristics are found: posterior alpha activities of varing amounts and frontal theta or delta activities during imcomplete lucid periods and increased slow waves predominant anteriorly at relapse phases.